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EXECUTIVE SUMMARY

The Endangered Species Act (ESA) allows listing of “distinct population segments” of

vertebrates as well as named species and subspecies. The policy of the National Marine

Fisheries Service (NMFS) on this issue for Pacific salmon and other anadromous salmonids is

that a population will be considered “distinct” for purposes of the ESA if it represents an

Evolutionarily Significant Unit (ESU) of the species as a whole. To be considered an ESU, a

population or group of populations must 1) be substantially reproductively isolated from other

populations, and 2) contribute substantially to ecological/genetic diversity of the biological

species. Once an ESU is identified, a variety of factors related to population abundance are

considered in determining whether a listing is warranted.

In September 1994, in response to a petition seeking protection for Baker Lake

(Washington) sockeye salmon under the ESA, NMFS initiated a coastwide status review of

sockeye salmon (Oncorhynchus nerka) (Walbaum, 1792) in Washington, Oregon, and

California, and formed a Biological Review Team (BRT) to conduct the review. This report

summarizes biological and environmental information gathered in that process.

West Coast Sockeye Salmon ESUs

The BRT examined genetic, life history, biogeographic, geologic, and environmental

information in the process of identifying ESUs. In particular, genetic data; physical,

chemical, and biological characteristics of nursery lakes; sockeye salmon river entry and

spawn timing; and smolt outmigration timing were found to be most informative for this

process. Based on this examination, the BRT identified six sockeye salmon ESUs and one

provisional ESU in Washington, as follows:

1) Okanogan River

This ESU is named after the Okanogan River in the Columbia River drainage of

Washington and includes all sockeye salmon that spawn in areas upstream from Lake

Osoyoos, in Lake Osoyoos, or the downstream tributary Similkameen River (below Enloe

Dam). The spawning and main rearing area for this ESU is in British Columbia, while the

migration corridor for both juveniles and adults is through the Columbia River in Washington

and Oregon. Important factors that differentiate this population as a separate ESU include:

1) the use of a very eutrophic lake-rearing environment (Lake Osoyoos), which is unusual for

sockeye salmon, 2) the tendency for a relatively large percentage of the Okanogan River

sockeye salmon population to return as 3-year-olds (age 1.1), 3) the juvenile outmigrationtiming differences between Okanogan River and Lake Wenatchee-origin fish, 4) the

adaptation of Okanogan River sockeye salmon to much higher temperatures during adult

migration in the Okanogan River, and 5) protein electrophoretic data that indicate that this

population is genetically distinct from other sockeye salmon currently in the Columbia River
viii

drainage. If “kokanee-sized” O. nerka observed spawning with sockeye salmon in the

Okanogan River are identified as residual or resident sockeye salmon, then they are to be

considered as part of the Okanogan River sockeye salmon ESU.

2) Lake Wenatchee

This ESU is named after Lake Wenatchee on the Wenatchee River in the Columbia

River drainage of Washington and includes all sockeye salmon that spawn above or in Lake

Wenatchee and rear in Lake Wenatchee. Important factors that distinguish this ESU include

electrophoretic data that indicate this population is genetically the second most distinctive

population (after Redfish Lake, ID) within the contiguous United States, and life history and

environmental differences with sockeye salmon from the Okanogan River ESU (juvenile

outmigration timing, environmental differences in lake-rearing habitat, and age composition).

If “kokanee-sized” O. nerka observed spawning with sockeye salmon in Lake Wenatchee

tributaries are identified as residual or resident sockeye salmon, then they are to be considered

as part of the Lake Wenatchee sockeye salmon ESU.

3) Quinault Lake

This ESU is named after Quinault Lake on the Olympic Peninsula of Washington and

includes all sockeye salmon that spawn in the Quinault River drainage and rear in Quinault

Lake. Early river-entry timing, protracted adult run timing, extended lake residence prior to

spawning, unusually lengthy spawn timing, unusual skin pigmentation of spawners, and

genetic differences from other coastal Washington sockeye salmon are important factors in

identifying this ESU.

4) Ozette Lake

This ESU is named after Ozette Lake on the Olympic Peninsula of Washington and

includes all sockeye salmon that spawn in the Ozette River drainage and rear in Ozette Lake.

Important factors that distinguish this ESU include electrophoretic data that indicate this

population is genetically distinct from all other sockeye salmon stocks in the Northwest, early

river-entry timing, and the relatively large adult body size and large average smolt size of

sockeye salmon in Ozette Lake compared to other coastal Washington sockeye salmon

populations. If “kokanee-sized” O. nerka observed spawning with sockeye salmon in Ozette

Lake are identified as residual or resident sockeye salmon, then they are to be considered as

part of the Ozette Lake sockeye salmon ESU.

5) Baker River

This ESU is named after the Baker River in the Skagit River drainage in northern

Puget Sound, Washington and includes sockeye salmon that return to the Baker River.

Important factors that distinguish this ESU include electrophoretic data that indicate that

Baker River sockeye salmon are genetically distinct from sockeye salmon populations from
ix

the lower Fraser River and from other localities in Washington, the limnology of old Baker

Lake (typically cold, oligotrophic, well-oxygenated, and influenced by glacial runoff, in

contrast to other sockeye salmon systems under review with the exception of Lake

Wenatchee), and the very large average smolt size of sockeye salmon in Baker Lake

compared to other Washington sockeye salmon populations.

6) Lake Pleasant

This ESU is named after Lake Pleasant on the Olympic Peninsula of Washington and

includes sockeye salmon that ascend the Quillayute and Sol Duc Rivers and Lake Creek to

spawn in Lake Pleasant. Important factors that differentiate this population as a separate ESU

include: 1) protein electrophoretic data that indicate that this population is genetically distinct

from other Washington sockeye salmon populations, 2) the distinctive small body size of

adult spawners, and 3) the unusual age structure of the population, with significant numbers of

juveniles remaining for 2 years in freshwater and/or spending only 1 year at sea. If “kokaneesized” O. nerka observed spawning with sockeye salmon in Lake Pleasant are identified as

residual or resident sockeye salmon, then they are to be considered as part of the Lake

Pleasant sockeye salmon ESU.

Big Bear Creek

The Big Bear Creek provisional ESU is named after a tributary of the Sammamish

River in the Lake Washington/Lake Sammamish Basin and includes sockeye salmon that

spawn in Big Bear Creek and its two tributaries, Cottage Lake Creek and Evans Creek.

Genetically, sockeye salmon from Big Bear and Cottage Lake Creeks are distinct from other

stocks of sockeye salmon in the Lake Washington/Lake Sammamish drainage. A great deal

of uncertainty remains concerning the historical presence of sockeye salmon within the Lake

Washington/Lake Sammamish drainage prior to sockeye salmon transplants, which occurred

in the 1930s-1950s. The relationship of this stock to native and transplanted kokanee is also

uncertain, although genetically it is unlike the current parent stock from which these kokanee

transplants originated (Lake Whatcom). If “kokanee-sized” O. nerka observed spawning with

sockeye salmon in Big Bear Creek are identified as residual or resident sockeye salmon they

are to be considered as part of the provisional Big Bear Creek sockeye salmon ESU.

Other Population Units

Historical records, stocking history, and genetic data indicate that sockeye salmon that

spawn in the Cedar River, Issaquah Creek, and on lakeshore beaches in Lake Washington in

the Lake Washington Basin and in the Methow and Entiat Rivers in the Columbia River Basin

originated from transplants from outside these basins. Therefore, the BRT concluded that

these populations are not presently considered as ESUs or as part of any other ESUs and are

therefore not an ESA issue. The ESU status of two other population units could not be

determined due to a lack of biological and historical information. These units are classified as

follows:
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1) Riverine-spawning sockeye salmon

This population unit consists of multiple aggregations of small numbers of sockeye

salmon that spawn in Washington rivers without lake-rearing habitat. Although genetic data

were available for riverine spawners in the Nooksack, Skagit, and Sauk Rivers, the data were

insufficient to eliminate the possibility that these sockeye salmon may be derived from recent

or historical straying of British Columbia lake-type or sea/river-type sockeye salmon. Genetic

data were unavailable for riverine spawners in other Washington rivers on the west side of the

Cascade Mountains. The BRT concluded that insufficient information exists concerning

riverine-spawning sockeye salmon to make a decision as to this group’s ESU status.

2) Deschutes River, Oregon

This population unit consists of sockeye salmon that are observed at the base of Pelton

Re-regulating Dam on Oregon’s Deschutes River, a tributary of the lower Columbia River.

The BRT concluded that sockeye salmon that historically migrated up the Deschutes River via

the Columbia River to spawn in Suttle Lake were a separate ESU, but due to lack of genetic

and life-history information, it is uncertain whether remnants of this ESU exist.

Assessment of Extinction Risk

The ESA (section 3) defines the term “endangered species” as “any species which is in

danger of extinction throughout all or a significant portion of its range.” The term “threatened

species” is defined as “any species which is likely to become an endangered species within

the foreseeable future throughout all or a significant portion of its range.” According to the

ESA, the determination whether a species is threatened or endangered should be made on the

basis of the best scientific information available regarding its current status, after taking into

consideration conservation measures that are proposed or are in place. In this review, the

BRT did not evaluate likely or possible effects of conservation measures, and therefore did

not make recommendations as to whether identified ESUs should be listed as threatened or

endangered species; rather, the BRT drew scientific conclusions about the risk of extinction

faced by identified ESUs under the assumption that present conditions will continue.

The BRT concluded that five sockeye salmon ESUs (Okanogan River, Lake

Wenatchee, Quinault Lake, Baker River, Lake Pleasant) and one provisional ESU (Big Bear

Creek) are not in danger of extinction, nor are they likely to become so in the foreseeable

future. The BRT also concluded that one sockeye salmon ESU (Ozette Lake), although not

presently in danger of extinction, is likely to become so if present conditions continue into the

foreseeable future. Information used by the BRT in coming to these conclusions follow for

each ESU.
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1) Okanogan River

Major concerns regarding health of this ESU were the channelization of spawning

habitat in Canada, the summer high water-temperatures that periodically block migration in

the lower Okanogan River, and effects of hydropower development in the Columbia River.

The run-size for this ESU has been highly variable over time, with recent 5-year average

annual escapement at about 11,000. Recent (1986-1995) abundance, as demonstrated by the

abundance trend, has declined at about 2-20% per year. This is heavily influenced by high

abundance in 1985 and low abundance in 1990, 1994, and 1995. Although the BRT

concluded that sockeye salmon in this ESU are not in danger of extinction, nor are they likely

to become so in the foreseeable future, they had several concerns about the overall health of

this ESU and they concluded that the status of this ESU bears close monitoring.

2) Lake Wenatchee

There was unanimous agreement among the BRT that sockeye salmon in this ESU are

not in danger of extinction and are not likely to become endangered in the foreseeable future

if present trends continue. Despite this conclusion, the BRT had concerns about the overall

health of this ESU, including the effects of hydropower development in the Columbia River

and the effects of hatchery production and potential interbreeding with non-native kokanee on

genetic integrity of the unit. Although production is apparently limited by the oligotrophic

conditions in Lake Wenatchee, habitat conditions are generally considered good in this basin.

The recent 5-year average annual escapement for this ESU was about 19,000 adult sockeye

salmon, and recent (1986-1995) abundance has been declining by about 10% per year, with

years of very low abundance in 1994 and 1995. The long-term (1961-1996) abundance trend

for this ESU is flat.

3) Quinault Lake

The BRT concluded that sockeye salmon in this ESU are not in danger of extinction,

nor are they likely to become endangered in the future if present trends continue. Despite this

conclusion, the BRT was concerned that this ESU is presently near the lower end of its

historical abundance range. This condition may be largely attributed to severe habitat

degradation in the upper Quinault River that contributes to poor spawning habitat quality and

possibly impacts juvenile rearing conditions in Quinault Lake. Recent (1991-1995) 5-year

average annual escapement was about 32,000 sockeye salmon for this ESU. While abundance

data from 1967-1995 show an increase of about 1% per year, the period from 1986-1995

shows a decrease in abundance of about 3% per year. Recent escapement is probably near the

low end of historical abundance for this ESU; historical escapement estimates ranged from

20,000 to 250,000 in the 1920s, while run sizes in the early 1900s ranged from 50,000 to

500,000.
xii

4) Ozette Lake

Major concerns that led the BRT to conclude that if present conditions continue into

the future, Ozette Lake sockeye salmon are likely to become in danger of extinction in the

foreseeable future include: siltation of beach spawning habitat, very low abundance compared

to harvest in the 1950s, overall downward trend in abundance coupled with large fluctuations

in abundance, and potential genetic effects of ongoing hatchery production and past practices

of sockeye salmon being interbred with genetically dissimilar kokanee. Current escapements

average below 1,000 adults per year, with little room for further declines before abundances

would be critically low. The most recent (1992-1996) 5-year average annual escapement

(based on weir counts) for this ESU was 700 adults, while historical run-size estimates range

from a few thousand sockeye salmon in the mid-1920s to a peak recorded harvest of about

18,000 in the late 1940s. Abundance decreased by about 3% per year from 1977-1995 and by

about 10% per year between 1986-1995.

5) Baker River

Despite the BRT’s conclusion that the Baker River sockeye salmon ESU is not

presently in danger of extinction, nor likely to become so in the foreseeable future, the BRT

had several concerns about the overall health of this ESU that indicate that the ESU bears

close monitoring. It is likely that this stock would become extinct if present human

intervention (trap, haul, and spawning beach activities) were suspended. In addition, the BRT

felt this ESU bears close monitoring due to proposed changes in management (confining

spawners to a single artificial spawning beach) that could substantially increase risk to the

population. Recent (1990-1994) average annual escapement for this ESU was about 2,700

adult sockeye salmon compared to historical pre-dam estimates of escapement averaging

20,000 fish near the turn of the century; however, other data indicates that this 20,000 figure

is a peak value and that the average may have been substantially less than 20,000. Although

sockeye salmon escapement in 1994 (about 16,000) was near the historic pre-dam maximum,

recent average abundance is probably near the lower end of the historical abundance range for

this ESU. Although stock abundance has fluctuated considerably over time, long-term

abundance (1926-1995) has decreased by about 2% per year, while recent abundance (1986-

1995) has increased at about 32% per year.

6) Lake Pleasant

At the time the BRT met, little information was available concerning recent

escapement levels, and the majority of the BRT felt that there was insufficient information to

adequately assess extinction risk for the Lake Pleasant ESU. However, a minority concluded

that the ESU is not presently in danger of extinction nor likely to become so in the foreseeable

future. Spawning ground peak counts from the late 1980s (and data received for the 1990s,

subsequent to the BRT meeting) appear roughly comparable to habitat capacity for this small

lake. Weir counts in the early 1960s ranged from 763 to 1,485 fish. Recently received

spawner survey data (unavailable at the time of the BRT meeting) for the years 1987 to 1996
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ranged from highs above 2,000 in 1987 and 1992 to a low of 90 in 1991 (a year with limited

sampling). The BRT expressed concerns regarding potential urbanization of habitat and

effects of sport harvest during the migration delay in the Sol Duc River.

Big Bear Creek

Relatively high recent average escapement levels between 10,000 and 20,000

spawners led a majority of the BRT to conclude that the Big Bear Creek sockeye salmon

provisional ESU is not presently in danger of extinction, nor is it likely to become endangered

in the foreseeable future if present conditions continue. A minority of the BRT felt that

information was insufficient to adequately assess extinction risk in this ESU. However,

several factors led to a second minority opinion that this provisional ESU is likely to become

endangered in the foreseeable future. These factors included extreme fluctuations in recent

abundances and potential effects of urbanization in the watershed. Recent development of a

county growth-management plan was seen by the BRT as a possible benefit to freshwater

habitat for this population. The BRT felt that the status of this population bears close

monitoring. Recent escapements have ranged from a high of 39,700 in 1994 to a low of 1,800

in 1989. The most recent (1991-1995) 5-year average annual escapement for this provisional

ESU was 11,400 adults. Abundance decreased by about 7% per year from 1982-1995 and by

about 4% per year between 1986-1995.

Consideration was also given to the condition of the two population units for which

ESU status has not been determined. There was insufficient information available to assess

the risk of extinction for riverine-spawning sockeye salmon. The BRT concluded that the

final population unit (Deschutes River, Oregon sockeye salmon) is clearly in danger of

extinction if not already extinct.
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ACKNOWLEDGMENTS

The status review for west coast sockeye salmon was conducted by a team of

researchers from the National Marine Fisheries Service’s (NMFS) Northwest Fisheries

Science Center (NWFSC). This biological review team (BRT; technical terms and

abbreviations such as “BRT” are defined in Appendix A) relied on the West Coast Sockeye

Salmon Administrative Record, which was developed pursuant to this review and is

comprised of comments and informational reports submitted by the public and by state, tribal,

and federal agencies. The authors acknowledge the efforts of all who contributed to this

record, especially the Washington Department of Fish and Wildlife, the Northwest Indian

Fisheries Commission, the Quinault Indian Nation, the Makah Tribe, the Quileute Indian

Tribe, Oregon Department of Fish and Wildlife, and U.S. Fish and Wildlife Service, and

Olympic National Park.

Numerous fishery scientists and managers provided information that aided in

preparation of this document and deserve special thanks. These include Jim Ames, Don

Hendrick, Larrie LaVoy, Dr. James Shaklee, John Sneva, Gary Sprague, and Sewall Young of

the Washington Department of Fish and Wildlife; Dr. Chris Wood and Dr. Kim Hyatt of the

Canadian Department of Fisheries and Oceans; Kevin Craig, Dr. Chris Foote, Andrew

Hendry, and Dr. Tom Quinn of the University of Washington; Dr. Ernest L. Brannon of the

University of Idaho; Dr. Jeffrey K. Freyer of the Columbia River Inter-tribal Fish

Commission; Gary Graves and Keith Lutz of the Northwest Indian Fisheries Commission;

Eric Warner of the Muckleshoot Indian Tribe, Fisheries Department; Del Boyer Jr. and Scott

Chitwood of the Quinault Fisheries Division; Jeff Haymes of Quileute Natural Resources;

Ned Currence and Denise Dailey of Makah Fisheries Management; and Kathryn Kostow and

John Leppink of Oregon Department of Fish and Wildlife.

The biological review team for this status review included: Thomas Flagg, Dr.

Stephen Grabowski, Dr. Richard Gustafson, Dr. Robert Iwamoto, Dr. Conrad Mahnken, Gene

Matthews, Dr. Michael Schiewe, Dr. Thomas Wainwright, Dr. Robin Waples, Laurie

Weitkamp, Dr. John Williams, and Dr. Gary Winans, all from the NWFSC.
1

INTRODUCTION

Sockeye salmon, Oncorhynchus nerka (Walbaum, 1792) (locally called blueback

salmon in the Columbia and Quinault Rivers, red salmon in Alaska, krasnaya ryba or nerka in

Russia, and benimasu or benizake in Japan), occur in North America around the Pacific Rim

from the Columbia River in the south to the Nome River (and perhaps the Noatak River),

Alaska in the north. In Asia, this species ranges from Hokkaido, Japan, the Kuril and

Komandorskiy Islands, and the northwest coast of the Sea of Okhotsk in the south to the

Anadyr River in the north (Atkinson et al. 1967, Foerster 1968, Burgner 1991, Forrester

1987). Recent publications (Konkel and McIntyre 1987, Nehlsen et al. 1991, Wilderness

Society 1993) reported that a number of local populations of sockeye salmon in Washington,

Idaho, and Oregon have become extinct, and the abundance of many others is depressed. The

U.S. Endangered Species Act (ESA) is intended to conserve threatened and endangered

species in their native habitats. Under the ESA, the term “species” is defined rather broadly to

include subspecies as “distinct population segments” of vertebrates (such as salmon) as well

as taxonomic species.

On 14 March 1994, the National Marine Fisheries Service (NMFS) was petitioned by

the Professional Resources Organization-Salmon (PRO-Salmon) to list Baker River sockeye

salmon as a threatened or endangered species under the ESA (PRO-Salmon 1994). At about

the same time, NMFS also received petitions for numerous other populations of Pacific

salmon in the Puget Sound area. In response to these petitions, and to the more general

concerns for the status of Pacific salmon throughout the region, NMFS (1994) announced that

it would initiate ESA status reviews for all species of anadromous salmonids in the Pacific

Northwest. These comprehensive reviews include all populations in the states of Washington,

Idaho, Oregon, and California. This proactive approach should facilitate more timely,

consistent, and comprehensive evaluation of the ESA status of Pacific salmonids than would

be possible through a long series of reviews of individual populations.

Scope and Intent of the Present Document

This document reports results of the comprehensive ESA status review of sockeye

salmon from Washington and Oregon (Fig. 1). Presently, there are no known sockeye salmon

populations in California, and a previous review (Waples et al. 1991) considered the ESA

status of sockeye salmon from Idaho. To provide a context for evaluating U.S. populations of

sockeye salmon, biological and ecological information for populations of sockeye salmon in

British Columbia was also considered (Fig. 2, Table 1). This review thus encompasses, but is

not restricted to, the single population identified in the PRO-Salmon petition.

Because the ESA stipulates that listing determinations should be made on the basis of

the best scientific information available, NMFS formed a team of scientists with diverse
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backgrounds in salmon biology to conduct this review. This Biological Review Team (BRT)1

discussed and evaluated scientific information presented at public meetings and also reviewed

information submitted to the ESA administrative record for west coast sockeye salmon.

Key Questions in ESA Evaluations

An ESA status review involves answering two key questions: 1) Is the entity in

question a “species” as defined by the ESA? and 2) If so, is the “species” in danger of

extinction or likely to become so? These two questions are addressed in separate sections in

the text that follows. If it is determined that a listing(s) is warranted, then NMFS is required

by law (1973 ESA Sec. 4(a)(1)) to identify one or more of the following factors responsible

for the species’ threatened or endangered status: 1) destruction or modification of habitat;

2) over-utilization by humans; 3) disease or predation; 4) inadequacy of existing regulatory

mechanisms; or 5) other natural or human factors. This status review does not formally

address factors for decline, except insofar as they provide information about the degree of risk

faced by the species in the future.

The “Species” Question

As amended in 1978, the ESA allows listing of “distinct population segments” of

vertebrates as well as named species and subspecies. However, the ESA provides no specific

guidance for determining what constitutes a distinct population, and the resulting ambiguity

has led to the use of a variety of criteria in listing decisions over the past decade. To clarify

the issue for Pacific salmon, NMFS published a policy describing how the agency will apply

the definition of “species” in the ESA to anadromous salmonid species, including sea-run

cutthroat trout and steelhead (NMFS 1991). A more detailed discussion of this topic appeared

in the NMFS “Definition of Species” paper (Waples 1991a). The NMFS policy stipulates that

a salmon population (or group of populations) will be considered “distinct” for purposes of

the ESA if it represents an evolutionarily significant unit (ESU) of the biological species. An

ESU is defined as a population that 1) is substantially reproductively isolated from

conspecific populations and 2) represents an important component of the evolutionary legacy

of the species.

The term “evolutionary legacy” is used in the sense of “inheritance”—that is,

something received from the past and carried forward into the future. Specifically, the

evolutionary legacy of a species is the genetic variability that is a product of past evolutionary

events and that represents the reservoir upon which future evolutionary potential depends.

Conservation of these genetic resources should help to ensure that the dynamic process of

evolution will not be unduly constrained in the future.

1 A list of the Biological Review Team members for west coast sockeye salmon is included in

the acknowledgements section.
6

The NMFS policy identifies a number of types of evidence that should be considered

in the species determination. For each of the criteria, the NMFS policy advocates a holistic

approach that considers all types of available information as well as their strengths and

limitations. Isolation does not have to be absolute, but it must be strong enough to permit

evolutionarily important differences to accrue in different population units. Important types

of information to consider include natural rates of straying and recolonization, evaluations of

the efficacy of natural barriers, and measurements of genetic differences between populations.

Data from protein electrophoresis or DNA analyses can be particularly useful for this criterion

because they reflect levels of gene flow that have occurred over evolutionary time scales.

The key question with respect to the second criterion is: If the population became

extinct, would this represent a significant loss to the ecological/genetic diversity of the

species? Again, a variety of types of information should be considered. Phenotypic and life

history traits such as size, fecundity, migration patterns, and age and time of spawning may

reflect local adaptations of evolutionary importance, but interpretation of these traits is

complicated by their sensitivity to environmental conditions. Data from protein

electrophoresis or DNA analysis provide valuable insight into the process of genetic

differentiation among populations but little direct information regarding the extent of adaptive

genetic differences. Habitat differences suggest the possibility for local adaptations but do not

prove that such adaptations exist.

The “Extinction Risk” Question

The ESA (section 3) defines the term “endangered species” as “any species which is in

danger of extinction throughout all or a significant portion of its range.” The term “threatened

species” is defined as “any species which is likely to become an endangered species within

the foreseeable future throughout all or a significant portion of its range.” NMFS considers a

variety of information in evaluating the level of risk faced by an ESU. Important

considerations include 1) absolute numbers of fish and their spatial and temporal distribution;

2) current abundance in relation to historical abundance and carrying capacity of the habitat;

3) trends in abundance, based on indices such as dam or redd counts or on estimates of

spawner-recruit ratios; 4) natural and human-influenced factors that cause variability in

survival and abundance; 5) possible threats to genetic integrity (e.g., selective fisheries and

interactions between hatchery and natural fish); and 6) recent events (e.g., a drought or a

change in management) that have predictable short-term consequences for abundance of the

ESU. Additional risk factors, such as disease prevalence or changes in life history traits, may

also be considered in evaluating risk to populations.

According to the ESA, the determination of whether a species is threatened or

endangered should be made on the basis of the best scientific information available regarding

its current status, after taking into consideration conservation measures that are proposed or

are in place. In this review, we do not evaluate likely or possible effects of conservation

measures. Therefore, we do not make recommendations as to whether identified ESUs should

be listed as threatened or endangered species, because that determination requires evaluation
7

of factors not considered by us. Rather, we have drawn scientific conclusions about the risk

of extinction faced by identified ESUs under the assumption that present conditions will

continue (recognizing, of course, that natural demographic and environmental variability is an

inherent feature of “present conditions”). Conservation measures will be taken into account

by the NMFS Northwest Regional Office in making listing recommendations.

Artificial Propagation

NMFS policy (Hard et al. 1992, NMFS 1993) stipulates that in determining

1) whether a population is distinct for purposes of the ESA, and 2) whether an ESA species is

threatened or endangered, attention should focus on “natural” fish, which are defined as the

progeny of naturally spawning fish (Waples 1991a). This approach directs attention to fish

that spend their entire life cycle in natural habitat and is consistent with the mandate of the

ESA to conserve threatened and endangered species in their native ecosystems. Implicit in

this approach is the recognition that fish hatcheries are not a substitute for natural ecosystems.

Nevertheless, artificial propagation is important to consider in ESA evaluations of

anadromous Pacific salmonids for several reasons. First, although natural fish are the focus of

ESU determinations, possible effects of artificial propagation on natural populations must also

be evaluated. For example, stock transfers might change the genetic or life-history

characteristics of a natural population in such a way that the population might seem either less

or more distinctive than it was historically. Artificial propagation can also alter

life-history characteristics such as smolt age and size and migration and spawn timing.

Second, artificial propagation poses a number of risks to natural populations that may

affect their risk of extinction or endangerment. These risks are discussed below in the

“Assessment of Extinction Risk” section. In contrast to most other types of risk for salmon

populations, those arising from artificial propagation are often not reflected in traditional

indices of population abundance. For example, to the extent that habitat degradation,

overharvest, or hydropower development have contributed to a population’s decline, these

factors will already be reflected in population abundance data and accounted for in the risk

analysis. The same is not true of artificial propagation. Hatchery production may mask

declines in natural populations that will be missed if only raw population abundance data are

considered. Therefore, a true assessment of the viability of natural populations cannot be

attained without information about the contribution of naturally spawning hatchery fish.

Furthermore, even if such data are available, they will not in themselves provide direct

information about possibly deleterious effects of fish culture. Such an evaluation requires

consideration of the genetic and demographic risks of artificial propagation for natural

populations. The sections on artificial propagation in this report are intended to address these

concerns.

Finally, if any natural populations are listed under the ESA, then it will be necessary to

determine the ESA status of all associated hatchery populations. This latter determination

would be made following a proposed listing and is not considered in this document.
8

Summary of Information Presented by the Petitioners

The single sockeye salmon population petitioned by PRO-Salmon (1994), Baker

River, was characterized as “critical” by WDF et al. (1993). With respect to the two criteria

established by NMFS to define a “species” of sockeye salmon in the context of the ESA, the

petitioner argued that the Baker River population of sockeye salmon is the only significant

remaining population of sockeye salmon in Puget Sound, with the exception of Lake

Washington/Lake Sammamish populations. The petitioners argued that Lake Washington/

Lake Sammamish populations originated from transplants of Baker River stock.

Reproductive isolation was inferred primarily on the basis of geographic separation from

other sockeye salmon populations. Other observations of sockeye salmon spawning in the

Skagit River drainage were postulated to represent Baker River strays or perhaps small rivertype populations. The Washington State Salmon and Steelhead Stock Inventory (SASSI)

cited NMFS unpublished genetic data, which is based on protein electrophoresis, and which

shows that the Baker River stock is significantly different from all other Washington sockeye

salmon stocks (WDF et al. 1993). In its petition, PRO-Salmon provided little information that

addresses the criterion of “evolutionary significance.” The petitioner argued that since there

are few records of introductions of sockeye salmon into this population, and it is separated

geographically from other populations, it should be considered an ESU.

The petitioner identified several threats to viability of Baker River sockeye salmon.

Access to native spawning habitat is obstructed by two dams, Lower and Upper Baker Dams.

Beginning in 1924, adult sockeye salmon returning to the Baker River were trapped and lifted

over Lower Baker Dam and released in Lake Shannon to continue their migration to Baker

Lake. Native beach-spawning habitat in Baker Lake was eliminated when Upper Baker Dam

was constructed in 1959, inundating the original Baker Lake and forming Upper Baker

Reservoir, which continues to be called Baker Lake. Since 1958, most adult sockeye salmon

returning to the Baker River have been trapped at the barrier dam and fish trap below Lower

Baker Dam and hauled by tanker truck to one of several artificial spawning beaches (ponds

designed to simulate natural beach spawning habitat).

Major concerns of the petitioners included: 1) Puget Sound Power and Light

Company’s plans to curtail operation of artificial spawning beaches 2 and 3 and confine

sockeye salmon spawning to a single beach (beach 4), 2) the potential for recurrence of the

intrusion of silt and sand into the intake water source for spawning beach 4, which has caused

siltation of spawning gravels, and 3) the potential for recurrence of the disease, infectious

hematopoietic necrosis (IHN), in sockeye salmon confined to spawning beach 4. The water

intake on Sulfur Creek for artificial spawning beach 4 is located at the base of a steep,

unstable slope, and the petitioners were concerned that intrusion of fine sand present at the

intake could trigger the turbidity meter (installed following intrusion of sand and mud into

beach 4 in 1990-1991) to cut off the supply of fresh water to the spawning gravel. The

petitioners were most concerned that a system to recirculate the water within spawning beach

4, in the event of an intake water shutdown, has not been installed.
9

The petitioners pointed out that mixed stock fisheries targeting early Fraser River

stocks may harvest some Baker River sockeye salmon. The petitioners also suggested that

juvenile sockeye salmon are likely taken in the spring recreational kokanee fishery that

operates in this reservoir, since the range of fork lengths of 1-year-old sockeye salmon smolts

in Baker Lake (up to 200 mm, average of 149 mm) overlaps the minimum retention size

(152 mm) for kokanee. Two-year-old sockeye salmon smolts, though rare in Baker Lake, are

all longer than 200 mm. In addition, the petitioners pointed out that in years when shore and

lower tributary spawning of wild sockeye salmon is allowed to occur in Baker Lake

(extensive wild spawning occurred in 1994), the late-fall and winter reservoir drawdowns

leave many sockeye salmon redds dewatered (PRO-Salmon 1994).

INFORMATION RELATING TO THE SPECIES QUESTION

Environmental Features2

Spawning populations of west coast sockeye salmon that are the focus of this review

are presently distributed over the northwest region of the contiguous United States, from the

Washington-British Columbia border (49oN) south to the Deschutes River (44oN) in Oregon’s

interior. Climate and geological features vary markedly over this region, with diverse patterns

of vegetation, weather, soils, land use, and water quality. This section summarizes

environmental and biological information that may be relevant to determining the nature and

extent of ESUs for sockeye salmon in Washington and Oregon.

Physical Features of the Freshwater Environment

The following discussion includes climate data from USDOC (1968) and Farley

(1979), calculations of river flow patterns using U.S. Geological Survey (USGS) data from

Hydrosphere Data Products, Inc. (1993), and information from Forstall (1969). Because some

populations of sockeye salmon spawn and undergo early development in small tributaries,

egg-alevin survival and, to a lesser degree, river- and lake-entry timing and spawn timing are

sensitive to patterns in river flow. In this respect, river flow patterns and seasonal water

temperature help define both early survival success and the temporal availability of access to

lake habitat for these populations. Water temperatures in all regions of Washington and

Oregon are generally highest in July and August (Hydrosphere Data Products, Inc., 1993).

Run-timing and spawn-timing are sensitive to these factors.

2

 Much of the information in this section is excerpted from Weitkamp et al (1995) and Busby

et al. (1996).
10

Along the west coast of North America, climate varies primarily with latitude; this

coastal region exhibits south to north gradients of increasing average precipitation and

declining average temperature. The coastal region has a mild climate, with warm, relatively

dry summers and cool, wet winters. Climate in the interior basins, east of the Cascade

Mountains, is greatly affected by topography and is influenced by continental air masses that

bring much warmer, dryer summer conditions and colder winters than coastal areas influenced

by maritime air to the west.

Columbia River Basin

Rivers draining into the Columbia River have their headwaters in increasingly dryer

areas moving from west to east, as the Columbia River cuts through the 500-1,000-m-high

Coast Range/Willapa Hills and the 1,000-2,000-m-high Cascade Mountains farther inland.

Rivers draining into the lower Columbia River have a single peak in flow in December or

January and relatively low flows in summer and fall. Rivers draining into the mid-upper

Columbia River experience peak flow in spring associated with snow melt. Occasionally,

rain-on-snow events in the fall give rise to widespread flooding.

Precipitation levels in the Willamette Valley in Oregon (100-120 cm/year) are much

lower than those on the coast (120-240 cm/year) or in the Cascades (120-280 cm/year).

Precipitation in the interior Columbia River Basin ranges from about 85 cm/year on the

eastern slope of the Cascade Mountains, to between 25 and 36 cm/year in the dry central

basin, and between 23 and 70 cm/year in the Snake River drainage. Water and air

temperatures also reflect the more extreme climate east of the Coast Range. Maximum water

temperatures in rivers draining into the Columbia River are slightly warmer (13-25o

C) and

minimum temperatures are slightly cooler (3-6oC) than those along the coast. Similarly,

maximum (around 27o

C) and minimum (around -1oC) air temperatures during the summer and

winter are warmer and cooler, respectively, than along the coast. The Willamette Valley

receives 2,000-2,200 hours/year sunshine, the lower Columbia River less than 2,000 hours/

year, and the mid-Columbia River between 2,200-2,800 hours/year.

Olympic Peninsula

The Olympic Peninsula is much wetter (160-380 cm precipitation per year) than areas

farther east and receives considerable snowfall (over 150 cm/year) at higher elevations (1,000-

2,000 m). Currently, persistent spawning populations of sockeye salmon on the Olympic

Peninsula are found only in watersheds draining the peninsula’s western side. Many of the

rivers draining the western Olympic Peninsula derive much of their water from snow and

glacier melt that causes a second flow peak each year. These rivers have relatively high flows

even in summer and have comparatively high annual flows. Maximum and minimum air and

water temperatures are cooler in the Olympic Peninsula than farther south, reflecting effects

of both latitude and elevation. Annual maximum and minimum water temperatures are 10-

14o

C and 2-4oC, respectively, while annual maximum and minimum air temperatures are

approximately 21o

C and 2oC, respectively. Annual sunshine along the Olympic Peninsula
11

coast is the lowest of anywhere in the continental United States, averaging less than 1,800

hours/year.

Coastal British Columbia

The wet climate of the Olympic Peninsula continues north along the west coast of

Vancouver Island and along the British Columbia mainland north of Vancouver Island.

Limited hydrographic data (Farley 1979) indicate that river flow patterns in this area are

similar to those on the Olympic Peninsula, with relatively high flows throughout the year,

although glacial melt-water does not contribute as much to this flow on Vancouver Island as it

does on the Olympic Peninsula and mainland coastal British Columbia. There is a general

decrease in summer air temperatures with increasing north latitude; the Olympic Peninsula

coast is 3-5oC warmer than the southwest coast of Vancouver Island, which is 3-5oC warmer

than the northwest coast and the mainland north of Vancouver Island.

Inland waters

East of the Olympic Peninsula, precipitation rapidly decreases because of the

rainshadow caused by the Olympic and Vancouver Island Mountains to the north, and Willapa

Hills to the south. The rainshadow, which becomes apparent along the northern coastline of

the Peninsula west of the Elwha River, continues through lowland Puget Sound, up the

lowlands bordering the Strait of Georgia to the south end of Queen Charlotte Strait. Several

Washington streams that support sockeye salmon are found in Puget Sound. This area

receives rainfall of less than 120 cm/year, with some areas receiving as little as

50 cm/year. Mountains to the east and west of this rainshadow receive high precipitation (up

to 280 cm/year) and have an annual snowfall of 500-1,020 cm/year. Due to snow, and in

some cases glacier melt in their headwaters, rivers draining into Puget Sound, Hood Canal,

and the southeastern Strait of Juan de Fuca have relatively high flows in summer and two

annual high flow peaks. These flow patterns are similar to those of rivers on the western

Olympic Peninsula, and limited data from western British Columbia rivers indicate similar

flow patterns (Farley 1979). Occasionally, rain-on-snow events in the fall-winter give rise to

widespread flooding. There appears to be a slight summer temperature cline within the

northern rainshadow region; average maximum air temperatures in Puget Sound and Hood

Canal (20-24oC) are slightly higher than in the Strait of Georgia (16-20oC), which in turn are

higher than areas inside Vancouver Island farther north (14-16o

C). In contrast, winter air

temperatures are more uniform and average 0-5oC throughout the area. Stream temperatures

in the area are fairly cold, with a maximum of 12-20oC in summer and 0-4oC in winter. The

greater Puget Sound area receives 2,000-2,200 hours/year of sunshine.

Physiography and geology

Sockeye salmon inhabit areas in Washington, Oregon, Idaho, and southern British

Columbia that are represented by several physiographic regions: 1) the Coast Range
12

Province, which extends in the U.S. from the Strait of Juan de Fuca south to the Klamath

Mountains and from the Pacific Ocean east to Puget Sound; 2) the Puget-Willamette Lowland,

which encompasses Puget Sound and the Willamette River Valley in the U.S.; 3) the Cascade

Mountain Range of Washington and Oregon; 4) the Columbia Plateau, which incorporates the

Columbia and Okanogan River valleys between the Cascade and Rocky Mountains in

Washington; 5) the Northern Rocky Mountains in Idaho; 6) the Coast Mountains of British

Columbia; 7) the Coastal Trough, which constitutes the area surrounding the Strait of Georgia

and Johnstone Strait; and 8) the Vancouver Island Mountains of Vancouver Island. These

regions are geologically diverse (Easterbrook and Rahm 1970, McKee 1972).

Glaciation events during the Pleistocene were instrumental in the formation of many

lakes that were historically used or continue to be used as rearing habitat by sockeye salmon.

Terminal moraines left behind by retreating glaciers created Quinault, Ozette, Wenatchee, Cle

Elum, Kachess, Keechelus, and Wallowa Lakes; glacial scouring deepened existing river

valleys that allowed formation of Okanagan3, Osoyoos, Washington, Sammamish, and Upper

and Lower Arrow Lakes (Easterbrook and Rahm 1970, McKee 1972).

Pleistocene Ice Age glaciation in the form of gigantic continental ice sheets and local

alpine glaciers had a profound impact on the topography of the North Cascades, the Puget

Lowland, the Olympic Peninsula section of the Coast Range Province, and the northern

Columbia Plateau. Changes in climate during the Pleistocene caused several advances and

retreats of the ice, and northern Washington was probably glaciated in every ice age. In the

North Cascades, alpine glaciers were inundated by later advance of the continental ice sheet,

whereas the South Cascades were not overwhelmed by large ice sheets, and the effects of

alpine glaciers are more evident in this region than they are farther north (Easterbrook and

Rahm 1970). During the last major continental glaciation event west of the Cascades, the

Fraser Glaciation, the ice sheet split into two lobes; the Juan de Fuca Lobe, flowing westward,

and the Puget Lobe, flowing south. This continental glaciation scoured out the deep troughs

of Puget Sound and left behind extensive morainal deposits in the Puget Lowlands. The Juan

de Fuca Lobe and Puget Lobe of the Fraser Glaciation heavily impacted the northern and

eastern flanks of the Olympic Mountains, up to an altitude of about 915 m, but the

southwestern side of the Olympics was beyond the continental glacier’s reach, and evidence

of the extent of alpine glaciation in river valleys of the southwestern Olympics is much clearer

there. The southwestern Olympics were glaciated at least four times during the Pleistocene.

Valley glaciers extended to at least the mouth of the Hoh River, to near Taholah on the

Quinault River, and to near Queets on the Queets River during the Pleistocene (Easterbrook

and Rahm 1970, McKee 1972). During the last, or Late Wisconsin, glaciation on the east side

of the Cascades, the Okanogan Lobe of the continental ice sheet extended down the Okanogan

3

 The accepted spelling in Canada is Okanagan, in the United States it is Okanogan. In this

document Okanagan will be used when referring to geographic features in Cnada and

Okanagon when referring to geographic features in the U.S.
13

and Columbia River Valleys to south of Lake Chelan (Easterbrook and Rahm 1970).

Physical and chemical characteristics of sockeye salmon nursery lakes

Juvenile sockeye salmon typically spend 1 or more years in the limnetic zone of a

nursery lake prior to smoltification. Growth and survival while in the lacustrine environment

depend on the morphological and limnological conditions of the nursery lake. Factors

affecting a lake’s productivity may be grouped into three major categories: morphometric,

edaphic, and climatic (Rawson 1952, Northcote and Larkin 1956). Morphometric factors

include lake area, volume, mean and maximum depth, and drainage area, while edaphic

factors are defined by the abundance of dissolved nutrients, measured as concentrations of

chlorophyll-a, total phosphorus, total nitrogen, and total dissolved solids. Climatic factors

include effects of temperature, wind, and solar radiation. Values for a number of these

parameters, together with distance from the sea, altitude, transparency (as measured by

Secchi-disk depth), and dissolved oxygen from lakes in the Pacific Northwest are listed in

Appendix Tables B-1 and B-2.

Lakes may be classified as oligo-, meso-, or eutrophic based on the relationships

between nutrient concentrations, algal abundance, and water clarity (USEPA 1974). Lakes

with a Secchi-disk depth greater than 3.7 m, and with less than 10 μg/L total phosphorus and

less than 7 μg/L chlorophyll-a are classified as oligotrophic. Lakes with a Secchi-disk depth

between 2.0 and 3.7 m, and concentrations of total phosphorus between 7-12 μg/L and

chlorophyll-a between 10-20 μg/L, are classified as mesotrophic. Lakes with a Secchi-disk

depth less than 2.0 m, and concentrations of chlorophyll-a and total phosphorus of greater

than 12 and 20 μg/L, respectively, are classified as eutrophic (USEPA 1974). Oligotrophic

lakes generally have greater diversity, but smaller populations of algal, zooplankton, and fish

species, than eutrophic lakes (Brenner et al. 1990).

Lakes in the Pacific Northwest typically develop a summer thermocline resulting from

solar heating, with water below the thermocline remaining colder and denser than the lighter

water above it. Surface water in a thermally stratified lake is termed the epilimnion, whereas

water below the thermocline is termed the hypolimnion. The hypolimnion may become

depleted in oxygen as a result of natural decomposition of plant and animal matter on the lake

bottom, if mixing is inhibited by thermocline formation. Lakes in the Pacific Northwest also

undergo a single mixing event of the epi- and hypolimnion in the fall or winter in a process

called turnover and are therefore referred to as monomictic (Brenner et al. 1990). Phosphorus

is particularly important in limiting the abundance of phytoplankton, and thus zooplankton

food for juvenile sockeye salmon, in Pacific Northwest lakes (Edmondson 1977b).

Several indices of fish production in lake environments have been developed,

including the morphoedaphic index (MEI) (Ryder 1965, Henderson et al. 1973), the planktonacre index (IPSFC 1972, Blum 1988), the mean-depth index (Rawson 1952), the bio-index

(Northcote and Larkin 1956), the lake-surface-area index (Youngs and Heimbuch 1982), the
14

chlorophyll-a index (Oglesby 1977), and indices based on phosphorus concentration or

macrobenthos biomass divided by mean depth (Hanson and Leggett 1982). The

morphoedaphic index is the most widely used index of potential fish production and is

derived by dividing a lake’s total dissolved solids (mg/L), or its conductivity, by its mean

depth in meters to provide a metric expression of the MEI (Henderson et al. 1973). The mean

depth of a lake is usually derived by dividing the lake’s volume by its surface area. The level

of total dissolved solids (TDS) is thought to be proportional to one of the limiting nutrients

such as phosphorus or nitrogen, whereas mean depth depicts the extent of a lake’s euphoticlittoral zone to some degree (Henderson et al. 1973). Relatively unproductive lakes have a

low MEI, great depth, occupy U-shaped basins, and are located on firm igneous substrate,

whereas productive north-temperate lakes have a high MEI, often have restricted depths, and

are underlain by rich sedimentary deposits (Henderson et al. 1973). Available MEI values for

selected Pacific Northwest lakes containing sockeye salmon are listed in Appendix Table B-2.

Ecoregions: Vegetation and Land Use

The U.S. Environmental Protection Agency has developed a system of ecoregions,

based on the perceived pattern of factors such as climate, topography, natural vegetation, land

use, and soils (Omernik and Gallant 1986, Omernik 1987). Under this system, the range of

sockeye salmon in Washington, Oregon, and Idaho covers two ecoregions that border on salt

water and three interior ecoregions. The Coast Range Ecoregion (containing the SASSI

sockeye salmon stocks Ozette, Pleasant, and Quinault (WDF et al. 1993)) extends north and

south from the Strait of Juan de Fuca to Monterey Bay, and east from the ocean to

approximately the crest of the coastal mountains. The Puget Lowland Ecoregion (containing

the three SASSI sockeye salmon stocks in the Lake Washington watershed (WDF et al.

1993)) begins in Washington at approximately the Dungeness River near the eastern end of

the Strait of Juan de Fuca and extends through Puget Sound to the British Columbia border

and up to the Cascade foothills. The Cascades Ecoregion (containing the SASSI stocks Baker

River and Wenatchee (WDF et al. 1993) and the original lake habitat of Deschutes River,

Oregon sockeye salmon) includes the high mountains and deeply dissected valleys of the

Cascades Mountain Range in Washington and Oregon. The Columbia Basin Ecoregion

(containing the SASSI sockeye salmon stock Okanogan (WDF et al. 1993)) is bordered on the

west by the Cascade Mountains, on the east by the foothills of the Rocky Mountains, on the

south by the Blue Mountains of Oregon, and extends north to the Canadian border through the

Okanogan River valley. Finally, the Northern Rockies Ecoregion (containing Redfish Lake

sockeye salmon) is comprised of the sharp ridges and steep slopes of the northern portion of

the Rocky Mountains in Idaho and Montana between elevations of about 400 and 2400 m.

The Coast Range Ecoregion is forested with dense stands of Douglas fir, western

hemlock, Sitka spruce, western red cedar, big-leaf maple, and red alder. Forest understories

consist of herbaceous vegetation and shrubs such as rhododendron, vine maple, willow,

salmonberry, and evergreen huckleberry (Omernik and Gallant 1986). Timber harvesting and
15

logging road construction has occurred extensively throughout the northern section of the

Coast Range Ecoregion, with consequent hill slope and stream bank erosion and increased

stream sedimentation (Omernik and Gallant 1986).

The Puget Lowland Ecoregion is forested with Douglas fir, western hemlock, western

white pine, lodgepole pine, ponderosa pine, western red cedar, big-leaf maple, and red alder.

Localized habitats include prairie, oak woodland, northwestern paper birch, quaking aspen,

and swamp and bog communities. Timber harvest, agriculture, and urban development are

important land uses in this ecoregion. Stream water quality is affected by industrial and

municipal wastes, increasing urbanization, and erosion resulting from timber harvest and road

construction (Omernik and Gallant 1986).

The Cascades Ecoregion, located at an altitude between 600 and 2100 m, is densely

forested with Douglas fir, noble fir, Pacific silver fir, western white pine, western hemlock,

and western red cedar. Forest understories in this region consist of shrubs such as Oregon

grape, salal, vine maple, rhododendron, oceanspray, huckleberry, and blackberry. At higher

elevations, mountain hemlock, subalpine fir, whitebark pine and Englemann spruce

predominate. Land uses are predominantly timber harvest, wildlife habitat, and recreation.

Stream degradation is exacerbated by timber harvest, logging, and recreational road

construction that, coupled with periods of heavy rainfall and rapid snowmelt, lead to scouring

and disruption of stream habitat (Omernik and Gallant 1986).

Natural vegetation in the steppe and grassland habitat of the Columbia Basin

Ecoregion consists of sagebrush, wheatgrass, and smaller amounts of bluegrass and fescue.

Dryland wheat and irrigated vegetable, fruit, and pasture agriculture, together with cattle

grazing, are the primary land uses in this ecoregion. Water withdrawals for irrigation and

agricultural runoff, coupled with low annual precipitation, impact the quality and amount of

water available to local streams (Omernik and Gallant 1986).

Natural vegetation in the Northern Rockies Ecoregion consists of stands of lodgepole

pine, western white pine, western red cedar, western hemlock, western larch, Douglas fir,

subalpine fir, Englemann spruce, and Ponderosa pine, with understory vegetation consisting

of forbs and grasses. Wheatgrass, fescue, and needlegrass occur in localized prairie habitats.

Major land uses include timber harvesting, recreation, wildlife habitat, mining, and livestock

grazing on lower elevations. Stream water quality is affected by timber harvest, logging road

construction, and mine waste runoff (Omernik and Gallant 1986).

Ocean Upwelling

Ocean upwelling (the movement of cold, nutrient-rich subsurface water to the surface)

along the coasts of British Columbia, Washington, and Oregon is primarily wind driven

(Bakun 1973, 1975). Upwelling in the area is both seasonal and episodic because winds that

cause upwelling are more frequent in the spring and summer, but do not occur uniformly

during those times (Smith 1983, Landry et al. 1989). Wind-driven upwelling also occurs
16

within the Strait of Georgia, where it is similarly limited both spatially and temporally

(Thompson 1981). One exception to this pattern has been observed off the southwest corner

of Vancouver Island, where consistent and strong upwelling appears to occur throughout the

year (Denman et al. 1981). Upwelling in this area is thought to be caused by current-driven as

well as wind-driven events, leading to relative temporal and spatial stability.

Zoogeography

Patterns of marine and freshwater species’ distributions indicate changes in the

physical environment that are shared with sockeye salmon. These environmental differences

may affect salmon habitat and provide different selective pressures in different areas to which

salmon must adapt.

Marine fishes

Along the east coast of the North Pacific Ocean within the range considered in this

status review, there is one distinct faunal boundary for marine fishes off the northern tip of

Vancouver Island (approximately 50oN) (Allen and Smith 1988). Marine fishes north of 50oN

are primarily cold-water, subarctic species, whereas those between 50oN and 34o30’N are

primarily temperate species.

Marine invertebrates

The distribution of marine invertebrates shows transitions between major faunal

communities similar to those of marine fishes (Hall 1964, Valentine 1966, Hayden and Dolan

1976, Brusca and Wallerstein 1979). Invertebrate faunal boundaries along the west coast of

North America occur at approximately Dixon Entrance (between Prince of Wales Island,

Alaska and the Queen Charlotte Islands, B. C.) and the Strait of Juan de Fuca (between

Vancouver Island and the Olympic Peninsula). The primary cause of this zonation is

attributed to temperature (Hayden and Dolan 1976), but other abiotic (Valentine 1966) and

biotic (Brusca and Wallerstein 1979) factors may also influence invertebrate distribution

patterns.

Freshwater fishes

Freshwater fishes in south/central British Columbia, Washington and most of coastal

Oregon are of Columbia River origin (McPhail and Lindsey 1986, Minckley et al. 1986).

Variations in the makeup of freshwater fish communities in these areas reflect the varied

dispersal patterns of fishes between river basins. The Stikine River in northern British

Columbia is the point at which freshwater fishes from the north displace the Columbia River

fish fauna (McPhail and Lindsay 1986). Thus, there is no evident pattern of variation in

freshwater fishes associated with sockeye salmon in Washington and southern British

Columbia.
17

Estuarine fishes

Estuarine fishes also show regional differences based on presence or absence of

species and can be roughly divided into four groups in Washington and Oregon (Monaco et al.

1992). Two groups were identified in Washington: the Fjord Group, which is restricted to

Puget Sound and Hood Canal, and a second group, which is found in Grays Harbor, Willapa

Bay, and the Columbia River estuary. Two other large groups, with considerable geographic

overlap, extend from Willapa Bay in Washington to the Eel River estuary in California. Other

estuary groupings are less evident and seem to depend more on characteristics of individual

estuaries rather than geographic location.

Freshwater mollusks

Freshwater mollusks and anadromous salmonids share similar freshwater habitat and

water quality requirements, while the distributions of salmonids, large prosobranch snails, and

freshwater mussels are similarly constrained by the requirement for continuous waterways for

dispersal (Clarke 1981). Small sphaeriacean clams and small freshwater snails are not good

indicators of zoogeographic regions, as they may be dispersed when attached to bird feathers,

or imbedded in mud attached to the feet of water birds. The distribution of freshwater

mussels, whose larvae (glochidia) parasitize the gills or fins of fish and require fish hosts to

complete their life cycle, may be particularly dependent on the distribution of host fish.

Certain bivalve glochidia rely on specific species of fish as hosts, whereas others tolerate a

wide range of fish hosts. Within the range of west coast sockeye salmon, glochidia of the

Yukon floater mussel Anodonta beringiana parasitize the gills of sockeye and chinook

salmon, while glochidia of the western pearlshell Margaritifera falcata parasitize the gills of

chinook salmon and other fishes (Clarke 1981). The host fishes for other species of

freshwater mussels in this region are unknown, but likely include juvenile sockeye salmon.

Five recognized species of freshwater mussels occur within the range of west coast

sockeye salmon: Anodonta beringiana (Yukon floater), A. nuttalliana (winged floater), A.

kennerlyi (western floater), Margaritifera falcata (western pearlshell), and Gonidea angulata

(western ridgemussel). Dall (1905), Zhadin (1965), and Clarke (1981) record A. beringiana

from Kamchatka to central Alaska and into the upper Yukon drainage, whereas Henderson

(1929) and Ingram (1948) extend this species’ range south into Oregon and include several

western Washington lakes in this species’ distribution including Whatcom, Samish,

Washington, and Crescent. Anodonta nuttalliana (which has been synonymized with A.

oregonensis and A. wahlamatensis) occurs in the Fraser and Columbia Rivers south into

central California (Clarke 1981) and east into Idaho in the Snake and Spokane Rivers

(Henderson 1929). It has been recorded from Shuswap, Nicola, Sumas, and Chilliwack Lakes

on the Fraser River; Okanagan Lake, The Dalles, and Astoria in the Columbia River Basin;

Nootka Sound on Vancouver Island; Lakes Whatcom, Sammamish, Union, and Washington

in the Puget Sound lowlands; Upper Klamath Lake in Oregon; and the Sacramento and San

Joaquin Rivers in California (Dall 1905; Henderson 1929, 1936; Ingram 1948; Clarke 1981).

Anodonta kennerlyi occurs on the Queen Charlotte Islands south through the Skeena and
18

Fraser Rivers, Vancouver Island, and into the Pacific drainage of Oregon. It has been seen in

Quinault and Samish Lakes in western Washington, at Spokane and Yakima on the Columbia

River, and in Eugene and just north of Coos Bay, Oregon (Henderson 1929, 1936; Ingram

1948; Clarke 1981). Margaritifera falcata ranges from California to the southern interior of

British Columbia, to the Queen Charlotte Islands, and to Revillagigedo Island in Southeast

Alaska (Clarke 1981). It has been recorded north to Naha Bay, Alaska (at 550N); in the Fraser

River; the Snake River in Idaho (Stanford 1942); at Spokane, Yakima, Walla Walla, The

Dalles, and Portland on the Columbia River; in Lake Crescent and the Chehalis River on the

Olympic Peninsula; in North Creek (Sammamish River drainage), Whatcom Creek, Samish

River, and Snoqualmie River in the Puget Sound lowlands; in the Deschutes River (at Bend,

Oregon); in the Umpqua and Coos Rivers in Oregon; and in the Sacramento River, California

(Dall 1905; Henderson 1929, 1936; Ingram 1948; Clarke 1981). Gonidea angulata occurs

from the upper Columbia River in British Columbia (Okanagan and Kootenai Rivers) south to

southern California in rivers that drain into the Pacific. It has been recorded from Vaseux

Lake on the Okanagan River; from Spokane, The Dalles, the Willamette River, and the Snake

River (at Weiser, Idaho) all in the Columbia River drainage; and in California from the

Klamath River south to Los Angeles (Dall 1905; Henderson 1929, 1936; Ingram 1948; Clarke

1981).

The combined range of A. beringiana, A. nuttalliana, and A. kennerlyi encompasses

the range of sockeye salmon, as well as other Pacific salmon species, and may indicate either

a close link in habitat requirements between this species complex of freshwater mussels and

anadromous salmonids or a direct reliance by these mussels on Pacific salmonid juveniles as

hosts for the larval glochidial stage. The range of M. falcata is likewise coincident with the

range of sockeye salmon south of Alaska.

Three large freshwater prosobranch snails also occur within the range of west coast

sockeye salmon: Juga plicifera, J. bulbosa, and J. hemphilli. The latter two species appear

confined to the lower Columbia River (Burch 1989), whereas J. plicifera occupies the lower

Columbia River and the Willamette and Santiam Rivers, as well as drainages on the southern

Olympic Peninsula and south into northern California (Henderson 1929, 1936; Millimann and

Knapp 1970; Clarke 1981; Burch 1989). Juga plicifera is the first intermediate host for the

trematode Nanophyetus salminicola, which is the vector for the rickettsia-like organism

Neorickettsia helminthoeca that causes “salmon poisoning disease” in dogs and other canids

(Millimann and Knapp 1970).

Amphibians

Although most amphibians are not restricted to aquatic habitats, and therefore have

little direct habitat overlap with sockeye salmon, many amphibian species have very restricted

distributions, suggesting preferences for specific habitat types and environmental conditions.

Because of this sensitivity, patterns of amphibian distributions may serve as indicators of

subtle differences in environmental conditions.
19

The distributions of many amphibians appear to begin and end at several common

geographical areas within the range of sockeye salmon in Washington; the Strait of Georgia

and Vancouver Island are the northern extent of many amphibian distributions (tailed and redlegged frogs; Pacific giant, western long-toed, western red-backed, Oregon, and brown

salamanders) (Cook 1984). In addition, several amphibians are restricted to the Olympic

Peninsula (Olympic torrent and Van Dyke’s salamanders), whereas other species occur in

most areas in western Washington and Oregon except in the Olympic Peninsula (Pacific giant

and Dunn’s salamanders) (Leonard et al. 1993).

Life History of Oncorhynchus nerka

With the exception of certain river-type and sea-type populations, the vast majority of

sockeye salmon spawn in or near lakes, where the juveniles rear for 1 to 3 years prior to

migrating to sea. For this reason, the major distribution and abundance of large sockeye

salmon stocks is closely related to the location of rivers that have accessible lakes in their

watersheds for juvenile rearing (Burgner 1991). Although there are no commercially

exploited sockeye salmon populations north of the Kuskokwim River in Alaska, small

populations occur in the Yukon River and rivers flowing into Norton Sound (L. Buklis4

), and

perhaps in the Noatak River in Kotzebue Sound (Atkinson et al. 1967). In North America, the

two dominant areas of sockeye salmon production occur in areas with extensive lake-rearing

habitat: the Bristol Bay watershed in Alaska (Kvichak, Naknek, Ugashik, Egegik, Wood, and

Nushagak Rivers) and the Fraser River in British Columbia. Other watersheds with major

sockeye salmon stocks include the Chignik, Karluk, and Copper Rivers, and rivers draining

into Cook Inlet in Alaska; and the Skeena, Nass, and Somass Rivers, and Rivers and Smith

Inlets of British Columbia (Ricker 1966, Aro and Shepard 1967, Atkinson et al. 1967, Poe and

Mathisen 1981, Burgner 1991). In Asia, the major sockeye salmon producing systems are on

the Kamchatka Peninsula: the Kamchatka River, draining east through central Kamchatka;

the Paratunka River in south-eastern Kamchatka; and the Ozernaya and Bolshaya Rivers in

southwestern Kamchatka (Hanamura 1967, Burgner 1991). Kuril Lake in the Ozernaya River

Basin on the Kamchatka Peninsula produces nearly 90% of all Asian sockeye salmon.

Approximately 8% of sockeye salmon production in Asia comes from the Kamchatka River,

while all other systems account for only about 2% (N. V. Varnavskaya5).

Sockeye salmon exhibit a greater variety of life history patterns than either chum,

coho, chinook, or pink salmon. The vast majority of sockeye salmon spawn in either inlet or

4 Larry Buklis, Regional Research Biologist, AYK Region, Alaska Department of Fish and

Game, Anchorage, AK (Pers. commun. to M.L. Dahlberg, NOAA, NMFS, AFSC, Auke Bay

Laboratory, 11305 Glacier Highway, Juneau, AK 99801-8626).

5 Dr. N.V. Varnavskaya, Kamchatka Institute of Fisheries and Oceanography

(KamchatNIRO), Petropavlosk-Kamchatsky, 683602, Russia (Pers. commun. to M.L.

Dahlberg, NOAA, NMFS, AFSC, Auke Bay Laboratory, 11305 Glacier Highway, Juneau,

AK 99801-8626).
20

outlet streams of lakes or in lakes themselves. The offspring of these “lake-type” sockeye

salmon utilize the lake environment for juvenile rearing for 1, 2, or 3 years and then migrate

to sea, returning to the natal lake system to spawn after spending 1, 2, 3, or 4 years in the

ocean. However, some populations of sockeye salmon spawn in rivers without juvenile lake

rearing habitat. The offspring of these riverine spawners utilize the lower slow-velocity

sections of rivers as the juvenile rearing environment for 1 or 2 years (“river-type” sockeye

salmon), or migrate to sea as underyearlings after spending only a few months in the natal

river and therefore rear primarily in saltwater (“sea-type” sockeye salmon) (Gilbert 1918,

Foerster 1968, Wood 1995). In common with lake-type sockeye salmon, river/sea-type

sockeye salmon return to the natal spawning habitat following 1 to 4 years in the ocean.

Certain populations of O. nerka that become resident in the lake environment over

long periods of time are called kokanee, silver trout, or little redfish in North America and

himemasu in Japan (Burgner 1991). Occasionally, a proportion of the juveniles in an

anadromous sockeye salmon population will remain in the rearing lake environment

throughout life and will be observed on the spawning grounds together with their anadromous

siblings. Ricker (1938) defined the terms “residual sockeye” and “residuals” to identify these

resident, non-migratory progeny of anadromous sockeye salmon parents. Kokanee and

residual or resident sockeye salmon are further discussed in the “Nonanadromous forms”

section below.

Sockeye salmon exhibit the greatest diversity in selection of spawning habitat among

the Pacific salmon. Sockeye salmon also exhibit great variation in river entry timing and the

duration of holding in lakes prior to spawning. Although sockeye salmon typically spawn in

inlet or outlet tributaries of a nursery lake, they may also spawn in 1) suitable habitat between

lakes, 2) along the nursery lakeshore on outwash fans of tributaries or where upwelling occurs

along submerged beaches, 3) along beaches where the gravel or rocky substrate is free of fine

sediment and the eggs can be oxygenated by wind-driven circulation, or 4) in mainstem rivers

without juvenile lake-rearing habitat (Foerster 1968, Burgner 1991).

Adaptation to a greater degree of utilization of lacustrine environments for both adult

spawning and juvenile rearing has resulted in the evolution of complex timing for incubation,

fry emergence, spawning, and adult lake entry that often involves intricate patterns of adult

and juvenile migration and orientation not seen in other Oncorhynchus species (Burgner

1991). Adult sockeye salmon home precisely to the natal stream or lake habitat (Hanamura

1966, Quinn 1985, Quinn et al. 1987). Stream fidelity in sockeye salmon is thought to be

adaptive, since this ensures that juveniles will encounter a suitable nursery lake. Wood (1995)

inferred from protein electrophoresis data that river/sea-type sockeye salmon have higher

straying rates within river systems than lake-type sockeye salmon.

Velsen (1980) reported that, at a constant temperature of 10o

C, sockeye salmon had

the longest incubation period to 50% hatch of five salmon species tested. Benefits of

intergravel incubation include protection from predation, freezing, fluctuating flows, and

desiccation. Survival during incubation is influenced by environmental conditions, the degree
21

of crowding during spawning (Foerster 1968, Burgner 1991), the type of gravel in which eggs

are laid, and the gravel’s permeability to water (Foerster 1968). Little is known about

predation during incubation. Desiccation, freezing (in northern latitudes), low oxygen due to

siltation, and dislodgement by later spawning fish are important mortality factors (Burgner

1991). In addition, severe water-flow changes (floods or drought) can lead to heavy losses

during incubation (Foerster 1968).

Upon emerging from the substrate, sockeye salmon alevins exhibit varied behavior:

1) Inlet spawners may proceed downstream to the nursery lake or remain in the stream and

show substantial growth before migrating downstream; 2) lakeshore beach spawners take up

residence directly in the lake; 3) outlet spawners may require a period of growth before

migrating upstream to the nursery lake; and 4) riverine spawners without lake access travel

downstream to backwater sections of the lower river, where they may rear for a short period

before going to sea as underyearlings (sea-type sockeye salmon) or they may rear for longer

periods prior to going to sea in their second or third year of life (river-type sockeye salmon).

Predation on migrating sockeye salmon fry varies considerably with spawning location

(lakeshore beach, creek, river, or spring area). Sockeye salmon fry mortality, due to predation

by other fish species and birds, can be extensive during downstream and upstream migration

to nursery lake habitat and is only partially reduced by the nocturnal migratory movement of

some fry populations (Burgner 1991). Predation losses during fry migration to Lakelse Lake,

British Columbia down Scully Creek were estimated at 63-84% over 4 years (Foerster 1968).

In Karymaisky Spring (Bolshaya River, Kamchatka) predation losses ranged from 13% to

91% over 8 years (Semko 1954). In the Cedar River, predation losses of sockeye salmon fry

migrating to Lake Washington were 25% and 69% in two separate tests (Stober and

Hämäläinen 1980), while 15% of the migrating sockeye salmon fry in the Cedar River in 1985

were eaten by wild steelhead smolts (Beauchamp 1995).

Juvenile sockeye salmon in lakes are visual predators, feeding on zooplankton and

insect larvae (Foerster 1968, Burgner 1991). In certain lakes (Wood River lakes in Alaska,

Lake Dalnee in Kamchatka, and Babine Lake in British Columbia), sockeye salmon fry feed

initially in the littoral zone and subsequently migrate offshore to the limnetic zone (various

references in Burgner 1991). In other lakes (Cultus Lake beach spawners and fry migrating

from the Cedar River to Lake Washington), fry move directly into the limnetic zone upon

reaching the nursery lake (Brannon 1972b, Woodey 1972, Dawson 1972). Although previous

studies have not found sockeye salmon fry in the littoral zone of Lake Washington or other

lakes in Washington (WDFW 1996), Martz et al. (1996) reported that

The majority of the sockeye fry were found in the limnetic zone; however, a smaller

but significant number of sockeye fry also utilize the littoral zone for up to one month

after emigrating from the Cedar River.

Juvenile sockeye salmon in lakes commonly undergo diel vertical migrations such that

they are present in deeper water by day than by night (Levy 1987). In Lake Washington,

juvenile sockeye salmon were reported to undergo diel vertical migrations at all times of year
22

and to occupy certain depths in direct relation to water temperature (Woodey 1972). The

surface area and productivity of a nursery lake limit population size of sockeye salmon, and

offspring of large return years may show reduced growth due to intraspecific competition.

Increased growth in freshwater may lead to higher marine survival and decreased ocean age at

return.

Smolt migration typically occurs between sunset and sunrise, beginning in late April

and extending through early July, with southern stocks migrating earliest. Some sockeye

salmon smolts undergo a complicated migration to reach the lake system outlet (Johnson and

Groot 1963). Once in the ocean, sockeye salmon feed on copepods, euphausiids, amphipods,

crustacean larvae, fish larvae, squid, and pteropods. Increase in length is typically greatest in

the first year of ocean life, whereas increase in weight is greater during the second year.

Northward migration of juveniles to the Gulf of Alaska occurs in a band relatively close to

shore, and offshore movement of juveniles occurs in late autumn or winter. Sockeye salmon

prefer cooler ocean conditions than other Pacific salmon (Burgner 1991).

Lake-Type Sockeye Salmon

The vast majority of sockeye salmon typically spawn in inlet or outlet tributaries of

lakes or along the shoreline of lakes where upwelling of oxygenated water through gravel or

sand occurs. Growth influences the duration of stay in the nursery lake and is influenced by

intra- and interspecific competition, food supply, water temperature, thermal stratification,

migratory movements to avoid predation, lake turbidity, and length of the growing season.

Lake residence time is usually greater the farther north a nursery lake is located. In

Washington and British Columbia, lake residence is normally 1 or 2 years, whereas in Alaska

some fish may remain 3, or rarely 4 years in the nursery lake, prior to smoltification (Burgner

1991, Halupka et al. 1993).

While in the lacustrine environment, fry and yearlings feed as visual predators,

primarily on copepods (Cyclops, Epischura, and Diaptomus), cladocerans (Bosmia, Daphnia,

and Diaphanosoma), and insect larvae. In some lakes, sockeye salmon fry initially feed near

the lake shoreline in the littoral zone, subsequently shifting to the deeper waters of the

limnetic zone. In other lakes, sockeye salmon fry enter the limnetic zone directly. In many

lakes, juveniles feed in the limnetic zone at dusk and dawn to avoid day-time visual predators,

and this feeding pattern may be tied to diel vertical migrations (Eggers 1978, Pauley et al.

1989, Burgner 1991). In summer and fall 1972, juvenile Lake Washington sockeye salmon

fed intensively during the afternoon through dusk. In winter 1972-1973, a high percentage of

the population did not feed on a daily basis. No feeding occurred at night during any season

of the year (Doble and Eggers 1978).

Competitors for common food of sockeye salmon during lake residence may include

threespine and ninespine sticklebacks (Gasterosteus aculeatus and Pungitius pungitius), red

sided shiner (Richardsonius balteatus), pond smelt (Hypomesus olidus), pygmy whitefish

(Prosopium coulteri), lake whitefish (Coregonus clupeaformis), northern squawfish
23

(Ptychocheilus oregonensis), yellow perch (Perca flavescens), peamouth (Mylocheilus

caurinus), and kokanee (Foerster 1968, Dlugokenski et al. 1981, Burgner 1991). Longfin

smelt (Spirinchus thaleichthyes) are reportedly an important competitor with sockeye salmon

in Lake Washington (WDFW 1996). Nursery lake area and productivity coupled with interand intra-specific competition can exert a limiting effect on smolt size, and ultimately

population size, of sockeye salmon (Kyle et al. 1988).

Potential predators on lake resident sockeye salmon fry throughout their North

American range include: lake trout (Salvelinus namaycush), rainbow trout (O. mykiss), Dolly

Varden charr (Salvelinus malma), Arctic charr (Salvelinus alpinus), cutthroat trout (O. clarki),

juvenile coho (O. kisutch) and chinook salmon (O. tshawytscha), lake whitefish (Prosopium

clupeaformis), mountain whitefish (Prosopium williamsoni), northern squawfish

(Ptychocheilus oregonensis), burbot (Lota lota), northern pike (Esox lucius), prickly sculpin

(Cottus asper), and bird predators (Foerster 1968, Hartman and Burgner 1972, Burgner 1991,

Emmett et al. 1991, Beauchamp et al. 1995). Principle bird predators include: common loon

(Gavia immer), red-necked grebe (Podiceps grisegna), common merganser (Mergus

merganser), belted kingfisher (Megaceryle alcyon), osprey (Pandion haliaetus), bald eagle

(Haliaeetus leucocephalus), terns, and gulls (Emmett et al. 1991).

River-Type and Sea-Type Sockeye Salmon

In areas where lake-rearing habitat is unavailable or inaccessible, sockeye salmon may

utilize river and estuarine habitat for rearing or may forgo an extended freshwater rearing

period (Birtwell et al. 1987; Wood et al. 1987a, Heifitz et al. 1989; Murphy et al. 1988, 1989,

1991; Lorenz and Eiler 1989; Eiler et al. 1992; Levings et al. 1995; Wood 1995). Riverine

spawners that rear in rivers for 1 or 2 years are termed “river-type” sockeye salmon. Riverine

spawners that migrate as fry to sea or to lower river estuaries in the same year emergence

occurs, following a brief freshwater rearing period of only a few months, are referred to as

“sea-type” sockeye salmon.

River-type and sea-type sockeye salmon are common in northern areas and may

predominate over lake-type sockeye salmon in some river systems (Wood et al. 1987a, Eiler

et al. 1988, Halupka et al. 1993, Wood 1995) (see Table 2). River/sea-type sockeye salmon

have been rarely reported in rivers south of the Stikine River, although those that spawn in the

Harrison River rapids and rear in the lower Fraser River system of southern British Columbia

are the exception (Gilbert 1918, 1919; Schaefer 1950, 1951; Birtwell et al. 1987; Levings et

al. 1995). Halupka et al. (1993) suggested that the lack of reported river/sea-type sockeye

salmon stocks south of the Stikine River, with the exception of the Fraser River population,

may be due to any of three factors: 1) the lack of sufficient colonists with the genetic capacity

for developing this life-history pattern, 2) the lack of suitable habitat for development of a

river/sea-type life history pattern, or 3) small river/sea-type stocks exist in southern rivers but

their presence has been overlooked. Eiler et al. (1992) indicated that riverine spawning has

been reported (if only sometimes anecdotically) throughout the range of sockeye salmon.
24

Known self-sustaining populations of river/sea-type sockeye salmon throughout the Pacific

Rim are listed in Table 2.

Many populations of river/sea-type sockeye salmon spawn and rear in close proximity

to glaciers or in glacially influenced drainages. Milner and Bailey (1989) observed that

sockeye salmon were one of the first salmonids to colonize clearwater streams in Glacier Bay

National Park, Alaska following glacial retreat. Lorenz and Eiler (1989) noted that river/seatype sockeye salmon in the glacial Taku River, Alaska preferred main channel or off-channel

areas for spawning, where upwelling groundwater occurs. Fish spawning in these areas had,

on average, two times more fine sediment in their redds than had been previously measured in

other sockeye salmon redds.

Several studies have indicated that sea-type sockeye salmon possess heritable

physiological adaptations for successful migration to sea as underyearlings (Rice et al. 1994,

Wood 1995). Underyearling sea-type sockeye salmon from the East Alsek River, Alaska

(Rice et al. 1994) and river/sea-type sockeye salmon from the Scud River in the Stikine River

basin (Wood 1995) showed superior seawater adaptability over lake-type fry when exposed to

similar seawater challenge. When reared in 30 ppt seawater, sea-type sockeye salmon fry

from the East Alsek River grew significantly faster than river-type sockeye salmon, which in

turn grew faster than lake-type sockeye salmon (Rice et al. 1994). Underyearling sockeye

salmon in the Situk River, Alaska and Fraser River estuaries grow unusually fast in nature,

obtaining a size similar to that of age 1+ lake-type smolts by the middle to end of their first

summer (Birtwell et al. 1987, Rice et al. 1994). Juvenile sea-type sockeye salmon in the Situk

River estuary in southeast Alaska rear in the estuary for 3-4 months in 0-30 ppt salinity until

they are large enough to tolerate full-strength ocean salinity as underyearlings greater than 50

mm in length (Heifitz et al. 1989). Both Craig (1985) and Wood (1995) have

reported that egg size in river/sea-type sockeye salmon is significantly larger than in lake-type

sockeye salmon within the Stikine River Basin, and this may provide a size advantage to

river/sea-type sockeye salmon fry over lake-type fry. At present, it is unknown whether these

egg size differences are heritable (Wood 1995).

In studies of genetic variation of sockeye salmon in the Stikine River drainage, widely

separated spawning populations of river/sea-type sockeye salmon showed much less genetic

differentiation than did widely separated spawning populations of lake-type sockeye salmon

(Wood 1995). This apparent lack of reproductive isolation among spawning populations of

river/sea-type sockeye salmon in the Stikine River (some populations separated by over 180

km) was interpreted by Wood (1995) to indicate that precise homing may be relaxed in river/

sea type sockeye salmon in systems where river/sea-type fry from throughout the watershed

rear together in the lower river or estuary.

Wood (1995) speculated further that the combined traits of living in glacially

influenced drainages and having higher straying rates than lake-type sockeye salmon give

river/sea-type sockeye salmon the role of primary colonists of new habitat following glacial

retreat.
25
26
27
28
29

Nonanadromous Forms

“Kokanee,” for the purposes of this review, are defined as the self-perpetuating,

nonanadromous form of O. nerka that occurs in balanced sex-ratio populations and whose

parents, for several generations back, have spent their whole lives in fresh water. Commonly,

kokanee occur in land-locked lakes, where access from the ocean has become difficult or

impossible (such as Lake Whatcom, Washington). Kokanee and sockeye salmon also cooccur in many interior lakes of the Skeena, Fraser, and Columbia River Basins, where access

from the sea is possible, although energetically costly. Kokanee are rarely found in easily

accessible coastal lakes that contain sockeye populations and where the energetic costs of

migration are minimal.

The terms “residual sockeye” and “residuals” have been used to identify resident, nonmigratory progeny of anadromous sockeye salmon (Ricker 1938). Ricker (1938) was of the

opinion that it would be unusual if residual sockeye salmon were not found in most lakes

which have an anadromous sockeye population, although Burgner (1991) stated that residual

sockeye salmon are rare or absent in most northern sockeye salmon lakes. For the purposes of

this review, we have defined the term “resident sockeye salmon” to indicate those fish that are

the progeny of anadromous parents, yet spend their adult life in freshwater and are observed

together with their anadromous siblings on the spawning grounds. The degree to which

resident sockeye salmon produce anadromous offspring is generally unknown.

Both kokanee and resident sockeye salmon are normally smaller at maturity than

anadromous sockeye salmon, primarily because of productivity differences between their

respective freshwater and oceanic post-juvenile rearing environments. According to Ricker

(1938, 1940, 1959), Burgner (1991), and Wood (1995), “residual” or resident sockeye salmon

1) mature earlier (males earlier than females) and at a smaller size than anadromous sockeye

salmon, 2) have a sex ratio biased toward males, 3) spawn in the vicinity of anadromous

individuals, and 4) develop a dull olive-green spawning coloration, although this later

character may not be expressed in all resident sockeye salmon populations (Ricker 1959).

According to Ricker (1938, 1940, 1959), Burgner (1991), and Wood (1995), kokanee have a

balanced sex ratio, spawn earlier in the year, mature at a smaller size, have more gill rakers,

and absorb their scale margins to a greater degree upon maturity than anadromous sockeye

salmon. These same authors stated that kokanee typically display a bright red body coloration

at spawning, although this trait is not expressed in all populations of kokanee. On the other

hand, Brannon (1996) argued that exceptions to the above differences in spawn timing, size at

maturity, and spawning coloration between kokanee and resident sockeye salmon invalidate

these criteria as characters that can be used to define the types.

All three forms (sockeye salmon, resident sockeye salmon, and kokanee) typically

spawn in the vicinity of a nursery lake, die after spawning a single time, and as juveniles rear

in the pelagic zone of a nursery lake. Kokanee and resident sockeye salmon remain in fresh

water for their entire life cycle, whereas sockeye salmon migrate to sea following 1 to 4 years
30

in freshwater, grow to maturity in the ocean, and return to the natal freshwater habitat to

spawn following an additional 1 to 4 years at sea.

Genetic differentiation among sockeye salmon and kokanee populations indicates that

kokanee are polyphyletic, having arisen from sockeye salmon on multiple independent

occasions, and that kokanee may occur sympatrically or allopatrically in relation to sockeye

salmon (Foote et al. 1989, Wood and Foote 1990, Foote et al. 1992, Taylor et al. 1996, Wood

and Foote 1996, Winans et al. 1996). In some cases, both forms may spawn at the same time

and place (Hanson and Smith 1967, McCart 1970, Foote and Larkin 1988, Foote et al. 1994),

although typically kokanee spawn earlier than sockeye salmon. According to Brannon

(1996), early spawning is not a universal kokanee trait, as some populations spawn at the

same time or later than sympatric sockeye salmon. In the locations that have been studied

where sockeye salmon and kokanee remain sympatric and spawn in the same place and time,

there is a high degree of size-based assortative mating (Foote and Larkin 1988). Assortative

mating by body size usually leads to assortative mating by type; kokanee with kokanee and

sockeye salmon with sockeye salmon. Even where sneak-spawning by small satellite kokanee

males occurs, and results in successful fertilization of sockeye salmon eggs, substantial postzygotic isolating mechanisms between kokanee and sockeye salmon may reduce gene flow

(Wood and Foote 1996).

In relation to co-occurring sockeye salmon and kokanee-sized O. nerka, McCart

(1970) asked the question, “Do they constitute distinct, non-interbreeding populations or are

they simply alternative life-history types arising within single populations?” McCart (1970)

showed that spawning sockeye salmon and kokanee in shallow streams tributary to Babine

Lake, British Columbia, overlap almost completely in their spawning season and in their

distribution on the spawning grounds. He suggested that hybridization between the forms

probably occurs under natural conditions. Foote et al. (1989) studied genetic relatedness of

sockeye salmon and kokanee from these same streams in Babine Lake and stated that “there

were significant differences between sockeye and kokanee in all systems where they spawn

sympatrically.” In relation to the Babine Lake tributaries, Foote et al. (1989) stated that

“Despite apparent interbreeding, there is an effective restriction in gene flow between sockeye

and kokanee that indicates that they do not constitute a single panmictic population.”

Foote et al. (1989) further showed that sympatric kokanee and sockeye salmon in each

of three different lake systems in British Columbia were genetically distinct from each other,

but were more similar to each other within a lake system than either was to the same morph in

another lake system. Likewise, Taylor et al. (1996) showed that, based on allelic variation in

mitochondrial DNA Bgl II endonuclease restriction sites and two minisatellite nuclear DNA

repeat loci, genetic affinities among sockeye salmon and kokanee throughout their range in

the North Pacific were organized more by geographic proximity than by life-history type.

Within Takla Lake, British Columbia, Wood and Foote (1996) showed that genetic

differences between kokanee and sockeye salmon in the same stream were much greater than

within morph differences among either sockeye salmon or kokanee spawning in different

streams in the same lake system.
31

However, there are exceptions to the above pattern of sockeye salmon and kokanee

genetic relatedness. Winans et al. (1996) investigated the genetic similarity of sympatric

populations of kokanee and sockeye salmon in the Lower Shuswap River (in the Fraser River

drainage of British Columbia) and Ozette Lake on the Olympic Peninsula and found

significant genetic differences between sympatric morphs in both cases. In addition, kokanee

from the Lower Shuswap River were genetically more similar to kokanee from Okanagan

Lake in the Columbia River drainage than they were to sympatric sockeye salmon from the

Lower Shuswap River. Robison (1995) also found genetic similarity between Lower

Shuswap River kokanee and Okanagan Lake kokanee, which he interpreted as suggestive of

transplantation of Shuswap Lake kokanee into Okanagan Lake. Winans et al. (1996) showed

that kokanee from Ozette Lake were divergent from sympatric sockeye salmon, as well as

from all other contiguous U.S. stocks of O. nerka investigated.

Craig (1995) has shown that although both sockeye salmon and kokanee from Takla

Lake, British Columbia exhibit similar red spawning coloration, they are genetically divergent

in the ability to utilize the carotenoid pigments in the diet that, when mobilized from the

muscle tissue and deposited in the skin, produce the red coloration. Carotenoids are more

abundant in the marine diet of sockeye salmon than in the freshwater diet of kokanee, and

apparently, kokanee in the Takla Lake population are able to compensate for this difference

by being more efficient at extracting carotenoids. Craig (1995) demonstrated that when

reared under identical conditions in the hatchery, Takla Lake kokanee turned red at maturity,

Takla Lake sockeye salmon were olive-green, and hybrid forms were intermediate in

coloration. In addition, Craig (1995, p. 25) stated that “residuals do not turn red at maturity,

presumably because they lack the genetic adaptations for increased carotenoid absorption

needed to turn red in freshwater.”

Taylor and Foote (1991) compared sustained swimming performance and morphology

of sockeye salmon, kokanee, and hybrid juveniles obtained from sympatrically spawning

populations in Babine Lake, British Columbia and showed that juvenile sockeye salmon are

stronger swimmers than kokanee or sockeye salmon x kokanee hybrids. Similar comparisons

of developmental rate (Wood and Foote 1990), ontogeny of seawater adaptability (Foote et al.

1992), and growth and onset of maturity (Wood and Foote 1996) between juvenile sockeye

salmon, kokanee, and sockeye salmon × kokanee, indicated that progeny of hybrid crosses

may be less successful than progeny of pure crosses of either type in their respective

environments.

Danner (1994) studied behavioral, physiological, and genetic differences among

sockeye salmon, sockeye salmon x kokanee hybrids, and kokanee. Danner (1994) showed

that sockeye salmon were able to adapt to a 24-hour saltwater challenge 3 to 6 weeks before

either sockeye x kokanee hybrids or pure kokanee, although he suggested that this earlier

onset of saltwater adaptability may be a function of the larger size of sockeye versus sockeye

× kokanee hybrids or pure kokanee of the same age. Growth rates of the three types exposed

to identical conditions were greatest for sockeye salmon, intermediate for the hybrids, and

slowest for kokanee (Danner 1994), although survival was not significantly different among
32

types. Pure sockeye salmon also had significantly higher interlamellar chloride cell density

than sockeye × kokanee hybrids or pure kokanee. Danner (1994) also measured migratory

tendency of sockeye salmon, kokanee, and their hybrids by their ability to exit rearing tanks

through a modified central standpipe. Migration tendency was similar for all three forms.

According to Danner (1994), mixed DNA fingerprints of seven O. nerka populations

differentiated stocks by origin but failed to reveal a marker separating migratory and nonmigratory O. nerka stocks. Danner (1994) concluded that kokanee stocks with “smoltification

characteristics similar to anadromous stocks have not likely separated far from anadromous

ancestors” and that “characteristics necessary to become anadromous are maintained” in

kokanee populations.

Robison (1995) examined mtDNA genetic divergence between sockeye salmon and

freshwater resident O. nerka, in four systems where these life history forms spawn

sympatrically: 1) Pierre Creek in the Babine Lake Basin, British Columbia, 2) Eagle River,

British Columbia, 3) the Middle Shuswap River, British Columbia, and 4) a beach spawning

site in Redfish Lake, Idaho. Freshwater residents and sockeye salmon were genetically

indistinguishable in the Eagle River and on beach sites in Redfish Lake, but sympatric

populations of the two forms were divergent in Pierre Creek and the Middle Shuswap River

(Robison 1995). Robison (1995) interpreted these data to indicate that in the Eagle River and

Redfish Lake populations, either sockeye salmon or the freshwater residents have been

established recently from their counterpart form.

The above studies indicate that both sockeye salmon and kokanee exhibit a suite of

heritable differences in morphology, rate of early development, seawater adaptability, growth,

and maturation that appear to be divergent adaptations that have arisen from different

selective regimes associated with anadromous vs. non-anadromous life histories. Although

these heritable differences are strongly expressed in many populations, both indirect and

direct evidence exists showing that kokanee are capable of producing anadromous offspring

that return from the ocean with the sockeye salmon morphology (Chapman 1941, Foerster

1947, Rounsefell 1958a, Fulton and Pearson 1981, Chapman et al. 1995) and that sockeye

salmon are capable of producing freshwater resident offspring (Ward 1932; Ricker 1938,

1959; Scott 1984; Graynoth 1995).

Based on indirect evidence, Chapman (1941) and Rounsefell (1958a) postulated that

sockeye salmon observed at the base of Enloe Falls on the Similkameen River, and those

below falls that are a natural barrier to fish passage downstream from Lake Chelan, may have

been derived from downstream passage of kokanee from up-river lakes. Similarly, sockeye

salmon that have been observed at the Whatcom Creek Hatchery of the Bellingham Technical

School (Bellingham, Washington) (from 6 to 8 in most years, although none were observed in

1994 and only 2 in 1995), and below natural upstream passage barriers in Whatcom Creek
33

itself, are presumed to be derived from returns of outmigrating Lake Whatcom kokanee

(E. Steele6).

Several other researchers have provided more direct evidence that kokanee may at

times go to sea, survive ocean life, and then return to spawn in freshwater. Foerster (1947)

released almost 64,000 marked Kootenay Lake yearling kokanee in the outlet stream of Cultus

Lake in 1934 and observed 5-year-old adult sockeye salmon with these markings that returned

in 1937, with a calculated survival rate of 0.14% (Chapman et al. 1995). For comparison,

survival rates for sockeye smolts returning as sockeye salmon to Cultus Lake were in the

range of 1.9-2.6% during this time period (Foerster 1947). According to Foerster (1947) and

Ricker (1972), since Kootenay Lake kokanee were known to mature at age-3, with a few at

age-2 and age-4, surviving anadromous kokanee were expected to return at age-3 or age-4, not

as age-5 sockeye salmon in 1937. Marked Kootenay Lake kokanee returning to Cultus Lake

exhibited spawn-timing concurrent with Cultus Lake sockeye salmon

(October-November) (Foerster 1947) rather than with the spawn-timing of Kootenay Lake

kokanee (August-September) (Vernon 1957). The results of this study “indicated that, when

liberated in a stream below a lake and barred from ascending into the lake, some of the

kokanee proceeded to sea and returned” (Foerster 1947).

Similar kokanee-marking experiments were conducted in the Columbia River Basin in

the 1940s (Fulton and Pearson 1981). Fin-clipped yearling Lake Chelan kokanee released in

the Entiat River and Lake Wenatchee kokanee released in Lake Wenatchee and Icicle Creek

returned as adults at rates of 0.004%, 0.50%, and 0.27%, respectively. Kokanee in Lake

Chelan had been introduced from Lake Whatcom kokanee transplants. In the case of Lake

Wenatchee kokanee, Fulton and Pearson (1981) stated that “there was a question as to

whether [these] fish were far enough removed from seaward migratory behavior to be

classified as kokanee.” Also in reference to Lake Wenatchee, Ricker (1972) stated that “there

may still be a very incomplete separation of kokanee from sockeye at this lake” and that Lake

Wenatchee kokanee may have diverged from sockeye salmon only within the past 90 years, as

difficulties in migrating up the Wenatchee River have increased due to water diversions,

dams, and high water temperatures. Fulton and Pearson (1981) concluded that in these

experiments “adult sockeye salmon that had kokanee parents were slightly smaller than adult

sockeye salmon that had anadromous parents.”

Kaeriyama et al. (1992) documented returns of sockeye salmon derived from marked

kokanee plants in Lake Toro, Japan. Of the 60,000 smolt-sized O. nerka released in

1988-1989 in Lake Toro, a total of 20 adult sockeye returned (0.03% of those released).

According to Kaeriyama et al. (1992), the parent kokanee population from Lake Shikotsu,

Japan that was used in this experiment had been derived from sockeye salmon in Lake

Urumbetsu on Iturup Island that were introduced into Lake Shikotsu between 1925 and 1940

6 E. Steele, Hatchery Manager, Whatcom Creek Hatchery, Bellingham Technical College,

Maritime Heritage Center, Bellingham, WA. Pers. commun., 20 October 1995.
34

and were subsequently landlocked for 15 generations. As such they may have retained more

capability for anadromy than is typical of kokanee in general. Kaeriyama et al. (1992)

concluded that “both anadromous and nonanadromous types of Oncorhynchus nerka can be

produced from both sockeye and kokanee salmon.”

Not only may kokanee occasionally give rise to anadromous individuals, but in several

documented instances sockeye salmon stocked in lakes without ocean access have developed

into self-sustaining resident “kokanee” or “residual sockeye salmon” populations (Scott 1984,

Kaeriyama et al. 1992). For the sake of completeness, it should also be noted that in at least

two instances (Ozette Lake, Washington and Lake Cowichan, Vancouver Island), large viable

kokanee populations with no documented anadromous members exist in lake basins where

access to and from the sea is relatively easy (Dlugokenski et al. 1981, Rutherford et al. 1988).

Historical Distribution

Most modern sockeye salmon populations in Alaska, Canada, and northern

Washington arose within the last 10,000 years following retreat of the Cordilleran ice sheet at

the close of the last ice age (Wood 1995). Sockeye salmon are thought to have survived the

ice ages in refugia in the Bering Sea region of Alaska, south of the ice sheet in the Columbia

River, on coastal islands in British Columbia, in Kamchatka, and perhaps on Kodiak Island in

Alaska (Wood 1995).

Spawning populations of sockeye salmon do not presently occur in California, and it is

uncertain whether they existed there historically. Jordan and Evermann (1896) stated that

sockeye salmon occurred in the Klamath River, and Scofield (1916) relates the

unsubstantiated claim that 20 sockeye salmon were taken in the commercial fishery in the

Klamath River in the summer of 1916. Klamath Lake was accessible to migrating salmon

prior to the construction of Copco Dam on the Klamath River in 1917. However, early

reports of sockeye salmon in the Klamath River may be explained by Wilcox’s (1898)

statement that “silver salmon are locally known as blueback” and that “blueback” is the

common name for sockeye salmon on the Columbia and Quinault Rivers. Taft (1937)

reported the taking of a single sockeye salmon in the Klamath River in August 1936.

Cobb (1911, p. 8) reported that “small runs [of sockeye salmon] are said to occur in

Mad and Eel Rivers” in Humboldt County, whereas Jordan and Gilbert (1881a) indicated that

sockeye salmon were unknown in the Eel and Sacramento Rivers. Jordan and Gilbert (1881b)

did not observe sockeye salmon in the Sacramento River. Rutter (1904) reported the

occurrence of a single sockeye salmon in the Sacramento River in 1899. Hallock and Fry

(1967) described the recovery of 22 sockeye salmon from the Sacramento River between 1949

and 1958 and speculated as to whether these fish may have been strays, part of a remnant run,

or partially derived from kokanee planted in Shasta Lake. Currently, there are no recognized

runs of sockeye salmon in California, although introduced kokanee populations have been

established in numerous reservoirs and lakes.
35

Jordan and Gilbert (1881a) indicated that sockeye salmon were unknown in the Rogue

River, Oregon, whereas Jordan and Evermann (1896) stated that sockeye salmon occurred in

the Rogue River. Oakley and Kruse (1963) reported the occurrence of a stray female sockeye

salmon in 1961 in the Kilchis River, a tributary of Tillamook Bay. Currently, there are no

recognized populations of sockeye salmon in coastal Oregon streams.

Only about 5% of the pre-1900 nursery lake habitat in the Columbia River drainage

remains accessible today to sockeye salmon (Mullan 1986). Historically, two Oregon lakes

within the Columbia River Basin supported populations of sockeye salmon: Suttle Lake in

the Deschutes River Basin (Nielson 1950, Nehlsen 1995), and Wallowa Lake in the Snake/

Grande Ronde River Basin (Mullan 1986).

Suttle Lake, at the head of the Metolius River, has a surface area of 0.1 km2

(250 acres) and probably never supported a large population of sockeye salmon. A small dam

and screen installed at the outlet of Suttle Lake in 1930 (Fulton 1970, Nehlsen 1995) blocked

fish passage both into and out of the lake, while a swimming pool dam, built sometime

between 1925 and 1938 at Lake Creek Lodge, impeded fish passage in Lake Creek below

Suttle Lake (Nehlsen 1995). Three further dams were subsequently constructed downstream

of Suttle Lake, on the Deschutes River: Pelton Dam and Pelton Re-regulating Dam were

constructed in 1958, and Round Butte Dam was constructed in 1964. A small number of

sockeye salmon are currently observed at the base of the Pelton Re-regulating Dam each

summer; however, neither their origin nor whether they spawn below the dams, is known

(ODFW 1995a).

Wallowa Lake, near the head of the Wallowa River in northeastern Oregon, once

supported a substantial sockeye salmon population. Bartlett (1967) indicated that following

the forced removal of members of the Nez Perce Tribe in 1877 and elimination of their

ceremonial and subsistence fishery based on sockeye salmon from the Wallowa Valley,

seining by horse and rowboat at the head of Wallowa Lake became a small industry that

produced an annual catch of about 27,216 kg (60,000 pounds) of sockeye salmon by 1881.

Bendire (1881) reported the taking of several O. nerka specimens in Wallowa Lake on 31

August and 1 September 1880. A rough dam to supply water to a small shingle mill was built

across the lake outlet in 1884, and a more substantial dam and irrigation ditch were

constructed in 1890 (Bartlett 1967). Bartlett (1967) indicated that this latter dam blocked the

migration corridor for the Wallowa Lake population and resulted in land-locked sockeye

salmon, locally termed “yanks,” that spawned in tributary creeks in the fall. Evermann and

Meek (1898) reported that both “large and small redfish” occurred in Wallowa Lake and

spawned together. The small redfish or “yanks” or “grayling” were likely residual sockeye

salmon, as they were overwhelmingly males and more silvery in color than larger fish

(Evermann and Meek 1898).

Several authors (CBFWA 1990, ODFW 1995a) have reported that prior to increasing

the height of the dam at Wallowa Lake in 1916, sockeye salmon continued to return and

spawn above the lake. The last reported sockeye salmon were apparently observed in
36

Wallowa Lake in 1916 (Toner 1960) or 1917 (CBFWA 1990). However, Cramer (1990)

stated that “sockeye were extinct from the lake by 1904.” ODFW (1995a) reported that

sockeye salmon were observed until the early 1930s in the Wallowa River below the lake,

while Parkhurst (1950a) and Fulton (1970) reported that construction of a 12-m high concrete

dam at the lake outlet in 1929 finished off the population. Cramer (1990) stated that a 4-m

tall dam that existed between 1906 and 1924 at the Wallowa River Hatchery, 43 miles below

Wallowa Lake, completely blocked upstream fish passage. Considerable numbers of nonnative sockeye salmon were stocked in the Wallowa River below Wallowa Lake in the 1920s

and 1930s (Cramer 1990; his Appendix 8), perhaps contributing to reports of sockeye salmon

returning to the Wallowa River up until the early 1930s (see Appendix Table D-2).

Historically, sockeye salmon spawned and reared in the Snake River in several high

mountain lakes in Idaho. In the Salmon River Basin, sockeye salmon occurred in Alturas,

Redfish, Pettit, and Stanley Lakes (Evermann 1895, 1896; Evermann and Scovell 1896;

Evermann and Meek 1898), and perhaps in Yellowbelly Lake (Bjornn et al. 1968, Mullan

1986, Chapman et al. 1990). Mullan (1986) stated that the presence of kokanee indicated that

sockeye salmon once used Little Redfish Lake and Hell Roaring Lake in the Stanley Basin

and Warm Lake on the South Fork Salmon River. In the Payette River Basin, sockeye salmon

reportedly occurred in Big Payette, Upper Payette (Evermann 1895, 1896; Evermann and

Scovell 1896; Fulton 1970), and Little Payette Lakes (Mullan 1986). Currently, a genetically

distinct sockeye salmon population exists in Redfish Lake, Idaho and is listed as endangered

under the federal Endangered Species Act. Other anadromous O. nerka populations in Idaho

are thought to be extinct, although O. nerka in Alturas Lake have been known to produce

outmigrating individuals. In addition, kokanee stocks in Redfish, Alturas, and Stanley Lakes

are genetically more similar to sockeye salmon from Redfish Lake than they are to other O.

nerka stocks investigated from outside the Stanley Basin (Winans et al. 1996, Waples et al. in

press).

The history of the decline of sockeye salmon in the Stanley Basin lakes on the Salmon

River was reviewed in Bjornn et al. (1968), Chapman et al. (1990), and Waples et al. (1991).

Evermann (1895) observed sockeye salmon spawning in the inlet to Big Payette Lake and

related that local residents informed him that between 1870 and 1880 two fisheries operated

on this lake and in some years took up to 75,000 fish (or 13,600 to 18,140 kg) and that a few

sockeye salmon may have gone as far as Upper Payette Lake. A diversion dam built about

1914 near Horseshoe Bend on the Payette River, and Black Canyon Dam constructed in 1923,

blocked access by sockeye salmon to the Payette Lakes (Parkhurst 1950b, Fulton 1970,

Mullan 1986). Current accessible lake-rearing habitat for sockeye salmon in Idaho, based on

lake area, represents about 25% of historically available habitat (Hassemer et al. 1996).

Within the Columbia River Basin in Washington, historical populations of sockeye

salmon existed in the Yakima, Wenatchee, and Okanogan Rivers. Sockeye salmon

populations reportedly existed in two small lakes at the head of the Yakima River on the

present site of Lake Keechelus, as well as in Cle Elum Lake in the Yakima/Cle Elum River

Basin, in Kachess Lake in the Yakima/Kachess River Basin, and in Bumping Lake in the
37

Yakima/Naches/Bumping River Basin (Davidson 1953, Fulton 1970, Mullan 1986). The

historical total run size of Yakima River sockeye salmon has been estimated at either 100,000

(Davidson 1953) or 200,000 (CBFWA 1990). Construction of crib dams without fish passage

facilities at Lakes Keechelus and Kachess in 1904 and at Lake Cle Elum in 1905 eliminated

sockeye salmon populations in these lakes (Bryant and Parkhurst 1950, Davidson 1953,

Fulton 1970, Mullan 1986). Construction of an impassable storage dam at Bumping Lake in

1910 likewise eliminated a sockeye salmon population in that lake, with an estimated annual

run of 1,000 fish (Davidson 1953, Fulton 1970).

The native population of sockeye salmon in Lake Wenatchee was severely depleted

during the early 1900s (Bryant and Parkhurst 1950, Davidson 1966, Fulton 1970), with

returns counted over Tumwater Dam on the Wenatchee River in 1935, 1936, and 1937

amounting to 889, 29, and 65 fish, respectively (WDF et al. 1938). Small dams and

unscreened irrigation diversions on the Wenatchee River contributed to the decline of this

population (Bryant and Parkhurst 1950).

Historically, sockeye salmon are thought to have utilized Lakes Okanagan, Skaha, and

Osoyoos in the Okanogan River Basin for juvenile rearing (Bryant and Parkhurst 1950, Fulton

1970, Mullan 1986). Sockeye salmon access to Lakes Okanagan and Skaha in British

Columbia was blocked by dams in 1915 and 1921, respectively. Access to Lake Osoyoos

remained open, but the population was severely depleted in the early 1900s (Davidson 1966,

Fulton 1970), with returns to the Okanogan River in 1935, 1936, and 1937, amounting to 264,

895, and 2,162 sockeye salmon, respectively (WDF et al. 1938).

In order to preserve a portion of the sockeye salmon stocks denied access to the Upper

Columbia River in 1939 by Grand Coulee Dam, the Grand Coulee Fish-Maintenance Project

(GCFMP) trapped all sockeye salmon at Rock Island Dam between 1939 and 1943 and

relocated them to Lakes Wenatchee or Osoyoos or to one of three national fish hatcheries

(Leavenworth, Entiat, and Winthrop) for artificial propagation. Numerous descendants of

artificially propagated sockeye salmon trapped at Rock Island and Bonneville Dams, together

with progeny of Quinault Lake sockeye salmon, were stocked into Lakes Wenatchee and

Osoyoos between 1940 and 1968 (Mullan 1986, see Appendix Table D-2). Consequently, the

current populations of sockeye salmon that return to Lake Wenatchee and the Okanogan River

may consist of some mixture of native and non-native fish (see “Artificial Propagation”

section below).

Fulton (1970) listed Palmer Lake on the Similkameen River, a tributary of the

Okanogan River, as originally supporting native sockeye salmon, although some authors

(Craig and Suomela 1941) suggested that salmon could not have ascended Enloe Falls. The

current Enloe Dam blocks access to all but the lower six miles of the Similkameen River.

Sockeye salmon have been observed on numerous occasions since 1936 in the Similkameen

River below the dam, during the Okanogan River sockeye salmon migration (Chapman 1941,

Bryant and Parkhurst 1950, Chapman et al. 1995). Sockeye salmon (see Appendix Table D-
38

2) and kokanee (see Appendix Table D-5) have been released above Enloe Dam at various

times.

In reference to sockeye salmon, WDF et al. (1938) stated that “it is certain that none

go into the Entiat, and none have ever been seen in the Methow.” During operation of the

GCFMP, sockeye salmon fry and fingerlings were released in the Methow and Entiat Rivers

(Mullan, 1986, see Appendix Table D-2), and currently small numbers of sockeye salmon are

consistently seen each year in these rivers (Langness 1991, Chapman et al. 1995; see section

below on “Information Specific to Sockeye Salmon Populations Under Review”).

Historically, it is likely that Upper Arrow, Lower Arrow, Whatshan, and Slocan Lakes

in the Upper Columbia River drainage in British Columbia were utilized by sockeye salmon,

as nursery lake habitat (Mullan 1986). In addition, Fulton (1970) stated that sockeye salmon

probably ascended to Kinbasket, Windermere, and Columbia Lakes in the Canadian portion of

the Columbia River, and Mullan (1986) suggested that the presence of kokanee indicated the

past use of these lakes by sockeye salmon. WDF et al. (1938) and Chapman (1943) reported

observations of sockeye salmon at Kettle Falls on the Columbia River and at Upper and

Lower Arrow Lakes on the Upper Columbia River in British Columbia prior to Grand Coulee

Dam construction. Comparison of sockeye salmon counts at Rock Island Dam, Tumwater

Dam on the Wenatchee River, and Zosel Dam at Oroville on the Okanogan River between

1935 and 1937 indicated that more than 85% of the sockeye salmon passing Rock Island Dam

were bound for spawning areas above the Grand Coulee Dam site (WDF et al. 1938).

Chapman et al. (1995) indicated that this value was likely overestimated by the amount of prespawning mortality that might have occurred between Rock Island Dam and both Tumwater

Dam on the Wenatchee River and the mill dam at Oroville on the Okanogan River. Recent

escapement data on Okanogan River sockeye salmon indicate that pre-spawning mortality

between Wells Dam and spawning grounds on the Okanogan River is about 30%. If similar

pre-spawning mortality occurred upstream of the Grand Coulee Dam site in the years 1935

through 1937, the percentage of sockeye salmon passing Rock Island Dam that spawned

upstream of Grand Coulee Dam would have been 60-64% (Chapman et al. 1995).

Historically, sockeye salmon were known to occur in Puget Sound at Baker Lake on

the Baker River, a tributary of the Skagit River, and probably in Mason Lake at the base of the

Kitsap Peninsula (Nehlsen et al. 1991). It is uncertain whether sockeye salmon were present

historically in the Skokomish River, which drains into Hood Canal, or in the Lake

Washington/Lake Sammamish Basin, which drains into Puget Sound (see following

discussion). A sockeye salmon population may have spawned in Mason Lake but was

reportedly eliminated in 1852 when a dam was placed on Sherwood Creek, the outlet creek of

Mason Lake (Nehlsen et al. 1991). It should be noted, however, that the information cited in

Nehlsen et al. (1991) concerning Mason Lake was attributed to a Twana Indian born 13 years

after this stock reportedly went extinct, and as such is second-hand information at best. Baker

River sockeye salmon continue to return to the lower Baker River, where they are trapped and

transported above one or both dams on the Baker River to spawn in artificial beaches

provided with gravel substrate and upwelling water.
39

Historical information indicates that sockeye salmon may once have ascended the

North Fork of the Skokomish River, located at the southern end of Hood Canal (Wampler

1980, N. Lampsakis7). The original Lake Cushman had a surface area of 500 acres (Henshaw

et al. 1913) and had the potential to support sockeye salmon, prior to a dam being placed at its

outlet.

Numerous introductions of Baker Lake, Cultus Lake, and an unknown stock of

sockeye salmon have occurred in the Lake Washington/Lake Sammamish Basin (see

Appendix Table D-2), and presently the largest population of sockeye salmon in the

contiguous U.S. spawns in the Cedar River, the main tributary of Lake Washington (Royal

and Seymour 1940, Kolb 1971, WDF et al. 1993). Historical accounts concerning the

presence and distribution of sockeye salmon within the Lake Washington/Lake Sammamish

drainage are equivocal (see discussion in “Information Specific to Sockeye Salmon

Populations Under Review” section below). Kokanee were present within this drainage

historically and are known to be native (Crawford 1979).

Construction of Elwha Dam in 1910 on the Elwha River on Washington’s Olympic

Peninsula reportedly eliminated a native sockeye salmon population that spawned and reared

in Lake Sutherland (Brown 1982, Wunderlich et al. 1994, Hiss and Wunderlich 1994, NPS

1995). However, Gilbert (1914), in reference to Lake Sutherland, stated that

we are acquainted with certain colonies of dwarf redfish which have been inaccessible

to the sea-run form for a very long period. Such are the colonies which inhabit Lakes

Crescent and Sutherland, on the northern slopes of the Olympic Mountains in

Washington. The outlets of these lakes open on the southern shore of the Straits of

Fuca [sic]. No run of sockeyes occurs along this shore nor into any of the streams tributary to

it.

Hiss and Wunderlich (1994) recorded that 7,128,000 kokanee from outside the Elwha Basin

were released in Lake Sutherland between 1933 and 1964. In 1993, an estimated 3,174

kokanee of unknown heritage spawned in Lake Sutherland (Hiss and Wunderlich 1994).

Native sockeye salmon populations exist in Ozette and Quinault Lakes on the outer

coast of the Olympic Peninsula in Washington (Evermann and Goldsborough 1907, Cobb

1911, Kemmerich 1945, Atkinson et al. 1967, WDF et al. 1993). Sockeye salmon currently

exist in Lake Pleasant on the Olympic Peninsula of Washington, but whether this population

is native or the result of introductions is uncertain (Kemmerich 1945, WDF et al. 1993).

Numerous sources indicate that Ozette and Quinault Lake sockeye salmon were of great

importance for subsistence and in ceremonies of the Makah and Quinault Indian cultures,

respectively (Willoughby 1889, Lestelle and Workman 1990, Storm et al. 1990). Although

7

 N. Lampsakis, Point No Point Treaty Council, 7999 W. Salish Lane, Kingston, WA 98346.

Pers. commun. 14 June 1995.
40

sockeye salmon may not currently run up the Dickey River to Dickey Lake (a tributary system

of the Quillayute River on the Olympic Peninsula), a sockeye salmon population existed in

the lake historically (according to E. L. Brannon8).

Age Composition

Overall age of maturity in sockeye salmon ranges from 3 to 8 years. Male sockeye

salmon are capable of maturing at any of 22 different combinations of freshwater and ocean

ages, while female sockeye salmon may mature at any of 14 different age compositions

(Healey 1986, 1987). Kokanee generally mature after either 2, 3, or 4 years in fresh water.

Formulas for designating freshwater and ocean age in sockeye salmon have been reviewed by

Koo (1962) and Foerster (1968). In this report, the European method of age designation will

be used, in which a decimal point separates the number of winters spent in freshwater (minus

the incubation period) from the number of winters spent in saltwater (Burgner 1991). Total

age is calculated by adding 1 year to the total of freshwater and saltwater age. This is the

method adopted by the Fisheries Research Institute (University of Washington) and the

Pacific Salmon Commission to designate age of sockeye salmon. For example, an age 1.2

fish would have spent one winter in fresh water and 2 winters in the sea for a total age of 4

years.

A combination of both environmental and genetic factors is thought to influence age

composition and age at maturity. Rogers (1987) reported that among sockeye salmon from

Wood River, Alaska, ocean age was most often determined by parental ocean age, whereas

environmental factors most often determined freshwater age. Godfrey (1958) and Ricker

(1972) thought that hereditary factors were more important than environmental factors in

determining age at maturity in sockeye salmon, whereas Peterman (1985) thought that

environmental conditions during early marine life were of primary importance in determining

age at maturity.

While age composition and total age at maturity among sockeye salmon populations

may vary year-to-year within a population, due to environmental variation and maternal

influences (Bilton 1970), age composition also varies between populations, both in different

river systems and within river systems (Ricker 1972, Smirnov 1975, Peterman 1985, Healey

1987, Rogers 1987, Burgner 1991, Rutherford et al. 1992, Blair et al. 1993). Further

complicating analyses of age structure comparisons between populations is the fact that for

some populations the percent age composition is known to change over the course of a single

year’s run, and selective harvests can alter the age structure of escapements (Halupka et al.

1993). Available data on age composition (see Appendix Table C-1) or total age at maturity

(see Appendix Table C-2) for sockeye salmon in Washington and selected British Columbia

populations reveals temporal variability within populations, as well as geographical

differences among populations.

8

 E.L. Brannon, University of Idaho, Moscow, Idaho 83843. Pers. commun., 22 May 1995.
41

With the exceptions of Quinault Lake, Lake Washington Basin, Lake Wenatchee, and

Okanogan River, multiple-year freshwater/saltwater age composition data on populations of

sockeye salmon in Washington and Oregon were extremely limited (see Appendix Table C1). Figure 3 compares the overall mean percentage of returning sockeye salmon in each age

category among eleven localities in Washington. Since these data were collected over

different years and have been derived from both long-term (30 years, Quinault Lake) and

short-term (1 year-Ozette Lake, 2 years-Lake Pleasant) data sets, they should be interpreted in

light of the above-mentioned potential for temporal variation in population age structure.

Figure 4 compares age composition of adult sockeye salmon in the Quinault River tribal

fishery for the years 1912 to 1924 and 1974 to 1993.

In general, there has been a shift in sockeye salmon age at return to the Lake

Washington Basin over the past 25 years, with adults appearing to return at an older age than

they did in the 1970s (J. Ames9). Although return-year data for sockeye salmon in Lake

Washington show large fluctuations, comparison of data from 1970 to 1994 indicates that in

early years less than about 5% of returning sockeye salmon were 5-year-olds; presently, an

average of 19.5% (range 8-63% between 1989 and 1994) are 5-year-olds (J. Ames10) (see

Appendix Table C-1). Hendry (1995) and Hendry and Quinn (1997) concluded that in 1992

and 1993, a greater proportion of sockeye salmon of age 1.1 (3-year-olds) occurred in Big

Bear and Cottage Lake Creeks than in the Cedar River or Issaquah Creek, within the Lake

Washington Basin. However, the sampling methods used on the Cedar River could easily

have missed the jacks because of their smaller size or potentially different migration timing.

The weir on the Cedar River where sockeye salmon were caught was less than 100% “jacktight” (J. Ames11). Therefore, Hendry’s (1995) data may not characterize the normal sockeye

salmon jack composition of Lake Washington stocks. Ricker (1972, p. 65) reports that a

“large number” of 0-age or underyearling sockeye salmon smolt were observed leaving Lake

Washington in summer 1966. About 4% of the sockeye salmon smolts leaving Lake

Washington in 1996 were thought to be underyearlings (see Appendix Table C-4).

In both Lake Wenatchee and on the Okanogan River, adult sockeye salmon spawners

are typically 4-year-olds; however, in some years fish of age 1.1 (3-year-olds) may be more

abundant than 4-year-olds in the Okanogan River population (Mullan 1986, Chapman et al.

1995) (see Appendix Tables C-1 and C-2). Three-year-old sockeye salmon in the Okanogan

River population are predominately males, however limited sex-ratio data of carcasses on the

spawning grounds extracted from Allen and Meekin’s (1980) Table 15, indicated that

9

 J. Ames, Washington Department of Fish and Wildlife, 600 Capitol Way N., Olympia, WA

98501-1091. Pers. commun., 24 April 1995.

10 J. Ames, Washington Department of Fish and Wildlife, 600 Capitol Way N., Olympia, WA

98501-1091.

11 J. Ames, Washington Department of Fish and Wildlife, 600 Capitol Way N., Olympia, WA

98501-1091. Pers. commun., 13 March 1996.
42
43
44

3-year-old returns in 1971, 1972, and 1973 consisted of 20%, 28%, and 22% females,

respectively. The population age structure of Lake Pleasant sockeye salmon is highly

unusual, with both a high number of 3-year-old spawners (36-40%) and of smolts that have

spent 2 years in freshwater (40-50%) (Fig. 3 and Appendix Table C-1).

Rutherford et al. (1992) found that among coastal British Columbia sockeye salmon

lakes, Mikado and Mercer Lakes had greater than 50% freshwater age-2 spawners, and this

freshwater age was more common in the northern mainland and Queen Charlotte Island

populations than in populations from Vancouver Island or the southern mainland. Some small

coastal lakes on Vancouver Island, like Cheewhat Lake and Muriel Lake, reportedly have a

high proportion of both male (jacks) and female (jills) 3-year-old returns (K. Hyatt12).

Halupka et al. (1993) identified 14 populations out of 230 in southeast Alaska with

substantial proportions of zero freshwater age (= sea-type sockeye salmon) individuals

(Table 2). In addition, they found 4 populations dominated by fish having spent 2 years in

freshwater prior to smoltification, including those from Benzeman Lake on Baranof Island,

which had the shortest length of any sockeye salmon population investigated and were listed

as unique. The Hasselborg River stock on Admiralty Island was listed as unique; it is

dominated by sea-type individuals and spawns in a clearwater stream, whereas other sea-type

stocks listed by Halupka et al. (1993) were restricted to glacial drainages.

Fecundity and Egg Size

For a given fish size, female sockeye salmon have the highest fecundity and the

smallest egg size among the Pacific salmon (Burgner 1991). Average fecundity across the

range of sockeye salmon is from 2,000 to 5,200, and from about 300 to slightly less than

2,000 for kokanee (Burgner 1991, Manzer and Miki 1985). Because larger females have

higher fecundity than smaller females, any comparison of fecundity between populations is

confounded by differences in female age and size (Rounsefell 1957, Bagenal 1978).

However, studies have shown that once the size of females has been taken into account,

differences between age classes are not significant (Beacham 1982, Manzer and Miki 1985).

Consequently, comparisons of fecundity should be adjusted for size (Beacham 1982), which

requires measurements of both size and fecundity from the same individuals. Available

information that provides these measurements for naturally spawning sockeye salmon

populations was insufficient to adequately evaluate patterns of relative fecundity among

sockeye salmon populations in the Pacific Northwest (see Appendix Table C-3). Data on

average fecundity were available for Okanogan River, Lake Wenatchee, Cedar River, and

Quinault Lake sockeye salmon stocks in Washington (see Appendix Table C-3). Chapman et

al. (1995) pointed out that sockeye salmon from Okanogan River and Lake Wenatchee in the

mid-Columbia River have some of the lowest fecundity estimates reported in the literature,

12 K. Hyatt, Department of Fisheries and Oceans, Fisheries Research Branch, Pacific Biological STation, Nanaimo, B.C., Canada V9R 5K6. Pers. commun., 5 June 1995.
45

and that this low fecundity may be related to the long migration distance inherent to these

populations. Quinault Lake sockeye salmon also have a relatively low average fecundity (see

Appendix Table C-3).

In other areas, researchers have reported that fecundity can be effectively used to

differentiate between sockeye salmon populations in different river systems (Hartman and

Conkle 1960, Foerster 1968, Ivankov and Andreyev 1969, Manzer and Miki 1985, Burgner

1991) and between spawning locations within the same river system (Aro and Broadhead

1950, Gard et al. 1987, Beacham and Murray 1993, Blair et al. 1993). Manzer and Miki

(1985) found that within British Columbia, coastal sockeye salmon stocks were about 18%

more fecund than interior stocks. Beacham and Murray (1993) also found that fecundity was

less in upper river stocks of sockeye salmon than lower river stocks in both the Skeena and

Fraser Rivers, although the relationship was statistically significant only in the former.

With the exception of the Lake Washington Basin, no information on egg size was

found for sockeye salmon populations in Washington and Oregon. Mean egg weight differed

among sockeye salmon populations in the Lake Washington Basin (Cedar River, Issaquah

Creek, Big Bear Creek, Cottage Lake Creek, and Lake Washington beach spawners) in both

1992 and 1993, although large inter-annual variation was evident in all populations except the

Cedar River, which had larger sample sizes than the other populations (Hendry 1995). In the

Cedar River, Quinn et al. (1995) found body length of females to be positively correlated with

gonad weight, egg number, and egg weight. In other locations the size of sockeye salmon

eggs has been used to differentiate populations (Robertson 1922, Brannon 1987, Beacham and

Murray 1993). Within Fraser River sockeye salmon, upper river populations had smaller

diameter and lighter eggs than did lower river populations (Beacham and Murray 1993),

whereas sea-type sockeye salmon in Harrison Rapids (on the Fraser River) had larger eggs

than did nearby lake-type populations (Robertson 1922, Beacham and Murray 1993). Quinn

et al. (1995) reported very high correlations between egg weight and size composition of

incubation gravels, whereas neither body length nor snout length were well correlated with

egg weight among 18 Alaskan sockeye salmon populations.

Fry Emergence Timing and Fry Migration

 Sockeye salmon populations may differ in spawn timing and rates of development

and fry emergence as adaptations to different thermal regimes (Brannon 1987, Beacham and

Murray 1989). Beacham and Murray (1989) observed that development rate (based on

hatching and emergence timing) was faster for interior-spawning sockeye salmon in the Fraser

River, which experienced colder temperatures, than for lower Fraser River sockeye salmon.

Sockeye salmon eggs spawned in lake outlet tributaries or on lakeshore beaches are typically

exposed to warmer temperatures than eggs spawned in inlet tributaries, since lakes cool more

slowly in the fall. It has been postulated that in order to synchronize fry emergence in these

three spawning habitats with optimal feeding and survival conditions in common lake

environments, differences in egg size, incubation period, and spawn timing have arisen

(Godin 1982, Brannon 1987, Burgner 1991). This has been suggested to explain the
46

observation that inlet spawners typically spawn earlier than lakeshore beach and lake outlet

spawners, which experience higher incubation temperatures (Burgner 1991).

Sockeye salmon fry emerge in the Cedar River from January through early June, with

peak emergence occurring from early March to mid-May (Stober and Hämäläinen 1979, 1980;

Seiler and Kishimoto 1996). Within Lake Washington/Lake Sammamish populations,

Hendry (1995) observed different hatching and emergence timing among Cedar River, Big

Bear Creek, Cottage Lake Creek, Issaquah Creek, and Lake Washington beach spawners.

Emerging fry possess heritable rheotactic and directional responses that allow fry from

outlet tributaries to move upstream and fry from inlet tributaries to move downstream, in

order to reach the nursery lake habitat (Raleigh 1967, Brannon 1972a, Burgner 1991). Fry of

some populations that spawn in side tributaries connected to lake outlet streams must first

travel downstream and then reverse orientation and travel upstream to the nursery lake

(Egorova 1970, Brannon 1972a). Fry spawned in rivers without nursery-lake habitat rear in

spring areas, side channels, and sloughs or travel to the lower estuary to rear (Birtwell et al.

1987, Eiler et al. 1992). Raleigh (1967), Brannon (1972a, b), and Miller and Brannon (1982)

indicated that fry migration patterns of sockeye salmon are under genetic control.

Quinn (1980, 1981) showed that sockeye salmon fry have innate directional

preferences, with Cedar River fry displaying a northerly direction preference, corresponding

to the direction they take in migrating into Lake Washington. Fry emigrating from the Cedar

River do so primarily at night (less than 1% were seen to migrate in daylight) (Hämäläinen

1978; Stober and Hämäläinen 1979, 1980) and in normal flows from 24% to 98% of marked

released fry migrated to Lake Washington in one night (Seiler and Kishimoto 1996). Hendry

(1995) observed no difference between migration patterns of sockeye salmon fry from the

Cedar River and those from Lake Washington beach spawners (both populations were

positively rheotactic), although beach spawners were predicted to lack a particular rheotactic

response based on studies of beach fry from Cultus Lake (Brannon 1972b).

Smolt Size and Outmigration Timing

Summaries of available data on sockeye salmon smolt size (see Appendix Table C-4)

and smolt migration timing (see Appendix Table C-5) reveal differences between populations

that are related to lake productivity, thermal regime, and altitude (Burgner 1991). Sockeye

salmon smolt size is influenced by length of stay in the lake habitat and lake productivity.

Smolts migrating earlier in the season tend to be larger than later migrants, and both survival

at sea and age and size at maturity are dependent on smolt size (Burgner 1991). Unfertilized

coastal lakes of British Columbia reportedly produce smaller smolts than more productive

interior lakes (Pauley et al. 1989). Freshwater age-1 smolts from Lake Washington, Ozette

Lake, Baker Lake, and Lake Osoyoos tend to be relatively large, whereas the smallest laketype sockeye salmon smolts are found in glacial Owikeno Lake in coastal British Columbia

(see Appendix Table C-4). Although large smolt size in the Lake Osoyoos population

apparently results in a large proportion of small 3-year-old returns, large smolt size in the
47

Baker River, Ozette Lake, and Lake Washington populations has not resulted in large

numbers of 3-year-old returning adults in those systems (see Appendix Table C-1).

Since most sockeye salmon lakes in the north are ice-covered in the winter, and

sockeye salmon migration begins soon after ice break-up, there is both a south-to-north cline

and an altitude-dependent factor in sockeye salmon smolt outmigration timing (Hartman et al.

1967, Burgner 1991). Besides time of ice breakup, variations in outmigration timing can be

affected by water temperatures; wind direction and its effects on the lake surface; and age,

size, and physiological condition of the smolts (Burgner 1991).

Because of their responses to lake productivity, smolt size and outmigration timing

have been influenced by anthropogenic activities that affect lake productivity, including

artificial fertilization (Hyatt and Stockner 1985) and agricultural (Allen and Meekin 1980,

Chapman et al. 1995) and municipal pollution (Edmondson and Lehman 1981). Densitydependent processes may also lead to smolts leaving overcrowded lakes at a smaller than

normal size (Hartman and Burgner 1972, Goodlad et al. 1974, Hyatt and Stockner 1985).

These factors thoroughly complicate the assessment of any regional pattern that may exist for

either smolt size or outmigration timing, since these activities have occurred throughout the

range of sockeye salmon. Sampling design may also influence reported smolt sizes and

outmigration timing.

Sockeye salmon smolts migrate from most nursery lake systems at night, with greatest

numbers leaving between sunset and early morning (Burgner 1991). However, this migration

pattern is reversed in Lake Washington, with most sockeye salmon smolts exiting the system

during daylight hours (Warner 1997).

Adult Run-Timing

In general, river entry13 and spawn timing14 of sockeye salmon show considerable

spatial and temporal variability. Sockeye salmon enter Puget Sound rivers from mid-June

through August, while Columbia River populations begin river entry in May, passing

Bonneville Dam from very late May to late August (see Appendix Table C-6). Sockeye

salmon spawn in Puget Sound from late September to late December and occasionally into

January, and in the Columbia River from late September to early November (see Appendix

Table C-6). Small numbers of spawners are present in the Cedar River into February

13 River entry was taken from reports which specifically listed it, or was based on the timing

of peak in-river catches of sockeye salmon.

14 Spawn timing was compiled from reports listing spawn timing, or was based on dates when

peaks in spawning occurred, as reported in spawning ground surveys.
48

(WDFW 1996). Sockeye salmon on the western Olympic Peninsula of Washington and on

Vancouver Island, British Columbia begin entering rivers much earlier than the above stocks,

in April and May, and in the case of Quinault Lake as early as January. Sockeye salmon

begin entering Cheewhat Lake on Vancouver Island in late February or early March, and the

migration continues into September with a peak in mid-June to mid-July (K. Hyatt15).

Sockeye salmon on the Olympic Peninsula may spend 3 to 6 months in fresh water before

spawning, and in the extreme case of Quinault Lake from 3 to 10 months. Spawning on the

Olympic Peninsula begins later in the fall and extends further into the new year than in Puget

Sound or on the Columbia River (see Appendix Table C-6).

Fraser River sockeye salmon exhibit remarkably consistent chronological separation

of river entry and spawn timing among individual spawning populations (Killick 1955;

Gilhousen 1960, 1990). Two Fraser River sockeye salmon stocks, early Stuart and early

Nadina, overlap in run-timing with Puget Sound stocks from Baker River and Lake

Washington. Other Fraser River stocks overlap the run-timing of Okanogan River and Lake

Wenatchee sockeye salmon (see Appendix Table C-6). Adaptation of round-the-clock video

technology to sockeye salmon escapement counts at Tumwater Dam on the Wenatchee River

revealed that up to 5% of the sockeye salmon were passing up-river at night and would not

normally have been counted (Hatch et al. 1992).

Halupka et al. (1993) found no latitudinal pattern in run-timing in an analysis of 230

sockeye salmon stocks in southeast Alaska, although interior stocks had later mean migration

dates and more compact run-timing than coastal mainland or island stocks. Five sockeye

salmon populations in southeast Alaska were identified as having protracted run-timing,

including two that may have had separate population segments and one interior stock that was

identified as having run-timing lasting more than twice as long as any other interior stock

(Halupka et al. 1993).

Egorova (1970) reported that in comparison with other Kamchatka sockeye salmon

stocks, both river-entry timing and spawning duration are unusually protracted in sockeye

salmon from the Ozernaya River on the southwestern coast of Kamchatka. River entry begins

at the end of May, peaks in August, and is not over until the beginning of October. Spawning

in this system lasts from the end of July to the beginning of February.

Burgner (1991) stated that since there is an optimum time for fry emergence that

coincides with maximum conditions for juvenile survival, accurate spawn timing is crucial to

allow these events to coincide. Spawn timing depends to some degree on spawning gravel

temperature (Brannon 1987, Burgner 1991). Sockeye salmon river- and lake-entry timing is

also influenced by other factors including river flow, as in Lake Pleasant (WDF et al. 1993),

and river temperature, as in the Okanogan River (Major and Mighell 1966, Allen and Meekin

15 K. Hyatt, Department of Fisheries and Oceans, Fisheries Research Branch, Pacific Biological Station, Nanaimo, B.C., Canada V9R 5K6. Pers. commun., 5 June 1995.
49

1980, Mullan 1986, Swan et al. 1994). Blackbourne (1987) reported that Fraser River and

Quinault River sockeye salmon run-timing is closely correlated with winter-to-spring seasurface temperatures in the Gulf of Alaska; presumably these stocks tend not to travel so far

north in a cold year and thus reverse direction earlier, approaching their natal rivers earlier

than usual. All these factors make determinations and comparisons of “average” or “peak”

river entry and spawn timing difficult because of the high spatial and temporal variability

exhibited within basins.

Available information on dates of occurrence and spawn timing for sockeye salmon

observed in rivers without accessible lake rearing habitat in Washington is summarized in

Appendix Table C-7.

Spawner Size

Like the other life history traits discussed above, adult spawner size16 in naturally

spawning populations shows considerable spatial and temporal variability, which may obscure

regional patterns of variation. Based on fishery catch data, which tends to select for larger

fish than are present in the total run, Columbia River sockeye salmon average about 1.58 kg

after two winters at sea; Fraser River sockeye salmon average 2.73 kg after a similar time at

sea; Bristol Bay, Alaska sockeye salmon average 2.56 kg after two years at sea; and Chignik

River, Alaska sockeye salmon average 3.16 kg after three winters at sea (Burgner 1991). At

the same age, males are generally larger than females after two and three winters at sea

(Burgner 1991). Halupka et al. (1993) found that within populations in southeast Alaska, age1.3 and 2.3 males were larger than females, whereas age-1.2 females were larger than males

of the same age.

Adult body size may also be affected by variations in stock abundance. McKinnell

(1995) found that from 1912 to the late 1960s, the mean lengths of age-1.3 sockeye salmon

from northern and central British Columbia stocks (Rivers Inlet, Nass, and Skeena Rivers)

were significantly smaller (P = 0.05) in years when Bristol Bay sockeye salmon abundance

was high. Density-dependent effects during ocean life on sockeye salmon growth and adult

body length have also been reported by Rogers (1980), Peterman (1984), and Rogers and

Ruggerone (1993).

Although the size at maturity of pink, coho, and chinook salmon caught in coastal

British Columbia (Ricker 1982, 1995) and chum salmon caught in Asia and Alaska (Ogura

et al. 1991, Helle and Hoffman 1995) has declined in recent decades, Ricker (1995) did not

detect similar declines in length or weight at maturity in mixed-stock commercial catch data

16 The data presented come from measurements of naturally spawning sockeye salmon and

fish landed in in-river fisheries. This latter source of data is included because of the scarcity

of direct data for naturally spawning populations.
50

for Canadian sockeye salmon. However, Cox and Hinch (1997), using stock-specific data for

10 Fraser River sockeye salmon stocks, showed that size at maturity for females in all 10

stocks and for males in 8 of the 10 stocks has generally declined over the past 4 decades.

These declines are similar to those documented for other Pacific salmon stocks. In general,

growth and subsequent size at maturity for Fraser River sockeye salmon were reduced when

sea surface temperatures were relatively warm (Hinch et al. 1995a,b; Cox and Hinch 1997).

Various methods are used to measure body lengths of adult sockeye salmon: the

Alaska Department of Fish and Game uses the mid-eye to the tail fork (MEF), the Canadian

Department of Fisheries and Oceans uses the post-orbit of the eye to the hypural plate (POH),

the Quinault Indian Nation and Columbia River Intertribal Fisheries Commission use the

snout to the tail fork (SNF), investigators reporting on Fraser River sockeye salmon have used

the tip of the snout to the base of the caudal peduncle (“standard length,” similar to POH)

(STD), and other investigators (Woodey 1966, Hendry 1995) use the mid-eye to the hypural

plate (MEH). Because SNF includes the length of the snout, which displays great sexual

dimorphism in spawning sockeye salmon, and SNF and MEF lengths include a portion of the

caudal fin, which erodes on the spawning grounds, direct conversions between these different

measurements should be considered as gross approximations.

Since the majority of length data available for west coast sockeye salmon exist in the

form of SNF, all adult body lengths in this report were converted to SNF length using

generalized equations for converting sockeye salmon lengths (Ricker 1982, Pahlke 1989,

Linley 1993) (see Appendix Table C-8). Although some of these conversion equations were

developed from ocean-caught sockeye salmon in British Columbia (Ricker 1982) and

Southeast Alaska (Pahlke 1989), they remain the best available conversions. Linear

regression equations to convert MEH, MEF, and STD to SNF were not available, nor were

separate sex-specific linear regression equations available to convert MEH or MEF to POH.

The equations relating MEH and MEF to POH and POH to SNF and their correlation

coefficients and sample sizes, where available, are these:

POH = 0.891(MEF) - 9.064; r2 = 0.977 (n = 820) (Pahlke 1989)

POH = 0.982(MEH) + 0.606; r2 = 0.986 (n = 820) (Pahlke 1989)

POH = 0.857 (STD) + 20.29 (Linley 1993)

males: SNF = 1.2605(POH) - 28.47 (Ricker 1982)

females: SNF = 1.191(POH) + 0.24 (Ricker 1982).

Among coastal British Columbia sockeye salmon populations, Rutherford et al. (1992)

showed that Skidegate Lake in the Queen Charlotte Islands and Cheewhat Lake on Vancouver

Island had the smallest spawners at age 1.2, while the smallest average lengths were recorded

for sockeye salmon in the Queen Charlotte Islands, and the largest tended to occur in the

northern mainland populations (Rutherford et al. 1992). Lowe Lake, where adults have to

ascend a 3-m-high falls, had the longest fish at both age 1.2 and 1.3 (Rutherford et al. 1992)

(see Appendix Table C-8).
51

Halupka et al. (1993) found no significant differences in length between lake-type and

river/sea-type sockeye salmon. In general, Halupka et al. (1993) determined that body length

was a poor trait for identifying unique stocks due to high within-population variability, and

they were unable to detect geographic or temporal trends in body length or weight. However,

Blair et al. (1993) showed that six populations of sockeye salmon, from various spawning

sites within the Iliamna Lake system, Alaska, varied significantly in size at age.

One population of sockeye salmon in southeast Alaska, out of 230 investigated,

consisted of unusually small individuals (Halupka et al. 1993). Individuals in this population,

which rears in Benzeman Lake in Necker Bay on Baranof Island, weigh on average about

1 kg (Moser 1899), have an average length of 460 mm at age 1.2, and 457 mm at age 2.2.

Age 2.2 sockeye salmon predominate in this population (McPherson and McGregor 1986,

Halupka et al. 1993). Similarly, Britton et al. (1982) reported that a “race of small sockeye

averaging about 1.5 kg accounts for 60% of the escapement” in some years in Cridge Inlet

Creek on the south coast of Pitt Island in coastal British Columbia.

In 1992 and 1993, average length of same-age male and female Baker River sockeye

salmon was greater than that of Lake Washington fish (Hendry 1995). However, sockeye

salmon of similar age did not differ significantly in length among these populations within the

Lake Washington Basin: Big Bear Creek, Cottage Lake Creek, Cedar River, Issaquah Creek,

and Lake Washington beach spawners (Hendry 1995). Likewise, within a common age-class

and sex, length at maturity differs little between sockeye salmon from Lake Wenatchee and

Okanogan River, although these populations reportedly have the smallest body size of any

major stock of sockeye salmon (Chapman et al. 1995). In fact, in some years, average length

of sockeye salmon from Quinault Lake is smaller than the length of fish of the same age from

the mid-Columbia populations (see Appendix Table C-8).

Adult spawner lengths of sockeye salmon in the Lake Pleasant population are very

small. In 1996, age-1.2 sockeye salmon from Lake Pleasant averaged approximately 464 mm

in fork length for males and 456 mm for females (see Appendix Table C-8). The small body

size of Lake Pleasant sockeye salmon is comparable to that noted above for the Benzeman

Lake population in Southeast Alaska.

After noting differences in sample size and number of sampling years between stocks,

as well as potential for interannual variations in lengths, Shaklee et al. (1996) classified

age-1.2 sockeye salmon from populations in Washington into three size groups based on SNF

length: large (males >520 mm and females >510 mm), small (males <515 mm and females

<500 mm, but both sexes >460 mm), and very small (males and females <460 mm). Using

these criteria, Shaklee et al. (1996) classified sockeye salmon adults from Ozette Lake, Baker

River, Cedar River, and Lake Washington and Lake Sammamish tributaries as “large size”;

Quinault Lake, Lake Wenatchee, Okanogan River, and Lake Washington beach locations as

“small size”; and Lake Pleasant as “very small size.”
52

Appendix Table C-9 summarizes data on kokanee adult spawner lengths in selected

lakes in Washington, Oregon, Idaho, and British Columbia. With the exception of kokanee in

Odell Lake, Oregon; Donner Lake, California; and Issaquah Creek, Washington, average size

of kokanee at maturity is typically <300 mm fork length. Odell and Donner Lake kokanee are

reportedly the remnants of transplanted populations, whereas early entry Issaquah Creek

kokanee are native. Comparison of body length of native kokanee in Issaquah Creek between

the early 1980s and 1993 indicates a recent decline in size for both males and females

(Appendix Table C-9). Kimsey (1951) reported finding spawning kokanee in Donner Lake,

California with an average length of 470 mm fork length, which is greater than the average

length of sockeye salmon from Lake Pleasant, Washington and from Benzeman Lake, Alaska

(see above).

Ocean Life and Migration

Populations of sockeye salmon have a genetic disposition to specific migratory

patterns in the ocean (Burgner 1991). Ocean distribution of sockeye salmon has been studied

using tagging, morphological, parasitological, serological, and scale pattern analyses

(Margolis et al. 1966, French et al. 1976, Forrester 1987). Season, temperature, salinity, age,

size, and prey distribution also affect sockeye salmon movements in the open ocean. Initially,

sockeye salmon juveniles travel northward from Washington and British Columbia to the

Gulf of Alaska staying in a migratory band relatively close to the coast (Hartt 1980). Fraser

River sockeye salmon smolts migrate north through the Gulf of Georgia, either staying close

to the mainland coast or crossing the Gulf and traveling north along the Gulf Islands, where

they later rejoin the north migrating mainland coast smolts (Groot and Cooke 1987). The rate

of travel for northward migrating Fraser River sockeye salmon juveniles was estimated at 18.5

km/day (Hartt and Dell 1986). Once in the Gulf of Alaska, offshore movement of juveniles is

conjectured to occur in late autumn or winter.

Burgner (1991) reported that Blackbourn’s (1987) study implies, although indirectly,

that sockeye salmon have stock-specific winter distributions in the Gulf of Alaska. French

et al. (1976) provided separate models of migration for Asian stocks, western Alaskan stocks,

and northeastern Pacific stocks of sockeye salmon, but not for finer-scale stock separation.

The ocean distribution of Asian and North American sockeye salmon appears to overlap a

broad area of the Bering Sea and North Pacific Ocean, although in general the center of North

American fish abundance is east of 175o

E, and the center of Asian fish abundance is west of

this longitude (French et al. 1976, Burgner 1991). Although there is also considerable overlap

in distribution among sockeye salmon originating all the way from the Alaska Peninsula to

the Columbia River, scale pattern analyses indicate that sockeye salmon from central Alaska

are distributed much further to the west than populations from southeast Alaska, British

Columbia, and Washington (French et al. 1976, Burgner 1991). British Columbian and

Washington populations of sockeye salmon utilize the area east and south of Kodiak Island in

concert with Alaskan stocks, but tend to be distributed further to the south than the Alaskan

stocks (down to 46oN) (French et al. 1976, Burgner 1991). We found no data that could be
53

used to distinguish between the general ocean distribution of Washington, Oregon, and British

Columbia sockeye salmon or of individual stocks from these regions.

Parasitism

The occurrence of parasites and parasite resistance in sockeye salmon phenotypes are

additional traits to consider when determining the ecological/genetic importance of salmon

populations under the ESA (Waples 1991a, p. 14). Extensive work has been done in Russia

and Canada utilizing prevalence of parasites acquired by juveniles in freshwater to

differentiate local sockeye salmon populations (Margolis 1963, Margolis et al. 1966,

Konovalov 1975). As a consequence of their long freshwater life as juveniles, sockeye

salmon as a species host as many as 36 freshwater parasite species, and the occurrence of

parasites specific to Bristol Bay and Kamchatkan-origin sockeye salmon, respectively, have

been used to differentiate the continent of origin of fish samples on the high seas (Burgner

1991).

Bower and Margolis (1984) reported that populations of sockeye salmon (from the

Fraser and Skeena Rivers) exhibit a genetic difference in susceptibility to infection by the

hemoflagellate Cryptobia salmositica. In British Columbia, occurrence of the myxosporeans

Myxobolus arcticus and Henneguya salminicola, parasites of the brain and musculature,

respectively, have been utilized to differentiate stocks of sockeye salmon (Quinn et al. 1987;

Wood et al. 1987a,b, 1988, 1989; Moles et al. 1990; Rutherford et al. 1992). Among British

Columbia coastal lakes, Awun, Yakoun, Kitlope, Kimsquit, Skidegate, and Long Lakes were

free of M. arcticus, while other populations had levels of infection varying up to 100%.

Geographical patterns in prevalence of infection were not observed (Rutherford et al. 1992).

Information relative to parasite or disease prevalence in sockeye salmon stocks from

Washington and Oregon was largely unavailable. However, Bailey and Margolis (1987)

compared parasite fauna of juvenile sockeye salmon from Lake Washington with sockeye

salmon populations from several British Columbia lakes. Populations from Lakes

Washington, Nimpkish (on Vancouver Island), and Cultus (lower Fraser River) clustered

together based on their particular parasite faunas. Based on this study, Bailey and Margolis

(1987) stated that although “geography influences the characteristics of the parasite fauna . . .

the trophic status of the lake and many biotic variables clearly have strong influences on the

parasite faunas studied.”

Information Specific to Sockeye Salmon Populations Under Review

Oregon

The only river systems in Oregon, besides the mainstem Columbia, where anadromous

O. nerka are consistently seen each year are the Deschutes and Willamette Rivers.
54

Deschutes River, Oregon

Small numbers of sockeye salmon are consistently seen each year and trapped at the

base of the re-regulating dam below Pelton Dam (which forms Lake Simtustus) on the

Deschutes River. These fish are subsequently released at the same location and it is unknown

whether they spawn below the Pelton/Round Butte Dam complex (ODFW 1995a, Kostow

1996b). Historically, sockeye salmon occurred in the Deschutes River sub-basin, migrating

up the Columbia River to the Deschutes River and then up the Metolius River to Suttle Lake.

Fulton (1970) reported that a 1.2-m-tall power dam and upright screen were installed

at the outlet of Suttle Lake in 1930 (Mullan 1986). Nielson (1950) reported that “Blueback

salmon formerly ascended to Suttle Lake, but none have been seen for a number of years.”

Nielson (1950) also reported that a fish passage survey of the Deschutes River in 1942

revealed that

There is a concrete power dam, 4 feet high, at the outlet of the stream from Suttle

Lake. This dam . . . may have been responsible for the disappearance of the blueback

salmon run. The spillway has a 15 inch flashboard at the upper end of a sloping

concrete apron 11 feet long that would be impassable except under very favorable

circumstances. The 3-step fishway is too small for large fish and is blocked at the

upper end by a stationary screen. Two rotary screens prevent the escapement of fish

from the lake to the creek. The diversion to the small power plant is screened.

Nehlsen (1995) also reported on this dam at Suttle Lake, and added that a swimming pool

dam (built between 1925 and 1938) and power dam (built between 1925 and 1942) were

installed at Lake Creek Lodge on Lake Creek, the outlet stream of Suttle Lake, and both likely

hindered or blocked upstream and downstream fish passage.

Several subsequent authors (CBFWA 1990, Olsen et al. 1994, ODFW 1995a)

indicated that sockeye salmon continued to return to the Metolius River and spawned below

Suttle Lake after fish passage to Suttle Lake was blocked. ODFW (1995a) suggested that

sockeye salmon persisted in the Metolius River after construction of the Suttle Lake barrier,

until construction of Pelton Re-regulating Dam and Pelton Dam in 1958 and Round Butte

Dam (which formed Lake Billy Chinook) in 1964. Sockeye salmon may have persisted by

continued spawning in the Metolius River, with juvenile rearing occurring in the Deschutes

River or Columbia River, or by return of outmigrants of residual sockeye salmon or kokanee

that had escaped over the Suttle Lake barrier. However, Gunsolus and Eicher (1962) stated

that, “The spawning of blueback salmon is confined to the Suttle Lake area of the Metolius

River and the run is composed, for all practical purposes, of hatchery fish which the Oregon

Fish Commission has planted in an attempt to generate a run.”

Presently, two kokanee populations occur above the dams: one population resides in

Suttle Lake and spawns in the lake inlet stream (Link Creek), and a second population resides

in Lake Billy Chinook and spawns in the upper Metolius River (ODFW 1995a). Both
55

kokanee populations have a distinctive blue-black body coloration and are distinguished from

hatchery kokanee reared in Lake Simtustus and Deschutes River basin hatcheries by their

color pattern (ODFW 1995a). The Lake Billy Chinook/Metolius kokanee reportedly spawn

about the same time that Deschutes River sockeye salmon arrive at the Pelton Dam hatchery

trap, whereas the Suttle Lake/Link Creek kokanee spawn 2 to 3 weeks later (ODFW 1995a).

Sockeye salmon enter the Deschutes River from July to September.

ODFW (1995a) and Kostow (1996b) suggested that sockeye salmon that are

consistently trapped in the Deschutes River may derive from 1) a self-sustaining sockeye

salmon population that spawns below the Pelton/Round Butte Dam complex and rears in

mainstem Columbia River reservoirs, 2) strays from elsewhere on the Columbia River, or

3) outmigrating smolts of “kokanee-sized” fish that escape over the Pelton/Round Butte Dam

complex and return as sockeye salmon.

Artificial propagation data (see Appendix Table D-2) indicate that over 740,000

sockeye salmon fry and fingerlings from the Leavenworth National Fish Hatchery and 15,000

smolt from the Bonneville Hatchery were released into Suttle Lake between 1937 and 1958.

Additionally over 478,000 sockeye salmon fry, fingerlings, and smolts of mixed Metolius,

Leavenworth, and unknown parentage were released in the Metolius River or its tributaries

between 1948 and 1961 (see Appendix Table D-2). Many of the reported returns of sockeye

salmon to the Deschutes River prior to the 1960s may have been derived from these juvenile

sockeye salmon releases.

Willamette and Santiam Rivers

Foy et al. (1995a) and Chapman et al. (1995) reported that small numbers of adult

sockeye salmon currently return to the Willamette, Middle Santiam, and South Santiam

Rivers. Juvenile sockeye salmon were introduced into several reservoirs in the upper reaches

of the Willamette and Santiam Rivers in the 1950s (see Appendix Table D-2), and presumably

the downstream migration of some individuals derived from these transplants led to returns of

anadromous sockeye salmon (Foy et al. 1995a, Chapman et al. 1995, p. 21).

Washington

The following nine spawning populations of sockeye salmon have been identified in

Washington by WDF et al. (1993): 1) Baker River, 2) Ozette Lake, 3) Lake Pleasant,

4) Quinault Lake, and 5) Okanogan River, classified as native stocks; 6) Cedar River

classified as a non-native stock; 7) Lake Wenatchee classified as having mixed stock origin;

and 8) Lake Washington/Lake Sammamish tributaries, and 9) Lake Washington beach

spawners, classified as having unknown stock origin. Chapman et al. (1995) listed four

additional spawning aggregations of sockeye salmon that appear consistently in Columbia

River tributaries: the Methow, Entiat, and Similkameen Rivers and Icicle Creek in the

Wenatchee River drainage.
56

Sockeye salmon have been periodically observed in other Washington rivers that lack

accessible lake habitat, including the Nooksack, Samish, mainstem Skagit, Sauk,

Stillaguamish, Green, Skokomish, Dungeness, Calawah, Hoh, Queets and North Fork Lewis

Rivers. Reportedly, several sockeye salmon are observed yearly during spawner surveys in

almost every river in Puget Sound; this phenomenon is more common, and numbers of

sockeye salmon are higher, in north Puget Sound rivers than in south Puget Sound rivers (J.

Ames17).

Okanogan River

Okanogan River sockeye salmon rear in Lake Osoyoos, which is composed of three

connected basins: north, middle, and south. WDF et al. (1993) reported that Okanogan River

sockeye salmon bound for Lake Osoyoos begin migrating up the Columbia River in mid- to

late-June and peak in early July. In contrast, Chapman et al. (1995) reported that sockeye

salmon bound for the mid-Columbia River begin entering the Columbia River in April and

May, peaking at Bonneville Dam in the third week of June and at Rock Island Dam in the

third week of July. Chapman et al. (1995) compared sockeye salmon run-timing data from

dam counts in 1933-1947 to similar counts in 1988-1992 and found that current run-timing is

about a week earlier than it used to be. This change in timing was believed to be due to

reduced water velocities in mainstem reservoir reaches of the Columbia River, with later

velocities allowing for more rapid upriver fish migration (Chapman et al. 1995). Quinn and

Adams (1996) also reported that sockeye salmon upriver migration timing is about 6 days

earlier now than it was in 1949. Based on scale pattern analysis, Fryer and Schwartzberg

(1994) suggested that Okanogan River sockeye salmon migrate past Bonneville Dam later

than the population bound for Lake Wenatchee. Major and Mighell (1966) reported that most

adult sockeye salmon begin migrating up the Okanogan River in mid- to late-July and enter

Lake Osoyoos in August, although in some years sockeye salmon may reach Lake Osoyoos as

early as mid- to late-July. WDFW (1996) stated that

Okanogan sockeye begin migrating slightly later than the Wenatchee stock, based on

scale analysis at Bonneville Dam which shows Wenatchee fish dominating the early

portion and shifting to Okanogan stock later. Okanogan sockeye probably begin their

entry in early to mid-June and peak at Bonneville Dam in early July.

Migration may be impeded by as much as 3 weeks in some years by high water temperatures

during mid-summer in the Okanogan River (Major and Mighell 1966, Allen and Meekin

1980, Mullan 1986, Swan et al. 1994, Chapman et al. 1995). Sockeye salmon congregate at

the confluence of the Okanogan and Columbia Rivers when water temperatures exceed 21.1o

C

and only migrate up the Okanogan River when temperatures fall below this level (Major and

Mighell 1966, Allen and Meekin 1980, Chapman et al. 1995).

17 J. Ames, Washington Department of Fish and Wildlife, 600 Capitol Way N., Olympia, WA

98501-1091. Pers. commun., April 1995 and 13 March 1996.
57

Swan et al. (1994) reported that upon reaching Lake Osoyoos, sockeye salmon stay in

the lake from less than 1 day to 46 days, with a median of 28 days, prior to moving upstream

to the spawning grounds. WDF et al. (1993) indicated that this population spawns upstream

from Lake Osoyoos in the Okanogan River but below the Southern Okanagan Lands Project

Dam (=Oliver Diversion Dam = Vaseux Dam) during late September through October.

According to Chapman et al. (1995), spawning occurs primarily from about 1 to 23 October,

with a peak about the third week in October.

Burner (1951) observed a few sockeye salmon redds on the shoreline of Lake

Osoyoos. Allen and Meekin (1980) observed about 1,200 sockeye salmon spawning on the

shoreline of Lake Osoyoos in October of 1971, whereas only a “few” to none were observed

in 1972-1974.

Lake Osoyoos has been variously characterized as eutrophic (Mullan 1986) and as

displaying the range of conditions known as mesotrophic (see Appendix Table B-2) (Rensel

1995, cited in Chapman et al. 1995). Lake Osoyoos is atypical of sockeye salmon rearing

lakes, which are typically oligo- or ultra-oligotrophic (Mullan 1986, Chapman et al. 1995).

From data provided in Mullan (1986), the morphoedaphic indices for the northern, middle,

and southern basins of Lake Osoyoos were estimated as 10.91, 4.69, and 14.74 respectively;

these values are at the high end of the scale for sockeye salmon nursery lakes and indicate the

potential for high primary production (see Appendix Table B-2). Lake Osoyoos has been

ranked as one of the most productive of all sockeye salmon rearing lakes, based on

phytoplankton and zooplankton abundance (Foerster 1968, Allen and Meekin 1980, Chapman

et al. 1995). A strong thermocline develops in Lake Osoyoos during the summer, when

surface temperatures can reach 25o

C and the hypolimnion becomes anoxic, leaving only a

narrow 1- to 2-m sub-surface layer of water in the south basin with conditions suitable to

sockeye salmon survival. These conditions indicate that sockeye salmon juveniles may be

limited to the north and middle basins of Lake Osoyoos during summer months (Rensel 1995,

cited in Chapman et al. 1995).

High plankton productivity has led to the production in Lake Osoyoos of “some of the

largest sockeye salmon smolts reported in the literature” (Mullan 1986). The average length

of known age-1+ sockeye salmon smolts from Lake Osoyoos has ranged over a number of

years from 94 to 114 mm with a median of about 110 mm (Allen and Meekin 1980, Chapman

et al. 1995), a length exceeded only by sockeye salmon smolts from Lake Washington, Baker

Lake, and Ozette Lake (see Appendix Table C-4). Age composition data presented in Allen

and Meekin (1980) and Chapman et al. (1995) show that in some years an unusually large

percentage of adult spawners in the Okanogan River sockeye salmon population are 3-yearold fish, whereas 3-year-olds are extremely rare in the Lake Wenatchee population (see

Appendix Tables C-1 and C-2). Okanogan River sockeye salmon are thought to have the

youngest average age at maturity for sockeye salmon throughout their range (Chapman et al.

1995).
58

Fry emergence and migration downstream to Lake Osoyoos has been reported to occur

mostly at night, beginning in early March (prior to the Lake Wenatchee migration), peaking in

mid-April, and concluding by the third week in May (Allen and Meekin 1980, Shepherd and

Inkster 1995 as cited in Chapman et al. 1995). Data presented in Chapman et al. (1995)

indicate that currently sockeye salmon smolts leave Lake Osoyoos in mid- to late May and

migrate past Rock Island Dam in May (Peven 1987). In contrast, Wenatchee-origin sockeye

salmon smolts typically arrive at Rock Island Dam in April (Peven 1987). Chapman et al.

(1995) pointed out that currently, sockeye salmon smolts appear to arrive at downstream dams

on the Columbia River earlier than they did in the 1940s through 1960s, although the reasons

for this earlier run-timing are not clear.

Between 1939 and 1943, all adult sockeye salmon returning to the Columbia River

above the confluence with the Snake River were trapped at Rock Island Dam on the Columbia

River as part of the Grand Coulee Fish Maintenance Project. A total of 19,795 of these

trapped adult sockeye salmon of mixed Okanogan River, Lake Wenatchee, and Upper

Columbia River heritage were transported to and released in Lake Osoyoos. Appendix Table

D-2 shows that between 1940 and 1968, about 395,000 fry resulting from a mixed-stock

spawning of Rock Island Dam and Quinault Lake stock, and over 4.2 million fish descended

from original spawners collected at Rock Island and Bonneville Dams, were released into

Lake Osoyoos (Mullan 1986). In the brood years 1992 and 1993, 73,000 and 110,500 penreared juvenile sockeye salmon (adults captured at Wells Dam) were released in Lake

Osoyoos (Chapman et al. 1995). No adult returns from the releases in 1992 and 1993 have

been noted (Chapman et al. 1995).

Sockeye salmon and kokanee-sized O. nerka are reported to spawn at the same time

and place in the Okanogan River, often with overlapping redds, although it is unknown

whether peak spawn timing of these two groups of fish are the same. Kokanee-sized fish

reportedly acquire a drab-olive spawning coloration, whereas sockeye salmon in this

population have the typical spawning color pattern (L. LaVoy18). Dark colored residual O.

nerka presumably occur to some degree in all years on the sockeye salmon spawning grounds

of the Okanogan River (Chapman et al. 1995, p. 21).

Kokanee stocking history in Lake Osoyoos includes the release of 195,550 kokanee

fry from an unnamed source into Lake Osoyoos between 1919 and 1920 (WDFG 1921a) (see

Appendix Table D-5). Further kokanee stocking information was not obtained from either

U.S. or Canadian sources.

18 L. LaVoy, Washington Department of Fish and Wildlife, 3860 Chelan Highway North,

Wenatchee, WA 98801-0452. Pers. commun., 31 May 1995.
59

Lake Wenatchee

WDF et al. (1993) reported that sockeye salmon bound for Lake Wenatchee begin

migrating up the Columbia River in mid-June, peaking in early July, and enter Lake

Wenatchee in late July to early August. It was stated in WDFW (1996) that “Wenatchee

sockeye enter the Columbia in May and peak at Bonneville Dam in late June or early July.”

Based on scale pattern analysis, Lake Wenatchee sockeye salmon appear to migrate past

Bonneville Dam earlier than the population bound for the Okanogan River (Fryer and

Schwartzberg 1994). As mentioned above for Okanogan River, Chapman et al. (1995)

reported that sockeye salmon bound for the mid-Columbia River begin entering the Columbia

River in April and May, peaking at Bonneville Dam in the third week of June and at Rock

Island Dam in the third week of July. Chapman et al. (1995) reported that comparison of runtiming data from dam counts in 1933-1947 and 1988-1992 indicate that current sockeye

salmon run-timing is about a week earlier than it used to be. Quinn and Adams (1996) also

reported that sockeye salmon upriver migration timing is about 6 days earlier now than it was

in 1949. Run-timing of sockeye salmon in the Wenatchee River, as measured at Tumwater

Dam, appears to be as much as a month earlier at the present time than it was in the 1930s

(Chapman et al. 1995). Factors contributing to this run-timing change may include

improvements to fish ladders at Tumwater and Dryden Dams on the Wenatchee River, lower

river flows in recent years, and faster within-reservoir migration in the Columbia River since

modern dam construction (Allen and Meekin 1980, Mullan 1986, Chapman et al. 1995).

The Wenatchee population spawns from mid-September through October in the Little

Wenatchee, White, and Napeequa Rivers above Lake Wenatchee (WDF et al. 1993).

According to Chapman et al. (1995), main spawning activity currently occurs from midSeptember to about the beginning of October, with a peak in the third week of September.

Gangmark and Fulton (1952) reported two lakeshore seepage areas in Lake Wenatchee that

were used by spawning sockeye salmon. Mullan (1986) indicated that only limited shore

spawning occurs in Lake Wenatchee. Although no active surveys targeting beach-spawning

sockeye salmon have been undertaken, shoreline spawning has not been observed in recent

years in Lake Wenatchee (L. LaVoy19).

Lake Wenatchee has been characterized as a typical oligotrophic or ultra-oligotrophic

sockeye salmon nursery lake: clear, cold, well-oxygenated, and with low productivity (Allen

and Meekin 1980, Mullan 1986, Chapman et al. 1995). Lake Wenatchee has an estimated

metric morphoedaphic index of 0.51, which is within the range of MEI typical for sockeye

salmon nursery lakes (see Appendix Table B-2) and is considerably lower than the MEI for

Lake Osoyoos (Mullan 1986). Water residence time in Lake Wenatchee was estimated at the

relatively rapid rate of 2.2 exchanges per year (Mullan 1986). A strong thermocline does not

apparently develop in Lake Wenatchee in the summer, and dissolved oxygen and temperature

19 L. LaVoy, Washington Department of Fish and Wildlife, 3860 Chelan Highway North,

Wenatchee, WA 98801-0452. Pers. commun., 31 May 1995.
60

conditions allow sockeye salmon to use all depths of the lake (Chapman et al. 1995, p. 83).

Thompson and Tufts (1967) identified Dolly Varden and northern squawfish as predators of

sockeye salmon juveniles in Lake Wenatchee, although only 12% of Dolly Varden and 1% of

northern squawfish collected had consumed wild sockeye salmon fingerlings.

The average size of known age-1+ sockeye salmon smolts from Lake Wenatchee have

ranged from 65 to 124 mm fork length, with a median of about 88 mm (Allen and Meekin

1980, Chapman et al. 1995) (see Appendix Table C-4). Peven (1987) indicated that sockeye

salmon smolts from Lake Wenatchee are generally smaller than 100 mm, whereas Okanogan

River smolts are generally larger than 100 mm. Age composition data show (see Appendix

Tables C-1 and C-2) that although an unusually large percentage of adult spawners in the

Okanogan River sockeye salmon population are 3-year-old fish, very few Lake Wenatchee

sockeye salmon exhibit this age pattern. Chapman et al. (1995) pointed out that sockeye

salmon from Wenatchee show a stronger tendency to spend 2 years in freshwater prior to

smoltification than do members of the Okanogan River population.

Dawson et al. (1973) found that sockeye salmon fry were entering Lake Wenatchee

between March and May, while Chapman et al. (1995) deduced from data in Gangmark and

Fulton (1952) that fry emerge from redds in the Wenatchee River by mid-March.

Peven (1987) showed that Wenatchee-origin sockeye salmon smolts typically arrive at Rock

Island Dam in April. As mentioned above for Okanogan River sockeye salmon, Chapman et

al. (1995) pointed out that currently, sockeye salmon smolts appear to arrive at downstream

dams on the Columbia River earlier than they did from the 1940s through 1960s, although the

reasons for this earlier run-timing are not clear.

Between 1939 and 1943, all sockeye salmon entering the mid-Columbia River were

trapped at Rock Island Dam, and over 32,000 mixed Lake Wenatchee, Okanogan River, and

Arrow Lakes adult sockeye salmon were released into Lake Wenatchee as part of the Grand

Coulee Fish Maintenance Project. Between 1940 and 1968, over 2.4 million fry derived from

original Quinault Lake stock, and over 52.8 million fry descended from original spawners

collected at Rock Island and Bonneville Dams, were released into Lake Wenatchee (see

Appendix Table D-2). Starting with the 1989 brood year, between 167,500 and 372,100

pen-reared Lake Wenatchee-origin juvenile sockeye salmon have been released yearly into

Lake Wenatchee. From the 1990 release, an estimated 4,133 sockeye salmon returned in

1994, for a fry-to-adult survival rate of 1.6% (survival estimate based on scale pattern

analysis) (Chapman et al. 1995).

Kokanee are reportedly native to Lake Wenatchee (Crawford 1979). Sockeye salmon

and kokanee have been seen to spawn at the same time and place in tributaries of Lake

Wenatchee (the forms may have overlapping redds in the White, Napeequa, and lower end of

the Little Wenatchee Rivers), and the kokanee reportedly acquire a drab olive spawning

coloration, whereas Wenatchee sockeye salmon have the typical spawning color pattern
61

(L. LaVoy20). Residual O. nerka reportedly occur on the spawning grounds with Lake

Wenatchee sockeye salmon (Chapman et al. 1995). Between 1934 and 1966, 22.5 million

Lake Whatcom kokanee were released in Lake Wenatchee (Mullan 1986) and approximately

0.5 million kokanee of the same broodstock origin were released in 1983 (Knutzen 1995) (see

Appendix Table D-5).

Quinault Lake

This sockeye salmon population is the most southerly coastal population of this

species in North America. WDF et al. (1993) indicated that sockeye salmon, or blueback

salmon as they are known locally, begin entering the lower Quinault River in small numbers

in January and continue to the end of July, peaking in late May to early July. Sockeye salmon

have been known to enter the Quinault River as early as December and as late as August (QIN

1981). The duration of this run is unusually long for sockeye salmon, lasting over 7-9 months

(Burgner 1991, p. 9). Johnson (1977) stated that it takes sockeye salmon approximately 3

days to migrate between the mouth of the Quinault River and Quinault Lake. Sockeye salmon

adults may remain in Quinault Lake for 3-10 months without feeding (QIN 1981) prior to

moving upstream to spawn from November through February, primarily in the upper Quinault

River and its tributaries (WDF et al. 1993). Sockeye salmon spawn timing for the Quinault

stock is unusually protracted; observed duration has been 7 months, from August through

March, although peak spawning occurs from November through January (QIN 1981).

The majority of sockeye salmon in the Quinault system take on a drab gray-green

(D. Boyer, Jr.21) or olive (Storm et al. 1990) spawning coloration, in contrast to the typical red

body coloration of sockeye salmon, but are very red-fleshed with high oil content when they

enter the river (D. Boyer Jr.22). Storm et al. (1990) stated that a small segment of early

spawners take on the more typical coloration of spawning sockeye salmon, and these may

represent a unique strain. Due to carotenoid metabolism, spawning sockeye salmon may

contain up to 65% less carotenoid than pre-spawning sockeye salmon taken at sea (Crozier

1969). The loss of tissue carotenoids in Quinault Lake sockeye salmon may result from the

prolonged non-feeding adult lake-residence period prior to maturation and spawning.

Although a green coloration at spawning is not common for sockeye salmon, spawning

individuals of two sockeye salmon stocks in British Columbia (Weaver Creek (lower Fraser

20 L. LaVoy, Washington Department of Fish and Wildlife, 3860 Chelan Highway North,

Wenatchee, WA 98801-0452. Pers. commun., 31 May 1995.

21 Del Boyer, Jr., Quinault Fisheries Division, P.O. Box 189, Taholah, WA 98587. Pers.

commun., 24 April 1995.

22 Del Boyer, Jr., Quinault Fisheries Division, P.O. Box 189, Taholah, WA 98587. Pers.

commun., 24 April 1995.
62

River) and Alastair Lake (Skeena River)) also reportedly appear more green than red (C. C.

Wood23).

Smolt outmigration occurs in May and June (Davidson and Barnaby 1936) or April

and May (Tyler and Wright 1974), and takes place during the hours of darkness (Tyler and

Wright 1974) (see Appendix Table C-5). The percentage in each age group, and length and

weight of sockeye salmon captured in the fishery for various years, are presented in Appendix

Tables C-1 and C-8. Figure 4 illustrates temporal changes in freshwater and saltwater age

composition of Quinault Lake sockeye salmon by return year.

The Quinault sockeye salmon or blueback has always been culturally and

economically important to the Quinault Indians, and its flavor has often been remarked upon.

Lestelle and Workman (1990) stated that

Culturally, this salmon run links Quinault people to their rich heritage as nothing else

does. The salmon was always the very lifeblood of Quinault society, and the blueback

was the most sacred of the various fish runs.

Brown (1982, p. 32) related that

The Chinook tribe . . . esteemed the Quinault sockeye so highly that they used it as an

all-purpose term of excellence. Whites . . . picked this up and mistakenly applied the

name to the most prized of the Columbia’s runs, the salmon known as the Chinook.

For half a century Chinook salmon were known as “Quinnat” . . .

Numerous early references to the superior quality of Quinault Lake sockeye salmon exist

(Willoughby 1889, Curtright 1979), and the unusual quality of the flesh has often been

attributed to the stored energy reserves necessary to maintain these fish through the long lake

residence period prior to maturation (QIN 1981, Lestelle and Workman 1990). This

population of sockeye salmon has long supported a commercial set-net fishery operated by the

Quinault Indian Nation near Taholah on the lower Quinault River.

The U.S. Bureau of Fisheries operated a fish hatchery from 1914 to 1947 at Falls

Creek on Quinault Lake (this hatchery was referred to as the “Quinault, Washington Station,”

and should not be confused with the present-day Quinault National Fish Hatchery). This

hatchery program utilized native broodstock for the most part; however, out-of-basin

transplant history includes the transfer from Alaska of about 20 million sockeye salmon eggs

from 1916 to 1921 and 260,000 kokanee eggs from Lake Whatcom in 1925 to the Quinault,

Washington Station on Falls Creek (see Appendix Tables D-1 and D-5). Kokanee do not

currently inhabit Quinault Lake, although over 300,000 kokanee fry from unnamed sources

23 C.C. Wood, Department of Fisheries and Oceans, Pacific Biological Station, Nanaimo,

B.C., Canada V9T 5K6. Pers. commun., August 1996.
63

were released in Quinault Lake between 1917 and 1922 (WDFG 1919, 1921a, 1923)

(see Appendix Table D-5).

A portion of the lower watershed above Quinault Lake was logged in association with

early homesteading and Sitka spruce harvest for war plane construction during the First World

War. Around this period of time, severe erosion of the banks of the upper Quinault River

occurred, although it is unknown whether logging caused this accelerated erosion, or whether

the erosion was part of a natural process (D. Boyer, Jr24). Today, much of the upper Quinault

River below the North Fork, where most sockeye salmon spawning occurs, is a braided stream

subject to severe meander (Davidson and Barnaby 1936, Brown 1982, WDF et al. 1993).

Davidson and Barnaby (1936) reported that

The early settlers and inhabitants of this region describe the upper Quinault River as a

large stream that flowed between two rather narrow heavily wooded banks. . . . the

logging off of the watersheds of the river has caused excessive washing to the extent

that there is no definite river bed but a wide river valley through which the stream

frequently changes its course with the winter and spring freshets.

Severe storm runoff problems in the upper Quinault River in the fall of 1990 and winter of

1990-1991 led to a prolonged period of lake turbidity (S. A. Chitwood and D. Boyer, Jr.25).

Ozette Lake

Migration of adult sockeye salmon up the Ozette River and into Ozette Lake occurs

between dusk to dawn from April to early August (WDF et al. 1993) (see Appendix Table C6) or May to August (Dlugokenski et al. 1981). Kemmerich (1945) counted sockeye salmon

past a weir constructed in the Ozette River in 1924, 1925, and 1926 between 27 May and 8

August, 8 June and 15 September, and 28 May and 8 September, respectively. Jacobs et al.

(1996) noted that the tribal sockeye salmon fishery in the lower Ozette River that operated

between 1948 and 1957, began in mid-April and peaked from 2 to 15 June. Fifty sockeye

salmon were seen moving up the Ozette River on 20 October 1989 following a rise in the lake

level (LaRiviere 1991).

High water temperatures in Ozette Lake and River and low water flows in the summer

may create a thermal block to migration and influence timing of the sockeye salmon migration

(LaRiviere 1991). Recorded water temperatures in late-July and August in the Ozette River

24 Del Boyer, Jr., Quinault Fisheries Division, P.O. Box 189, Taholah, WA 98587. Pers.

commun., 13 March 1996.

25 S.A. Chitwood and Del Boyer, Jr., Quinault Fisheries Division, P.O. Box 189, Taholah,

WA 98587. Pers. commun., 24 April 1995.
64

near the lake outlet have exceeded the temperature range over which sockeye salmon are

known to migrate (J. Meyer26).

Currently, spawning is restricted to submerged beaches where upwelling occurs along

the lakeshore or to tributary outwash fans (Dlugokenski et al. 1981, WDF et al. 1993).

Spawning has been variously reported to occur from mid- to late November through early

February (WDF et al. 1993) and from late November to early April (Dlugokenski et al. 1981)

(see Appendix Table C-6). Dlugokenski et al. (1981) suggested that discreet sub-populations

may be present in the lake, as evidenced by disjunct spawning times between beach spawners

in different parts of the lake.

The two principle shoreline spawning beaches for sockeye salmon in Ozette Lake are

Olsen’s Beach (or Olsen’s Landing) (north of Siwash Creek on the lake’s eastern shore) and

the beach area north of Allen’s Bay on the lake’s western shore (WDF et al. 1993, Jacobs

et al. 1996). Reportedly, some spawning has also been seen recently on the south shore of

Baby Island at the southern end of Lake Ozette (Jacobs et al. 1996). Historically, sockeye

salmon reportedly spawned in tributary creeks of Ozette Lake, on the shoreline north of

Umbrella Point, and in Ericson’s Bay (Dlugokenski et al. 1981, WDF et al. 1993, Jacobs et al.

1996). A small degree of outlet spawning may occur in the Ozette River or in Coal Creek, a

tributary of Ozette River below Ozette Lake (WDF et al. 1993, Jacobs et al. 1996, E. Currence

and D. Dailey 27). A number of sockeye salmon fry were inadvertently released in Umbrella

Creek near the tribal hatchery in 1987, and 13 adult sockeye salmon were noted spawning in

this creek 4 years later, in 1991. Over 8,000 sockeye salmon fry of the 1991 brood year were

released in Umbrella Creek in 1992 and approximately 30-50 sockeye salmon redds were

counted in Umbrella Creek in the fall of 1995 (Jacobs et al. 1996, E. Currence28).

Kemmerich (1945) reported that during his work with sockeye salmon at Ozette Lake

in the years 1923-1926, “there was no evidence that they ascended any of the tributaries of the

lake to spawn.” In reference to Ozette Lake sockeye salmon, Kemmerich (1939) in a letter to

R. E. Foerster stated that

We made no special investigations of spawning beds during the years covered . . . but

merely observed from time to time that most of the spawning seemed to be along the

lake shore in suitable places and especially at the mouths of the several creeks. I do

26 J.H. Meyer, Olympic National Park, 600 E. Park Ave., Port Angeles, WA 98362. Pers.

commun., 19 march 1996.

27 E. Currence and D. Dailey, Makah Fisheries Management, Makah Tribe, P.O. Box 115,

Neah Bay, WA 98357. Pers. commun., 22 March 1995.

28 E. Currence, Makah Fisheries Management, Makah Tribe, P.O. Box 115, Neah Bay, WA

98357. Pers. commun., 19 March 1996.
65

not recall that any sockeyes ascended any of the creeks to spawn but it seems to me

that spawning took place during the latter part of September and October.

Abundance of sockeye salmon outmigrant smolts from Ozette Lake was estimated in

1977 at 9,600 (Dlugokenski et al. 1981), in 1990 at 7,942, and in 1992 at 2,752 (Jacobs et al.

1996). Based on these numbers and adult returns 2 years later (see Jacobs et al. 1996,

their table 3), ocean survival of broodyears 1975, 1990, and 1991 were 5.6%, 18%, and 27%,

respectively (Jacobs et al. 1996).

A total of 13 species of fish occur in Ozette Lake (see Appendix Table B-4).

Dlugokenski et al. (1981) and Blum (1984) listed potential competitors with sockeye salmon

juveniles in Ozette Lake, including kokanee, red sided shiner (Richardsonius balteatus),

northern squawfish (Ptychocheilus oregonensis), yellow perch (Perca flavescens), and

peamouth (Mylocheilus caurinus). Potential predators listed by these same authors included

cutthroat trout (Salmo clarki), northern squawfish (Ptychocheilus oregonensis), and prickly

sculpin (Cottus asper). Beauchamp et al. (1995) showed that competition is unlikely to limit

the sockeye salmon population in Ozette Lake; however, predation on juvenile sockeye

salmon, which was 25 times greater by individual cutthroat trout than by individual

squawfish, may be limiting, although total predator abundance has yet to be assessed.

Harbor seals (Phoca vitulina) migrate up the Ozette River into Ozette Lake and have

been seen feeding on adult sockeye salmon off the spawning beaches in Ozette Lake. The

numbers of seals and the number of salmon taken by each seal is unknown. Seal predation on

sockeye salmon at the river mouth and during the salmon’s migration up the Ozette River may

also be occurring. The upriver migration of harbor seals to feed on adult sockeye salmon is

common in British Columbia, occurring 100 miles upriver on the Fraser River at Harrison

Lake and up to 200 miles inland on the Skeena River (Foerster 1968). Sockeye salmon

migrate up to Ozette Lake in less than 48 hours and the majority of adults travel at night

(Jacobs et al. 1996).

 Chamberlain (1907, p. 40) reported that “dwarf sockeye” were present in Ozette Lake

around the turn of the century, and it is likely that kokanee were present prehistorically in

Ozette Lake. Between 5,000 and 10,000 kokanee spawn in small tributaries to Ozette Lake,

and Dlugokenski et al. (1981) and Beauchamp et al. (1995) thought that these numbers of

kokanee were insufficient to deplete food resources for sockeye salmon. Dlugokenski et al.

(1981, p. 34) reported that kokanee spawn not only in tributaries, but also spawn interspersed

with sockeye salmon on the lakeshore in mid-November to early December. Over 108,000

kokanee fry from the Lake Crescent Trout hatchery were planted in Ozette Lake in 1940

(Kloempken 1996, see Appendix Table D-5). An unknown number of kokanee from an

unknown stock were reportedly planted in Ozette Lake in 1958 (Dlugokenski et al. 1981).

Kemmerich’s (1945) escapement counts for sockeye salmon to Ozette Lake were

3,241 in 1924 (a portion of the run was missed), 6,343 in 1925, and 2,210 in 1926. No

information relative to the down-river catch of sockeye salmon in the Makah Tribal fishery
66

was available for this time period. Dlugokenski et al. (1981) reported that smolt outmigration

occurs during the hours of darkness and peaks around 6 May, and that Ozette Lake sockeye

salmon have the third largest yearling smolt size of any population reported in the literature.

Data on smolt size and age are presented in Appendix Table C-4 and smolt outmigration

period in Appendix Table C-5.

In 1937, almost 450,000 sockeye salmon fingerlings cultured at the U.S. Bureau of

Fisheries Quilcene Hatchery derived from eggs received from the Birdsview Hatchery on

Grandy Creek (Skagit River Basin) were released into Ozette Lake (Kemmerich 1945,

Boomer 1995) (see Appendix Table D-2). Sockeye salmon of the 1936 brood-year at the

Birdsview Hatchery were composed primarily of Baker Lake broodstock and a probable

Fraser River and Quinault Lake component (Kemmerich 1945). In 1983, 120,000 Quinault

Lake sockeye salmon fry were released into Ozette Lake (MFMD n.d., Hill 1984). Between

1984 and 1995, almost 0.5 million Ozette Lake-origin sockeye salmon fry were reared at the

Makah Tribal Hatchery on Umbrella Creek, a tributary of Ozette Lake, and released into the

Ozette Lake drainage (MFMD n.d.) (see Appendix Table D-2). Spawning stock for this

hatchery effort have been captured on the lakeshore spawning grounds (WDF et al. 1993).

Outside of that portion in Olympic National Park, virtually the entire watershed of

Ozette Lake has been logged (Blum 1988). A combination of past overfishing and spawning

habitat degradation, due to stream and tributary outwash fan siltation, associated with timber

harvest and road building, have been cited as major causes of this stock’s decline (Bortleson

and Dion 1979, Dlugokenski et al. 1981, Blum 1988, WDF et al. 1993). McHenry et al.

(1994) found that percent fine sediments (<0.85 mm) averaged 18.7% in Ozette Lake

tributaries (although these levels may be partly attributable to the occurrence of sandstones,

siltstones, and mudstones in this basin) and fine sediment levels were consistently higher in

logged watersheds than in unlogged watersheds on the Olympic Peninsula, as a whole.

During low water levels in summer, much of the beach habitat may become exposed

(Bortleson and Dion 1979). The exotic plant, reed canary grass (Phalaria arundinacea), has

been encroaching on sockeye salmon spawning beaches in Ozette Lake, particularly on the

shoreline north of Umbrella Creek, where sockeye spawning has not occurred for several

years. This plant survives overwinter submergence in up to 3 feet of water and may possibly

provide cover for predators of sockeye salmon fry (J. H. Meyer29). Suitable lakeshore

spawning habitat for sockeye salmon is reported to be extremely limited in Ozette Lake (Blum

1984, Pauley et al. 1989).

29 J.H. Meyer, Olympic National Park, 600 E. Park Ave., Port Angeles, WA 98362. Pers.

commun., 19 March 1996.
67

Lake Pleasant

Sockeye salmon that spawn and rear in Lake Pleasant enter the Quillayute River and

migrate up the Sol Duc River in May to September. Normally, this stock remains, throughout

the summer, in the Sol Duc River at the confluence with Lake Creek (the Lake Pleasant outlet

stream) until the creek receives sufficient water input to allow the fish to migrate up to Lake

Pleasant. Sufficient stream discharge to allow upstream migration does not usually occur

until late October to early November (WDF et al. 1993, J. Haymes30). Sockeye salmon spawn

predominantly on lakeshore beaches from late November to early January. Little spawning

has been observed in streams tributary to Lake Pleasant (WDF et al. 1993). In describing a

survey of potential habitat for sockeye salmon introductions on the Olympic Peninsula

undertaken prior to 1932, Kemmerich (1945) stated that

It was found that a small run of sockeye or blueback salmon already enters Lake

Pleasant by way of the Sol Duc River and Lake Creek and these natural run fish were

found to be in individual size comparable with the size of the fish of the Lake Quinault

and Columbia River runs.

Currently, sockeye salmon in the Lake Pleasant stock are said to weigh no more than

about 2 to 3 pounds (0.9 to 1.4 kg) (J. Haymes31), which is considerably less than sockeye

salmon from Quinault Lake, with the exception of the very few jacks and jills recorded from

Quinault Lake (see Appendix Table C-8). Limited data on smolt size are presented in

Appendix Table C-4. Average length of spawners collected in 1995 and 1996 for genetic

analysis were 451 mm (n=10) and 460 (n=72) for males, and 459 mm (n=5) and 456 (n=28)

for females, respectively (see Appendix Table C-8). This stock has the smallest average adult

body size of any sockeye salmon stock in Washington.

The following out-of-basin introductions of sockeye salmon into Lake Pleasant

occurred in the 1930s: 1) in 1933, 210,000, and in 1937, 75,000, fingerlings derived from the

Birdsview Hatchery were released into Lake Pleasant (assuming a 4-year return cycle, the

1932 and 1936 Birdsview Hatchery broodstock were descended from mixed releases of the

progeny of Fraser River sockeye salmon in 1908 and 1912; Quinault Lake sockeye salmon in

1916; and Baker Lake sockeye salmon in 1920 and 1928), and 2) in 1934, 175,000 fingerlings

from the Birdsview Hatchery were released into Lake Pleasant (the 1933 broodyear was

composed of Baker Lake broodstock) (Kemmerich 1945, Boomer 1995) (see Appendix Table

D-2).

30 J. Haymes, Quileute Natural Resources, Quileute Indian Tribe, P.O. Box 187, La Push, WA

98350-0187. Pers. commun., 14 February 1995.

31 J. Haymes, Quileute Natural Resources, Quileute Indian Tribe, P.O. Box 187, La Push, WA

98350-0187. Pers. commun., 14 February 1995.
68

Fisheries biologists of the Washington Department of Fisheries undertook a survey of

Lake Pleasant in July and September of 1952, in part to determine its suitability for sockeye

salmon rearing (Smoker et al. 1952, Heg 1953). These two reports were written with the

assumption that sockeye salmon were absent from, or very rare in, Lake Pleasant at this time.

Smoker et al. (1952) stated that

The suitability of Lake Pleasant for the rearing of sockeye can be better determined by

further examination. Its carrying capacity can only be learned by making a plant and

watching the results. . . . Local residents speak rather vaguely of occasional

“bluebacks” being taken in the lower creek. These could be either sockeye or sea-run

cutthroats. . . . Upper Lake Creek would provide good spawning for early-run

sockeye. Spawning in the lake itself would be negligible.

Heg (1953) stated that

Local residents report that Lake Pleasant used to support a small run of sockeye

salmon. However, in view of the large scrap fish population, the unfavorable

temperature conditions, and the occurrence of dry years of extreme low flows in the

outlet stream, it does not appear likely that this lake can be developed into an

important sockeye producer.

In 1956, Lake Pleasant was treated with rotenone by the Washington Department of

Game in an attempt to eliminate all the resident fish in the lake and its tributaries in

anticipation of using Lake Pleasant as rearing habitat for winter steelhead. Since the rotenone

treatment only occurred in a single year, anadromous fish with multiple broodyear life

histories were probably less affected by this program than resident fish. A box-lattice type

fish trap was operated in the outlet creek (Lower Lake Creek) between 1958 and 1962 or 1963

during the winter steelhead run; however, this trap reportedly did not impede the adult

sockeye salmon migration (J. Ayerst32).

Crutchfield et al. (1965) reported that an adult trap was operated in Lake Creek in the

fall of 1960, 1961, and 1962. During these years, total counts of sockeye salmon at this trap

were 1,223, 1,485, and 763, respectively. In the spring of 1958, 64,946 juvenile sockeye

salmon smolts were counted in a downstream migrant trap placed in Lake Creek (Crutchfield

et al. 1965). Migration of sockeye salmon up Lake Creek may have been interrupted for a few

years in the early to mid-1970s due to operation of a weir to trap chinook salmon for artificial

propagation (S. A. Chitwood33).

32 J. Ayerst, Olympic National Forest, 1835 Black Lake Blvd. SW, Olympia, WA 98502.

Pers. commun., 27 June 1995.

33 S.A. Chitwood, Quinault Fisheries Division, P.O. Box 189, Taholah, WA 98587. Pers.

commun., 19 Sept. 1995.
69

Kokanee-size O. nerka currently occur in Lake Pleasant, although their origin is

uncertain. Smoker et al. (1952) stated that

The State Game Department made apparently unsuccessful plants of silver trout

[kokanee] in 1936, 1937 and 1938.

No further information on historical or recent kokanee introductions was available. Both

kokanee-sized fish and sockeye salmon have been observed spawning at the same place and

time on lakeshore beaches of Lake Pleasant (R. Gustafson, NMFS, Pers. observ., November

1995). Most Lake Pleasant sockeye salmon display a dirty red coloration on the spawning

grounds (J. Haymes34).

Baker River

Rathbun (1900) indicated that, historically, sockeye salmon began arriving at the

mouth of the Baker River in the middle of June and reached Baker Lake chiefly during July.

Spawning occurred both in the lake and in Noisy Creek and “Sutter River” (upper Baker

River?) beginning near the end of August or early September (Rathbun 1900, p. 269). The

State of Washington established a hatchery, principally for sockeye salmon propagation, at

Baker Lake in 1896. Baker Lake Hatchery was sold to the U.S. Fish Commission in 1899 and

continued propagating the majority of returning sockeye salmon to this system until the end of

1933 (Kemmerich 1945).

Early reports of the Baker Lake Station included in Reports of the U.S. Commissioner

of Fish and Fisheries (Ravenel 1901, 1902; Titcomb 1904), indicated that spawning sockeye

salmon occurred both along the shoreline and in the Upper Baker River. Around the turn of

the century, gill nets were used to capture adult sockeye salmon for hatchery broodstock along

lake shore spawning beds, and racks were placed in the upper Baker River in an attempt to

prevent sockeye salmon from ascending the river (Ravenel 1901, 1902; Titcomb 1904).

Ravenel (1902) estimated that in 1900 over 25% of adult sockeye salmon in Baker Lake

ascended the upper Baker River to spawn. Surveys conducted by WDF personnel in 1954 and

1955 showed that 95% of the sockeye salmon in the Baker River system at that time, spawned

in Baker Lake on shoreline beaches (Quistorff 1954a,b,c; Quistorff 1959; PRO-Salmon 1994).

Quistorff (1955) stated that

Spawning sockeye salmon were observed in heaviest concentrations along the midsouth shore of Baker Lake where a condition of underground water movement was

found.

34 J. Haymes, Quileute Natural Resources, Quileute Indian Tribe, P.O. Box 187, La Push, WA

98350-0187. Pers. commun., 12 May 1995.
70

Some spawning sockeye salmon were also observed by Quistorff (1955) in Channel Creek

and in the main upper Baker River one quarter mile downstream of Channel Creek.

Hamilton and Andrew (1954) stated that sockeye salmon spawned in the upper Baker River

without mention of shoreline spawning. However, Wayne (1961) stated that “the natural

spawning areas for sockeye salmon . . . had been located along the north shore of the lake.” It

is unknown whether sockeye salmon that originally spawned on the shoreline of Baker Lake,

and to some degree in tributaries of Baker Lake, consisted of a single genetic stock or

multiple stocks. However, as pointed out in Hendry and Quinn (1997), between 1899 and

1933 hatchery operations “thoroughly mixed the descendants of any subpopulations that

might initially have been present.”

Construction of Lower Baker Dam just above the town of Concrete on the Baker River

in 1924 to 1927 created Lake Shannon Reservoir (Wayne 1961). During dam construction in

1925, approximately 8,000-10,000 adult sockeye salmon were blocked from reaching Baker

Lake, and only 40 sockeye salmon were successively lifted over the dam and eventually

reached Baker Lake (Kemmerich 1945). Between 1926 and 1957, sockeye salmon were

trapped at the base of Lower Baker Dam and transported over the dam in small steel tanks on

a 244-m-long highline cableway and then chuted into the reservoir (Wayne 1961). Prespawner mortalities occurred below the dam (Wayne 1961), and escapement records for this

period are for sockeye salmon that actually passed over the dam; Kemmerich (1945)

estimated that 20-25% of sockeye salmon counted over the dam between 1926 and 1933 never

reached Baker Lake due to mortalities resulting from this handling.

Following cessation of propagation efforts in 1933, and until construction of Upper

Baker Dam in 1956, sockeye salmon that reached Baker Lake were allowed to spawn

naturally. At that time, outmigrating sockeye salmon either passed over the surface spillway

of Lower Baker Dam (where mortality was estimated at 64% when one spillway was open) or

through the turbines (where mortality was estimated at 34%) (Hamilton and Andrew 1954).

Hamilton and Andrew (1954) estimated that the sockeye salmon population had declined by

55% since dam construction. Use of a ski-jump spillway, first installed in 1955, considerably

decreased spillway mortalities (Regenthal 1955) but resulted in loss of potential hydroelectric

power (Wayne 1961).

Construction of Upper Baker Dam in 1959 inundated the original Baker Lake and

created New Baker Lake (Upper Baker Reservoir), submerging the natural lakeshore

spawning beaches and most of the potential tributary spawning areas beneath more than 18 m

of water (Wayne 1961). Today this reservoir is commonly referred to as Baker Lake.

Fish handling facilities were updated in the late 1950s with construction of a new

barrier dam and fish trap 0.8 km downstream of Lower Baker Dam. These events induced the

use of tanker trucks for transporting adult sockeye salmon to Baker Lake, construction of

artificial spawning beaches adjacent to Channel Creek above Baker Lake, the installation of

turbine-pump-operated smolt collecting barges (“gulpers”) at the head of each dam, and 20 to

25-cm-diameter fish transportation pipes that guided smolts from the gulpers through the face
71

of each dam to be deposited into the tailrace channel below each dam (Wayne 1961, Quistorff

1966). Use of the transportation pipe through Upper Baker Dam was discontinued in 1987,

and outmigrating juvenile sockeye salmon trapped since then at the Upper Baker Dam gulper

have been trucked from Upper Baker Dam to the Baker River below Lower Baker Dam.

Guide nets have subsequently been installed at both dams to discourage outmigrating fish

from going over the spillways or through the turbines.

Artificial sockeye salmon spawning beaches 1, 2, and 3 were constructed in 1957,

1959, and 1966, respectively above Baker Lake off Channel Creek. Beach 1 ceased operation

in 1965, but the spawner capacity of beaches 2 and 3 continues at 1,500 adult sockeye salmon

each. Sockeye salmon fry from beaches 2 and 3 currently leave the beaches on their own

volition through outlets into Channel Creek and from there into Baker Lake. The future of

spawning beaches 2 and 3 is uncertain. According to WDFW (1996), “the state and tribes

favor the continued use of beaches 2 and 3, but Puget Power and the Forest Service would like

to close them.” Spawning beach 4, on Sulphur Creek, below Upper Baker Dam, began

operating in 1990 with a spawner capacity of 3,000. Fry leaving beach 4 are captured and

hauled by tanker truck to Baker Lake.

Since the construction in 1958 of a barrier dam and fish trap below Lower Baker Dam,

adult sockeye salmon have been trapped and hauled by tanker truck to the spawning beaches

or to Baker Lake. Since 1986, a portion of the fry leaving the spawning beaches have been

collected and reared in net-pens in Lake Shannon Reservoir prior to being released as smolts

through the Lower Baker Dam gulper. Total smolt releases between 1987 and 1992 were over

400,000 (WDF et al. 1993) (see Appendix Table D-2 and “Artificial Propagation” section). It

was stated in WDFW (1996) that

The future of the net pen program is uncertain. There have been three consecutive

years of major IHN outbreaks in the net pens. Although the program did increase eggto-smolt survival, it did not increase smolt-to-adult survival. In 1996, sockeye fry

(brood year 1995) are not expected to be taken to the net pens.

Currently, adult sockeye salmon return to the Baker River trap from mid-June to midAugust and spawn in the artificial beaches from late September through December, peaking

from late October to late November (WDF et al. 1993). In addition to releases into the

artificial spawning beaches, significant numbers of adult sockeye salmon were released into

Baker Lake in 1967, 1972, and 1994, and most likely in 1962, 1963, and 1964, as well

(WDFW 1996). For instance, over 1,000 sockeye salmon (25% of the fish trap count) were

released in Baker Lake in 1967 (Orrell 1969). The return of almost 16,000 sockeye salmon to

Baker River in 1994 far exceeded the 4,000-fish capacity of the spawning beaches. Following

consultations between WDFW and the Skagit System Cooperative (representing Skagit River

area tribes) regarding a fishery on this stock, the remaining 12,000 adults were liberated into
72

Baker Lake in an experiment to determine survival rate and production potential for natural

spawning of sockeye salmon in Baker Lake (J. Ames35).

The lower portion of the upper Baker River is now a braided stream subject to severe

meander and, like shoreline spawning habitat, is subject to effects of reservoir drawdown in

winter and spring (G. Sprague36). Baker Lake and beaches 2 and 3 near Channel Creek

commonly freeze over in winter, but Lake Shannon and beach 4 never freeze over

(G. Sprague37).

Kokanee are present in the system, although Ward (1929, 1930, 1932) and

Kemmerich (1945) thought that “kokanee-sized” O. nerka in Baker Lake were derived from

sockeye salmon residuals. Following construction of Lower Baker Dam, resident O. nerka

were observed spawning in Baker Lake for the first time and were presumed to have

originated from sockeye salmon residualizing in Lake Shannon Reservoir (Ward 1929, 1930,

1932, Kemmerich 1945).

Between 1991 and 1994, 1,158,200 hatchery reared Lake Whatcom kokanee were

released in Lake Shannon (Knutzen 1995). Lake Whatcom kokanee were reportedly released

into Baker Lake in the past,38Mill Creek, WA 98012-1296. Pers. commun., 19 April 1996.

although we were unable to locate stocking records. In average years, 40-100 “kokaneesized” O. nerka spawn in the outlet channel that drains the two upper sockeye salmon

spawning beaches and flows into Channel Creek (W. Steuer39). It is possible that a portion of

the kokanee that have been recently planted in Lake Shannon Reservoir from Lake Whatcom

stock may have outmigrated through the Lower Baker Dam gulper. It is unknown whether

these potential outmigrating kokanee have returned as sockeye salmon; however, if they have,

they would presumably have been placed together with native sockeye salmon in the

spawning beaches (G. Sprague40).

35 J. Ames, Washington Department of Fish and Wildlife, 600 Capitol Way N., Olympia, WA

98501-1091. Pers. commun., April 1995.

36 G. Sprague, Habitat Program, Washington Department of Fish and Wildlife, 600 Capitol

Way N., Olympia, WA 98501-1091. Pers. commun., 15 March 1995.

37 G. Sprague, Habitat Program, Washington Department of Fish and Wildlife, 600 Capitol

Way N., Olympia, WA 98501-1091. Pers. commun., 15 March 1995.

38 J. Johnston, Washington Department of Fish and Wildlife, 16018 Mill Creek Blvd., Mill

Creek, WA 98012-1296. Pers. commun., 19 April 1996.

39 W. Steuer, Washington Department of Fish and Wildlife, 121 N. Ball St., Sedro Wooley,

WA 98284. Pers. commun., 1 November 1995.

40 G. Sprague, Habitat Program, Washington Department of Fish and Wildlife, 600 Capitol

Way N., Olympia, WA 98501-1091. Pers. commun., 15 March 1995.
73

Lake Washington

The following historical overview of changes to the Lake Washington Basin has been

compiled from Evermann and Meek (1898), Ajwani (1956), Woodey (1966), Larson (1975),

Stickney and McDonald (1977), Corsaletti (1981), Chrzastowski (1983), and Buerge (1985,

1989).

Between 1911 and 1916, construction of the Lake Washington Ship Canal, and

associated engineering projects, profoundly altered both the natural drainage patterns of Lake

Washington and potential migratory routes of anadromous fish native to the basin. During

this period, the Cedar River was diverted to discharge into Lake Washington, the level of

Lake Washington was lowered approximately 3 m, the outlet into the Black River ceased to

exist, the Sammamish River channel was widened and deepened, and the newly constructed

Lake Washington Ship Canal became the new lake outlet.

Historically, Lake Washington drained to the south through the Black River, which

flowed for 5.3 km to its confluence with the White River (now the Green River) to form the

Duwamish River and then flowed into Puget Sound. The Cedar River entered the Black River

less than 1 km below the Lake Washington outlet, and Lake Washington’s principal tributary

was the Sammamish River (historically called Squak Slough). The Black River had an

average depth of 1.2 m and ranged in width from 15 to 46 m. At flood stage, the Cedar River

commonly reversed the flow of the upper segment of the Black River, causing Cedar River

water to flow into Lake Washington. At these times, the Black River had water flowing in

opposite directions at its two ends, north into Lake Washington and west into the Duwamish

River. This is why the Black River was called “Mox La Push,” meaning “two mouths,” in the

Chinook jargon. Prehistorically, the Cedar River may have been a major tributary to Lake

Washington (Chrzastowski 1983).

In 1911, construction on the locks (now the Hiram M. Chittenden Locks), dam, and

Fremont and Montlake Cuts began. According to Chrzastowski (1983) and Buerge (1985,

1989), the Cedar River was permanently diverted into Lake Washington in the summer of

1912 by excavation of a channelway 24 m wide and 610 m long. This diversion was

precipitated by severe flooding on the Cedar River in the winter of 1911 that required the

evacuation of the city of Renton. The locks were completed in the spring of 1916, and by

25 July 1916 the level of Salmon Bay had been raised to equal that of Lake Union. The

lowering of the level of Lake Washington to that of Lake Union was gradual, occurring over a

4-month period from July to October 1916 (Stickney and McDonald 1977, Chrzastowski

1983). The lowering of Lake Washington also increased the gradient of the Sammamish

River, making it too shallow and narrow for navigation, and leading to the widening,

deepening, and channelization of the Sammamish River in 1916 by the U. S. Army Corps of

Engineers (Stickney and McDonald 1977, Chrzastowski 1983). The opening of the Lake

Washington Ship Canal was celebrated on 4 July 1917.
74

The lowering of Lake Washington in 1916 left the channel of the Black River high and

dry, while the diversion of the Cedar River into Lake Washington in 1912 caused the Cedar

River to become Lake Washington’s principal tributary and approximately doubled the flow

of freshwater into Lake Washington. Ajwani (1956) stated that

Whether the runs of fish occurring at the time of these diversions were eliminated or

what the degree of their reduction was, cannot be determined because of lack of data.

Reports in the literature are equivocal as to whether sockeye salmon were historically

present in the Lake Washington/Lake Sammamish Basin prior to 1916, although kokanee

were numerous. Prior to construction of the Lake Washington Ship Canal, fishing for

“silvers” and “trout” was reported to be at its best near the confluence of the Black River and

Lake Washington (Larson 1975, Slauson 1976). Silver salmon is a common local name for

coho salmon, while in the early part of this century kokanee were called “silver trout” (and are

still so designated in Washington State fishery regulations). Hammond (1886), in reference to

Lakes Washington and Sammamish, stated that

The only fish in them is a species of trout, very few in number, the largest of which are

about a foot in length.

Seale (1895) reported the collection of “six large specimens” of “dark” O. nerka taken

in Lake Washington on 7 November 1892 and two others, “more silvery in color,” taken on

30 June 1895. No dimensions for these fish were recorded, although the species was

reportedly “very abundant” (Seale 1895). Woodey (1966) surmised from the dates of

collection and coloration of the specimens that the O. nerka reported by Seale (1895) were

most likely kokanee. Four of Seale’s (1895) specimens of O. nerka collected in Lake

Washington on 7 November 1892 are currently deposited in the California Academy of

Sciences fish collection (D. Catania41). The relatively short fork lengths of these 4 specimens

(241-249 mm) indicate that Seale’s (1895) “six large specimens” of O. nerka were kokanee,

not sockeye salmon.

Jordan and Evermann (1896) reported that Prof. O. B. Johnson observed large

“redfish,” presumably sockeye salmon, at Lake Washington. Evermann (1896) reported that

the “small redfish” was found at Lake Washington, and goes on to say that

Prof. O. B. Johnson found the small form spawning in Lake Washington near the last

of November, 1888, and on October 8, 1889.

41 D. Catania, Ichthyology Department, California Academy of Sciences. Pers. commun., 27

March 1996.
75

Evermann and Meek (1898), in reference to Lake Washington, stated that

Salmon are said to enter the lake through the Black River early in the fall, but none

was seen. They are probably the large form of the redfish or sockeye (Oncorhynchus

nerka). Redfish are said to run up into shallow places during the latter part of October

and a part of November . . .

All stocks of sockeye salmon presently found in Lake Washington complete their migration

into Lake Washington before the end of August (WDF et al. 1993), suggesting that the salmon

Evermann and Meek (1898) reported as entering the Black River in the fall were not sockeye

salmon, or that sockeye salmon had radically different run-timing in Lake Washington in the

1890s compared to the present day, and that this stock is now extinct. While seining in Lake

Washington, Evermann and Meek (1898) collected 17 “small redfish” ranging in length from

24 to 27 cm, but did not collect anadromous-sized O. nerka.

In regard to Lake Sammamish, Evermann and Meek (1898) stated “no information

could be obtained as to what kind of salmon enter the lake,” but reported that local residents

said that redfish were plentiful in “Squak Slough” (Sammamish River) and that “salmon run

with the redfish.” Evermann and Meek (1898) presumed that redfish, or “grayling” as they

were called locally, spawned from the latter part of October to early or mid-November.

Subsequent authors either stated that a small population of sockeye salmon occurred in

Lake Washington (Rathbun 1900; Evermann and Goldsborough 1907; Cobb 1911, 1914,

1930) or that Baker River had the only population of sockeye salmon in Puget Sound (Cobb

1927, Rounsefell and Kelez 1938, Royal and Seymour 1940, Kemmerich 1945). Pratt and

Jewell (1972) reported that no record has been located of “sea-run” sockeye salmon in Lake

Washington prior to their introduction in 1935. Surveys conducted on the Cedar River, Big

Bear Creek, Cottage Lake Creek, and Evans Creek on 2 and 3 September 1930 did not report

the occurrence of sockeye salmon (WDFG 1932). Currently, early September is near the

beginning of sockeye salmon spawn timing for these streams (WDF et al. 1993). In reviewing

the history of O. nerka in the Lake Washington/Lake Sammamish drainage, Hendry (1995)

concluded that “limited runs of sockeye salmon . . . were probably present at the turn of the

century,” and that

The status of Lake Washington sockeye salmon during this period (1917-1937) will

probably never be fully determined but it is certainly unlikely that large populations

were present.

Sockeye salmon vertebral remains were identified in prehistoric fish remains from the

Duwamish No. 1 archeological site (45-KI-23), located 3.8 km upstream from Elliot Bay on

the Duwamish River, utilized by aboriginal humans between A.D. 15 and A. D. 1654 (Butler

1987). Fish remains from two archeological sites on the former Black River, Tualdad Altu

(45-KI-59, Earlington site) and Sbabadid-D (45-KI-51-D), revealed numerous Oncorhynchus
76

sp. remains, but identification to the species level was not undertaken in this study (Chatters

1988, Butler 1990).

Smith (1940), reporting on cultural interviews with local tribal elders, stated that

“when asked about the red salmon (O. nerka) informants said the silver side might be called

that as it turned red in freshwater, but they knew of no separate species by this name.” Smith

(1940) goes on to say

A small salmon was said to live permanently in Lake Washington spawning in the

creeks which emptied into the lake. The Duwamish of that section and even those at

the intersection of the White and Green Rivers were said to prefer this salmon to that

which entered the rivers from the Sound.

This reference to land-locked salmon most likely refers to the numerous kokanee then present

in Lake Washington.

The undisputed historic presence of kokanee in Lake Washington indicates that

sockeye salmon existed in Lake Washington, at least in prehistoric times. Several factors may

have favored subsequent evolution of kokanee (and non-anadromy) at the expense of

anadromous O. nerka in Lake Washington. Chrzastowski (1983) stated

For most of the year, Lake Washington in its natural state was a poorly flushed lake,

and water quality reportedly worsened noticeably during the dry season (July-Sept.)

when the lake was relatively stagnant. Average residence time for the lake water in

the natural state probably was about twice the present-day value, or nearly 5 years.

In addition, spring floods on the Cedar River that commonly backed up the Black River into

Lake Washington (preventing the lake from draining for a time) would probably have

occurred during the period of potential smolt outmigration (March to early June). Both these

factors (low flushing rate and difficulty of locating the outlet during flood stages) may have

inhibited smolt outmigration.

Foerster (1937) found that when surface epilimnion temperatures rose above 10o

C in

Cultus Lake, a physiological temperature barrier was formed that terminated downstream

migration of young sockeye salmon. The observations of Foerster (1937) may be used to

support the hypothesis that prior to diversion of the Cedar River into Lake Washington, which

more than doubled the lake’s water budget, relatively low outflow and seasonal development

of a deep epilimnion of warm water may have presented a physical and/or physiological

impediment to downstream sockeye salmon smolt migration. Recent historical changes in the

drainage pattern of Lake Washington may have created conditions that were more favorable to

development of anadromous O. nerka. However, it should be noted that currently sockeye

salmon smolts in Lake Washington are known to continue to outmigrate into June through

17o

C temperature water (Warner 1997).
77

WDF et al. (1993) recognized three separate stocks of sockeye salmon currently in the

Lake Washington/Lake Sammamish drainage: Cedar River, Lake Washington/Lake

Sammamish Tributaries, and Lake Washington beach spawning. WDF et al. (1993) indicated

that sockeye salmon stocks that spawned in the Cedar River were of non-native origin, and

stocks that spawned in other Lake Washington/Lake Sammamish tributaries and on lakeshore

beach habitat in Lake Washington were of unknown origin and were perhaps native to the

drainage.

Available artificial propagation data and transplantation records provide evidence that

the current Cedar River and Issaquah Creek (a tributary of Lake Sammamish) sockeye salmon

are introduced populations (Royal and Seymour 1940, Kolb 1971, Burgner 1991)

(see Appendix Table D-2). The majority of Cedar River sockeye salmon spawn from midSeptember into January (a few are still spawning in February), with a peak in mid- to late

October (WDF et al. 1993). The Cedar River population was believed by Kemmerich (1945),

Royal and Seymour (1940), Kolb (1971), and Pratt and Jewell (1972) to be derived from the

direct planting of over 1 million fry and fingerlings between 1935 and 1944 (see Appendix

Table D-2 and “Artificial Propagation” section). These introductions originated from a

sockeye salmon stock perpetuated at the U.S. Bureau of Fisheries Birdsview Hatchery on

Grandy Creek in the Skagit River Basin.

The Birdsview Hatchery stock was started in 1908 from Fraser River sockeye salmon

captured in commercial traps at Point Roberts, and egg takes in 1912 and 1916 indicate that

substantial numbers of adult fish returned from these initial releases in Grandy Creek and

Grandy Lake (Kemmerich 1945). In 1916, fry derived from Quinault Lake were used to

supplement the Birdsview Hatchery stock (Kemmerich 1945, see Appendix Table D-2).

However, over the years 1914-1945 the parent stock for this hatchery program was

overwhelmingly Baker Lake sockeye salmon (Kemmerich 1945).

Out-of-basin releases in the Lake Washington/Lake Sammamish Basin totaled over

3.4 million fry and fingerlings from releases of 1) an unknown stock in 1917, 2) Birdsview

Hatchery stock between 1935 and 1945, and 3) Cultus Lake stock released in 1944, 1950, and

1954 (Woodey 1966, Kolb 1971, Hendry 1995) (see Appendix Table D-2). From 1947 to

1970, adult sockeye salmon returning to the Issaquah Hatchery provided broodstock for

numerous additional fry and fingerling releases to Issaquah Creek, and limited releases to

Lake Union and the Cedar River (Kolb 1971).

Sockeye salmon in the Lake Washington/Lake Sammamish tributaries stock spawn

primarily in Big Bear Creek, Cottage Lake Creek, and East Fork Issaquah Creek, with minor

numbers in other Lake Sammamish tributaries (WDF et al. 1993), such as Laughing Jacobs

and Lewis Creeks (Ostergaard et al. 1994). Spawning in these creeks extends from early

September through November, with a peak in mid- to late October, depending on stream flow.

Issaquah Creek received sockeye salmon fry and fingerling plants of over 1.6 million

Birdsview Hatchery-origin fish between 1935 and 1945, and over 59,000 Cultus Lake-origin
78

fish in 1950 and 1954. North Creek, a Sammamish River tributary, received over 23,000

Cultus Lake sockeye salmon fry planted in 1944 (Kolb 1971).

Kemmerich (1945), reporting on the effectiveness of introductions of sockeye salmon

of the 1934 broodyear from the Birdsview Hatchery into the Cedar River and Issaquah Creek,

stated that two sockeye salmon were found “in the Bear Creek fish trap of the State Game

Department” on 5 October 1938. No sockeye salmon had been planted in Big Bear Creek up

to this point, with the exception of fry planted in the spring of 1937 which would not have

reached maturity in 1938. However, Kemmerich (1945) pointed out that 76,000 sockeye

salmon fry from Baker Lake had been planted in Issaquah Creek in the summer of 1935. Outof-basin releases of O. nerka fry into Big Bear Creek and its two tributaries, Cottage Lake

Creek and Evans Creek, included 576,000 sockeye salmon fry, primarily of Baker Lake

origin, stocked in Big Bear Creek in 1937 (Royal and Seymour 1940, Kemmerich 1945, Kolb

1971). In addition, over 34 million Lake Whatcom kokanee were stocked in Big Bear and

Evans Creeks between 1917 and 1969 (Pfeifer 1992), and over 177,000 kokanee from an

unknown source population stocked in Big Bear Creek in 1917 (Pfeifer 1992) (see Appendix

Tables D-2 and D-5).

Kokanee used for stock transfers in the early part of this century were most commonly

derived from either Kootenay Lake, British Columbia or Lake Whatcom, Washington (Pfeifer

1992). Pfeifer (1992) stated that

I cannot rule out the possibility that kokanee from Kootenay Lake were among the

many early introductions for which the egg or fry source was not explicitly recorded.

In the Lake Washington system, the kokanee found in Big Bear Creek exhibit a spawn

timing intermediate to that of the Kootenay and Whatcom strains, and are found

spawning alongside the anadromous form.

Currently, kokanee in the Lake Washington/Lake Sammamish Basin can be separated

into two groups based on very different spawn timing; 1) a group of early-entry kokanee in

Issaquah Creek (a tributary at the southern end of Lake Sammamish) that exhibit late July to

early September spawn timing, and 2) kokanee in the Sammamish River and Lake

Sammamish tributaries, including a second run of kokanee in Issaquah Creek that spawn in

September/October in Big Bear Creek, October/November in Issaquah Creek, and late

November/December in Laughing Jacobs and Lewis Creeks (Pfeifer 1992, Ostergaard et al.

1995). Ostergaard et al. (1995) stated that early entering kokanee in Issaquah Creek are

known to be native, while kokanee in other tributaries to Lake Sammamish and the

Sammamish River are believed to be non-native, based on their later run-timing. Ostergaard

(1996) listed 8 creeks, tributary to the east and south shores of Lake Sammamish, that

historically supported native early entering kokanee. Ostergaard (1996) estimated the 4-year

(1992-1995) total spawning population of these kokanee in Issaquah Creek at 81 fish.

Kokanee once existed in streams tributary to Lake Washington, other than the

Sammamish and Cedar Rivers. Shultz and Students (1935) observed kokanee spawning in
79

Swamp Creek, a tributary of the lower Sammamish River, from September to November

1933. The University of Washington Fish Collection has specimens of kokanee collected in

Swamp Creek on 30 August 1920, 28 October 1928, and 27 November 1933. Since these

observations and collections were made before the first recorded transplants of kokanee to

Swamp Creek (see Appendix Table D-5), it is apparent that not all kokanee native to the Lake

Washington/Lake Sammamish Basin had exclusively early run-timing.

Spawning sockeye salmon intermingle with spawning Big Bear Creek and late-entry

Issaquah Creek kokanee (Pfeifer 1992), as well as with kokanee spawning in Laughing Jacobs

and Lewis Creeks (Ostergaard et al. 1995). Kokanee are also reported to spawn together with

sockeye salmon in the Cedar River (Pfeifer 1992), although the coloration of Cedar River

kokanee-sized fish is typical of the coloration shown by residuals in other lake systems

(J. Ames42).

Pfeiffer (1992) stated that fish traps were operated in Big Bear Creek by the King

County Game Department and the Washington Department of Game in the 1930s. In

reference to Big Bear Creek, Ajwani (1956, p. 67-68) stated that

A wooden weir was constructed across the stream in 1925, when the County Game

Commission was in operation. At that time the county would take all the eggs

obtained from the silver trout run and either plant or trade these eggs elsewhere. . . .

For its size, this stream is . . . one of the largest producers of silver trout in the state.

The run-timing of kokanee in Big Bear Creek is essentially concurrent with that of

anadromous sockeye salmon: from early September to late November with a peak in the first

to second week of October (Ostergaard et al. 1995). Therefore, kokanee fish traps and weirs

operated in Big Bear Creek in the 1920s and 1930s would presumably have impeded

migration of sockeye salmon that may have been in the system at that time. Prior to the single

recorded transplant of 576,000 sockeye salmon fry into Big Bear Creek in 1937 and the

recorded return of 2 adults in October 1938 and another 2 adults in October 1940, no mention

of sockeye salmon in Big Bear Creek occurs in the published literature.

Surveys by King County Surface Water Management Division in 1992, 1993, and

1994 recorded only 242, 23, and 9 kokanee, respectively in the Big Bear Creek drainage

(Ostergaard et al. 1995). In addition, Ostergaard et al (1995) stated that the 9 fish seen in

1994 may have been residual sockeye salmon or sockeye salmon x kokanee hybrids. Past

results of electroshocking in Big Bear Creek by WDFW have indicated that the number of

kokanee visually observed is a small fraction of the actual number of fish present (WDFW

1996), therefore it is probable that the kokanee population in Big Bear Creek during

1992-1994 was larger than the numbers in Ostergaard et al. (1995) suggest. Ostergaard

42 J. Ames, Department of Fish and Wildlife, State of Washington, 600 Capitol Way N.,

Olympia, WA 98501-1091. Pers. commun., April 1995.
80

(1996) estimated an escapement of 317 kokanee to Big Bear Creek in the fall of 1995, based

on WDFW survey numbers.

Beach spawning sockeye salmon are found in both Lake Washington and Lake

Sammamish; WDF et al. (1993) considered the beach spawners in Lake Washington a

separate stock, but the status of the Lake Sammamish beach spawners was undetermined due

to lack of information. Berggren (1974) reported that the numbers of beach-spawning

sockeye salmon in Lake Sammamish between 1969 and 1972 ranged from a low of 125-200

in 1969 to a high of 1,400-1,900 in 1971. Recent estimates of Lake Sammamish beachspawning sockeye salmon were unavailable. Lake Washington beach spawning occurs

primarily between October and January. Spawning has been observed in many locations

around the perimeter of Lake Washington, but primarily at Pleasure Point Beach on the

southeast shoreline, in the Bellevue area, near Juanita Point, along Enatai Beach (Buckley

1965), and around the shoreline of Mercer Island (Woodey 1966, WDF et al. 1993).

Riverine spawning sockeye salmon in Washington

Methow River—Prior to the hatchery program at the Winthrop National Fish Hatchery

(NFH), sockeye salmon were apparently not present in the Methow River (WDF et al. 1938,

Mullan 1986, Chapman et al. 1995). Over 1.8 million sockeye salmon of Rock Island and

Bonneville Dam origin were released in the Methow River from Winthrop NFH between

1945 and 1957 as part of the GCFMP (Mullan 1986, Chapman et al. 1995) (see Appendix

Table D-2). Chapman et al. (1995) indicated that small numbers of sockeye salmon continue

to return to the Methow River every year and this population appears to be self-perpetuating.

Allen and Meekin (1973) reported that, based on weir counts, about 1% of the sockeye

salmon passing Wells Dam in 1965 and 1966 entered the Methow River. French and Wahle

(1960) and Fryer and Schwartzberg (1993) reported that sockeye salmon spawning occurred

between river kilometers 57 and 64 on the Methow River downstream of Twisp. Langness

(1991) reported that sockeye salmon were observed spawning in the Methow River from 1987

to 1990 and that the distribution of spawning was essentially the same as reported in French

and Wahle (1960). It has been postulated that sockeye salmon that spawn in the Methow

River may rear in mainstem reservoirs on the Columbia River (Chapman et al. 1995).

Allozyme data presented by Chapman et al. (1995) indicate a closer association of

Methow River sockeye salmon with Lake Wenatchee sockeye salmon than with Okanogan

River sockeye salmon. However, recent analysis of allozyme data based on sockeye salmon

collected in 1994 (Okanogan River fish collected at Wells Dam) indicate that sockeye salmon

from the Methow River, Wenatchee River, and Okanogan River (Wells Dam) belong to a

common gene pool (Utter 1995). The apparent genetic similarity between Wenatchee and

Okanogan River sockeye salmon reported in Utter (1995) is inconsistent with findings of

significant genetic distance between Wenatchee and Okanogan populations as reported in

Utter et al. (1984), Brannon et al. (1994), Thorgaard et al (1995), and Winans et al. (1996).
81

Entiat River—Prior to the hatchery program at the Entiat National Fish Hatchery, sockeye

salmon had not been observed in the Entiat River (WDF et al. 1938, Mullan 1986, Chapman

et al. 1995). Approximately 161,787 juvenile sockeye salmon derived from Quinault Lake

stock were released into the Entiat River in 1942 and 1943 (Chapman et al. 1995) (see

Appendix Table D-2). In addition, 22,341 Lake Chelan kokanee, derived from Lake

Whatcom stock, were released into the Entiat River in 1944 (Mullan 1986)

(see Appendix Table D-5).

Barnaby (1946) indicated that of 60,010 marked sockeye salmon juveniles of the 1941

brood released in the Entiat River on 8 May 1943, 93 were recovered as adults in 1944 and

658 in 1945. In 1945, 33 marked sockeye salmon were recovered in the Entiat River, 3 in the

Wenatchee River, and 622 in the Columbia River commercial fishery (Barnaby 1946). In

contrast, Fulton and Pearson (1981) indicated that 670 adults from this experiment were

recovered in the lower river fishery, with only one recovered in the Entiat River and 3 in the

Wenatchee River. Apparently, these introductions established a small sockeye salmon

population that provided enough returning adults to provide broodstock in the 1950s for

release into Lake Wenatchee, Lake Osoyoos, and Icicle Creek (Mullan 1986, Chapman et al.

1995) (see Appendix Table D-2).

Although Mullan (1986) believed that transplants of Quinault Lake stock established

sockeye salmon in the Entiat River, he postulated these three alternate hypotheses to explain

their occurrence: 1) inadvertent inclusion of sockeye salmon with other species of salmon

trapped at Rock Island Dam and released in 1939-1940 in the Entiat River, 2) escape of

juvenile sockeye salmon from the Entiat Hatchery, and 3) straying from other stocks. Since

natural sockeye salmon stocks had not become established in the Entiat River prior to the

GCFMP, Mullan (1986) discounted straying as a possible origin for Entiat River sockeye

salmon. Currently small numbers of sockeye salmon are observed in the Entiat River almost

every year (Chapman et al. 1995). Chapman et al. (1995) considered these fish either as

strays from Lake Wenatchee or Okanogan River or as artifacts of the hatchery stocking

program carried on during the 1940s and 1950s. It was postulated that sockeye salmon that

spawn in the Entiat River rear in mainstem reservoirs on the Columbia River (Chapman et al.

1995).

Similkameen River—Although the Similkameen River, which originates in British

Columbia, is considered the main tributary of the Okanogan River downstream from Lake

Osoyoos, it is considerably larger than the Okanogan, contributing some 3 to 4 times the

water volume of the mainstem Okanogan (WDF et al. 1938, Bryant and Parkhurst 1950,

Mullan 1986). Fulton (1970) and Allen and Meekin (1980) listed Palmer Lake and its inlet

tributary Sinlahekin Creek as historical sockeye salmon habitat. In contrast, Mitchell (1980)

suggested that prior to construction of Enloe Dam in 1920, the original Squantle

(Similkameen) Falls was 7.6 to 9.1 m high and would have acted as a block to upstream

migration of sockeye salmon to Palmer Lake. Bryant and Parkhurst (1950) reported that 500

dead unspawned sockeye salmon were found in the Similkameen River in 1936 and that these

fish may have been part of the population that normally spawned above Lake Osoyoos.
82

French and Wahle (1954) observed sockeye salmon below Enloe Dam on the Similkameen

River from early to mid-August, but not in late August or September of 1954. Other authors

reporting the occurrence of sockeye salmon in the Similkameen River included Chapman

(1941), French and Wahle (1960, 1965), CBFWA (1990), Langness (1991), and Chapman et

al. (1995).

Currently, small numbers of sockeye salmon are seen almost every year below Enloe

Dam on the Similkameen River (Chapman et al. 1995). The origin of these sockeye salmon is

uncertain; hypotheses proposed include straying of sockeye salmon from the Okanogan River

and returns of anadromous individuals derived from kokanee in upstream Palmer Lake

(Chapman 1941, Rounsefell 1958a, Fulton 1966). WDFG (1921a, 1921b) recorded the

release of 132,500 kokanee (silver trout) into Palmer Lake in 1919-1920. In 1966, Fulton

(1966) reported that 45,000 kokanee and 87,000 sockeye salmon were released in Sinlahekin

Creek and Palmer Lake (see Appendix Tables D-2 and D-5); 15 thermally marked

outmigrants from this release were captured at Priest Rapids Dam.

Icicle Creek—Icicle Creek is a tributary of the Wenatchee River below Lake Wenatchee and

is also the site of Leavenworth National Fish Hatchery. Over 1.5 million juvenile O. nerka

were released directly into Icicle Creek between 1942 and 1969: 1.1 million of Rock Island

Dam heritage, over 270,000 of Entiat River heritage (progeny of Quinault Lake stock), over

44,000 of Methow River heritage, over 100,000 of Lake Wenatchee heritage, about 3,000

from an unknown British Columbia sockeye salmon stock, and over 29,000 Lake Wenatchee

kokanee (Chapman et al. 1995, NRC 1995) (see Appendix Table D-2). Chapman et al. (1995)

stated that currently, small numbers of adult sockeye salmon are observed in Icicle Creek

almost every year. Since the Leavenworth NFH is located only 4.5 km from the Wenatchee

River, Mullan (1986) suggested that observations of sockeye salmon in Icicle Creek could

represent some residual attraction of hatchery-reared fish to the water they were reared in

before their release into Lake Wenatchee, or it could have represented straying into the wrong

tributary. As pointed out by Chapman et al. (1995), no sockeye salmon have been reared at

Leavenworth since the mid-1960s; however, “generally less than a few dozen” sockeye

salmon are still seen in Icicle Creek each year.

Nooksack River—In reference to the glacially influenced Nooksack River, Rathbun (1900)

stated that

The sockeye have been said to enter it, but the evidence to that effect is not conclusive.

Kershaw (1902) stated that “the sockeye occasionally ascend the river in small numbers.” In

reference to sockeye salmon, Crawford (1907) stated

a few have been known to enter the Nooksack River and spawn in one of its small

tributaries . . . those from the Nooksack . . . were noticed during the great run of 1905

when the sockeyes ran closer to the shore on the Sound than has ever been known

before. Last season a great many salmon ascended the Nooksack River.
83

FWTC (1970) stated that

At least one section of the Nooksack system supports a small run of sockeye salmon.

It is a half-mile-long side channel of the North Fork, located 3.5 miles upstream from

the town of Glacier. Other stream sections, and some tributaries, in both the North and

South Fork Nooksack, also receive limited sockeye runs.

Williams et al. (1975) also reported that sockeye salmon spawn along a half-mile side channel

of the North Fork Nooksack River about 3.5 miles above the town of Glacier and below

Lookout Creek (RKm 100.5). Small numbers of spawners are still seen each year in the North

and South Forks of the Nooksack and in Maple Creek (D. Hendrick43). As summarized in

Appendix Table C-7, WDFW Salmon Spawning Ground Survey Data (Egan 1977, 1995,

1997) indicated several locations, dates, and peak numbers of spawning sockeye salmon in the

Nooksack River.

Sockeye salmon are caught in the Nooksack River as by-catch in the Nooksack Tribal

coho harvest during the months of September through October. This freshwater fishery

occurs from the confluence of the North and South Forks of the Nooksack River, downstream

to the mouth (D. Grieggs44). Recent tribal harvest has ranged from 15 in 1992 to 386 in 1991

(Hoines 1995). Run-timing of sockeye salmon caught in the Nooksack Tribal fishery is

significantly later than either Baker River or Lake Washington sockeye salmon stocks, which

terminate by mid-August, but Nooksack River sockeye salmon run-timing does overlap the

timing of several lower Fraser River stocks (see Appendix Tables C-6 and C-7).

Several anecdotal reports indicated that early hatchery supplementation of sockeye

salmon occurred at the Nooksack Hatchery on Kendall Creek (Pacific Fisherman 1905a), and

that introductions into the Nooksack River of a small number of out-of-basin sockeye salmon

fry also occurred (Pacific Fisherman 1905b, 1906).

Samish River—WDFW Salmon Spawning Ground Survey Data (Egan 1977, 1995, 1997)

indicated several locations, dates, and peak numbers of spawning sockeye salmon in the

Samish River (see Appendix Table C-7). Anecdotal records indicated that extensive culture

of sockeye salmon, taken in fish traps in Puget Sound, occurred at the Samish State Hatchery

at least in the years 1915-1917 (Pacific Fisherman 1915a, 1915b, 1916, 1918). WDFG

(1916a, 1917, 1920) recorded the release into Lake Samish and Cain Lake of almost 9 million

sockeye salmon fry between 1915 and 1918. They reported that the fish released were

43 D. Hendrick, Washington Department of Fish and Wildlife, 333 E. Blackburn Rd., Mount

Vernon, WA 98273. Pers. commun., 8 August 1995.

44 D. Grieggs, Nooksack Tribal Fisheries Department, Deming, WA. Pers. commun., June

1995.
84

derived from sockeye salmon captured on the west side of Lummi Island (off Bellingham

Bay) (see Appendix Table D-2). In 1920, over 165 sockeye salmon spawned naturally above

the Samish Hatchery racks (WDFG 1921b).

Between 1934 and 1937, over 0.5 million sockeye salmon fry from the Birdsview

Hatchery on Grandy Creek were released in Lake Samish (Royal and Seymour 1940,

Kemmerich 1945) (see Appendix Table E-2). Several sockeye salmon were observed in 1937

and 1938 at the Samish State Hatchery and in the Samish River (Kemmerich 1945). An

estimated 300-400 sockeye salmon returned to the Samish Hatchery in the fall of 1940 (Royal

and Seymour 1940, Kemmerich 1945).

Skagit River Basin—In reference to riverine-spawning sockeye salmon in the glacially

influenced Skagit River Basin, WDF et al. (1993) stated

They are consistently found in very small numbers in the upper Sauk River and the

mainstem Skagit near Newhalem. Whether these represent strays from the Baker or

other river systems or are small self-sustaining populations of a few individuals is

unknown.

WDFW Salmon Spawning Ground Survey Data (Egan 1977, 1995, 1997) indicated several

locations, dates, and peak numbers of spawning sockeye salmon in the Skagit River Basin

(see Appendix Table C-7). Juvenile sockeye salmon displaying parr marks have been

observed in the mainstem Skagit River near the town of Lyman (D. Hendrick45).

In the 1930s, extensive sockeye salmon transplants were made from Birdsview

Hatchery into the following Skagit River tributaries: Day Creek, Illabot Creek, Bacon Creek,

and Diobsud Creek, as well as Lake McMurray, McMurray Creek, Big Lake, and Clear Lake

on Nookachamps Creek (Kemmerich 1945) (see Appendix Table D-2). No returns were

noted from these plantings to Nookachamps Creek, Illabot Creek, or Day Creek. About 300

sockeye salmon were seen in Bacon Creek in 1936, and 20 and 6 in Diobsud Creek in 1936

and 1937, respectively.

Stillaguamish River—WDFW Salmon Spawning Ground Survey Data (Egan 1977, 1995,

1997) indicated several locations, dates, and peak numbers of spawning sockeye salmon in the

Stillaguamish River (see Appendix Table C-7). Between 1929 and 1937, 322,175 juvenile

sockeye salmon were released into Lake Cavanaugh and Pilchuck Creek (see Appendix Table

D-2). In the fall of 1935, 1936, 1937, and 1938, returning sockeye salmon adults counted at

the base of the falls on Pilchuck Creek amounted to 40, 3,000-4,000, 1,000-2,000, and 200-

300, respectively (Kemmerich 1945). Recent tribal freshwater harvest information recorded

45 D. Hendrick, Washington Department of Fish and Wildlife, 333 E. Blackburn Rd., Mount

Vernon, WA 98273. Pers. commun., 8 August 1995.
85

186 sockeye salmon taken in 1989 on the Stillaguamish River, but none in other years

(Hoines 1995).

Duwamish River/Green River—WDFW Salmon Spawning Ground Survey Data (Egan

1977, 1995, 1997) indicated several locations, dates, and peak numbers of spawning sockeye

salmon in the Green River (see Appendix Table C-7). Sockeye salmon have been observed

spawning below Howard Hanson Dam on the Green River (E. Warner46). Recent tribal

freshwater harvest of sockeye salmon in the Duwamish-Green River Basin has ranged from 0

in 1987 to 278 in 1984 (Hoines 1995). At least 392,050 sockeye salmon fry derived from

Green River, Quinault Lake, and unspecified Alaska stocks were released into the Green

River from the Green River State Hatchery between 1925 and 1931 (WDFG 1928, 1930,

1932) (see Appendix Table D-2).

Puyallup River—Anadromous fish trapped at the base of Mud Mountain Dam on the White

River, a tributary of the Puyallup River in Puget Sound, are trucked around the dam and

placed in the White River above Mud Mountain Dam. Small numbers of sockeye salmon

have been reported in the yearly Mud Mountain Fish Haul Reports beginning in 1983, when

19 adult sockeye salmon were counted over the dam. Since 1985, when 378 sockeye salmon

were counted at Mud Mountain Dam, small numbers ranging from 5 to 114 have been

counted each year at this facility (MMDFHR 1996). Mud Mountain Reservoir is a run-of-theriver flood-control reservoir, and as such does not provide lake-rearing conditions for sockeye

salmon. Information on possible spawning locations for sockeye salmon released above Mud

Mountain Dam was not located.

Nisqually River—WDFW Salmon Spawning Ground Survey Data (Egan 1977, 1995, 1997)

indicated that 19 sockeye salmon and 6 sockeye salmon redds were observed in August 1966

at river kilometer 20 on the Nisqually River (see Appendix Table C-7). In addition a few

sockeye salmon have been reported in Mashel River and Ohop Creek, although none have

been reported in Nisqually River surveys since 1982. A very few sockeye salmon are

reported in the tribal freshwater harvest statistics for the Nisqually River (Hoines 1995).

Lewis River—According to WDFW (1996),

Anadromous size sockeye are occasionally observed in the North Fork Lewis River

downstream of Merwin Dam.

Hamilton and Rothfus (1963) reported that 890,000 sockeye salmon fry were released in Lake

Merwin in 1961 and that over 3,000 sockeye salmon smolt were counted in a downstream

migrant trap in spring 1962. Appendix Table D-2 also shows that large numbers of sockeye

salmon fry (over 900,000) were released in the Lewis River in 1961, and an additional 38,000

46 E. Warner, Muckleshoot Indian Tribe, 39015 172nd Ave. SE, Auburn, WA 98002. Pers.

commun., 14 June 1995.
86

fry were released in a tributary of Lake Merwin in 1965. Returns of sockeye salmon to the

Lewis River below Lake Merwin reported in WDFW (1996) may represent a remnant of these

transplants.

Dungeness River—Brannon (1996) reported that sockeye salmon have been observed

coming back to the same spawning ground on the Dungeness River and that “their timing was

earlier than other sockeye in Washington, suggesting they were not strays.” WDFW Salmon

Spawning Ground Survey Data (Egan 1977, 1995, 1997) indicated that 1-5 sockeye salmon

are observed in the Dungeness River during the months of August-September in most survey

years (see Appendix Table C-7).

Quillayute River/Calawah River—WDF (1973) reported that the Calawah and Bogachiel

Rivers supported “a small run of sockeye salmon that must rear in the stream.” Phinney and

Bucknell (1975) reported that a small number of “river-race” sockeye salmon spawn in the

lower reaches of the North Fork and South Fork Calawah Rivers as well as in several small

tributaries. During the 1960s, 3 to 6 sockeye salmon were reportedly seen every year in the

same place during July to August on the South Fork Calawah River near Hyas Creek (J.

Ayerst47). Houston (1983, 1984) suggested that the Quillayute River may have a “river

dwelling” population of sockeye salmon “of fewer than 10 fish per year average.”

Hoh River—Wendler and Deschamps (1955) reported that small numbers of sockeye salmon

are taken in the Hoh River in June and July. Houston (1983, 1984) suggested that the Hoh

River may have a “river dwelling” population of sockeye salmon “of fewer than 10 fish per

year average.” Up to 50 sockeye salmon were observed schooling around RKm 47.5 on the

Hoh River in mid-September 1985, and sockeye salmon were also observed around

RKm 45.8 in 1994 and 1995 (J. Haymes48). The Hoh River receives a large glacial melt-water

input and is milky in the summer, making fish identification difficult. Other indications are

that a self-sustaining spawning population of sockeye salmon does not occur in the Hoh River

(J. Jorgensen49). Recent tribal freshwater harvest of sockeye salmon in the Hoh River has

ranged from 0 in 1991 to 26 in 1992 (Hoines 1995).

Queets River/Clearwater River—In some years a large tribal fishery catch of sockeye

salmon occurred in the Queets River (Wendler and Deschamps 1955, Brix and Kolb 1971).

Wendler and Deschamps (1955), citing the fact that there are few, if any, accessible lakes in

the Queets River system, suggested that “sockeye salmon caught in the Queets River are

47 J. Ayerst, Olympic National Forest, 1835 Black Lake Blvd. SW, Olympia, WA 98502.

Pers. commun., 27 June 1995.

48 J. Haymes, Quileute Natural Resources, Quiuleute Indian Tribe, P.O. Box 187, La Push,

WA 98350-0187. Pers. commun., 1 June 1995.

49 J. Jorgenson, Hoh Tribe, 2464 Lower Hoh Road, Forks, WA 98331. Pers. commun., 14

February 1995.
87

probably strays from the nearby Quinault River.” Wendler and Deschamps (1955) also stated

that

In general, when the Quinault River has a good run of sockeyes, many are caught in

the Queets. Also, the converse is true.

Dipping-in of Quinault Lake sockeye salmon into the Queets River most likely explains the

bulk of the large sockeye salmon catch in the Queets River (Wendler and Deschamps 1955, S.

A. Chitwood and D. Boyer, Jr.50).

Houston (1983, 1984) suggested that the Queets River may have a “river dwelling”

population of sockeye salmon “of fewer than 100 fish per year average.” Brown (1982,

p. 30) observed mature sockeye salmon in Paradise Creek on the Queets River. WDF (1973)

stated that “limited numbers of sockeye reportedly spawn in the Clearwater River” and

Phinney and Bucknell (1975) stated that “sockeye salmon reportedly spawn in the mainstem

of the Clearwater River and several tributary streams.” The Clearwater River is a tributary of

the Queets River. Analysis of over 300 Queets River sockeye salmon scales collected

between 1975 and 1993 has revealed only one sea-type sockeye salmon in the Queets River

fishery (QIN 1995a), however, river-type sockeye salmon (that do not outmigrate as

underyearlings) cannot be differentiated by scale age from lake-type sockeye salmon (see

“Life History of O. nerka” section). The Queets River receives a large glacial melt-water

input from the Olympic Mountains. Both Edie (1975) and Cedarholm et al. (1978) stated that

the Clearwater River, a tributary of the Queets River, had small populations of sockeye

salmon.

British Columbia

A total of 917 anadromous sockeye salmon stocks have been identified in British

Columbia (Slaney et al. 1996). Major sockeye salmon stocks on Vancouver Island are as

follows: 1) Cheewhat Lake; 2) Hobiton River/Hobiton Lake; 3) Henderson Lake; 4) Sproat

Lake and Great Central Lake in the Somass River Basin; 5) Kennedy Lake, Upper Kennedy

River, Clayoquot River, Cold Creek, and Muriel Lake in the Kennedy River System; 6)

Mahatta River/O’Connell Lake in Quatsino Sound; and 7) Woss Lake, Nimpkish Lake, and

Vernon Lake in the Nimpkish River Basin (Aro and Shepard 1967).

Major sockeye salmon stocks in the Queen Charlotte Islands are these: 1)Mathers

Lake, 2) Copper Creek/Skidegate Lake, 3) Yakoun Lake, 4) Mercer Creek/Mercer Lake, 5)

Awun Lake, 6) Ian Lake, and 7) Naden River/Eden Lake. Major coastal sockeye salmon

stocks in central to south mainland British Columbia include: 1) Sakinaw Lake, 2) Heydon

Lake, 3) Phillips River, 4) Mackenzie Lake, 5) Klinaklini River, 6) Kakweiken River,

50 S.A. Chitwood and D. Boyer Jr., Quinault Fisheries Division, P.O. Box 189, Taholah, WA

98587. Pers. commun., June 1995.
88

7) Long Lake/Smokehouse Creek, 8) Rivers Inlet/Owikeno Lake, 9) Koeye Lake, 10) Atnarko

River/Tenas Lake, 11) Tankeeah Lake, 12) Kimsquit Lake, and 13) Port John Lake. Major

coastal sockeye salmon stocks in north mainland British Columbia are as follows: 1) Kitlope

Lake, 2) Canoona Lake, 3) Banks Lake, 4) Mikado Lake, 5) Devon Lake, 6) Lowe Lake, 7)

Curtis Lake, and 8) Bonilla Lake (Aro and Shepard 1967).

The following are major sockeye salmon stocks in the Fraser River: 1) Cultus Lake,

2) Upper Pitt River/Pitt Lake, 3) Weaver Creek/Harrison Lake, 4) Harrison River Rapids

(river/sea-type), 5) Birkenhead River/Lillooet Lake, 6) Seymour Creek/Shuswap Lake, 7)

Scotch Creek/Shuswap Lake, 8) Lower Adams River/Shuswap Lake, 9) Lower Shuswap

River/Shuswap Lake, 10) Gates Creek, 11) Raft River, 12) Fennel Creek, 13) Chilko Lake,

14) Taseko River, 15) Horsefly River, 16) Mitchell River, 17) Nadina River/François Lake,

18) Stellako River/Fraser Lake, 19) early Stuart (= Takla Lake/Trembleur Lake/Stuart Lake),

20) late Stuart = Trembleur Lake/Stuart Lake, and 21) Bowron River (Aro and Shepard 1967).

Lake-type sockeye salmon in British Columbia inhabit nursery lakes that can be

categorized as either coastal or interior, and as clear, humic-stained, or glacial. Coastal lakes

are thermally stratified in summer and become continuously mixed in winter following

turnover (monomictic); they experience cool, wet winters and warm, dry summers on the

south coast and wetter, colder summers on the north coast. Interior lakes have episodes of

mixing, before and after ice formation, and become thermally stratified in both summer and

winter (dimictic). However, these lakes experience a more typically continental climate on

the leeward side of the Coastal Mountains.

Coastal lakes experience peak flow and nutrient input in winter, when sunlight and

temperatures are low, a pattern leading to low nutrient concentrations and low productivity.

These lakes are generally classified as oligotrophic. Interior lakes, such as those upstream

from Hell’s Gate on the Fraser River, experience maximum water and nutrient input in spring

when light intensity and water temperatures are increasing. These lakes consequently have

higher nutrient and productivity levels, and are classified as oligo-mesotrophic (Stockner

1987).

Many coastal lakes in central British Columbia are humic-stained and smaller than

clear, larger lakes on the south mainland coast and Vancouver Island. Humic substances

reduce light penetration and diminish the depth of the euphotic zone (Stockner 1987). Glacial

lakes include both coastal and interior types, and their high turbidity is imparted by suspended

silts and clays (glacial flour) carried down by tributaries during summer glacial-melt.

Glacial lakes produce some of the smallest 1-year-old sockeye salmon smolts recorded

(Goodlad et al. 1974, Hyatt and Stockner 1985). Generally sockeye salmon smolts leaving

interior lakes of British Columbia as yearlings are larger than similar age smolts from coastal

systems. This may be due to the greater rearing area of interior lakes or to the higher

productivity of interior lakes (Foerster 1968, Hyatt and Stockner 1985).
89

Genetics

Previous Genetic Studies

Early studies of sockeye salmon population genetics examined variation at two highly

polymorphic loci coding the enzymes lactate dehyrogenase (Hodgins et al. 1969, Withler

1985) and phosphoglucomutase (Utter and Hodgins 1970) or both (Altukhov et al. 1975,

1983; Kirpichnikov and Ivanova 1977; Varnavskaya 1984; Varnavskaya et al. 1988).

Subsequent studies have gradually incorporated additional polymorphic loci (currently up to

about 48 loci) into their analyses of sockeye salmon population structure (Seeb and Wishard

1977; Grant et al. 1980; Altukhov and Varnavskaya 1983; Utter et al. 1984; Wilmot and

Burger 1985; Quinn et al. 1987; Wood et al. 1987b, 1988, 1994; Foote et al. 1988;

Kirpichnikov et al. 1990; Rutherford et al. 1992, 1994; Guthrie et al. 1994; Varnavskaya et al.

1994a,b; Wood 1995; Hendry et al. 1996, Winans et al. 1996). Some of these studies

analyzed allozymic variation among sockeye salmon populations or subpopulations from

geographically limited regions in Kamchatka (Altukhov et al. 1975, 1983; Kirpichnikov and

Ivanova 1977; Altukhov and Varnavskaya 1983; Varnavskaya et al. 1988, 1994b;

Kirpichnikov et al. 1990), Alaska (Grant et al. 1980, Wilmot and Burger 1985, Varnavskaya

et al. 1994b), British Columbia (Wood et al 1987b; Rutherford et al. 1992, 1994; Varnavskaya

et al. 1994b), and Washington (Seeb and Wishard 1977, Hendry 1995, Hendry et al. 1996).

Additional studies have taken a broader approach, comparing allozymic variation in selected

sockeye salmon populations from North America (Withler 1985), Kamchatka (Varnavskaya

1984), or from throughout the range of sockeye salmon (Hodgins et al. 1969, Utter and

Hodgins 1970). However, these studies relied on variation in only one or two polymorphic

loci and thus provided little resolution of population differences.

Utter et al. (1984) surveyed allozymic variation in 16 collections from southeast

Alaska through the Columbia River Basin, including Quinault, Okanogan, and Wenatchee

stocks, at 12 polymorphic loci and found a moderate degree of population structuring,

significant genetic distance between Quinault River and all other samples, and an apparent

genetic association between upper Fraser River and Columbia River sockeye salmon. Guthrie

et al. (1994) surveyed sockeye salmon allozymic variation at 28 variable loci in populations

from southeast Alaska and northern British Columbia and found substantial genetic

divergence among populations, with an underlying geographic structure. Although there were

several exceptions, sockeye salmon populations in this region generally fell into 3 main

geographic clusters: 1) northern mainland, 2) the southern mainland and inside waters, and 3)

the southern and central islands (Guthrie et al. 1994).

Wood et al. (1994) surveyed genetic variation at 33 allozyme loci in O. nerka from 83

sample sites throughout British Columbia. A hierarchical gene diversity analysis of sockeye

salmon in eight river systems (Fraser, Nass, Skeena, etc.) was conducted using the eight most

polymorphic loci. This procedure determines the relative contribution of different

components to the overall gene diversity (Chakraborty 1980). Wood et al. (1994) found that

variability was partitioned as follows:
90

Among river systems: 6.3%

among drainages within rivers: 2.9%

among lakes within drainages: 7.0%

among sites within lakes: 1.0%

within sites: 82.8%

Wood et al. (1994) concluded that most of the genetic variation occurred within spawning

sites, and the most important level of differentiation among samples was the nursery lake.

Variation among river systems that spanned the north-south breadth of British Columbia

accounted for only 6.3% of the variation. A neighbor-joining tree of Cavalli-Sforza and

Edwards chord distances based on six polymorphic loci revealed three large groups of

populations: southern rivers, northern rivers, and Skeena River/coastal populations. The

pattern of genetic similarity among populations within these groups was not strongly

geographic. Wood et al. (1994) reported that a “mosaic” pattern of variation was also

apparent in an “unweighted pair group method with arithmetic averages” (UPGMA) (Sneath

and Sokal 1973) dendrogram based on Nei’s unbiased genetic distance (Nei 1978). A

principal component analysis (PCA) also showed considerable overlap among regional groups

of rivers. The most distinctive group was the southern rivers, consisting of samples from the

upper Fraser River, the Thompson River, and the Columbia River (from the Okanogan River

Basin). Wood et al. (1994, p. 124) concluded that “geographic structuring was far from

perfect, and two populations in widely separated river systems sometimes resembled one

another genetically more than they resembled populations in their respective watersheds.”

In his most recent work, Wood (1995) concluded that on a time scale of human

generations, the best way to conserve genetic diversity in sockeye salmon was to preserve

populations in as many different lake systems as possible. From a long-term, evolutionary

perspective (> 10,000 yr), he felt it was prudent to save the genetically-diverse, large

populations of river/sea-type sockeye salmon (present today in glacially-influenced habitats)

that are adapted to a wide range of habitats and conditions and which might provide a source

for colonization in favorable interglacial periods.

In a genetic survey of O. nerka in the Pacific Northwest, Winans et al. (1996)

surveyed variation at 55 loci in 27 samples of sockeye salmon and kokanee from a total of 21

sites in Washington, Idaho, and British Columbia. They reported that sockeye salmon have

the lowest level of allozyme variability of any species of Pacific salmon and a high level of

interpopulation differentiation at a relatively few polymorphic loci. Using PCA and

clustering of Nei’s genetic distance (Nei 1978) to study geographic variation, they reported

first that there was no clear geographic pattern of differentiation among the populations of

sockeye salmon in the area studied, and second that four genetic clusters of kokanee

populations can be identified: 1) a Stanley Basin group including Redfish Lake and Alturas

Lake, 2) a late-summer spawning group (from several lakes and reservoirs in central Idaho),

3) a late-fall spawning group (from Lake Whatcom and northern Idaho stocks), and 4) an

Okanagan Lake-Shuswap River group.
91

Chapman et al. (1995) reported data for one additional sockeye salmon sample in the

Columbia River Basin. They showed that 14 sockeye salmon collected in the Methow River

(situated in the Columbia River Basin between the Wenatchee and Okanogan River systems)

were genetically more similar at four loci to two White River samples (from the Wenatchee

River basin) than to Okanogan River samples. In contrast, Utter (1995) reported that based on

sockeye salmon samples collected in 1994 and analyzed for six polymorphic protein-coding

(allozyme) loci and three nuclear DNA microsatellite loci, Wenatchee, Methow, and

Okanogan (Wells Dam) River samples were not genetically distinct. Utter (1995) proposed

that annual genetic monitoring of Okanogan River sockeye salmon and additional sampling of

Methow River sockeye salmon be undertaken to determine the cause of apparent temporal

fluctuations in allele frequencies in the Okanogan River population.

The lack of a discernible geographic pattern found by Winans et al. (1996) matches

similar studies of sockeye salmon populations in British Columbia, Alaska, and Kamchatka

(Varnavskaya et al. 1994a, Wood et al. 1994, Wood 1995). These studies generally indicate

that the nearest geographic neighbors of sockeye salmon populations are not necessarily the

most genetically similar. Whereas other species of Pacific salmon such as chinook, chum,

and pink salmon exhibit clear regional patterns of geographic differentiation (Utter et al. 1989,

Winans et al. 1994, Shaklee et al. 1991), geographic variability in sockeye salmon generally

resembles a mosaic of genetically distinct populations, at least in the studied portions of the

species’ distribution. The disjunct nature of differentiation among populations of O. nerka

may reflect the discontinuous nature of the habitat, the precise degree of homing to natal

streams and lakes (perhaps due to the requirement for nursery lake habitat), and the

concomitant decrease in gene flow among neighboring populations.

In a study of the structure and origins of sockeye salmon populations in Lake

Washington, Seeb and Wishard (1977) detected identical allele frequencies at five loci for

Baker Lake and Cedar River sockeye salmon, indicating that Cedar River sockeye salmon

were primarily descended from Baker Lake stock. Seeb and Wishard (1977) stated that Big

Bear Creek and Lake Washington beach-spawning sockeye salmon were genetically distinct

from potential donor stocks and that these stocks represent remnant native anadromous

sockeye salmon populations. However, Hendry (1995) and Hendry et al. (1996) could not

detect statistically significant allelic differences at seven polymorphic loci between Lake

Washington beach spawning and Cedar River sockeye salmon. Hendry (1995) and Hendry et

al. (1996) identified two genetically distinct sockeye salmon groups in the Lake Washington

Basin: 1) Cedar River, Lake Washington beach spawners, and Issaquah Creek, which showed

genetic affinity with Baker Lake sockeye salmon and 2) Big Bear and Cottage Lake Creeks,

which showed genetic distinctiveness from other stocks in the basin and from potential donor

stocks. Hendry et al. (1996) inferred from these genetic affinities that the first group of

sockeye salmon was of Baker Lake lineage and the second group was predominately of native

ancestry.

Hershberger et al. (1982) surveyed genetic variation at 37 allozyme loci (only 2 of

which were polymorphic) in sockeye salmon from Ozette Lake, Washington. Hershberger et
92

al. (1982) reported that phenotype frequencies of one variable loci, PGM-1*, suggested that

two groups (or populations) of sockeye salmon may be present in Ozette Lake, separated by a

difference in run-timing.

Several population surveys of DNA-level variation in O. nerka have been completed.

Bickham et al. (1995) examined nucleotide sequence variation of the mtDNA cytochrome b

gene in four sockeye salmon populations ranging from Kuril Lake in Kamchatka to Lower

Shuswap River in the Fraser River. Three haplotypes were identified. The most common

haplotype was found in all populations (in 58% of all individuals); the second most common

haplotype was found in all samples (30% of all individuals) except the Fraser River samples.

The third haplotype was found in the Skeena River system (at 10%) and the Fraser River (at

40%). Haplotypic frequencies in the Fraser River samples were significantly different from

those in the three other samples. The Skeena River sample was also different from the

Iliamna Lake samples. Despite this statistical heterogeneity, Bickham et al. (1995) concluded

that the three northern samples and the Fraser River samples represent two biogeographic

groups post-glacially derived from separate refugia (Beringia and Columbia River). They

discussed the evidence for the presence of a generalized north-south phylogeographic break

for anadromous fish on the west coast of North America.

Beacham et al. (1995) reported levels of variation in nuclear DNA of O. nerka using

minisatellite probes. They used seven of the eight samples used by Bickham et al. (1995)

(Pierre Creek, Skeena River was excluded) and two west coast Vancouver Island samples, as

well as samples from Lake Wenatchee in the Columbia River Basin. Genomic DNA was

digested with one of two restriction enzymes and probed with one of three repeat-sequence

probes. Bands were scored for four restriction enzyme/probe marker combinations; three of

these appeared to reflect single locus variation. Electrophoretic bands were pooled or binned

into size classes for statistical analyses. They interpreted their results as did Bickham et al.

(1995)—i.e., the Kamchatka and Iliamna Lake samples were different from the other samples.

Other interpretations are also possible. In the cluster analysis, the Lake Wenatchee sample

was different from all the other southern samples which, considered together, were different

from both the Alaskan samples and Kamchatka samples. However, these latter two samples

were also dissimilar from one another. Similarly, along the first two PC axes, the southern

samples were different from the two northern groups (Kamchatka and Iliamna). Because only

51% of the variance was explained along PC1 and PC2, relationships may be distorted (viz.

Lake Wenatchee) and an examination of PC3 might prove useful.

Thorgaard et al. (1995) examined the use of multilocus DNA fingerprinting to

discriminate among 14 sockeye salmon and kokanee populations. DNA extracts were pooled

among individuals within the populations. Five oligonucleotide probes were used to visualize

bands following digestion with a restriction enzyme and electrophoresis. Electrophoretic

bands were grouped by size classes, and each band class was scored as present or absent in

each population. Dendrograms based on analysis of banding patterns for four of the five

probes produced a concordant pattern of relationships. An analysis of all data produced a tree

with a grouping of Redfish Lake, Wenatchee, and Okanogan O. nerka that was separate from
93

kokanee of Oregon and Idaho and a sockeye salmon sample from the mid-Fraser River. Trees

of relationship based on three of the five DNA probes showed a clustering of kokanee and

sockeye salmon from Redfish Lake (the other two probes grouped Redfish Lake sockeye

salmon with either Okanogan River or Lake Wenatchee sockeye salmon), while four of the

five probes placed sockeye salmon from Okanogan River together with kokanee from a

tributary of Okanagan Lake, British Columbia. None of the five DNA probes showed a close

relationship between Lake Wenatchee and Okanogan River sockeye salmon. A portion of the

data from the above study were presented in Brannon et al. (1994).

New Data

As part of the comprehensive status review of west coast sockeye salmon, NMFS

biologists collected new allozyme genetic information for 17 sockeye salmon populations and

1 kokanee population in Washington and combined them with the existing Pacific Northwest

sockeye salmon and kokanee data for analyses. Collection locations, dates, life stage

sampled, and sample sizes are summarized in Table 3. We included samples from the Babine

River in northern British Columbia (sockeye salmon) and Ozette Lake (kokanee) that were

distinctive among their respective life history types (Winans et al. 1996). We examined

allelic frequencies for 29 variable loci: ADA-1*, ADA-2*, mAH-1,2* (treated as one locus),

mAH-3*, sAH*, mAH-4*, mAAT-1*, ALAT*, CK-B*, FH*, PEPA*, PEPC*, mIDHP-1*,

mIDHP-2*, sIDHP-1*, sIDHP-2*, LDH-A1* (used observed phenotypic frequencies of an

alternate homozygote *86/*86 because *86/*100 was not distinguishable from *100/*100),

LDH-B1*, LDH-B2*, LDH-C*, sMDH-A1,2* (treated as one locus), sMDH-B1,2* (treated as

one locus), MPI*, PGDH*, PGM-1* (used observed phenotypic frequencies of null allele),

PGM-2*, sSOD-1*, TPI-4*, and TPI-3*. Genetic relationships among samples were

examined in two ways: with ordination techniques of genetic distance statistics and with

Principal Component Analyses (PCA). Nei’s unbiased genetic distances (Nei 1978) and

Cavalli-Sforza and Edwards chord values (Cavalli-Sforza and Edwards 1967) among the 32

samples were calculated from the 29 variable loci using the computer program BIOSYS

(Swofford and Selander 1981). The distance values were illustrated in UPGMA dendrograms

(1-dimensional ordination technique) and multidimensional scaling analyses (2-dimensional

ordination techniques) using the computer program NTSYS (Rohlf 1993). A minimumlength spanning tree (MST) was superimposed on the 2-dimensional plots. A PCA was

performed using NTSYS (Rohlf 1993) with a correlation matrix for a subset of loci with

frequencies of less-common alleles greater than 0.05. Our experience is that less frequent

alleles do not contribute substantially to discrimination among samples in a PCA (Winans et

al. 1994).

The results from both distance measures (Figs. 5-8) were similar. On a broad

geographic scale, both Nei’s (Figs. 5-6) and Cavalli-Sforza and Edwards’ (Figs. 7-8) genetic

distances indicate that: 1) samples of sockeye salmon from Lake Wenatchee, Redfish Lake,

Ozette Lake, and Lake Pleasant are very distinct from other samples; 2) Lake WashingtonCedar River samples are distinct from a Big Bear Creek-Cottage Lake Creek association;

3) riverine-spawning sockeye salmon from the Nooksack, Skagit, and Sauk Rivers (n = 66)

cluster together and have an affinity with Babine Lake and Ozette Lake sockeye salmon;
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4) Baker River sockeye salmon are associated with a Lake Washington-Cedar River group, to

which Quinault Lake is most similar; and 5) Babine Lake sockeye salmon and Ozette Lake

kokanee are particularly distinctive. The Cavalli-Sforza and Edwards metric showed an

affinity between Okanogan River sockeye salmon and Lower Shuswap River sockeye salmon,

although several allele frequencies in the two samples were statistically different from each

other (Winans et al. 1996). Although not indicated by Cavalli-Sforza and Edwards genetic

distance (which does not adjust for different sample sizes, such as the small sample size for

river-spawners), Nei’s genetic distance indicated that riverine-spawning sockeye salmon from

the Nooksack, Skagit, and Sauk Rivers have a genetic affinity with Big Bear Creek-Cottage

Lake Creek sockeye salmon.

Results of the PCA generally paralleled the genetic distance analyses (Fig. 9). For

example, in PC1-PC2 space, Lake Wenatchee, Lake Pleasant, Babine Lake, Big Bear CreekCottage Lake Creek sockeye salmon, and Ozette Lake kokanee were distinct from one another

(Fig. 9A); along the PC1-PC3 axes, Redfish Lake and Quinault Lake sockeye salmon were

distinctive (Fig. 9B). Riverine-spawning sockeye salmon from the Nooksack, Skagit, and

Sauk Rivers were most closely related genetically to the Babine Lake sample.

Neither the ordination of genetic distances nor the PC analysis revealed a clear

geographic pattern of genetic relationships for the sockeye salmon populations studied. For

example, sockeye salmon from the Columbia River Basin (Lake Wenatchee, Okanogan River,

and Redfish Lake) did not form a coherent genetic group. Likewise the three coastal

populations of sockeye salmon in Washington (Ozette Lake, Lake Pleasant, and Quinault

Lake) that are geographically closest, were not very similar to each other genetically.

We examined between-year variability in two locales. We found significant temporal

variation in the five Lake Wenatchee samples. The log likelihood ratio statistic (G-test)

(Sokal and Rohlf 1981) was used to compare allele frequencies of samples taken in different

years in the same locale. G-tests were performed for each polymorphic locus, and the results

were summed over all loci for an overall G-value and a standardized G-value. Low levels of

statistical significance appeared among the 5 Lake Wenatchee samples: of 10 pair-wise

comparisons using sum-G tests, 5 were statistically significant. Lake Wenatchee broodyear

1987 accounted for three of the significant comparisons; it had unusually high frequencies of

ALAT*95 and ALAT*108 (Winans et al. 1996). On the other hand, there was no significant

temporal variability in three samples from Big Bear Creek (P = 0.27) over 12 loci. In other

species of Pacific salmon, temporal variation is usually a minor component of overall genetic

variability (e.g., chum salmon (Winans et al. 1994) and pink salmon (Shaklee et al. 1991)).

We conclude that, in general, temporal variation at a locale was considerably less than

between-locale variation.

Substantial differences were seen among the four Ozette Lake samples of sockeye

salmon. Only one of six pair-wise comparisons among the four samples was statistically

nonsignificant. The two main remaining spawning beaches in Ozette Lake (at Allen’s Bay

and Olsen’s Beach) are on opposite sides of the south end of Ozette Lake, separated by
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approximately 3.2 km. The 1995 sample of sockeye salmon from Allen’s Bay (adults,

n = 33) was statistically different at seven loci from the 1995 Olsen’s Beach sample (adults, n

= 50). Although precise records concerning the origins of the 1994 sockeye salmon collection

from Ozette Lake (adults, n = 80) were not kept, this sample clustered with the Olsen’s Beach

1995 sample and differed at seven loci from the 1995 Allen’s Bay sample. Dlugokenski et al.

(1981) suggested within-lake population subdivision may be present in Ozette Lake based on

observed differences in peak spawning times between Allen’s Bay and Olsen’s Beach

spawning aggregates. Additional samples of sockeye salmon from Ozette Lake are currently

being pursued. The two samples of kokanee from the Ozette Lake Basin were not statistically

different from one another (P = 0.10), but they were divergent from all other O. nerka in each

analysis (Figs. 5-8).

We combined available data with information for British Columbia stocks to gain a

broader perspective of sockeye salmon variability in the Pacific Northwest. Analyses of Nei’s

unbiased and Cavalli-Sforza and Edwards chord distances based on nine loci revealed

clustering patterns among the British Columbia samples (Figs. 10-13). Sockeye salmon from

Vancouver Island, the Lower Fraser River, and the Babine River system formed distinctive

groups and were associated together. Riverine-spawning sockeye salmon from the Nooksack,

Skagit, and Sauk Rivers were similar to one sockeye salmon collection from Babine Lake, and

Ozette Lake kokanee clustered with one of the Vancouver Island sockeye salmon groups.

Several clusters of upper Fraser River sockeye salmon were recognized. However, Thompson

River sockeye salmon did not associate closely with one another. Both Nei’s unbiased and

Cavalli-Sforza and Edwards chord distances revealed that Washington coastal sockeye salmon

(Ozette Lake, Lake Pleasant, and Quinault Lake), and Lake Wenatchee, Okanogan Lake, and

Redfish Lake sockeye salmon were associated with one of several sockeye salmon clusters of

the upper Fraser River (with the exception of Lake Ozette, which was associated with Big

Bear Creek samples according to Nei’s unbiased genetic distance).

Artificial Propagation

Artificial propagation of sockeye salmon has been conducted since before 1900

throughout the Pacific Rim. Efforts at sockeye salmon supplementation in Asia began as a

small-scale operation in the 1870s on Hokkaido Island using local stocks, probably kokanee,

and then later using sockeye salmon eggs from Alaska (Moberly and Lium 1977). Recent

releases of O. nerka (sockeye salmon and kokanee) have continued to be a minor part of

overall Pacific salmon artificial propagation efforts in Japan (Kobayashi 1980).

The first salmon hatcheries in the Republic of Korea were not built until the 1960s,

and chum salmon were the principal species reared (Atkinson 1976). In Russia, experimental

sockeye salmon hatcheries were constructed around 1910 on the Kamchatka Peninsula, and

large-scale sockeye salmon fish-rearing facilities were constructed in 1928, also in Kamchatka

(Konovalov 1980). The number of sockeye salmon released from Russian hatcheries is small

compared to the numbers of artificially reared pink and chum salmon (Roukhlov 1982, Knapp

and Johnson 1995). There are hatcheries on the Kamchatka Peninsula producing sockeye
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salmon (Knapp and Johnson 1995), and Folsom et al. (1992) stated that about 80% of

Russia’s total hatchery production of sockeye salmon occurs on the Kamchatka Peninsula.

Long-term plans formulated by Russian authorities in the 1970s called for the annual release

of approximately 80 million juvenile sockeye salmon by the year 2000 (Konovalov 1980).

However, Knapp and Johnson (1995) reported that in 1993, approximately 1,880,000 and

500,000 sockeye salmon were released from “enhanced production” and “fed fry only”

programs, respectively, in the Russian Far East (Kamchatka and Magadan Provinces).

Because sockeye salmon have always been an extremely valuable commercial species

in Alaska, artificial propagation of sockeye salmon was initiated there before the turn of the

century (Roppel 1982). During this period, two federal hatcheries were the most important

sockeye salmon facilities: Afognak Hatchery (located on Afognak Island, northeast of

Kodiak Island) and Yes Bay Hatchery (at Yes Bay, off Behm Canal north of Ketchikan).

These facilities took millions of eggs per year, and not only planted sockeye salmon from the

facilities, but transferred eggs to hatcheries in the contiguous United States, sometimes even

to Atlantic coast states such as Maine (see Appendix Table D-1).

Catastrophic problems with IHN in ADFG production-scale sockeye salmon

hatcheries in Alaska limited sockeye salmon enhancement through the 1970s in Alaska. In

1980, new sockeye salmon culture policies of IHN containment have served to minimize the

effects of each outbreak (Burke 1996).

Currently, the Alaska Department of Fish and Game has sockeye salmon smolt

production facilities at Snettisham Hatchery near Juneau; Main Bay Hatchery in Prince

William Sound; Kitoi Bay Hatchery on Afognak Island; and Trail Lakes, Kasilof and Eklutna

Hatcheries in Cook Inlet. Several of these hatcheries have large fry and pre-smolt production

programs, as do Beaver Falls Hatchery in Ketchikan, English Bay Hatchery in Cook Inlet,

Gulkana Hatchery in the Copper River Basin, and Pillar Creek Hatchery on Kodiak Island. In

addition, some of the above fry and pre-smolt facilities are associated with lake enrichment

programs (Burke 1996).

Eleven sockeye salmon hatcheries were constructed in British Columbia between 1894

and 1917, all of which were situated near healthy natural populations of sockeye salmon

(Foerster 1968). No consistent benefits were evident as a result of the operation of these

facilities (e.g., increases in sockeye salmon stocks and/or expansions of commercial fisheries),

and it was concluded that artificial propagation in British Columbia did not result in a

significant increase in efficiency over natural production in areas where there was a

reasonable expectation of successful natural propagation. As a consequence, most of these

turn-of-the-century facilities are no longer in operation (Foerster 1968). However, in recent

years, artificial propagation programs for sockeye salmon in British Columbia (especially

methods using natural rearing strategies and indigenous broodstocks (Miller et al. 1990)) have

received renewed attention.
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Spawning channels, lake fertilization, barrier removal, and habitat improvement are

the primary enhancement methods used for sockeye salmon in British Columbia (Miller et al.

1990). On the lower Fraser River below Hope, B. C., a hatchery on the Pitt River has been

releasing sockeye salmon since 1961, and the Weaver Creek and Seabird spawning channels

have been in operation since 1966 and 1985, respectively. The Gates, Nadina, Adams, and

Horsefly sockeye salmon spawning channels have operated in the upper Fraser River Basin

since 1969, 1974, 1981, and 1990, respectively (NRC 1995). The Fulton River and Pinkut

Creek spawning channels have operated in the Skeena River system from the mid-1960s to

the present. Vancouver Island artificial propagation facilities releasing sockeye salmon were

established in 1981 on the Nimpkish River, which empties into Johnstone Strait. In 1989,

similar programs were established on Hobiton, Cheewhat, and Nitinat Lakes on the southwest

section of the island.

Artificial propagation of sockeye salmon in the contiguous United States began in

1896 at Baker Lake Station in the Skagit River Basin of Washington State. This hatchery

remained in operation until its closure in 1933 (Kemmerich 1945). The Birdsview Station on

Grandy Creek, also in the Skagit River drainage, reared sockeye salmon from 1908 to 1945.

This facility also provided stock for many attempts at establishing populations of sockeye

salmon in various watersheds throughout western Washington, with the most notable success

being the introduction of a self-sustaining population of sockeye salmon into the Lake

Washington watershed.

Despite numerous stocking attempts, establishment of self-perpetuating sockeye

salmon runs have been documented only at these three sites: 1) Lake Washington (Royal and

Seymour 1940, Kolb 1971), 2) Frazer Lake, Kodiak Island (Blackett 1979), and 3) Upper

Adams River in the Fraser River system (Williams 1987). Successful, documented

transplants have all involved donor populations originating less than 100 km from the

transplant site (Wood 1995). The remainder of this section is intended to provide a summary

of the nature and scope of artificial propagation activities for west coast sockeye salmon

considered in this status review.

Grand Coulee Fish-Maintenance Project

The construction of Grand Coulee Dam completely blocked the passage of sockeye

salmon to the upper Columbia River. WDF et al. (1938) and Mullan (1986) reported that

about 85% of the sockeye salmon passing Rock Island Dam between 1935 and 1936

originated from natural stocks up-river from Grand Coulee Dam. To compensate for loss of

habitat resulting from the total blockage of up-river fish passage by Grand Coulee Dam, the

federal government initiated the Grand Coulee Fish-Maintenance Project in 1939 to maintain

fish runs in the Columbia River above Rock Island Dam. For sockeye salmon, this was

accomplished through relocation of adults returning to Rock Island Dam, improving habitat,

and establishing hatchery operations (Fish and Hanavan 1948). The foremost method of

habitat improvement used by the GCFMP was installation of screens on irrigation diversions
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in tributaries entering the Columbia River above Rock Island Dam, which prevented juvenile

salmon from being drawn into irrigation systems (Waknitz et al. 1995).

Between 1939 and 1943 all sockeye salmon adults returning to Rock Island Dam were

trapped and transported either to Lake Wenatchee or Lake Osoyoos, or to one of three

national fish hatcheries (Leavenworth, Entiat, or Winthrop) for artificial propagation (Fish and

Hanavan 1948, Mullan 1986). After 1944, all sockeye salmon passing Rock Island Dam and

returning to the Wenatchee and Okanogan Rivers were essentially the progeny of relocated

stock.

Mullan showed that between 1944 and 1948, hatchery-reared sockeye salmon

constituted 5-98% of the total run. By the mid-1960s, the contribution of hatchery fish as a

percentage of all returning adult sockeye salmon had decreased to about 10-22%; about one

third of what it had been in the 1940s. Mullan (1986) reported that artificial propagation

efforts at the GCFMP hatcheries were abandoned in the 1960s due to “low benefits to costs

and catastrophic losses from IHN.”

Releases from the GCFMP were thought to contribute to reestablishing healthy

sockeye salmon populations in the Wenatchee and Okanogan River Basins (Chapman et al.

1995), as well as producing small populations in the Methow and Entiat Rivers, which

previous to the GCFMP apparently did not have sockeye salmon populations (Mullan 1986,

Chapman et al. 1995). Mullan (1986) thought it likely that releases of juvenile sockeye

salmon (derived from Rock Island Dam, Bonneville Dam, and Lake Wenatchee broodstock)

at Winthrop NFH (on the Methow River) gave rise to the Methow River sockeye salmon

population, while other releases (derived from Quinault Lake broodstock and their progeny) at

the Entiat NFH (on the Entiat River) gave rise to the Entiat River sockeye salmon population.

Stock Transfers and Artificial Propagation

Okanogan River

During the GCFMP (1939-1944), about 2 million sockeye salmon juveniles of the

aforementioned upper Columbia River mixed stock (as well as an unknown number of

Quinault Lake stock in 1942) were planted into the Okanogan River system, and a total of

about 2 million local sockeye salmon have been released since then (see Appendix Table D2). Average return rates from early plants (1940s) into the Okanogan River system (GCFMP)

averaged 0.93% (Fulton and Pearson 1981) and have decreased since then (Mullan 1986).

Current artificial propagation programs in the Okanogan River watershed are intended

to replace adult production lost to juvenile sockeye salmon mortality at mainstem

hydroelectric projects without reducing natural production or changing the fitness and genetic

diversity of natural stocks (Chapman et al. 1995). The Colville Indian Nation has recently

initiated an annual release program from its Cassimer Bar Hatchery. Adult sockeye salmon
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will be collected at Wells Dam and the progeny will be released from net-pens in Lake

Osoyoos.

In addition to releases of juveniles during the GCFMP, 19,795 adult sockeye salmon

were trapped at Rock Island Dam and released into Lake Osoyoos between 1939 and 1940

(Chapman et al. 1995). There are very limited reports of introductions of artificiallypropagated kokanee into the Okanogan River system (see Appendix Table D-5).

Lake Wenatchee

Between 1941 and 1969 almost 60 million sockeye salmon juveniles (only a small

percentage of which were of non-upper Columbia River origin (see Appendix Table D-2))

were released into the Wenatchee River system. The Wenatchee River system has been the

largest recipient of hatchery fish in the upper Columbia River. Sockeye salmon now returning

to the White and Little Wenatchee Rivers are undoubtedly the descendants of stock

manipulations during the GCFMP, since Lake Wenatchee sockeye salmon were extremely

depressed prior to the construction of Grand Coulee Dam (Fish and Hanavan 1948, see above

“Information Specific to Sockeye Salmon Populations Under Review” section). Small

numbers of fish that continue to return to Icicle Creek may also be descendants of the GCFMP

(Chapman et al. 1995).

Returns from releases of sockeye salmon into the Wenatchee watershed in the 1940s

were about 0.90%, which decreased to about 0.15% to 0.67% by the early 1960s (Chapman

et al. 1995). However, hatchery fish still contributed to Columbia River sockeye salmon runs

in appreciable numbers in some years (Mullan 1986).

No releases of artificially-reared sockeye salmon occurred in the Wenatchee watershed

during the years 1970 to 1989 (see Appendix Table D-2). Since 1990, releases into Lake

Wenatchee have resumed, these being from the Rock Island Fish Hatchery Complex,

constructed and funded by Chelan PUD, and operated by WDFW (Chapman et al. 1995).

This facility was designed to supplement the natural production of sockeye salmon in the

White and Little Wenatchee Rivers, primarily through the use of extended rearing strategies in

net-pens in Lake Wenatchee (Chapman et al. 1995).

In addition to releases of juveniles during the GCFMP, over 32,000 mixed upper

Columbia River stock adult sockeye salmon trapped at Rock Island Dam were released into

Lake Wenatchee between 1939 and 1943, over 90% of which successfully spawned according

to surveys in 1939 and 1942 (Fish and Hanavan 1948).

Over 23 million Lake Whatcom kokanee were released into Lake Wenatchee between

1934 and 1983 (Mullan 1986) (see Appendix Table D-5). Experimental releases in 1946 of

fin-marked Lake Wenatchee kokanee, which had been reared at Leavenworth Hatchery, into

Icicle Creek and Lake Wenatchee resulted in adult anadromous returns to the Columbia River

of 0.27% and 0.50%, respectively (Fulton and Pearson 1981). Fulton and Pearson (1981)
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questioned whether broodstock used for these experiments were “far enough removed from

seaward migratory behavior to be classified as kokanee.” Mullan (1986) thought it possible

that Lake Wenatchee kokanee may have evolved from the lake’s sockeye salmon population

within the last 90 years (due to migrational problems for anadromous individuals imposed by

water diversions, dams, and resultant high water temperatures in the Wenatchee River) and

that, consequently, there may be an incomplete separation of kokanee and sockeye salmon in

this lake.

Quinault Lake

Artificial propagation of sockeye salmon has long been a significant feature of

sockeye salmon management in Quinault Lake. Since 1916, over 196 million hatchery

sockeye salmon have been released in the Quinault River Basin, although most of these were

released as fry or fingerlings (see Appendix Table D-2). Two periods of hatchery production

of sockeye salmon have occurred in this watershed. The first period spanned the years 1914

to 1947, when the federal government was the primary agency responsible for hatchery efforts

in the Quinault Basin. During the second period, from 1973 to the present, an artificial

propagation program in Quinault Lake has been operated by the Quinault Indian Nation, while

WDFW released sockeye salmon in Quinault Lake in 1985 (NRC 1995).

Prior to 1947, fish were released from the U.S. Bureau of Fisheries Hatchery at Falls

Creek on Quinault Lake (“Quinault, Washington Station”), and were mostly native stock,

although about 20 million Alaskan sockeye salmon eggs were transferred to the Falls Creek

facility prior to 1920 (see Appendix Table D-1). All tribal and WDFW releases since 1973

have been of current Quinault Lake stock; the tribal releases came mostly from an extended

rearing program utilizing net-pen rearing in Quinault Lake (Donaldson 1980, NRC 1995, QIN

1995b). To the best of our knowledge, only minor kokanee releases into Quinault Lake have

occurred (see Appendix Table D-5).

Although the actual impact of these hatchery programs on native stock are unknown, it

is possible to roughly evaluate their relative contribution to total production. Between 1914

and 1947 estimated total escapement of female sockeye salmon to Quinault Lake was about

2,154,000 (assuming a 1:1 sex ratio, total escapement was 4,309,237), and the Quinault,

Washington Station on Falls Creek took 237,783,455 native sockeye salmon eggs and

released 191,696,000 juvenile sockeye salmon (QIN 1981) (see Appendix Table D-2). Since

average fecundity at this hatchery was 2,700 (QIN 1981), total egg production of naturally

spawning fish (minus the egg output of the estimated 88,068 females taken at the hatchery) is

estimated at over 5.5 billion. Using Foerster’s (1968) estimate of egg-fry mortality of 0.88,

approximately 669,562,000 naturally produced fry are estimated to have recruited to Quinault

Lake between 1914 and 1947. Using these values, approximately 22% of the fry entering

Quinault Lake over this period of time were hatchery produced. In reference to the Quinault,

Washington Station, QIN (1981) reported that “hatchery releases were of sufficient size to

have potentially large effects on the estimated returns per spawner” and “termination of the
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hatchery operation in 1947 certainly contributed to at least part of the subsequent loss of

productivity.”

Between 1974 and 1994, over 5 million juvenile sockeye salmon were released in

Quinault Lake, and estimated female escapement was 398,562 (assuming a 1:1 sex ratio, total

escapement was 797,124), and the calculated natural egg production (again assuming average

fecundity of 2,700 and subtracting for the estimated 2,596 female spawners taken for hatchery

efforts) was approximately 1,069,100,000. Again using Foerster’s (1968) estimate of egg-fry

mortality of 0.88, approximately 128,292,000, naturally produced fry are estimated to have

recruited to Quinault Lake between 1974 and 1994. Therefore, approximately 3.8% of the fry

entering Quinault Lake over this time period were hatchery produced.

Ozette Lake

Artificial propagation has not been extensive in this population. Approximately one

million sockeye salmon have been released into the Ozette Lake watershed from 1937 to the

present (see Appendix Table D-2). Although this number is small compared to some other

sockeye salmon populations discussed in this review, non-indigenous sockeye salmon

introductions have been prominent in this watershed. The largest single release of 449,000

fish in 1937 was entirely of Grandy Creek (Birdsview Hatchery) stock, which were reared at

the Quilcene National Fish Hatchery before transfer to Ozette Lake (Kemmerich 1945,

Boomer 1995, NRC 1995). In addition, 120,000 Quinault stock sockeye salmon were

released in 1983 (NRC 1995). Small-scale releases since 1984, when hatchery efforts were

undertaken by the Makah Indian Nation, were primarily of Ozette Lake stock (NRC 1995).

About 14,400 Ozette Lake kokanee/sockeye salmon hybrids were released in 1991-1992

(MFMD 1995, NRC 1995).

Although the actual impact of the recent hatchery program on the native sockeye

salmon stock in Ozette Lake is unknown, it is possible to roughly evaluate the relative

hatchery contribution to total production. Between 1988 and 1995, about 330,340 juvenile

sockeye salmon were released in Ozette Lake, estimated female escapement between 1988

and 1994 was 3,486 (assuming a 1:1 sex ratio, estimated total escapement was 6,971), and the

calculated natural egg production (assuming average fecundity of 2700 and subtracting for the

estimated 171 female spawners taken for hatchery efforts) was 8,950,500. Using Foerster’s

(1968) estimate of egg-fry mortality of 0.88, approximately 1,074,000 naturally produced fry

are estimated to have recruited to Ozette Lake between 1988 and 1995. This very coarse

approximation leads to the conclusion that about 24% of the fry entering Ozette Lake over

this time period were hatchery produced.

Baker River

Artificial propagation has a long history in this population. Between 1896 and 1933,

over 202 million sockeye salmon eggs were taken for culture efforts at Baker Lake Hatchery

and essentially 100% of the native population was under cultivation (with the exception of
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some fish that escaped holding pens to spawn naturally) (Kemmerich 1945) (see Appendix

Table D-2). Baker Lake Hatchery was constructed in 1896 by the State of Washington (and

subsequently sold to the U.S. Commission of Fish and Fisheries in 1899, which later became

the U.S. Bureau of Fisheries), while the U.S. Bureau of Fisheries Birdsview Station on

Grandy Creek, a nearby tributary of the Skagit River, was established in 1901.

The Grandy Creek-Birdsview Hatchery sockeye salmon stock was started in 1908 with

sockeye salmon captured at Point Roberts near Blaine, Washington (Kemmerich 1945).

Initially, sockeye salmon propagated at Birdsview Hatchery most likely consisted of mixed

stocks of sockeye salmon bound for the Fraser River. In later years, large numbers of Baker

Lake (and some Quinault Lake) sockeye salmon were released in Grandy Lake and Creek,

together with progeny of sockeye salmon returning to Grandy Creek and the Birdsview

Hatchery (Kemmerich 1945) (Appendix table D-2). After 1917 this hatchery population was

maintained entirely by propagation of sockeye salmon returning to Grandy Creek and from

transfers of eyed eggs from the Baker Lake hatchery.

Over 0.5 million Birdsview Hatchery sockeye salmon fry were released in Baker Lake

between 1941 and 1944 (Kemmerich 1945, Appendix table D-2). Birdsview Hatchery

sockeye salmon, together with some Baker Lake stock, were extensively transplanted to other

locations in Washington, including numerous releases in the Skagit River watershed, the Lake

Washington drainage, the Samish River, the Stillaguamish River Basin, Lake Stevens, Mason

Lake, Isabella Lake, the Big Quilcene River, Ozette Lake, Beaver Lake, and Lake Pleasant

(see Appendix Table D-2). Baker Lake and Birdsview Hatcheries ceased operations in 1934

and 1942, respectively.

Between 1934 and 1957, artificial enhancement efforts for Baker Lake sockeye

salmon were suspended (with the exception of lifting adult fish over Lower Baker Dam), and

fish spawned and reared naturally in Baker Lake. Between 1957 and 1993, combined

enhancement efforts of WDFW and Puget Sound Power and Light Co. contributed over 42

million sockeye salmon juveniles to the Baker River Basin, with over 41.5 million of these

produced as fry from the Baker Lake spawning beaches, and the remainder coming from

releases from a net-pen program in Lake Shannon (Lower Baker Reservoir) (see Appendix

Table D-2).

Most enhancement efforts in Baker Lake used native stock; one small release of fish in

1959 was from Issaquah Creek, which itself was established from Baker River stock (NRC

1995), while some mixed Fraser River and Quinault Lake sockeye salmon were released in

Grandy Creek in 1909 and 1917, respectively (Kemmerich 1945) (see Appendix Table D-2).

Approximately 955,000 sockeye salmon fry derived from Yes Bay, Alaska stock are known to

have been released in Baker Lake in 1931 (Leach 1932) (see Appendix Table D-2). However,

the disposition of almost 7 million sockeye salmon eggs transferred from the Samish River

Hatchery in 1917-1918, and of over 11 million sockeye salmon eggs transferred from Yes

Bay, Alaska in 1925-1926, to the Baker Lake Hatchery is unknown (see Appendix Table D1). Similarly, the disposition of about 900,000 Quinault Lake stock eggs, 278,000 Afognak,
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Alaska stock eggs, and 1.2 million Yes Bay, Alaska stock eggs (see Appendix Table D-1)

transferred to Birdsview Hatchery between 1917 and 1930, in 1922, and in 1931, respectively,

is unknown.

To the best of our knowledge, this watershed was not planted with kokanee until very

recently. Approximately 1.1 million Lake Whatcom kokanee were released into Lake

Shannon (Lower Baker Reservoir) between 1991 and 1994 to bolster the sport fishery

(Appendix Table D-5).

Lake Washington/Sammamish River tributaries

With the exception of sockeye salmon currently in Big Bear Creek, it is likely that

most sockeye salmon currently in the Lake Washington Basin result from transplants that

occurred between 1935 and 1954, primarily from the Birdsview Hatchery in the Skagit River

Basin (Kolb 1971). The Lake Washington Basin received an initial plant of 19,700 sockeye

salmon fry from an unknown source in 1917 (Appendix Table D-2). In the 1930s,

populations of sockeye salmon were established in Issaquah Creek, the main tributary of

Lake Sammamish, and in the Cedar River, the main tributary of Lake Washington, from

Birdsview Hatchery stock (Kemmerich 1945, Kolb 1971). Over 0.5 million sockeye salmon

juveniles from Birdsview Hatchery (Skagit River) were released in Big Bear Creek in 1937,

while approximately 23,600 Cultus Lake sockeye salmon were released in North Creek in

1944 (see Appendix Table D-2). Both Big Bear and North Creeks are tributaries of the

Sammamish River.

Egg-box projects released a total of over 25 million juveniles derived from in-basin

egg sources into the Cedar River between 1978 and 1982. This project was terminated after it

was determined that IHN-mediated mortalities were likely close to 100%. Washington

Department of Fish and Wildlife currently operates a “portable hatchery” facility for sockeye

salmon enhancement at the base of the Landsburg Dam on the Cedar River, with an 8 million

egg/year capacity. This facility is scheduled to increase capacity to 17 million eggs/year in

1996 (WDF et al. 1993, J. Ames51). The percentage of fry emigrating from the Cedar River

that were hatchery-produced was estimated at 6%, 6%, 27%, and 40% in the years 1992,

1993, 1994, and 1995, respectively (Seiler and Kishimoto 1996).

Between 1917 and 1969, over 44 million kokanee were introduced into Big Bear

Creek and its tributaries. Over 35 million of these kokanee were from Lake Whatcom in

northwest Washington (see Appendix Table D-5). Lake Sammamish proper, as well as the

Sammamish River, have also received extensive plants of kokanee. Between 1917 and 1951,

over 18 million kokanee were planted here, at least 6 million of which were Lake Whatcom

stock (see Appendix Table D-5).

51 J. Ames, Department of Fish and Wildlife, State of Washington, 600 Capitol Way N.,

Olympia, WA 98501-1091. Pers. commun., April 1995 and 13 March 1996.
114

Lake Pleasant

Lake Pleasant received just under half a million Grandy Creek (Skagit River,

Birdsview Hatchery) and Baker Lake sockeye salmon juveniles between 1933 and 1937

(Kemmerich 1945, Boomer 1995) (see Appendix Table D-2). NRC (1995) did not locate

records of sockeye salmon stocking in this lake after 1937. A recreational sport fishery exists

for kokanee in Lake Pleasant, and Smoker et al. (1952) stated that kokanee (silver trout) from

an unknown source were planted in Lake Pleasant in 1936, 1937, and 1938. No further

evidence of kokanee plants in Lake Pleasant was found (Kloempken 1996).

Riverine-spawning sockeye salmon

There are very few records of artificial propagation programs for populations of

sockeye salmon in Washington or Oregon that spawn in rivers without access to lake-rearing

habitat (NRC 1995). Rivers without accessible lake-rearing habitat, with present-day

occurrence of spawning sockeye salmon (see Appendix Table C-7), and with a history of

sockeye salmon stocking (see Appendix Table D-2) include Icicle Creek and portions of the

Skagit, Samish, Stillaguamish, Snohomish, Green, Sol Duc, Chelan, Entiat, Methow, and

Similkameen Rivers. Locations where records of spawning sockeye salmon and stocking

release location overlap include Icicle Creek and the Samish, Entiat, and Methow Rivers.

Sockeye salmon stocking history and present day spawning activity in these rivers are

discussed in the above “Information Specific to Sockeye Salmon Populations Under Review”

section.

Deschutes River, Oregon

Between 1937 and 1960, Suttle Lake and the headwaters of the Metolius River, into

which it drains, were planted with 1.3 million juvenile sockeye salmon, the majority of which

were from stock developed during the Grand Coulee Fish Maintenance Project in the upper

Columbia River (see Appendix Table D-3). Most of these plants were made directly into the

lake. The effect of these plants, if any, on any remnant sockeye salmon that might be

indigenous to the Deschutes River basin is unknown. Between 1963 and 1973, 210,658

kokanee of unknown origin were planted into Suttle Lake (ODFW 1995b) (see Appendix

Table D-5).

Discussion and Conclusions for ESU Determinations

Based on genetic, life-history, and ecological evidence presented above, the BRT

identified six ESUs for sockeye salmon in the state of Washington; fish from one of these

ESUs spawns in British Columbia, rears in a lake that straddles the U.S./Canadian border, and

migrates to and from the sea through Washington. In addition, sockeye salmon from Big Bear

Creek in the Lake Washington/Lake Sammamish Basin of Washington were provisionally

identified as an ESU. There was insufficient evidence to determine the ESU status for two
115

additional groupings of sockeye salmon, one in Washington and the other in Oregon. In the

following discussion, we describe these ESUs and outline the issues that were important to the

BRT in making each ESU determination.

Status of Transplanted Populations

Available artificial propagation data and transplantation records provide evidence that

within the Lake Washington Basin, the current Cedar River and Issaquah Creek sockeye

salmon are introduced populations, originating from transplants of Baker Lake stock that had

been perpetuated at the Birdsview Hatchery. Allozyme data based on 29 allozyme loci

indicate a close genetic relationship between Cedar River, Lake Washington beach-spawning,

and Baker River sockeye salmon. Similar artificial propagation data and transplantation

records provide evidence that spawning aggregations of sockeye salmon that are annually

seen in Icicle Creek and the Methow and Entiat Rivers in the Columbia River Basin are the

result of transplants that occurred during the Grand Coulee Fish Maintenance Project.

Waples (1991a, p. 18-19), in the NMFS “Definition of Species” paper, suggested that

In general, populations resulting from the introduction of fish into a local area not

occupied by the biological species... are probably not ESU’s because they do not

contribute to maintaining diversity of the species in its native habitat.

However, Waples (1991a, p. 19) went on to say that

Some introduced populations should not be excluded from ESA consideration, and

these include populations occupying habitat that is ecologically similar and

geographically proximate to the source population, and those that represent the only

remaining component of the native gene pool.

These ecological and geographic criteria do not appear to apply in the present case.

Although introduced sockeye salmon populations in the Lake Washington/Lake Sammamish

system and native Baker River sockeye salmon are both geographically within Puget Sound,

the natural ecosystems are dissimilar. Baker Lake is a cold-water, glacially influenced, low

productivity mountain lake system, and the Lake Washington/Lake Sammamish drainage is a

relatively warm-water, high productivity coastal lake system.

The BRT concluded that historical records, stocking history, and genetic data indicate

that sockeye salmon that spawn in the Cedar River, Issaquah Creek, on lakeshore beaches in

Lake Washington (in the Lake Washington drainage), and in Icicle Creek and the Methow and

Entiat Rivers (in the Columbia River Basin) originated from transplants from outside the

basins. As these populations are considered non-native and not part of any ESU, they are not

considered to be an ESA issue.
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Status of Nonanadromous Oncorhynchus nerka

Within the range of west coast sockeye salmon, “kokanee-sized” O. nerka occur

sympatrically with several sockeye salmon populations in their respective spawning and/or

juvenile rearing environments. In the Okanogan River, Lake Wenatchee, Sammamish River

tributaries, Cedar River, Lake Pleasant, and Ozette Lake populations, sockeye salmon and

kokanee-sized O. nerka are often observed together on the spawning grounds at the same time

and in the same place. In addition, kokanee-sized O. nerka are often observed at the time of

sockeye salmon spawning in the channel which drains the upper spawning beaches at Baker

Lake, but these fish cannot gain access to these artificial sockeye salmon spawning beaches.

Kokanee-sized fish have not been reported on the sockeye salmon spawning grounds of

Quinault Lake to any appreciable degree. On the other hand, native kokanee that have

relatively easy access to the ocean spawn in the absence of anadromous sockeye salmon in

several tributary streams of Ozette Lake and in Issaquah Creek, a tributary of Lake

Sammamish. Juvenile kokanee from these two populations rear sympatrically with sockeye

salmon in Ozette Lake and Lake Sammamish, respectively.

Several native and numerous introduced populations of kokanee exist within the

geographic range of west coast sockeye salmon. Several of these native kokanee populations

may be genetically distinct and reproductively isolated from one another and from other O.

nerka populations. The BRT acknowledged that it has long been known that kokanee can

produce anadromous fish; however, the number of outmigrants that successfully return as

adults is typically quite low. In three instances where populations of native kokanee occur in

coastal lakes in the Pacific Northwest and where access from the ocean is relatively easy

(Ozette Lake and Lake Sammamish in Washington, and Cowichan Lake on Vancouver

Island), the sockeye salmon morphology is absent on the kokanee spawning grounds. If

kokanee in these populations were producing anadromous outmigrants in any appreciable

numbers that were surviving to adulthood, the sockeye salmon morphology should be visible

on the kokanee spawning grounds.

Occasionally, a proportion of the juveniles in an anadromous sockeye salmon

population will remain in the rearing-lake environment throughout life and will be observed

on the spawning grounds together with their anadromous siblings. For the purposes of this

review, we have defined these fish as “resident sockeye salmon,” to indicate that they are the

progeny of anadromous sockeye salmon parents, yet spend their adult life in freshwater and

are observed together with their anadromous siblings on the spawning grounds.

Foote et al. (1989), Wood and Foote (1990), Foote et al. (1994), Taylor and Foote

(1991), Taylor et al. (1996), Wood and Foote (1996), and Winans et al. (1996) provide

evidence that sympatric populations of sockeye salmon and kokanee can be both genetically

distinct and reproductively isolated. In the following compilation of sockeye salmon ESUs,

the status of kokanee-sized O. nerka that spawn together with sockeye salmon will be

addressed on a case-by-case basis for each ESU.
117

In considering the ESU status of resident forms of O. nerka, a key issue is evaluating

the strength and duration of reproductive isolation between resident and anadromous forms.

Many kokanee populations appear to have been strongly isolated from sympatric sockeye

salmon populations for long periods of time. Since the two forms experience very different

selective regimes over their life cycle, reproductive isolation provides an opportunity for

adaptive divergence in sympatry. Kokanee populations that fall into this category will

generally not be considered part of sockeye salmon ESUs. On the other hand, resident fish

appear to be much more closely integrated into some sockeye salmon populations. For

example, in some situations anadromous fish may give rise to progeny that mature in

freshwater (as is the case with residual sockeye salmon), and some resident fish may have

anadromous offspring. In these cases, where there is presumably some regular or at least

episodic genetic exchange between resident and anadromous forms, they should be considered

part of the same ESU.

Sockeye Salmon ESUs

1) Okanogan River

This ESU consists of sockeye salmon that return to Lake Osoyoos through the Okanogan

River via the Columbia River and spawn primarily in the Canadian section of the Okanagan

River above Lake Osoyoos. Genetic, environmental, and life history information were the

primary factors in distinguishing this ESU. Factors important to the BRT in identifying this

ESU were these: 1) the very different environmental and habitat conditions encountered by

sockeye salmon in Lakes Osoyoos and Wenatchee during juvenile rearing; 2) the near absence

of 3-year-old sockeye salmon returns to Lake Wenatchee coupled with the tendency for a

large percentage of 3-year-olds to return to the Okanogan population; 3) the apparent 1 month

separation in juvenile outmigration-timing between Okanogan and Wenatchee-origin fish; and

4) the adaptation of Okanogan River sockeye salmon to much higher temperatures during

adult migration in the Okanogan River. Protein electrophoretic data (with the exception of

Utter’s (1995) preliminary report) also indicate that this population is genetically distinct from

other sockeye salmon currently in the Columbia River drainage. Utter’s (1995) data, which

show sockeye salmon collected in 1994 (at Wells Dam on the Columbia River and

presumably bound for the Okanogan River) and Wenatchee sockeye salmon (collected in

multiple years) to be genetically indistinguishable, is at odds with all other genetic studies that

have shown high levels of genetic differentiation between Okanogan River and Lake

Wenatchee sockeye salmon (Winans et al. 1996, Wood et al. 1996, Thorgaard et al. 1995)

The overall effect of the Grand Coulee Fish Maintenance Project (GCFMP) on the

current composition of sockeye salmon in this ESU is difficult to determine. A majority of

the sockeye salmon returning to the mid- to upper Columbia River prior to the operation of

Grand Coulee Dam most likely spawned in the Arrow Lakes region of British Columbia. The

redistribution and long-term propagation of mixed Arrow Lakes, Okanogan, and Wenatchee

stocks of adult sockeye salmon originally captured at Rock Island Dam, as well as
118

introductions of Quinault Lake sockeye salmon stocks, may have altered the genetic make-up

of indigenous sockeye salmon in the Okanogan River, particularly considering the relatively

low estimated returns of native sockeye salmon immediately prior to the beginning of the

GCFMP. However, electrophoretic analysis of current Okanogan River sockeye salmon

reveals little affinity with either Lake Wenatchee or Quinault Lake sockeye salmon or with

kokanee currently residing in Lower Arrow Lake (see statement above concerning Utter

(1995)).

Kokanee are reported to occur in Lake Osoyoos, and one known plant of 195,000

kokanee from an unknown source occurred in this lake in the years 1919-1920. Kokanee-sized

fish (L. LaVoy52) or residuals (Chapman et al. 1995) with a reportedly olive drab or “typically

dark” coloration, respectively, have been observed spawning with sockeye salmon in the

Okanogan River. Genetic samples of kokanee-sized fish from Lake Osoyoos have not been

obtained. However, kokanee from Okanagan Lake, above Vaseux Dam and Vaseux Lake on

the Okanagan River, are genetically quite distinct from Okanogan River sockeye salmon

(Wood et al. 1994, Thorgaard et al. 1995, Utter 1995, Robison 1995, Winans et al. 1996).

Robison (1995) suggested that Okanagan Lake kokanee may have been transplanted into this

system, as they appear genetically similar to Shuswap Lake kokanee.

The BRT concluded that if “kokanee-sized” O. nerka observed spawning with sockeye

salmon on the Okanogan River are identified as resident sockeye salmon they are to be

considered part of this sockeye salmon ESU. Based on the large genetic distance between

Okanagan Lake kokanee and Okanogan River sockeye salmon, the BRT decided that

Okanagan Lake kokanee are not part of the Okanogan sockeye salmon ESU. The BRT

concluded that spawning aggregations of sockeye salmon that are occasionally observed

downstream from Lake Osoyoos and below Enloe Dam on the Similkameen River are most

likely wanderers from the Okanogan River population and are therefore to be considered part

of this ESU.

2) Lake Wenatchee

This ESU consists of sockeye salmon that return to Lake Wenatchee through the

Wenatchee River via the Columbia River and spawn primarily in tributaries above Lake

Wenatchee (the White River, Napeequa River, and Little Wenatchee River). Genetic,

environmental, and life history information were the primary factors in distinguishing this

ESU. Allozyme data indicate that, of the populations examined, the Lake Wenatchee sockeye

salmon population is genetically very distinctive (but see discussion above concerning Utter

(1995)). Several ecological and biological factors were important in distinguishing the

Okanogan River and Lake Wenatchee sockeye salmon ESUs. These include: 1) the very

different environmental conditions encountered by sockeye salmon in Lakes Wenatchee and

52 L. LaVoy, Washngton Department of Fish and Wildlife, 3860 Chelan Highway North,

Wenatchee, WA 98801-0452. Pers. commun., 31 May 1995.
119

Osoyoos, 2) the near absence of 3-year-old sockeye salmon returns to Lake Wenatchee

coupled with the tendency for a large percentage of 3-year-olds to return to the Okanogan

population, and 3) the apparent 1 month separation in juvenile outmigration-timing between

Okanogan- and Wenatchee-origin fish.

The overall effect of the GCFMP on the current make-up of sockeye salmon in this

ESU is difficult to determine. The redistribution and long-term propagation of mixed Arrow

Lakes, Okanogan, and Wenatchee stocks of sockeye salmon originally captured at Rock

Island Dam, as well as introductions of Quinault Lake sockeye salmon stocks, may have

altered the genetic makeup of indigenous sockeye salmon in the Lake Wenatchee system,

particularly considering the low estimated returns of native sockeye salmon to Lake

Wenatchee immediately prior to the beginning of the GCFMP. It is possible that a significant

portion of the current gene pool of Lake Wenatchee sockeye salmon is derived from

introduced Arrow Lakes sockeye salmon. However, electrophoretic analysis of current Lake

Wenatchee sockeye salmon reveals little affinity with either Okanogan River (but see

discussion of Utter (1995) in Okanogan River ESU section) or Quinault Lake sockeye salmon

or with kokanee from Lower Arrow Lake.

Spawning aggregations of sockeye salmon that appear in the Entiat and Methow

Rivers and in Icicle Creek (a tributary of the Wenatchee River) were presumed by the BRT to

be nonnative and the result of transplants carried on during the GCFMP. Both the Methow

and Entiat Rivers had no history of sockeye salmon prior to stocking (WDF et al. 1938,

Mullan 1986). Leavenworth National Fish Hatchery is located on Icicle Creek, and between

1942 and 1969 over 1.5 million sockeye salmon juveniles (of mixed Columbia, Entiat,

Methow Rivers heritage) were liberated from this facility into Icicle Creek (Mullan 1986,

Chapman et al. 1995).

Kokanee-sized fish with a reportedly olive-drab coloration have been observed

spawning with sockeye salmon in the White, Napeequa, and Little Wenatchee Rivers (L.

LaVoy53). Over 23 million Lake Whatcom kokanee were released in Lake Wenatchee

between 1934 and 1983; however, the current genetic make-up of the Lake Wenatchee

sockeye salmon population reveals little or no affinity with Lake Whatcom kokanee. Genetic

samples of kokanee-sized fish from Lake Wenatchee have not been obtained.

The BRT concluded that if “kokanee-sized” O. nerka observed spawning with sockeye

salmon on the White and Little Wenatchee Rivers are identified as resident sockeye salmon

they are to be considered part of the Lake Wenatchee sockeye salmon ESU.

53 L. LaVoy, Washngton Department of Fish and Wildlife, 3860 Chelan Highway North,

Wenatchee, WA 98801-0452. Pers. commun., 31 May 1995.
120

3) Quinault Lake

This ESU consists of sockeye salmon that return to Quinault Lake and spawn in the

mainstem of the upper Quinault River, in tributaries of the upper Quinault River, and in a few

small tributaries of Quinault Lake itself. The BRT felt that Quinault Lake sockeye salmon

deserved separate ESU status based on its unique life history characteristics and degree of

genetic differentiation from other sockeye salmon populations.

Key factors in identifying this ESU were: 1) the distinctive early river-entry timing, 2)

the protracted adult run-timing, 3) the long 3- to 10-month lake-residence period prior to

spawning, 4) the unusually long spawn timing, and 5) the genetic differences from other

coastal Washington sockeye salmon. In addition, the relative absence of red skin

pigmentation and the presence of an olive-green spawning coloration by the majority of the

Quinault stock appear to be unique among major sockeye salmon stocks in Washington

(Storm et al. 1990, D. Boyer, Jr.54), although at least two sockeye salmon stocks in British

Columbia appear more green than red at spawning (C. C. Wood55). The rather large genetic

distance between U.S. and Vancouver Island sockeye salmon, together with the apparently

unique life-history characters of Quinault Lake sockeye salmon (very early, yet protracted

run-timing, and lengthy lake-residency as adults), persuaded the BRT to exclude Vancouver

Island stocks from this ESU.

Kokanee-sized O. nerka have not been identified within the Quinault River Basin;

however, stocking history reveals over 300,000 kokanee transplanted into Quinault Lake

between 1917 and 1922 from an unknown source and 260,000 kokanee eggs transferred from

Lake Whatcom to the “Quinault, Washington Station” in 1925.

4) Ozette Lake

This ESU consists of sockeye salmon that return to Ozette Lake through the Ozette

River and currently spawn primarily in lakeshore upwelling areas in Ozette Lake (particularly

at Allen’s Bay and Olsen’s Beach). Minor spawning may occur below Ozette Lake in the

Ozette River or in Coal Creek, tributary of the Ozette River. Sockeye salmon do not presently

spawn in tributary streams to Ozette Lake, although they may have spawned there historically.

Genetic, environmental, and life history information were the primary factors in

distinguishing this ESU. The BRT felt that Ozette Lake sockeye salmon were a separate ESU

based on the degree of genetic differentiation from other sockeye salmon populations and on

life history characteristics.

54 Del Boyer, Jr., Quinault Fisheries Division, P.O. Box 189, Taholha, WA 98587. Pers.

commun., 24 April 1995.

55 C.C. Wood, Department of Fisheries and Oceans, Pacific Biological Station, Nanaimo,

B.C., Canada V9T 5K6. Pers. commun., August 1996.
121

Ozette Lake sockeye salmon are genetically distinct from all other sockeye salmon

stocks in the Northwest. Sockeye salmon stocks from west coast Vancouver Island were

excluded from this ESU, in part because of the large genetic distance between Vancouver

Island and Ozette Lake sockeye salmon. On the other hand, Ozette Lake kokanee proved to

be the most genetically distinct O. nerka stock examined in the contiguous United States

(based on 29 allozyme loci). However, Ozette Lake kokanee were closely allied to several

sockeye salmon stocks on Vancouver Island (based on analysis of a nine allozyme loci data

set).

Kokanee are very numerous in Ozette Lake and spawn in inlet tributaries, whereas

sockeye salmon spawn on lakeshore upwelling beaches. Sockeye salmon have not been

observed on the inlet spawning grounds of kokanee in Ozette Lake, although there are no

physical barriers to prevent their entry into these tributaries. On the other hand, kokaneesized O. nerka are observed together with sockeye salmon on the sockeye salmon spawning

beaches at Allen’s Bay and Olsen’s Beach. One recorded plant of over 100,000 kokanee from

an unknown source stock occurred in 1940, and anecdotal reports of another kokanee plant in

1958 were found.

Based on the very large genetic distance between Ozette Lake kokanee that spawn in

tributaries and Ozette Lake sockeye salmon that spawn on shoreline beaches, the BRT

excluded Ozette Lake kokanee from this sockeye salmon ESU. In addition, the BRT

concluded that if “kokanee-sized” O. nerka observed spawning with sockeye salmon on

sockeye salmon spawning beaches in Ozette Lake are identified as resident sockeye salmon,

then they are to be considered as part of the Ozette Lake sockeye salmon ESU.

5) Baker River

This ESU consists of sockeye salmon that return to the barrier dam and fish trap on the

lower Baker River after migrating through the Skagit River. Adults are trucked to one of

three artificial spawning beaches above either one or two dams on the Baker River, and are

held in these enclosures until spawning.

The BRT felt that Baker River sockeye salmon are a separate ESU based on genetic,

life history, and environmental characters. Baker River sockeye salmon are genetically

distinct from sockeye salmon populations that spawn in the lower Fraser River (allozyme data

based on 9 loci) and are genetically distinct from all other native populations of Washington

sockeye salmon (allozyme data based on 29 loci). Prior to inundation behind Upper Baker

Dam, Baker Lake was a typical cold, oligotrophic, well-oxygenated, glacially turbid sockeye

salmon nursery lake, in contrast to other sockeye salmon systems under review, with the

exception of Lake Wenatchee.

The Birdsview Hatchery population on Grandy Creek in the Skagit River Basin was

established from Baker Lake sockeye salmon together with a probable mixture of Quinault

Lake stock and an unknown Fraser River stock. This stock was the ultimate source for the
122

apparently successful transplants of sockeye salmon to the Lake Washington/Lake

Sammamish system in the mid-1930s to early 1940s (Royal and Seymour 1940, Kolb 1971).

Numerous reports indicate that residual or resident sockeye salmon began appearing in

Baker Lake and Lake Shannon Reservoir following the installation of Lower Baker Dam in

1925 (Ward 1929, 1930, 1932; Ricker 1940; Kemmerich 1945). A spring-time recreational

kokanee fishery exists in Baker Lake, although substantial aggregations of spawning kokanee

have yet to be identified. We found no historical records of kokanee stocking in Baker Lake.

However, approximately 40-100 kokanee-sized O. nerka spawn each year in the outlet

channel that drains the two upper sockeye salmon spawning beaches at Baker Lake.

6) Lake Pleasant

A majority of the BRT concluded that Lake Pleasant sockeye salmon constituted a

separate ESU, while a minority thought that insufficient information existed to make a

decision as to its ESU status. Allozyme data for Lake Pleasant sockeye salmon indicate

genetic distinctiveness from other sockeye salmon populations. Sockeye salmon in this

population enter the Quillayute River from May through September and hold in the Sol Duc

River before entering Lake Pleasant, usually in early November, when sufficient water depth

is available in Lake Creek. Spawning occurs on beaches from late November to early

January. Kemmerich (1945) indicated that native sockeye salmon occurred in Lake Pleasant

prior to 1932 and that they were of an “individual size comparable with the size of the fish of

the Lake Quinault and Columbia River populations”; however, sockeye salmon currently in

Lake Pleasant are said to be small and no bigger than about 2 to 3 pounds (0.9 to 1.4 kg) (J.

Haymes56). Adult male and female Lake Pleasant sockeye salmon have an average fork

length of 460 mm or less for all ages combined, which is the smallest body size of any

anadromous O. nerka population in the Pacific Northwest. In some years, a majority of Lake

Pleasant sockeye salmon spend 2 years in freshwater prior to migrating to sea (Appendix

Table C-1).

Over 0.5 million sockeye salmon fry from Baker Lake and the Birdsview Hatchery in

the Skagit River Basin were released in Lake Pleasant in the 1930s; however, electrophoretic

analysis of current Lake Pleasant sockeye salmon reveals little genetic affinity with Baker

Lake sockeye salmon. It is assumed that poisoning of Lake Pleasant during “lake

rehabilitation” activities in the 1950s and 1960s (see previous information section) may have

impacted one or two broodyears of sockeye salmon in Lake Pleasant. Sockeye salmon

escapement to Lake Pleasant was between about 760 and 1,500 fish in the early 1960s;

indicating that “lake rehabilitation” failed to eliminate sockeye salmon from this system.

Although kokanee-sized O. nerka spawn together with sockeye salmon on the beaches in

56 J. Haymes, Quileute Natural Resources, Quileute Indian Tribe, P.O. Box 187, La Push, WA

98350-0187. Pers. commun., 12 May 1995.
123

Lake Pleasant, only anecdotal reference to kokanee being stocked in Lake Pleasant during the

1930s were found.

The BRT concluded that if “kokanee-sized” O. nerka observed spawning with sockeye

salmon on sockeye salmon spawning beaches in Lake Pleasant are identified as resident

sockeye salmon, then they are to be considered as part of the Lake Pleasant sockeye salmon

ESU.

Sockeye Salmon of Provisional ESU Status

Big Bear Creek

The BRT was divided on the ESU status of sockeye salmon that currently spawn in

Big Bear Creek and its two tributaries, Cottage Lake and Evans Creeks. Members did agree

that the available evidence does not clearly resolve this issue. In spite of various

uncertainties, about half of the BRT felt that the current sockeye salmon population in Big

Bear and Cottage Lake Creeks is a separate ESU that represents either an indigenous Lake

Washington/Lake Sammamish sockeye salmon population or a native kokanee population that

has naturally re-established anadromy. About half the members felt that the available

information was insufficient to determine the ESU status of sockeye salmon in Big Bear

Creek. This issue is particularly difficult due to the equivocal nature of historical accounts

concerning the presence and distribution of sockeye salmon within the Lake Washington/Lake

Sammamish Basin.

Genetically, Big Bear and Cottage Lake Creek sockeye salmon are quite distinct from

other stocks of sockeye salmon in the Lake Washington/Lake Sammamish Basin; they are

genetically more similar to Okanogan River sockeye salmon than they are to any other

sockeye salmon population examined. It was acknowledged that the genetic distinctiveness of

the current Big Bear Creek/Cottage Lake Creek sockeye salmon as revealed through analysis

of allozyme data could have resulted from genetic change (founder effect and/or subsequent

genetic drift) following the recorded transplant of Baker Lake sockeye salmon in 1937 and

observation of 2 adults in October 1940, or it could be indicative of a native population of O.

nerka indigenous to the Lake Washington/Lake Sammamish Basin.

A native kokanee population once spawned in Big Bear Creek and its tributaries,

although it is uncertain whether a remnant of this native stock still exists in this drainage. Big

Bear Creek was once the largest producer of kokanee for artificial propagation in Washington,

although relatively few kokanee currently spawn there. Currently a small number of kokaneesized O. nerka spawn in Big Bear Creek together with sockeye salmon. The spawn timing of

kokanee in Big Bear Creek is currently much later than the only remaining recognized native

kokanee stock in the Lake Washington Basin (early entry Issaquah Creek kokanee). There

were over 35 million Lake Whatcom kokanee fry released in Big Bear Creek between 1917

and 1969, and what effect this stocking program had on the native kokanee is open to
124

speculation. In addition, potential genetic interactions of these introduced kokanee with

sockeye salmon are unknown.

Sockeye Salmon of Uncertain ESU Status

Riverine-spawning sockeye salmon

Spawning ground survey data of the Washington Department of Fish and Wildlife and

numerous anecdotal references dating back to the turn of the century indicate that riverinespawning aggregations of sockeye salmon exist in certain rivers within Washington that lack

lake-rearing habitat. Consistent riverine- spawning aggregations of sockeye salmon have

been documented over a period of decades in the North and South Fork Nooksack, Skagit,

Sauk, North Fork Stillaguamish, Samish (D. Hendrick57), and Green Rivers. Riverinespawning sockeye salmon have also been reported in the Nisqually, Skokomish, Dungeness,

Calawah, Hoh, Queets, and Clearwater Rivers, and are occasionally seen in small numbers in

a number of other rivers and streams in Washington.

Protein electrophoretic data for riverine spawners from the Nooksack, upper Skagit,

and Sauk Rivers indicate that these aggregations are genetically similar to one another and

genetically distinct from other sockeye salmon in Washington. Genetic data of equal

resolution (29 allozyme loci) for comparison with river/sea-type and lake-type sockeye

salmon populations in the lower Fraser River are not available.

The BRT considered these hypotheses that might explain river-spawning aggregations

of sockeye salmon in Washington: 1) they represent multiple U.S. populations, 2) they

represent one U.S. population, 3) they represent strays from U.S. lake-type sockeye salmon,

4) they represent strays from British Columbia lake-type sockeye salmon, and 5) they

represent strays from river-type populations in British Columbia. Genetic data for river

spawning sockeye salmon in the Nooksack, Skagit, and Sauk Rivers do not support

hypothesis 3. The disjunct timing and geographic distance between individual aggregations

of riverine-spawning sockeye salmon suggest that more than one process may be responsible

for the occurrence of these aggregations.

The small size of the spawning aggregations of sockeye salmon periodically reported

in rivers without lake-rearing habitat in Washington raises the question of historic population

size and persistence of Pacific salmon over evolutionarily significant time scales. Because

many populations of Pacific salmon show large temporal fluctuations in abundance, Waples

(1991a, p. 19) argued in the NMFS “Definition of Species” paper that

57 D. Hendirck, Washington Department of Fish and Wildlife, 333 E. Blackburn Rd., Mount

Vernon, WA 98273. Pers. commun., 8 August 1995.
125

there must be some size below which a spawning population is unlikely to persist in

isolation for a long period of time. The fact that small spawning aggregations are

regularly observed may reflect a dynamic process of extinction, straying, and

recolonization. Such small populations are unlikely to be ESU’s, although a collection

of them might be.

However, Waples (1991a, p. 19) went on to say that

In making this evaluation, the possibility should be considered that small populations

observed at present are still in existence precisely because they evolved mechanisms

for persisting at low abundance.

The BRT acknowledged the evolutionary importance of existing river/sea-type

sockeye salmon in British Columbia and Alaska but felt that the evidence was insufficient to

determine whether sockeye salmon seen in rivers without lake-rearing habitat in Washington

were distinct populations. The ESU status of riverine-spawning sockeye salmon in

Washington remains an open question.

Deschutes River, Oregon

The BRT concluded that sockeye salmon that historically migrated up the Deschutes

River via the Columbia River to spawn in Suttle Lake were a separate ESU, but it is uncertain

whether remnants of this ESU exist. Fish passage into and out of Suttle Lake was blocked

sometime around 1930. Currently, sockeye salmon adults that are consistently seen each year

in the Deschutes River below the regulatory dam downstream from Pelton Dam may be

derived from 1) a self-sustaining population of sockeye salmon that spawn below Pelton Dam

on the Deschutes River, 2) strays from elsewhere in the Columbia River, or 3) outmigration of

smolts from populations of “kokanee-sized” O. nerka that exist above the Pelton/Round Butte

Dam complex. Two kokanee populations are present above the dams: one population resides

in Suttle Lake and spawns in the lake inlet stream (Link Creek), and a second population

resides in Lake Billy Chinook, behind Round Butte Dam, and spawns in the upper Metolius

River. Both kokanee populations have a distinctive blue-black body coloration that

distinguishes them from hatchery kokanee that are released in Lake Simtustus and other

Deschutes River Basin hatcheries.

Allozyme data for Deschutes River sockeye salmon do not exist; however, mtDNA

data (Brannon 1996), suggest the possibility that Lake Billy Chinook kokanee and Deschutes

River sockeye salmon are related. Protein electrophoretic data indicate that kokanee in Suttle

Lake and in Lake Billy Chinook cluster together genetically (unpublished data, NMFS,

Northwest Fisheries Science Center, 2725 Montlake Blvd East, Seattle, WA 98112). Over 1.2

million sockeye salmon were planted in the Metolius River and its tributaries before 1962,

and a significant portion of the adult sockeye salmon returns recorded at the Pelton Dam fish

trap, starting in 1956, may have been descended from these plantings.
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The majority of the BRT concluded that a remnant component of this historical

population cannot be identified with any certainty. A minority of the BRT felt that the

extensive transplant history of non-native sockeye salmon into this basin explains the

continued occurrence of anadromous O. nerka in the Deschutes River Basin and, as the

descendants of transplants, these sockeye salmon are not an ESA issue. It should be noted at

this point that sockeye salmon continue to return to the base of reservoir dams on the Middle

and South Santiam Rivers in Oregon, long after sockeye salmon fry were released into these

reservoirs. Sockeye salmon that return to the Santiam River are the putative progeny of

residualized sockeye salmon. The majority of the BRT agreed that the possibility exists that

recent sockeye salmon in the Deschutes River may result from some remnant outmigrants of

residualized sockeye salmon or kokanee. The ESU status of sockeye salmon returning to the

Deschutes River remains an open question.

ASSESSMENT OF EXTINCTION RISK

Background

As outlined previously in the “Introduction,” NMFS considers a variety of information

in evaluating the level of risk facing an ESU. Aspects of several of these risk considerations

are common to all sockeye salmon ESUs. These are discussed in general below; more

specific discussion of factors for each of the ESUs under consideration here can be found in

the following sections. Because we have not taken future effects of conservation measures

into account (see “Introduction”), we have drawn scientific conclusions about the risk of

extinction faced by identified ESUs under the assumption that present conditions will

continue. Future effects of conservation measures will be taken into account by the NMFS

Northwest Regional Office in making listing recommendations.

Absolute Numbers

The absolute number of individuals in a population is important in assessing two

aspects of extinction risk. For small populations that are stable or increasing, population size

can be an indicator of whether the population can sustain itself into the future in the face of

environmental fluctuations and small-population stochasticity; this aspect is related to the

concept of minimum viable populations (MVP) (see Gilpin and Soulé 1986, Thompson 1991).

For a declining population, the present abundance is an indicator of the expected time until the

population reaches critically low numbers; this aspect is related to the concept of “driven

extinction” (Caughley 1994). In addition to total numbers, the spatial and temporal

distribution of adults is important in assessing risk to an ESU. Spatial distribution is

important both at the scale of lake or river basins and at the scale of spawning areas within

basins (“metapopulation” structure). Temporal distribution is important both among years, as

an indicator of the relative health of different brood-year lineages, and within seasons, as an

indicator of the relative abundance of different life-history types or runs.
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Traditionally, assessment of salmonid populations has focused on the number of

harvestable and/or reproductive adults, and these measures comprise most of the data

available for Pacific salmon and steelhead. In assessing the future status of a population, the

number of reproductive adults is the most important measure of abundance, and we focus here

on measures of the number of adults escaping to spawn in natural habitat. However, total run

size (spawning escapement + harvest) is also of interest because it indicates potential

spawning in the absence of harvest. Data on other life-history stages (e.g., freshwater smolt

production) can be used as a supplemental indicator of abundance.

Because the ESA (and NMFS policy) mandates that we focus on viability of natural

populations, in this review we attempted to distinguish natural fish from hatchery-produced

fish. All statistics are based on data that indicate total numbers or density of adults that spawn

in natural habitat (“naturally spawning fish”). The total of all naturally spawning fish (“total

escapement”) is divided into two components (Fig. 14): “Hatchery produced” fish are reared

as juveniles in a hatchery but return as adults to spawn naturally; “Natural” fish are progeny

of naturally spawning fish.

Historical Abundance and Carrying Capacity

The relationship of current abundance and habitat capacity to that which existed

historically is an important consideration in evaluating risk for several reasons. Knowledge of

historical population conditions provides a perspective of the conditions under which present

stocks evolved. Historical abundance also provides the basis for establishing long-term trends

in populations. Comparison of present and past habitat capacity can also indicate long-term

population trends and problems of population fragmentation.

Although the relationship of present abundance to present carrying capacity is

important for understanding the health of populations, the fact that a population is near its

current capacity does not in itself mean that it is healthy. If a population is near capacity,

there will be limits to the effectiveness of short-term management actions in increasing

abundance, and competition and other interactions between hatchery and natural fish may be

an important consideration because hatchery fish will further increase population density in a

limited habitat.

All populations of sockeye salmon in this region have been affected by substantial loss

and degradation of freshwater habitat, although the causes vary among populations. Much of

the original sockeye salmon habitat in the Columbia River Basin has been blocked by

irrigation diversions, hydroelectric development, and other human actions: accessible nursery

lake habitat in the upper Columbia River is now only 4% (by surface area) of historical

habitat, and only one remnant population remains in the Snake River (Mullan 1986, TAC

1991, Fryer 1995). This has resulted in widespread extinctions of populations that formerly

occupied these areas. Coastal populations have also been affected by a variety of habitat

factors, particularly hydroelectric development (Baker River) and forest management

practices.
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Trends in Abundance

Short- and long-term trends in abundance are a primary indicator of risk in salmonid

populations. Trends may be calculated from a variety of quantitative data, including dam or

weir counts, stream surveys, and catch data. These data sources and methods are discussed in

more detail below (see “Approach”).

The important role of artificial propagation (in the form of hatcheries) for Pacific

salmon requires careful consideration in ESA evaluations. Artificial propagation has

implications for evaluating both production trends and the genetic integrity of populations.

Waples (1991a, b) and Hard et al. (1992) discussed the role of artificial propagation in ESU

determination and emphasized the need to focus on natural production in the threatened or

endangered status determination. A fundamental question in ESA risk assessments for mixedproduction stocks is whether natural production is sufficient to maintain the population

without the continued infusion of artificially produced fish. A full answer to this question is

difficult without extensive studies of relative production and interactions between hatchery

and natural fish. When such information is lacking, the presence of hatchery fish in natural

populations leads to substantial uncertainty in evaluating the status of the natural population.

Long-term trends in abundance of sockeye salmon in the Pacific Northwest can only

be approximated from historical records of commercial fishery landings (Fig. 15). However,

these trends largely reflect the harvest of Fraser River sockeye salmon in British Columbia

and Washington, and therefore do not provide a good indication of the status of ESUs we are

considering here. To the extent that landings reflect population abundance, these records

suggest fairly constant populations of sockeye salmon in this region except for large shortterm fluctuations (discussed in the next section). Harvest was somewhat higher near the turn

of the century than during 1920-1980, and increasing harvest in British Columbia since 1980

has restored harvest levels to near those of the early 1900s.

A major determinant of trends in salmon abundance is the condition of the freshwater,

estuarine, and ocean habitats on which salmon depend. While we rarely have sufficient

information to precisely predict the population-scale effects of habitat loss or degradation, it is

clear that habitat availability imposes an upper limit on the production of salmon, and any

reduction in habitat reduces potential production. Even in areas where we have no

information on trends in population abundance, evidence of widespread loss of habitat can

indicate a serious risk for sustainability of natural populations.

The National Research Council Committee on Protection and Management of Pacific

Northwest Anadromous Salmonids (NRCC 1996) identified habitat problems as a primary

cause of declines in wild salmon runs. NMFS (1996) identified habitat concerns as one of a

suite of factors affecting the decline of salmon within the range of west coast steelhead. Some

of the habitat impacts identified were: 1) the fragmentation and loss of available spawning

and rearing habitat; 2) alteration of stream flows and stream-bank and channel morphology;

3) migration delays; 4) degradation of water quality; 5) alteration of ambient stream water
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temperatures; 6) sedimentation; 7) loss of spawning gravels, pool habitat and large woody

debris; 8) removal of riparian vegetation; and 9) decline of habitat complexity.

The Pacific Fishery Management Council (PFMC 1995) also identified loss of habitat

as one of the main reasons for declines in salmon stocks and identified fourteen “vital habitat

concerns.” Their concerns relative to sockeye salmon are Columbia-Snake River hydropower

operations, instream flow, unscreened or inadequately screened water diversions, inadequate

fish passage at road culverts, water spreading (unauthorized use of federally-developed water

supplies), upland land-use practices and polluted runoff, fish passage at existing hydroelectric

projects, agricultural practices, urban growth and land conversion, contaminants in coastal

wetlands and estuaries, offshore oil and gas development and transportation, and dredge spoil

disposal.

Assessing the effects of habitat changes on future sustainability of populations is

difficult. Human populations are projected to continue increasing in most areas of the west

coast, and water impoundments and diversions, as well as logging and agricultural activities,

will continue into the future. These facts indicate that there will be some continuing losses of

salmon habitat in the foreseeable future. Balancing this, recent changes in forest and

agricultural practices and improved urban planning have reduced the rate of habitat loss in

many areas, and many areas are recovering from severe past degradation. Whether natural

recovery and active restoration in some areas will compensate for continued losses in other

areas is unknown.

Factors Causing Variability

Abundance of sockeye salmon populations tends to fluctuate around a general level,

either displaying predictable cyclic fluctuations or unexpected upward or downward changes

(Burgner 1991). In some populations, a large part of this variability is attributable to the

phenomenon of brood-cycle dominance, which is the tendency of single year-classes to

consistently dominate abundance trends in populations that return to spawn largely at a single

age (Ricker 1950, Ward and Larkin 1964, Eggers and Rogers 1987). This phenomenon was

seen in the 1901-brood cycle of sockeye salmon in the Fraser River in the early 1900s (Fig.

15), which clearly displayed dominance. This pattern in the overall Fraser River run was

disrupted by the Hells Gate slide, but is still apparent in the abundance trends of individual

Fraser River stocks. Ricker (1997) reviewed cycles in Fraser River sockeye salmon, and

suggested that interactions among dominant and other brood lines are the most plausible cause

of the cycles. Brood-cycle dominance is less evident in the U.S. populations we are

considering here, possibly because spawning age-structure is more variable in most of these

populations or because relative abundance has not been high enough to establish the pattern.

Where it occurs, however, cyclic dominance could be a major influence in abundance analysis

and recovery planning.

Variations in the freshwater and marine environments are also thought to be a primary

factor driving fluctuations in salmonid run size and escapement (Pearcy 1992, Beamish and
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Bouillon 1993, Lawson 1993). Recent changes in ocean conditions are an additional factor

and are discussed in the “Recent Events” section. Habitat degradation and harvest have

probably made stocks less resilient to poor climate conditions, but these effects are not easily

quantifiable.

Threats to Genetic Integrity

In addition to being a factor in evaluating natural replacement rates, artificial

propagation can have a substantial impact on genetic integrity of natural salmon and steelhead

populations. This can occur in several ways. First, stock transfers that result in interbreeding

of hatchery and natural fish can lead to loss of fitness in local populations and loss of diversity

among populations. The latter is important to maintaining long-term viability of an ESU

because genetic diversity among salmonid populations helps to buffer overall productivity

against periodic or unpredictable changes in the environment (Riggs 1990, Fagen and Smoker

1989). Ricker (1972) and Taylor (1991) summarized some of the evidence for local

adaptations in Pacific salmonids that may be affected by stock transfers.

Second, because a successful salmon hatchery dramatically changes the mortality

profile of a population, some level of genetic change relative to the wild population is

inevitable even in hatcheries that use local broodstock (Waples 1991b). These changes are

unlikely to be beneficial to naturally reproducing fish.

Third, even if naturally spawning hatchery fish leave few or no surviving offspring,

they still can have ecological and indirect genetic effects on natural populations. On the

spawning grounds, hatchery fish may interfere with natural production by competing with

natural fish for territory and/or mates. If they successfully spawn with natural fish, they may

divert production from more productive natural x natural crosses. The presence of large

numbers of hatchery juveniles or adults may also alter the selective regime faced by natural

fish.

Not all of these concerns will apply to every hatchery population, and the seriousness

of the concerns that do apply can vary considerably among different programs. For example,

although stock transfers are a major issue for some hatchery programs, many others have

exclusively used local broodstock. Some hatchery programs have also taken a number of

measures (e.g., in broodstock collection, spawning, rearing, and release protocols) to

minimize adverse effects on natural populations. Therefore, threats posed by hatchery

programs should be evaluated on a case-by-case basis whenever available data allow such an

evaluation. It should be recognized, however, that some changes associated with fish culture

cannot be avoided, and some risks are also inescapable because they involve a trade-off with

other risks. For example, changing the hatchery environment to more closely mimic selective

regimes faced in the wild can reduce opportunities for domestication, but there is a limit to

how far this process can go without sacrificing the early life history survival advantage that is

the primary benefit of a salmon hatchery. Similarly, although releasing hatchery fish as

smolts reduces opportunities for ecological interactions with natural fish, it also increases
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opportunities for genetic change associated with fish culture compared to releases at an earlier

life history stage.

For smaller salmon stocks (either natural or hatchery), small-population effects

(inbreeding, genetic drift) can also be important concerns for genetic integrity. Inbreeding

and genetic drift are well understood at the theoretical level, and researchers have found

inbreeding depression in various fish species (reviewed by Allendorf and Ryman 1987).

Other studies (e.g., Simon et al. 1986, Withler 1988, Waples and Teel 1990) have shown that

hatchery practices commonly used with anadromous Pacific salmonids have the potential to

affect genetic integrity. However, we have not found empirical evidence for inbreeding

depression or loss of genetic variability in any natural or hatchery populations of Pacific

salmon.

Recent Events

A variety of factors, both natural and human-induced, affect the degree of risk facing

salmonid populations. Because of time-lags in these effects and variability in populations,

recent changes in any of these factors may affect current risk without any apparent change in

available population statistics. Thus, consideration of these effects must go beyond

examination of recent abundance and trends. However, forecasting future effects is rarely

straightforward and usually involves qualitative evaluations based on informed professional

judgement. Events affecting populations may include natural changes in the environment or

human-induced changes, either beneficial or detrimental. Possible future effects of recent or

proposed conservation measures have not been taken into account in this analysis, but we

have considered documented changes in the natural environment. A key question regarding

the role of recent events is: Given our uncertainty regarding the future, how do we evaluate

the risk that a population may not persist?

For example, climate conditions are known to have changed recently in the Pacific

Northwest, and Pacific salmon stocks south of British Columbia have been affected by

changes in ocean production that occurred during the 1970s (Pearcy 1992, Lawson 1993).

There is mounting evidence that salmon populations are influenced by decadal-scale shifts in

climate patterns; such effects were discussed at a recent workshop sponsored by NMFS and

Oregon State University (Emmett and Schiewe 1997). Beamish et al. (1997) have related

production of Fraser River sockeye salmon to decadal-scale shifts in ocean productivity.

Much of the Pacific coast has also been experiencing drought conditions in recent years,

which may depress freshwater production. However, at this time we do not know whether

these climate conditions represent a long-term change that will continue to affect stocks in the

future or whether these changes are short-term environmental fluctuations that can be

expected to be reversed in the near future.
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Other Risk Factors

Other risk factors typically considered for salmonid populations include disease

prevalence, predation, and changes in life history characteristics such as spawning age or size.

Approach

Previous Assessments

In considering the status of the ESUs, we evaluated both qualitative and quantitative

information. Qualitative evaluations included aspects of several of the risk considerations

outlined above, as well as recent published assessments of population status by agencies or

conservation groups of the status of west coast sockeye salmon stocks (Nehlsen et al. 1991,

WDF et al. 1993). Nehlsen et al. (1991) considered salmonid stocks throughout Washington,

Idaho, Oregon, and California and enumerated all stocks that they found to be extinct or at

risk of extinction. Stocks that do not appear in their summary were either not at risk of

extinction or were not classifiable due to insufficient information. They classified stocks as

extinct, possibly extinct, at high risk of extinction, at moderate risk of extinction, or of special

concern. They considered it likely that stocks at high risk of extinction have reached the

threshold for classification as endangered under the ESA. Stocks were placed in this category

if they had declined from historic levels and were continuing to decline, or had spawning

escapements less than 200. Stocks were classified as at moderate risk of extinction if they had

declined from historic levels but presently appear to be stable at a level above 200 spawners.

They felt that stocks in this category had reached the threshold for threatened under the ESA.

They classified stocks as of special concern if a relatively minor disturbance could threaten

them, insufficient data were available for them, they were influenced by large releases of

hatchery fish, or they possessed some unique character. For sockeye salmon, they classified

22 stocks as follows: 16 extinct, 1 possibly extinct, 2 high risk, 1 moderate risk, and 2 special

concern (Table 4).

WDF et al. (1993) categorized all salmon and steelhead stocks in Washington on the

basis of stock origin (“native,” “non-native,” “mixed,” or “unknown”), production type

(“wild,” “composite,” or “unknown”) and status (“healthy,” “depressed,” “critical,” or

“unknown”). Status categories were defined as follows: healthy, “experiencing production

levels consistent with its available habitat and within the natural variations in survival for the

stock”; depressed, “production is below expected levels . . . but above the level where

permanent damage to the stock is likely”; and critical, “experiencing production levels that are

so low that permanent damage to the stock is likely or has already occurred.” Of the nine

sockeye salmon stocks identified, three (Quinault, Wenatchee, and Okanogan) were classified

as healthy, four (Cedar, Lake Washington/Sammamish Tributaries, Lake Washington Beach,

and Ozette) as depressed, one (Baker) as critical, and one (Lake Pleasant) as unknown.
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There are problems in applying results of these studies to ESA evaluations. One

problem is the definition of categories used to classify stock status. Nehlsen et al. (1991) used

categories intended to relate to ESA “threatened” or “endangered” status; however they

applied their own interpretations of these terms to individual stocks, not to ESUs as defined

here. WDF et al. (1993) used general terms describing status of stocks that cannot be directly

related to the considerations important in ESA evaluations. For example, the WDF et al.

(1993) definition of healthy could conceivably include a stock that is at substantial extinction

risk due to loss of habitat, hatchery fish interactions, and/or environmental variation, although

this does not appear to be the case for any west coast sockeye salmon stocks. Another

problem is the selection of stocks or populations to include in the review. Nehlsen et al.

(1991) did not evaluate (or even identify) stocks not perceived to be at risk, so it is difficult to

determine the proportion of stocks they considered to be at risk in any given area. There is

also disagreement regarding status of some stocks; for example, IDFG (1996) disagrees with

the classification of Alturas and Stanley Lakes’ populations as extinct by Nehlsen et al.

(1991).

Data Evaluations

Quantitative evaluations of data included comparisons of current and historical

abundance of west coast sockeye salmon, calculation of recent trends in escapement, and

evaluation of the proportion of natural spawning attributable to hatchery fish. Historical

abundance information for these ESUs is largely anecdotal, although estimates based on

commercial harvest are available for some coastal populations (Rounsefell and Kelez 1938).

Time series data were available for many populations, but data extent and quality

varied among ESUs. We compiled and analyzed this information to provide several summary

statistics of natural spawning abundance, including (where available) recent total spawning

run-size and escapement, percent annual change in total escapement, recent naturally

produced spawning run-size and escapement, and average percentage of natural spawners that

were of hatchery origin. Information on harvest and stock abundance was compiled from a

variety of state, federal, and tribal agency records (Foy et al. 1995a, b). Additional data were

provided directly to us by state and tribal agencies and private organizations. We believe

these records to be complete in terms of long-term adult abundance for sockeye salmon in the

region covered. Principal data sources were adult counts at dams or weirs and spawner

surveys.

Computed statistics

To represent current run size or escapement where recent data were available, we have

computed the geometric mean of the most recent 5 years reported (or fewer years if the data

series is shorter than 5 years). We tried to use only estimates that reflect the total abundance

for an entire river basin or tributary, avoiding index counts or dam counts that represent only a

small portion of available habitat.
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Where adequate data were available, trends in total escapement (or run-size if

escapement data were not available) were calculated for all data sets with more than 7 years of

data, based on total escapement or an escapement index (such as fish per mile from a stream

survey). Separate trends were estimated for each full data series and for the 1985-1994 period

within each data series. As an indication of overall trend in individual sockeye salmon

populations, we calculated average (over the available data series) percent annual change in

adult spawner indices within each river basin. Trends were calculated as the slope (a) of the

regression of ln(abundance) against years corresponding to the biological model N(t) = beat.

Slopes significantly different from zero (P<0.05) were noted. The regressions provided direct

estimates of mean instantaneous rates of population change (a); these values were

subsequently converted to percent annual change, calculated as 100(ea

 - 1). No attempt was

made to account for the influence of hatchery produced fish on these estimates, so the

estimated trends include any supplementation effect of hatchery fish.

These computed statistics, along with published estimates of historical abundance and

results of previous status assessments, are summarized in Appendix Table E-1 for all stocks

examined in this review.

Analysis of Biological Information by ESU

1) Okanogan River

The major abundance data series for Okanogan River sockeye salmon consists of

spawner surveys conducted in the Okanogan River above Lake Osoyoos since the late 1940s,

counts of adults passing Wells Dam since 1967, and records of tribal harvest (Colville and

Okanogan) since the late 1940s. Longer-term data were available for dams lower on the

Columbia River (notably Rock Island Dam counts starting in 1933), but these counts

represent a combination of this ESU with the Wenatchee populations and other historical

ESUs from the upper Columbia River above Grand Coulee Dam.

Blockage and disruption of freshwater habitat pose some risk for this ESU. Adult

passage is blocked by dams above Lake Osoyoos, prohibiting access to former habitat in

Vaseux, Skaha, and Okanagan Lakes (Chapman et al. 1995). (However, it is not known

whether sockeye salmon in these upper lakes belonged to the same ESU as those in Lake

Osoyoos.) Other problems in the Okanogan River include inadequately screened water

diversions and high summer water temperatures (Chapman et al. 1995), and channelization of

spawning habitat in Canada. Mullan (1986) stated that hydroelectric dams accounted for the

general decline of sockeye salmon in the mainstem Columbia River, while Chapman et al.

(1995) suggested that hydropower dams have “probably” reduced runs of sockeye salmon to

the Columbia River, particularly to Lake Osoyoos.

The most recent 5-year average annual escapement for this ESU was about 11,000

adults, based on 1992-1996 counts at Wells Dam (see Appendix Table E-1). No historic

abundance estimates specific to this ESU are available. However, analyses conducted in the
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late 1930s indicated that less than 15% of the total sockeye run in the upper Columbia River

went into Lakes Osoyoos and Wenatchee (Chapman et al. 1995). At that time, the total run to

Rock Island Dam averaged about 15,000, suggesting a combined total of less than 2,250

adults returning to the Okanogan River and Lake Wenatchee ESUs. Thus, abundance for the

Okanogan River ESU during the late 1930s was clearly substantially lower than recent

abundance. Trend estimates for this stock differ depending on the data series used (see

Appendix Table E-1), but the recent (1986-1995) trend has been steeply downward (declining

at 2-20% per year); however, this trend is heavily influenced by high abundance in 1985 and

low points in 1990, 1994, and 1995, which may reflect environmental fluctuations (Fig. 17).

The long-term trend (since 1960) for this stock has been relatively flat (-3% to +2% annual

change).

For the entire Columbia River basin, there has been a considerable decline in sockeye

salmon abundance since the turn of the century. Columbia River commercial sockeye salmon

landings that commonly exceeded 1,000,000 pounds in the late 1800s and early 1900s had

been reduced to about 150,000 pounds by the late 1980s (TAC 1991). Since 1988, harvest

has been fewer than 3,500 fish each year. The TAC (1991) attributes this decline to habitat

degradation and blockage, overharvest, hydroelectric development, and nursery lake

management practices. The two remaining productive stocks (Okanogan and Wenatchee)

occupy less than 4% of historic nursery lake habitat in the upper Columbia River basin.

Both Okanogan and Wenatchee runs have been highly variable over time. For harvest

purposes, these two ESUs are managed as a single unit, with an escapement goal of 65,000

adults returning to Priest Rapids Dam (TAC 1991). This goal has been achieved only ten

times since 1970, and has been met in 2 of the last 5 years. Examination of the historical

trend in total sockeye salmon escapement to the upper Columbia River (Fig. 16) shows very

low abundance (averaging less than 20,000 annually) during the 1930s and early 1940s,

followed by an increase to well over 100,000 per year in the mid-1950s. Since the mid-1940s,

abundance has fluctuated widely, with noticeable low points reached in 1949, 1961-62, 1978,

and 1994. The escapement of about 9,000 fish to Priest Rapids Dam in 1995 was the lowest

since 1945, but 1996 escapement (preliminary estimate, Fish Passage Center 1996) was

considerably higher, although still far below the goal. Escapement to Wells Dam (i.e., this

ESU) was at its lowest recorded value in 1994, but increased in both 1995 and 1996.

Past and present artificial propagation of sockeye salmon poses some risk to the

genetic integrity of this ESU. The GCFMP (discussed in the “Artificial Propagation” section

above) interbred fish from this ESU with those from adjacent basins for several years, with

unknown impacts on the genetic composition of this ESU. Current artificial propagation

efforts use local stocks and are designed to maintain genetic diversity, but there is some risk

of genetic change resulting from domestication. There is only one record of introduction of

sockeye salmon from outside the Columbia River Basin into this ESU: 395,420 mixed

Quinault Lake/Rock Island Dam stock released in 1942 (Mullan 1986) (see Appendix Table

D-2). Records of kokanee transplants are most likely incomplete (see Appendix Table D-5).
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In previous assessments of this stock, Nehlsen et al. (1991) considered Okanogan

River sockeye salmon to be of special concern because of “present or threatened destruction,

modification, or curtailment of its habitat or range,” including mainstem passage, flow, and

predation problems. While WDF et al. (1993) classified this stock as of native origin, wild

production, and healthy status they also suggested that this “native” classification will be

changed to “mixed” in the future (WDFW 1996).

2) Lake Wenatchee

The major abundance data series for Wenatchee River sockeye salmon consists of

spawner surveys conducted in the Little Wenatchee River and the White River since the late

1940s, counts of adults passing Tumwater Dam (sporadic counts 1935 to present), and

reconstructions based on adult passage counts at Priest Rapids, Rock Island, and Rocky Reach

Dams (early 1960s to present). Longer-term data are available for dams lower on the

Columbia River (notably Rock Island Dam counts starting in 1933), but these counts

represent a combination of this ESU with the Okanogan River ESU and other historic

potential ESUs from the upper Columbia River above Grand Coulee Dam.

There are no substantial blockages of sockeye salmon habitat in the Wenatchee basin,

and habitat condition in the basin is generally regarded as good, although production is

limited by the oligotrophic nature of Lake Wenatchee (Chapman et al. 1995). Mullan (1986)

and Chapman et al. (1995) concluded that the main freshwater-habitat problem presently

facing this ESU is hydropower dams in the mainstem Columbia River, which have probably

reduced runs of sockeye salmon.

The most recent 5-year average annual escapement for this ESU was about 19,000

adults, based on the 1992-1996 difference in adult passage counts at Priest Rapids and Rocky

Reach Dams (see Appendix Table E-1). No historic abundance estimates specific to this ESU

are available. However, as discussed above for the Okanogan River ESU, abundance of the

Lake Wenatchee ESU during the late 1930s was clearly substantially lower than recent

abundance. The recent (1986-1995) trend in abundance has been downward (declining at

10% per year), but this trend was heavily influenced by 2 years of very low abundance in

1994 and 1995 (Fig. 17). The long-term (1961-1996) trend for this stock is flat. Escapement

to this ESU in 1995 (counts at Priest Rapids Dam minus those at Rocky Reach Dam) was the

lowest since counting began in 1962, but 1996 escapement was somewhat higher (Fig. 17).

Other risk factors common to this ESU and other Columbia River Basin sockeye salmon

populations were discussed under the Okanogan River ESU above.

Past and present artificial propagation of sockeye salmon poses some risk to the

genetic integrity of this ESU. As for the Okanogan River ESU, the GCFMP interbred fish

from this ESU with those from adjacent basins for several years and introduced many sockeye

salmon descended from Quinault Lake stock (Mullan 1986) (Appendix D-2), with unknown

impacts on the genetic composition of this ESU. Current artificial propagation efforts use

local stocks and are designed to maintain natural genetic diversity, but there is some risk of
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genetic change resulting from domestication. Hatchery-raised kokanee have been released in

Lake Wenatchee, including native Lake Wenatchee stock and nonnative Lake Whatcom stock

(Mullan 1986) (see Appendix Table D-5). The effect of Lake Whatcom kokanee

introductions on the genetic integrity of this ESU is unknown.

Previous assessments of this ESU are similar to those for the Okanogan River ESU.

Nehlsen et al. (1991) considered Wenatchee River sockeye salmon to be of special concern

because of “present or threatened destruction, modification, or curtailment of its habitat or

range,” including mainstem passage, flow, and predation problems. WDF et al. (1993)

classified this stock as of mixed origin, wild production, and healthy status. Huntington et al.

(1996) identified this stock as “healthy–Level I,” indicating that current abundance is high

relative to what would be expected without human impacts.

3) Quinault Lake

The major abundance data series for Quinault River sockeye salmon consists of

escapement estimates derived from hydroacoustic surveys conducted in Quinault Lake since

the mid-1970s, supplemented with earlier estimates (beginning in 1967) based on spawner

surveys. The most recent (1991-1995) 5-year average annual escapement for this ESU was

about 32,000 adults, with a run-size of about 39,000 (see Appendix Table E-1 and Fig. 18).

Approximate historical estimates indicate escapements ranging between 20,000 and 250,000

in the early 1920s, and run sizes ranging between 50,000 and 500,000 in the early 1900s

(Rounsefell and Kelez 1938). Comparison of these estimates indicates that recent abundance

is probably near the lower end of the historical abundance range for this ESU.

This ESU has been substantially affected by habitat problems, notably those resulting

from forest management activities in the upper watershed outside Olympic National Park.

Early inhabitants of the area described the upper Quinault River as flowing between narrow,

heavily-wooded banks, but by the 1920s the river was in a wide valley with frequent course

changes and much siltation and scouring of gravels during winter and spring freshets

(Davidson and Barnaby 1936, QIN 1981); resultant loss of spawning habitat in the Quinault

River above Quinault Lake has continued to recent times (QIN 1981).

While stock abundance has fluctuated considerably over time (recent escapements

ranging from a low of 7,500 in 1970 to 69,000 in 1968), the overall trend has been relatively

flat. For the full data series (1967-1995), abundance has increased by an average of about 1%

per year; for the 1986-1995 period, abundance declined by about 3% per year.

Artificial propagation of sockeye salmon in the Quinault River basin has a long history

(see “Artificial propagation” section above). Releases have been primarily native Quinault

Lake stock, although Alaskan sockeye salmon eggs were brought into the system prior to

1920 (see Appendix Tables D-1 and D-2). Genetic effects of this introduction are unknown.

Since 1973, all releases have been of local stock, but there is some risk of genetic change

resulting from unnatural selective pressures.
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143

In previous assessments, Nehlsen et al. (1991) did not identify Quinault Lake sockeye

salmon as at risk, and WDF et al. (1993) classified this stock as of native origin, wild

production, and healthy status.

4) Ozette Lake

The major abundance data series for Ozette River sockeye salmon consists of

escapement estimates derived from counts at a weir located at the outlet of Ozette Lake.

Counting has occurred in most years since 1977 (Dlugokenski et al. 1981, WDF et al. 1993).

The most recent (1992-1996) 5-year average annual escapement for this ESU was about 700

adults (see Appendix Table E-1). Historical estimates indicate run sizes of a few thousand

sockeye salmon in 1926 (Rounsefell and Kelez 1938), with a peak recorded harvest of nearly

18,000 in 1949 (WDF 1974). Subsequently, commercial harvest declined steeply to only a

few hundred fish in the mid-1960s and was ended in 1974. A small ceremonial and

subsistence fishery continued until 1981 (Dlugokenski et al. 1981); there has been no direct

fishery on this stock since 1982 (WDF et al. 1993). Assuming that Ozette River harvest

consisted of sockeye salmon destined to spawn in this system, comparison of these estimates

indicates that recent abundance is substantially below the historical abundance range for this

ESU.

Three studies have been undertaken to evaluate habitat-related factors limiting

production of sockeye salmon in Ozette Lake. The U.S. Fish and Wildlife Service conducted

studies of the decline in this stock during the 1970s, culminating in a report describing

limiting factors and outlining a restoration plan (Dlugokenski et al. 1981). This report noted

that this population formerly spawned in tributaries but presently only uses the lakeshore, and

that food supply, competition, and predation in the lake are probably not limiting, but that

siltation has caused cementing of spawning gravels in tributaries. Dlugokenski et al. (1981)

suspected that sedimentation, resulting primarily from logging and associated road building,

coupled with log truck traffic on weak siltstone roadbeds, have led to decreased hatching

success of sockeye salmon in tributary creeks and creek outwash fans in Ozette Lake. The

authors concluded that “a combination of overfishing and habitat degradation have reduced

the sockeye population to its current level of less than 1,000 fish” (p. 43).

More recently, Blum (1988) conducted an assessment of the same problems and

concluded that “the absence of tributary spawners is the paramount problem explaining why

sockeye runs have not increased following the cessation of terminal-area fishing in 1973.” He

cited three main problems related to road-building and logging that limit spawning habitat:

increased magnitude and frequency of peak flows, stream-bed scouring, and degraded water

quality. He also noted that “the logging of the watershed was so extensive that stream

spawning and rearing conditions are still questionable, despite having 35 years to recover” (p.

1). Finally, Beauchamp et al. (1995) examined patterns of prey, predator, and competitor

abundance in Ozette Lake as potential limiting factors for juvenile production of sockeye

salmon and kokanee. They concluded that competition is unlikely to limit production but that
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predation could be a limiting factor; however, data on piscivore abundance were lacking, so

the authors could not evaluate predation impact accurately.

A recent National Park Service Technical Report (Jacobs et al. 1996) reported the

conclusions of a review panel concerning the status and management of sockeye salmon in

Ozette Lake. The panel was unanimous in expressing great concern about the future of this

population, but was unable to identify a single set of factors contributing to the population

decline. The panel concluded that declines were likely the result of a combination of factors,

possibly including introduced species, predation, loss of tributary populations, decline in

quality of beach-spawning habitat, temporarily unfavorable oceanic conditions, excessive

historical harvests, and introduced diseases. They felt that intra- and inter-specific

competition was unlikely as a contributing factor.

Harvest of sockeye salmon in the Ozette River fluctuated considerably over time

(Fig. 19), which would indicate similar fluctuations in spawner abundance if harvest rates

were fairly constant. Based on the full weir-count series (1977-1995), abundance has

decreased by an average of about 3% per year; for the 1986-1995 period the decrease

averaged 10% per year. However, in recent years the stock has exhibited dominance by a

single brood cycle returning every 4 years (1984, 1988, 1992, 1996), and this dominant cycle

has remained stable at between 1,700 and 2,200 adults; declines are apparent only in the

smaller returns during off-cycle years (Fig. 19).

Artificial propagation has not been extensive in this basin, but many of the releases

have been non-indigenous stocks (see “Artificial Propagation” section). Genetic effects of

these introductions are unknown. Recent hatchery production in Ozette Lake has been

primarily from local stock, with the exception of 120,000 Quinault Lake sockeye salmon

juveniles released in 1983. The release of 14,398 kokanee/sockeye salmon hybrids in

1991-1992 (MFMD 1995, NRC 1995) may have had deleterious effects on genetic integrity of

the ESU because Ozette Lake kokanee are genetically dissimilar to Ozette Lake sockeye

salmon (see above “Genetics” section).

In previous assessments, Nehlsen et al. (1991) identified Ozette sockeye salmon as at

moderate risk of extinction, citing logging and overfishing in the 1940s and 1950s as major

causes of the decline. WDF et al. (1993) classified this stock as of native origin, wild

production, and depressed status.

5) Baker River

The major abundance data series for Baker River sockeye salmon consists of

escapement estimates derived from counts of adults arriving at a trap below Lower Baker

Dam beginning in 1926 (Fig. 20). The most recent 5-year average annual escapement for this

ESU was about 2,700 adults (see Appendix Table E-1). Historical estimates indicate

escapements averaging 20,000 near the turn of the century, with a pre-dam low of 5,000 in

1916 (Rounsefell and Kelez 1938), although WDFW data suggest that the 20,000 figure is a
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146

peak value, not an average (Sprague 1996a). Comparison of these estimates indicates that

recent average abundance is probably near the lower end of the historical abundance range for

this ESU, although escapement in 1994 (16,000 fish) was near the turn-of-the-century

average.

Currently, spawning is restricted to artificial spawning “beaches” at the upper end of

Baker Lake (in operation since 1957) and just below Upper Baker Dam (beach constructed in

1990). Spawning on the beaches is natural, and fry are released to rear in Baker Lake. Before

1925, sockeye salmon had free access to Baker Lake and its tributaries. Lower Baker Dam

(constructed 1925) blocked access to this area, but passage structures were provided. Upper

Baker Dam was completed in 1959 and increased the size of Baker Lake, inundating most

natural spawning habitat; this was mitigated by construction of artificial spawning beaches.

In most years, all returning adults are trapped below Lower Baker Dam and transported to the

artificial beaches, with no spawning occurring in natural habitat (WDF et al. 1993). The only

recent exception to this was in 1994, when the large number of returning adults exceeded

artificial habitat capacity, and excess spawners were allowed to enter Baker Lake and its

tributaries (J. Ames58). At the time of this report, no quantitative reports regarding offspring

resulting from this spawning “experiment” are available (WDFW 1996).

The artificial nature of spawning habitat, use of net-pens for juvenile rearing, and

reliance on artificial upstream and downstream transportation poses a certain degree of risk to

the ESU. These human interventions in the life-cycle have undoubtedly changed selective

pressures on the population from those under which it evolved its presumably unique

characteristics, and thus pose some risk to the long-term evolutionary potential of the ESU.

There have been continuing potential problems with siltation at the newer (lower) spawning

beach (WDF et al. 1993), and recent proposals to close the two upper beaches in favor of

production at the lower beach would thus be likely to increase risk of spawning failure in

some years. The future use of the upper beaches is uncertain (WDFW 1996). Problems with

operations of downstream smolt bypass systems have been documented, and there may be

limitations to juvenile sockeye production due to inadequate lake productivity and interactions

with other salmonids (WDF et al. 1993). IHN has also been a recent problem for this stock

(G. Sprague59).

While stock abundance has fluctuated considerably over time (recent escapements

ranging from a low of about 100 in 1985 to 16,000 in 1994), the long-term trend has been

relatively flat. For the full data series (1926-1995), abundance has decreased by an average of

about 2% per year; for the 1986-1995 period, abundance increased by about 32% per year.

58 J. Ames, Washington Department of Fish and Wildlife, 600 Capitol Way N., Olympia, WA

98501-1091. Pers. commun., April 1995.

59 G. Sprague, Habitat Program, Washington Department of Fish and Wildlife, 600 Capitol

Way N., Olympia, WA 98501-1091. Pers. commun., 15 March 1995.
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Artificial production in this ESU began in 1896 with a state hatchery on Baker Lake;

hatchery efforts at Baker Lake ended in 1933, by which time the hatchery was being operated

by the U.S. Bureau of Fisheries (see “Artificial Propagation” section, WDF et al. 1993).

Current propagation efforts rely primarily on the spawning beaches and net-pen rearing. Lake

Whatcom kokanee were recently introduced to Lake Shannon (Knutzen 1995). Genetic

consequences of these releases and rearing programs are unknown, but there is some risk of

genetic change resulting from unnatural selective pressures.

In previous assessments, Nehlsen et al. (1991) identified Baker River sockeye salmon

as at high risk of extinction, and WDF et al. (1993) classified this stock as of native origin,

artificial production, and critical status.

6) Lake Pleasant

Although no recent complete escapement estimates are available for this stock, we

recently have received some spawner-survey data for the period 1987 to 1996 (Mosley 1995,

Tierney 1997). Peak spawner counts ranged from a low of 90 (1991–a year with limited

sampling) to highs above 2,000 (1987 and 1992). Abundance fluctuated widely during this

period, with a slight negative trend overall.

Complete counts at a trapping station on Lake Creek in the early 1960s showed

escapements of sockeye salmon ranging from 763 to 1,485 fish, and 65,000 sockeye salmon

smolts were reported to have outmigrated in 1958 (Crutchfield et al. 1965). This stock

supports small sport and tribal commercial fisheries, with probably fewer than 100 fish caught

per year in each fishery (WDF et al. 1993). Sockeye salmon from Grandy Creek stock were

released in 1933 and 1937; no sockeye salmon have been introduced since then

(see “Artificial Propagation” section above).

In previous assessments, Nehlsen et al. (1991) did not identify Lake Pleasant sockeye

salmon as at risk, and WDF et al. (1993) classified this stock as of native origin, wild

production, and unknown status.

Analysis of Biological Information for Provisional ESU

Big Bear Creek

Abundance data for Big Bear Creek sockeye salmon are derived from spawner surveys

conducted by WDFW from 1982 to the present (WDF et al. 1993, J. Ames60). The most

recent (1991-1995) 5-year average annual escapement for this unit was about 11,400 adults

60 J. Ames, Washington Department of Fish and Wildlife, 600 Capitol Way N., Olympia, WA

98501-1091. Pers. commun., October 1996.
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(see Appendix Table E-1). No historical estimates are available, but comparing habitat areas

in these basins with other sockeye salmon populations suggests that current production is

probably a substantial proportion of freshwater habitat capacity. Habitat in this basin is

subject to effects of urbanization.

Stock abundance has fluctuated considerably over time, with recent escapements

ranging from a low of 1,800 in 1989 to 39,700 in 1994. There has been little overall trend in

this unit; for the full data series (1982-1995), abundance has decreased by an average of about

7% per year; for the 1986-1995 period, abundance decreased approximately 4% per year.

1995 escapement was the second lowest on record, but 1994 was the highest.

 Releases of non-native sockeye salmon in this area have occurred on Big Bear and

North Creek (tributaries of the Sammamish River), using Grandy Creek stock from the Skagit

River and Cultus Lake stock from British Columbia, respectively (see Appendix Table D-2).

There have been extensive introductions of kokanee in this area, a substantial proportion of

which were from Lake Whatcom. Genetic interactions of these kokanee with sockeye salmon

are unknown.

In previous assessments, Nehlsen et al. (1991) did not identify this stock as at risk, and

WDF et al. (1993) classified this stock as of unknown origin, wild production, and depressed

status.

Analysis of Biological Information for Other Population Units

While the units discussed below are not presently considered to constitute ESUs, we

briefly examined available information regarding population status and extinction risk. Three

other sockeye salmon stocks (Cedar River, Issaquah Creek, and Lake Washington beach

spawners) are apparently introduced from outside the Lake Washington drainage and have not

been included in a recognized ESU at this time (see above “Discussion and conclusions on

ESU Determinations” section).

Riverine-Spawning Sockeye Salmon

Beyond WDFW Salmon Spawning Ground Survey Data (Egan 1977, 1995, 1997) and

anecdotal reports (see above section “Information Specific to Sockeye Salmon Populations

Under Review”) of small numbers of sockeye salmon observed regularly spawning in some

Puget Sound and coastal Washington rivers with no access to lake rearing habitat, we have no

information on overall abundance or trends for these stocks.

Deschutes River, Oregon

Counts of sockeye salmon adults reaching Pelton Dam on the Deschutes River have

been made during most years since the mid-1950s (Fig. 21). The most recent (1990-1994)
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5-year average annual escapement was only 9 adults (see Appendix Table E-1). No accurate

estimates of historical abundance are available for this unit, but a substantial run is known to

have spawned in Suttle Lake prior to construction of a dam in the 1930s, and is believed to

have continued to spawn in the Metolius River after that time (CBFWA 1990, Olsen et al.

1994, ODFW 1995a). Since construction of Pelton Dam, abundance has reached peaks of

about 300 fish in several years (1962, 1963, 1973, 1976–Fish Commission of Oregon 1967,

O’Connor et al. 1993). We have made no evaluation of abundance of kokanee in the

Deschutes River basin, which may be part of the same evolutionary unit as sockeye salmon in

this basin. Sockeye salmon derived from the GCFMP were introduced into Suttle Lake and

the Metolius River between 1937 and 1961 (see “Artificial Propagation” section) (see

Appendix Table D-3).

Sockeye salmon stock abundance has fluctuated considerably over time (recent

escapements ranging from a low of 1 in 1993 to 340 in 1963), but there has been a substantial

decline over the years for which data are available. For the full data series (1957-1994),

abundance decreased by an average of about 3% per year; for the 1985-1994 period,

abundance declined by about 13% per year. Nehlsen et al. (1991) identified Deschutes River

sockeye salmon as at high risk of extinction.

Conclusions: Risk Assessment

The BRT has concluded that if recent conditions continue into the future, one ESU

(Ozette Lake) is likely to become endangered, and four ESUs (Okanogan River, Lake

Wenatchee, Quinault Lake, and Baker River) and one provisional ESU (Big Bear Creek) are

not presently in significant danger of becoming extinct or endangered. For the sixth ESU

(Lake Pleasant), there was insufficient information to reach a conclusion regarding risk of

extinction.

Conclusions: Risk Assessment

Consideration was also given to the status of two other population units for which

ESU status has not been determined. For one of these (riverine sockeye salmon) there was

insufficient information to reach any conclusions regarding risk of extinction. For the other

unit (Deschutes River sockeye salmon), the BRT concluded that the anadromous component

is clearly in danger of extinction if not already extinct.

 The following paragraphs summarize the conclusions for each ESU or other population

unit, and major considerations leading to these conclusions are summarized in Tables 5 and 6.

These conclusions are tempered by uncertainties in specific critical information. For

several units, there are kokanee (either native or introduced) populations using the same water

bodies as sockeye salmon; potential interbreeding and ecological interactions could affect

population dynamics and (in the case of non-native kokanee) genetic integrity of the sockeye

salmon populations. With few exceptions, adult abundance data do not represent direct
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counts of adults destined to a single spawning area, so estimates of total population abundance

and trends in abundance must be interpreted with some caution.

ESUs

ESU 1) Okanogan River

The BRT had several concerns about the overall health of this ESU. Low abundance,

downward trends and wide fluctuations in abundance, land use practices, and variable ocean

productivity were perceived as resulting in low to moderate or increasing risk for the ESU.

Other major concerns regarding health of this ESU were restriction and channelization of

spawning habitat in Canada, hydrosystem impediments to migration, and water temperature

problems in the lower Okanogan River. Positive indicators for the ESU were escapement

above 10,000, which is probably a substantial fraction of historical abundance, and the limited

amount of recent hatchery production within the ESU. Recent changes in hydrosystem

management (increases in flow and spill in the mainstem Columbia River) and harvest

management (restrictions in commercial harvest to protect Snake River sockeye salmon) were

regarded as beneficial to the status of this ESU. The BRT concluded unanimously that the

Okanogan River sockeye salmon ESU is not presently in danger of extinction, nor is it likely

to become endangered in the foreseeable future. However, the very low returns in the 3 most

recent years suggest that the status of this ESU bears close monitoring and its status should be

reconsidered if abundance remains low.

ESU 2) Lake Wenatchee

The BRT had several concerns about the overall health of this ESU. Low abundance,

downward trends and wide fluctuations in abundance, and variable ocean productivity were

perceived as resulting in low to moderate risk for the ESU. Other major concerns regarding

the health of this ESU were the effects of hatchery production, hydrosystem impediments to

migration, and potential interbreeding with nonnative kokanee on genetic integrity of the unit.

Positive indicators for the ESU were escapement above 10,000, and the limited amount of

recent hatchery production within the ESU. Recent changes in hydrosystem management

(increases in flow and spill in the mainstem Columbia River) and harvest management

(restrictions in commercial harvest to protect Snake River sockeye salmon) were regarded as

beneficial to the status of this ESU. The majority of the BRT concluded that the Lake

Wenatchee sockeye salmon ESU is not presently in danger of extinction, nor is it likely to

become endangered in the foreseeable future. A minority concluded that this ESU is likely to

become endangered in the foreseeable future, largely on the basis of extremely low abundance

in the last 3 years. In any case, the very low returns in the 3 most recent years suggest that the

status of this ESU bears close monitoring and should be reconsidered if abundance remains

low.
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ESU 3) Quinault Lake

All risk factors were perceived as very low or low for this ESU. However, the BRT

had two concerns about the overall health of this ESU. The ESU is presently near the lower

end of its historical abundance range, a fact that may be largely attributed to severe habitat

degradation in the upper river, which contributes to poor spawning habitat quality and

possible impacts on juvenile rearing habitat in Quinault Lake. The influence of hatchery

production on genetic integrity is also a potential concern for the ESU. On the positive side,

the BRT noted that recent escapement averaged above 30,000, harvest management has been

responsive to stock status, and recent restrictions in logging to protect terrestrial species

should have a beneficial effect on habitat conditions. The BRT concluded unanimously that

the Quinault Lake sockeye salmon ESU is not presently in danger of extinction, nor is it likely

to become endangered in the foreseeable future.

ESU 4) Ozette Lake

Perceived risks ranged from low to moderate for genetic integrity and variable ocean

productivity, from low to moderate and increasing for downward trends and population

fluctuations, and from moderate to increasing for abundance considerations. Current

escapements averaging below 1,000 adults per year imply a moderate degree of risk from

small-population genetic and demographic variability, with little room for further declines

before abundances would be critically low. Other concerns include siltation of beach

spawning habitat, very low abundance compared to harvest in the 1950s, and potential genetic

effects of present hatchery production and past interbreeding with genetically dissimilar

kokanee. The BRT concluded that the Ozette Lake sockeye salmon ESU is not presently in

danger of extinction, but if present conditions continue into the future, it is likely to become

so in the foreseeable future.

ESU 5) Baker River

The BRT had several concerns about the overall health of this ESU, focusing on high

fluctuations in abundance, lack of natural spawning habitat, and the vulnerability of spawning

beaches to water quality problems. Large fluctuations in abundance were a substantial

concern. It is also likely that this stock would go extinct if present human intervention were

halted, and problems related to that intervention pose some risk to the population. In

particular, the BRT concluded that the proposed change in management to concentrate

spawning in a single spawning beach could substantially increase risk to the population. There

was considerable disagreement regarding the risks associated with several factors for this

ESU. For example, the assessment of perceived risk for abundance and habitat capacity

ranged among BRT members from very low to high, and classifications for risks related to

water quality and disease also had wide ranges. The majority of the BRT concluded that the

Baker sockeye salmon ESU is not presently in danger of extinction, nor is it likely to become

endangered in the foreseeable future if present conditions continue. A minority concluded

that this ESU is likely to become endangered in the foreseeable future, largely on the basis of
155

lack of natural spawning habitat and the vulnerability of the entire population to problems in

artificial habitats.

ESU 6) Lake Pleasant

Although escapement monitoring data are sparse, escapements (represented by peak

spawner counts) in the late 1980s, and 1990s appear roughly comparable to habitat capacity

for this small lake (peak spawner counts for the 1990s were not available at the time the BRT

met). Some concerns were expressed regarding potential urbanization of habitat and effects

of sport harvest during the migration delay in the Sol Duc River. It was noted that recent

restrictions in logging to protect terrestrial species should have a beneficial effect on habitat

conditions, although little or no old growth forest is present in the watershed. The majority of

the BRT concluded that there was insufficient information to adequately assess extinction risk

for the Lake Pleasant ESU, although a minority concluded that the ESU is not presently in

danger of extinction nor likely to become so in the foreseeable future.

Provisional ESU

Big Bear Creek

The BRT had several concerns about the health of this provisional ESU and felt that

the extreme fluctuations in recent abundances and potential effects of urbanization in the

watershed suggest that the status of this populations bears close monitoring. Recent average

abundance has been relatively high, with escapement between 10,000 and 20,000. Recent

development of a county growth management plan was seen as a possible benefit to

freshwater habitat for this population. The majority of the BRT concluded that the Big Bear

Creek sockeye salmon provisional ESU is not presently in danger of extinction, nor is it likely

to become endangered in the foreseeable future if present conditions continue. A minority

concluded that this provisional ESU is likely to become endangered in the foreseeable future,

while a second minority felt that information was insufficient to adequately assess extinction

risk.

Other Population Units

Riverine-spawning sockeye salmon

There was insufficient information to reach any conclusion regarding the status of this

unit.

Deschutes River, Oregon

The BRT concluded that if anadromous sockeye salmon recently seen in the lower

Deschutes River are remnants of the historic Deschutes River ESU, the ESU clearly is in
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danger of extinction due to extremely low population abundance. If there is an ESU that

includes sockeye salmon and native kokanee above Round Butte Dam, further evaluation of

the kokanee stock and its relationship to the sockeye salmon would need to be completed

before any conclusions regarding extinction risk could be made. If these sockeye salmon

originated from stocks outside the Deschutes River Basin, then they are not subject to

protection under the ESA.
157

CITATIONS

Ajwani, S. 1956. A review of Lake Washington watershed, historical, biological, and

limnological. Master’s Thesis, Univ. Washington, Seattle, WA, 148 p.

Allen, R. L., and T. K. Meekin. 1973. Columbia River sockeye salmon study, 1972 progress

report. Wash. Dep. Fish., 61 p.

Allen, R. L., and T. K. Meekin. 1980. Columbia River sockeye salmon study, 1971-1974.

Wash. Dep. Fish. Prog. Rep. 120, 75 p.

Allen, M. J., and G. B. Smith. 1988. Atlas and zoogeography of common fishes in the

Bering Sea and northeastern Pacific. U.S. Dep. Commer., NOAA Tech. Rep. NMFS

66, 151 p.

Allendorf, F. W., and N. Ryman. 1987. Genetic management of hatchery stocks. In N.

Ryman and F. Utter (editors), Population genetics & fishery management, p. 141-159.

Univ. Washington Press, Seattle.

Altukhov, Yu. P., A. Yu. Novoselskaya, E. A. Salmenkova, G. D. Ryabova, A. A.

Goncharova, S. M. Konovalov, V. E. Ilyin, A. G. Shevlyakov, and Yu. I. Novelselsky.

1983. Factors of differentiation and integration of genetical structure of a native

system of Oncorhynchus nerka Walb. (Pisces) subpopulations in Lake Azabachye

(Kamchatka). [In Russ., Engl. Summ.] Zh. Obshch. Biol. 44:316-331.

Altukhov, Yu. P., E. A. Salmenkova, G. D. Ryabova, S. M. Konovalov, and A. I. Pudovkin.

1975. Stationary distributions of the frequencies of lactate dehygrogenase and

phosphoglucomutase genes in a system of subpopulations of a local fish stock of

Oncorhynchus nerka Walb. I. Stability of a stock over generations with simultaneous

variability of the component subpopulations. Sov. Genet. 11:447-454.

Altukhov, Yu. P., and N. V. Varnavskaya. 1983. Adaptive genetic structure and its

relationship to intrapopulational sex, age, and growth rate differentiation in sockeye,

Oncorhynchus nerka (Walb.). Sov. Genet. 19:614-624.

Aro, K. V., and G. C. Broadhead. 1950. Differences between egg counts of sockeye salmon

at Lakelse and Babine lakes. Fish. Res. Board Can. Pac. Prog. Rep. 82:17-19.

Aro, K. V., and M. P. Shepard. 1967. Salmon of the North Pacific Ocean -- Part IV.

Spawning populations of North Pacific salmon. 5. Pacific salmon in Canada. Int.

North Pac. Fish. Comm. Bull. 23:225-322.
158

Atkinson, C. E. 1976. Salmon aquaculture in Japan, the Koreas, and the USSR. In D. H.

Rosenberg (editor), Proceedings of the conference on salmon aquaculture and the

Alaska fishing community, p. 79-154. Alsk. Sea Grant Rep. 76-2.

Atkinson, C. E., J. H. Rose, and O. T. Duncan. 1967. Salmon of the North Pacific Ocean --

Part IV. Spawning populations of North Pacific salmon. 4. Pacific salmon in the

United States. Int. North Pac. Fish. Comm. Bull. 23:43-223.

Bagenal, T. B. 1978. Aspects of fish fecundity. In S. D. Gerking (editor), Ecology of

freshwater fish production, p. 75-101. Blackwell Scientific Publications, Oxford.

Bailey, R. E., and L. Margolis. 1987. Comparison of parasite fauna of juvenile sockeye

salmon (Oncorhynchus nerka) from southern British Columbian and Washington State

lakes. Can. J. Zool. 65:420-431.

Bakun, A. 1973. Coastal upwelling indices, west coast of North America, 1946-71. U.S.

Dep. Commer., NOAA Tech. Rep. NMFS SSRF-671, 103 p.

Bakun, A. 1975. Daily and weekly upwelling indices, west coast of North America, 1967-73.

U.S. Dep. Commer., NOAA Tech. Rep. NMFS SSRF-693, 114 p.

Barnaby, J. T. 1946. Letter to Dr. R. Van Cleve from J. T. Barnaby, dated 6 May 1946. In

“Transplanting adult Quinault bluebacks”, File 1380.1-1, Pacific Salmon Commission.

(Available from Librarian, Pacific Salmon Commission, Suite 600 - 1155 Robson

Street, Vancouver, B.C., Canada V6E 1B9.)

Barraclough, W. E., and D. Robinson. 1972. The fertilization of Great Central Lake. III.

Effect on juvenile sockeye salmon. Fish. Bull., U.S. 70:37-48.

Bartlett, G. 1967. The story of Wallowa Lake. Published by Grace Bartlett, 14 p. (Available

from West Coast Sockeye Salmon Administrative Record, Environmental and

Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street, Portland,

OR 97232.)

Beacham, T. D. 1982. Fecundity of coho salmon (Oncorhynchus kisutch) and chum salmon

(O. keta) in the northeast Pacific Ocean. Can. J. Zool. 60:1463-1469.

Beacham, T. D., and C. B. Murray. 1989. Variation in developmental biology of sockeye

salmon (Oncorhynchus nerka) and chinook salmon (O. tshawytscha) in British

Columbia. Can. J. Zool. 67:2081-2089.

Beacham, T. D., and C. B. Murray. 1993. Fecundity and egg size variation in North

American Pacific salmon (Oncorhynchus). J. Fish Biol. 42:485-508.
159

Beacham, T. D., R. E. Withler, and C. C. Wood. 1995. Stock identification of sockeye

salmon by means of minisatellite DNA variation. N. Am. J. Fish. Manage. 15:249-

265.

Beamish, R. J., and D. R. Bouillon. 1993. Pacific salmon production trends in relation to

climate. Can. J. Fish. Aquat. Sci. 50:1002-1016.

Beamish, R. J., C. M. Neville, and A. J. Cass. 1997. Production of Fraser River sockeye

salmon (Oncorhynchus nerka) in relation to decadal-scale changes in the climate and

the ocean. Can. J. Fish. Aquat. Sci. 54:950-968.

Beauchamp, D. A. 1995. Riverine predation on sockeye salmon fry migrating to Lake

Washington. N. Am. J. Fish. Manage. 15:358-365.

Beauchamp, D. A., M. G. LaRiviere, and G. L. Thomas. 1995. Evaluation of competition

and predation as limits to juvenile kokanee and sockeye salmon production in Lake

Ozette, Washington. N. Am. J. Fish. Manage. 15:193-207.

Bendire, C. 1881. Notes on Salmonidae of the Upper Columbia. Proc. U. S. Natl. Mus.

6:81-87.

Berggren, T. J. 1974. Seasonal changes in the abundance, biomass, production, distribution,

and feeding of the 1971 year class of sockeye salmon in Lake Sammamish. Master’s

Thesis, Univ. Washington, Seattle, WA, 80 p.

Bickham, J. W., C. C. Wood, and J. C. Patton. 1995. Biogeographic implications of

cytochrome b sequences and allozymes in sockeye (Oncorhynchus nerka). J. Hered.

86:140-144.

Bilton, H. T. 1970. Maternal influences on the age at maturity of Skeena River sockeye

salmon (Oncorhynchus nerka). Fish. Res. Board Can. Tech. Rep. 167:1-20.

Birtwell, I. K., M. D. Nassichuk, and H. Buene. 1987. Underyearling sockeye salmon

(Oncorhynchus nerka) in the estuary of the Fraser River. Can. Spec. Publ. Fish.

Aquat. Sci. 96:25-35.

Bjornn, T. C., D. R. Craddock, and D. R. Corley. 1968. Migration and survival of Redfish

Lake, Idaho, sockeye salmon, Oncorhynchus nerka. Trans. Am. Fish. Soc.

97(4):360-373.

Blackbourn, D. J. 1987. Sea surface temperature and pre-season prediction of return timing

in Fraser River sockeye salmon (Oncorhynchus nerka). Can. Spec. Publ. Fish. Aquat.

Sci. 96:296-306.
160

Blackett, R. F. 1979. Establishment of sockeye (Oncorhynchus nerka) and chinook (O.

tshawytscha) salmon runs at Frazer Lake, Kodiak, Island, Alaska. J. Fish. Res. Board

Can. 36:1265-1277.

Blair, G. R., D. E. Rogers, and T. P. Quinn. 1993. Variation in life history characteristics and

morphology of sockeye salmon in the Kvichak River system, Bristol Bay, Alaska.

Trans. Am. Fish. Soc. 122:550-559.

Blum, J. P. 1984. Management strategies for restoration and rehabilitation of sockeye

salmon (Oncorhynchus nerka) in Lake Ozette, Washington. In J. M. Walton and D. B.

Houston (editors), Proceedings of the Olympic wild fish conference, p. 55-62.

Fisheries Technology Program, Peninsula College, Port Angeles, WA.

Blum, J. P. 1988. Assessment of factors affecting sockeye salmon (Oncorhynchus nerka)

production in Ozette Lake, WA. Master’s Thesis, Univ. Washington, Seattle, WA,

107 p.

Boomer, R. 1995. Letter to R. Gustafson, NMFS, from R. Boomer, Project Leader, Western

Washington Fishery Resource Office, Fish and Wildlife Service, re. Quilcene National

Fish Hatchery Log Books, 1920-1958, dated 11 May 1995. 1 p. plus attachment.

(Available from West Coast Sockeye Salmon Administrative Record, Environmental

and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street,

Portland, OR 97232.)

Bortleson, G. C., and N. P. Dion. 1979. Preferred and observed conditions for sockeye

salmon in Ozette Lake and its tributaries, Clallam County, Washington. U.S. Geol.

Surv. Water-Res. Investigations 78-64, 61 p.

Bortleson, G. C., N. P. Dion, J. B. McConnell, and L. M. Nelson. 1976. Reconnaissance data

on lakes in Washington. Vol. 1, Clallam, Island, Jefferson, San Juan, Skagit, and

Whatcom Counties. Water-Supply Bulletin 43, 248 p.

Bower, S. M., and L. Margolis. 1984. Detection of infection and susceptibility of different

Pacific salmon stocks (Oncorhynchus spp.) to the haemoflagellate Cryptobia

salmositica. J. Parasitol. 70(2):273-278.

Bowler, B. 1990. Additional information on the status of Snake River sockeye salmon.

Report submitted to ESA Administrative Record for sockeye salmon, December 1990.

Idaho Department of Fish and Game, Boise, 23 p.

Brannon, E. L. 1972a. Mechanisms controlling migration of sockeye salmon fry. Ph.D.

Thesis, Univ. Washington, Seattle, WA, 156 p.
161

Brannon, E. L. 1972b. Mechanisms controlling migration of sockeye salmon fry. Int. Pac.

Salmon Fish. Comm. Bull. 21:1-86.

Brannon, E. L. 1987. Mechanisms stabilizing salmonid fry emergence timing. Can. Spec.

Publ. Fish. Aquat. Sci. 96:120-124.

Brannon, E. L. 1996. Review of preliminary work product “Preliminary conclusions of the

review of the status of sockeye salmon (Oncorhynchus nerka) from Washington and

Oregon under the U. S. Endangered Species Act,” and “Supplemental information

regarding proposed sockeye salmon ESUs for Washington and Oregon,” dated 19 July

1996, 17 p. (Available from West Coast Sockeye Salmon Administrative Record,

Environmental and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E.

Oregon Street, Portland, OR 97232.)

Brannon, E., A. Setter, T. Welsh, R. Danner, K. Collins, M. Casten, G. Thorgaard, K. Adams,

and S. Cummings. 1994. Genetic analysis of Oncorhynchus nerka: life history and

genetic analysis of Redfish Lake Oncorhynchus nerka. Completion report. U.S. Dep.

Energy, Bonneville Power Administration, Proj. No. 90-93, Contract No. DE-BI79-

90BP12885, Portland, OR, 48 p.

Brenner, R., S. Hennig, A. Holt, and V. Ridge-Cooney. 1990. Quality of local lakes and

streams: 1988-1989 status report. Water Resources Section, Municipality of

Metropolitan Seattle, Publication 167, 297 p. plus 6 appendices.

Britton, E. W., A. J. Leaney-East, C. I. Manzon, and D. E. Marshall. 1982. Catalogue of

salmon streams and spawning escapements of Statistical Area 5. Can. Data Rep. Fish.

Aquat. Sci., No. 320, 250 p.

Brix, R., and R. Kolb. 1971. Catch and effort data for Washington coastal Indian fisheries.

Wash. Dep. Fish., Olympia, WA, 22 p.

Brown, B. 1982. Mountain in the clouds: A search for the wild salmon. Simon and

Schuster, New York, 239 p.

Brunson, R. B., G. B. Castle, and R. Pirtle. 1952. Studies of sockeye salmon (Oncorhynchus

nerka) from Flathead Lake, Montana. Proc. Montana Acad. Sci. 12:35-43.

Brusca, R. C., and B. R. Wallerstein. 1979. Zoogeographic patterns of idoteid isopods in the

Northeast Pacific, with a review of shallow water zoogeography of the area. Bull.

Biol. Soc. Wash. 3:67-105.
162

Bryant, F. G., and Z. E. Parkhurst. 1950. Survey of the Columbia River and its tributaries-4.

Area III, Washington streams from the Klickitat and Snake Rivers to Grand Coulee

Dam on the Columbia and its tributaries above Grand Coulee Dam. U.S. Fish Wildl.

Serv. Spec. Sci. Rep. Fish. 37, 108 p.

Bryant, M. D. 1976. Lake Washington sockeye salmon: biological production and simulated

harvest by three fisheries. Ph.D. Thesis, Univ. Washington, Seattle, WA, 159 p.

Buckley, R. 1965. Incidence of beach spawning sockeye salmon in Lake Washington and

Lake Sammamish. Wash. Dep. Fish., Annual Report, 1964, 28 p.

Budy, P., C. Luecke, W. A. Wurtsbaugh, and H. P. Gross. 1995. Limnology of Sawtooth

Valley lakes with respect to potential growth of juvenile Snake River sockeye salmon.

Northwest Sci. 69(2):133-150.

Buerge, D. M. 1985. Requiem for a river. The Weekly, Seattle’s News magazine. October

16-22:33-49.

Buerge, D. M. 1989. Renton, where the water took wing. Windsor Publ., Chatsworth,

California, 135 p.

Bugaev, V. F. 1984. Method for identification of sockeye salmon, Oncorhynchus nerka

(Salmonidae), of different spawning populations in the Kamchatka River Basin. J.

Ichthyol. 24(2):47-53.

Bugaev, V. F. 1987. Scale patterns and biology of juvenile sockeye salmon (Oncorhynchus

nerka) in the Kamchatka River. Can. Spec. Publ. Fish. Aquat. Sci. 96:36-43.

Bugaev, V. F. 1992. Age structure of sockeye salmon, Oncorhynchus nerka, and methods for

its study. J. Ichthyol. 32(8):1-19.

Burch, J. B. 1989. North American freshwater snails. Malacological Publications, Hamburg,

Michigan, 365 p.

Burgner, R. L. 1991. Life history of sockeye salmon Oncorhynchus nerka. In C. Groot and

L. Margolis (editors), Pacific salmon life histories, p. 3-117. Univ. British Columbia

Press, Vancouver, B.C., Canada.

Burke, J. 1996. Letter to Dr. M. Schiewe, NMFS, from J. Burke, Deputy Director, Division

of Sport Fish, Alaska Department of Fish and Game, dated 11 July 1996. 2 p.

(Available from West Coast Sockeye Salmon Administrative Record, Environmental

and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon

Street,Portland, OR 97232.)
163

Burner, C. J. 1951. Characteristics of spawning nests of Columbia River salmon. U.S. Fish.

Wildl. Serv., Fish. Bull. 52:95-110.

Busby, P. J., T. C. Wainwright, G. J. Bryant, L. J. Lierheimer, R. S. Waples, F. W. Waknitz,

and I. V. Lagomarsino. 1996. Status review of West Coast Steelhead from

Washington, Idaho, Oregon, and California. U.S. Dep. Commer., NOAA Tech.

Memo. NMFS-NWFSC-27, 261 p.

Butler, V. L. 1987. Chapter 10, Fish remains. In URS Corp., The Duwamish No. 1 site:

1986 data recovery, p. 10-1 to 10-37. METRO, Municipality of Metropolitan Seattle,

Renton effluent transfer system, Contact No. CW/F2-82, task 48.08. URS Corp.,

Seattle, WA.

Butler, V. L. 1990. Fish remains from the Black River sites (45-KI-59 and 45-KI-51-D).

Archaeology in Washington 2:49-65.

Caughley, G. 1994. Directions in conservation biology. J. Anim. Ecol. 63:215-244.

Cavalli-Sforza, L. L., and A. W. F. Edwards. 1967. Phylogenetic analysis: models and

estimation procedures. Evolution 21:550-570.

Cedarholm, C. J., L. C. Lestelle, B. G. Edie, D. J. Martin, J. V. Tagart, and E. O. Salo. 1978.

The effects of landslide siltation on the salmon and trout resources of Stequaleho

Creek and the main Clearwater River, Jefferson County, Washington, 1972-1975.

Final report - Part II. Fish. Res. Inst., Univ. Washington, Seattle, WA, FRI-UW-7804,

53 p.

Chakraborty, R. 1980. Gene-diversity analysis in nested subdivided populations. Genetics

96:721-726.

Chamberlain, F. M. 1907. Some observations on salmon and trout in Alaska. Report of the

Commissioner of Fisheries for the fiscal year 1906 and special papers, Bur. Fish. Doc.

No. 627, 112 p plus 5 figures, Government Printing Office, Washington, D.C.

Chapman, D., C. Peven, A. Giorgi, T. Hillman, F. Utter, M. Hill, J. Stevenson, and M. Miller.

1995. Status of sockeye salmon in the Mid-Columbia region. Don Chapman

Consultants, Inc., 245 p. plus 129 figs., 26 tables, and 1 appendix.

Chapman, D., W. S. Platts, D. Park, and M. Hill. 1990. Status of Snake River sockeye

salmon. Don Chapman Consultants, Inc., Final Report for Pacific Northwest Utilities

Conference Committee, 90 p.

Chapman, W. M. 1941. Observations on the migration of salmonid fishes in the Upper

Columbia River. Copeia 1941(4):240-242.
164

Chapman, W. M. 1943. The spawning of chinook salmon in the main Columbia River.

Copeia 1943(3):138.

Chatters, J. C. 1988. Tualdad Altu (45KI49), a 4th century village on the Black River, King

County, Washington. First City Equities, Seattle, WA, 140 p.

Chrzastowski, M. 1983. Historical changes to Lake Washington and route of the Lake

Washington Ship Canal, King County, Washington. Water Res. Invest Open-File

Rep. 81-1182, Map plus 9 p. text.

Clarke, A. H. 1981. The Freshwater Molluscs of Canada. National Museum of Natural

Sciences, National Museums of Canada, Ottawa, 446 p.

Clutter, R. I., and L. E. Whitesel. 1956. Collection and interpretation of sockeye salmon

scales. Int. Pac. Salmon Fish. Comm. Bull. 9, 159 p.

Cobb, J. N. 1911. The salmon fisheries of the Pacific coast. Report of the Commissioner of

Fisheries for the Fiscal Year 1910 and Special Papers, 180 p.

Cobb, J. N. 1914. The species of Pacific salmon and the runs. Pac. Fisherman Yearbook

1914, 12(2):31-33.

Cobb, J. N. 1927. Preliminary report of fishway work. Trans. Am. Fish. Soc. 57:181-201.

Cobb, J. N. 1930. Pacific salmon fisheries, 4th edition. Bureau of Fisheries, Washington,

D.C. 704 p.

Columbia Basin Fish and Wildlife Authority (CBFWA). 1990. Integrated system plan for

salmon and steelhead production in the Columbia River Basin. Columbia Basin

System Planning, 449 p. plus 40 subbasin volumes.

Cook, F. R. 1984. Introduction to Canadian amphibians and reptiles. National Museum of

Natural Sciences, National Museums of Canada, Ottawa, 200 p.

Corsaletti, L. T. 1981. A river forgotten. The Seattle Times, March 18, 1981, South Times

p. G1.

Cox, S. P., and S. G. Hinch. 1997. Changes in size at maturity of Fraser River sockeye

salmon (Oncorhynchus nerka) (1952-1993) and associations with temperature. Can. J.

Fish. Aquat. Sci. 54:1159-1167.

Craddock, D. R., and R. L. Major. 1958. The spawning escapement of Columbia River

blueback salmon (Oncorhynchus nerka) - 1958. Bur. of Commer. Fish., Seattle, WA,

10 p. plus figures and tables.
165

Craddock, D. R., and R. L. Major. 1959. The spawning escapement of Columbia River

blueback salmon (Oncorhynchus nerka) - 1959. Bur. of Commer. Fish., Seattle, WA,

13 p.

Craig, J. A., and A. J. Suomela. 1941. Time of appearance of the runs of salmon and

steelhead trout native to the Wenatchee, Entiat, Methow and Okanogan rivers.

Unpubl. manuscr., U.S. Fish Wildl. Serv., 35 p.

Craig, J. K. 1995. Genetic divergence in spawning color of sympatric forms of sockeye

salmon (Oncorhynchus nerka): investigation of an unknown form. Master’s Thesis,

Univ. Washington, Seattle, WA, 105 p.

Craig, P. C. 1985. Identification of sockeye salmon (Oncorhynchus nerka) stocks in the

Stikine River based on egg size measurements. Can. J. Fish. Aquat. Sci.

42:1696-1701.

Cramer, S. P. 1990. The feasibility for reintroducing sockeye and coho salmon in the Grande

Ronde River and coho and chum salmon in the Walla Walla River. Progress Report

prepared for Nez Perce Tribe, Umatilla Confederated Tribes, Warm Springs

Confederated Tribes, and Oregon Department of Fish and Wildlife by S. P. Cramer

and Associates, Gresham, OR, 132 p. (Available from West Coast Sockeye Salmon

Administrative Record, Environmental and Technical Services Division, Natl. Mar.

Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Crawford, B. A. 1979. The origin and history of trout brood stocks of the Washington

Department of Game. Wash. State Game Dep., Fish. Res. Rep. 76 p.

Crawford, J. M. 1907. Some plain truths relative to propagation. Pac. Fisherman 5(3):9-11.

Crozier, G. F. 1969. Tissue carotenoids in prespawning and spawning sockeye salmon

(Oncorhynchus nerka). J. Fish. Res. Board Can. 27(5):973-975.

Crutchfield, J. A., K. B. Kral, and L. A. Phinney. 1965. An economic evaluation of

Washington State Department of Fisheries’ controlled natural-rearing program for

coho salmon (Oncorhynchus kisutch). Submitted to U.S. Fish Wildl. Serv. by Wash.

Dep. Fish. Res. Division under Contract #14-17-0007-246, 152 p.

Curtright, S. 1979. The Quinault blueback. Quinault Dept. Natural Resources Economic

Development Newsletter, May 1979:4-5.

Dall, W. H. 1905. Land and freshwater mollusks of Alaska and adjoining regions. Harriman

Alsk. Expedition 13:1-171.
166

Danner, G. R. 1994. Behavioral, physiological and genetic differences among anadromous

and resident Oncorhynchus nerka populations. Master’s Thesis, Univ. Idaho, Boise,

ID, 107 p.

Davidson, F. A. 1953. Historical notes on development of Yakima River Basin. Manuscript

report, 21 p. (Available from West Coast Sockeye Salmon Administrative Record,

Environmental and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E.

Oregon Street, Portland, OR 97232.)

Davidson, F. A. 1966. Population trends in the blueback and Upper Columbia River fall

chinook salmon. Grant County PUD, Ephrata, WA, 36 p. plus figures and tables.

Davidson, F. A., and J. T. Barnaby. 1936. Survey of Quinault river system and its runs of

sockeye salmon. Unpublished manuscript, Bureau of Fisheries, 17 p. (Available from

West Coast Sockeye Salmon Administrative Record, Environmental and Technical

Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street, Portland, OR

97232.)

Dawson, J. J. 1972. Determination of seasonal distribution of juvenile sockeye salmon in

Lake Washington by means of acoustics. Master’s Thesis, Univ. Washington, Seattle,

WA. 112 p.

Dawson, J. J., R. E. Thorne, and J. J. Traynor. 1973. Acoustic surveys of Lake Wenatchee

and Lake Osoyoos in 1973. Final Report, Service Contr. 526, to Wash. Dep. Fish., by

Fish. Res. Inst., Coll. of Fish., Univ. Washington, Seattle, WA, 18 p.

Denman, K. L., D. L. Mackas, H. J. Freeland, M. J. Austin, and S. H. Hill. 1981. Persistent

upwelling and mesoscale zones of high productivity off the west coast of Vancouver

Island, Canada. In F. A. Richards (editor), Coastal upwelling, p. 514-521. American

Geophysical Union, Washington, D.C.

Dion, N. P., G. C. Bortleson, J. B. McConnell, and J. K. Innes. 1976a. Data on selected lakes

in Washington, Part 5. Water-Supply Bulletin 42, Part 5, 125 p.

Dion, N. P., G. C. Bortleson, J. B. McConnell, and J. K. Innes. 1976b. Reconnaissance data

on lakes in Washington, Vol. 5, Chelan, Ferry, Klickitat, Okanogon, and Yakima

counties. Water-Supply Bulletin 43, Part 5, 264 p.

Dlugokenski, C. E., W. H. Bradshaw, and S. R. Hager. 1981. An investigation of the limiting

factors to Lake Ozette sockeye salmon production and a plan for their restoration.

U.S. Fish Wildl. Serv., Fisheries Assistance Office, Olympia, WA, 52 p.
167

Doble, B. D., and D. M. Eggers. 1978. Diel feeding chronology, rate of gastric evacuation,

daily ration, and prey selectivity in Lake Washington juvenile sockeye salmon

(Oncorhynchus nerka). Trans. Am. Fish. Soc. 107:36-45.

Donaldson, L. R. 1980. Salmon ranching in Washington State. In J. E. Thorpe (ed.) Salmon

ranching, p. 29-45. Academic Press, New York.

Easterbrook, D. J., and D. A. Rahm. 1970. Landforms of Washington, the geologic

environment. Union Printing Co., Bellingham, WA, 156 p.

Edie, B. G. 1975. A census of the juvenile salmonids of the Clearwater River Basin,

Jefferson County, Washington, in relation to logging. Master’s Thesis, Univ.

Washington, Seattle, WA, 86 p.

Edmondson, W. T. 1977a. Section VI - Washington. Lake Washington. In Seyb, L. and K.

Randolph (eds.) North American project — A study of U. S. water bodies, p. 288-300.

U.S. Environmental Protection Agency, Environmental Research Laboratory -

Corvallis, EPA-600/3-77-086.

Edmondson, W. T. 1977b. Trophic equilibrium of Lake Washington. U.S. Environmental

Protection Agency, Ecological Research Series, EPA-6000/3-77-087, 35 p.

Edmondson, W. T., and S. E. B. Abella. 1988. Unplanned biomanipulation in Lake

Washington. Limnologica 19:73-79.

Edmondson, W. T., and J. T. Lehman. 1981. The effect of changes in the nutrient income on

the condition of Lake Washington. Limnol. Oceanogr. 26:1-29.

Edmondson, W. T., and A. H. Litt. 1982. Daphnia in Lake Washington. Limnol. Oceanogr.

27:272-293.

Egan, R. 1977. Salmon spawning ground data report. State of Wash. Dep. Fish. Prog. Rep.

17, 346 p.

Egan, R. 1995. Letter to R. Gustafson, NMFS, from R. Egan, WDFW, re. Sockeye Salmon

Spawning Ground Survey Data, dated 28 June 1995. 1 p. plus 33 p. computer

printout. (Available from West Coast Sockeye Salmon Administrative Record,

Environmental and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E.

Oregon Street, Portland, OR 97232.)
168

Egan, R. 1997. Letter to R. Gustafson, NMFS, from R. Egan, WDFW, re. Sockeye Salmon

Spawning Ground Survey Data, dated 10 January 1997. 1 p. plus 9 p. computer

printout. (Available from West Coast Sockeye Salmon Administrative Record,

Environmental and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E.

Oregon Street, Portland, OR 97232.)

Eggers, D. M. 1978. Limnetic feeding behavior of juvenile sockeye salmon in Lake

Washington and predator avoidance. Limnol. Oceanogr. 23:1114-1125.

Eggers, D. M., and D. E. Rogers. 1987. The cycle of runs of sockeye salmon (Oncorhynchus

nerka) to the Kvichak River, Bristol Bay, Alaska: cyclic dominance or depensatory

fishing? Can. Spec. Publ. Fish. Aquat. Sci. 96:343-366.

Egorova, T. V. 1970. Reproduction and development of sockeye in the basin of Ozernaya

River. Izv. Tikhookean. Nauchno-Issled. Inst. Rybn. Khoz. Okeanogr. 73:39-53.

[Fish. Res. Board Can. Transl. Ser. No. 2619]

Eiler, J. H., B. D. Nelson, R. F. Bradshaw, J. R. Greiner, and J. M. Lorenz. 1988.

Distribution, stock composition, and location and habitat type of spawning areas used

by sockeye salmon on the Taku River. NWAFC Processed Rep. 88-24, 44 p.

Eiler, J. H., B. D. Nelson, and R. F. Bradshaw. 1992. Riverine spawning by sockeye salmon

in the Taku River, Alaska and British Columbia. Trans. Am. Fish. Soc.

121(6):701-708.

Emmett, R. L., and M. H. Schiewe (eds.). 1997. Estuarine and ocean survival of northeastern

Pacific salmon. Proceedings of the workshop, March 20-22, 1996, Newport, OR.

U.S. Dep. Commer., NOAA Tech. Memo. NMFS-NWFSC-29, 313 p.

Emmett, R. L., S. L. Stone, S. A. Hinton, and M. E. Monaco. 1991. Distribution and

abundance of fishes and invertebrates in west coast estuaries, Volume II: species life

history summaries. ELMR Rep. No. 8 NOAA/NOS Strategic Environmental

Assessments Division, Rockville, MD, 329 p.

Evermann, B. W. 1895. A preliminary report upon salmon investigations in Idaho in 1894.

U.S. Fish Comm., Bull. 15:253-284.

Evermann, B. W. 1896. A report upon salmon investigations in the headwaters of the

Columbia River, in the state of Idaho, in 1895, together with notes upon the fishes

observed in that state in 1894 and 1895. U.S. Fish Comm., Bull. 16:151-202.

Evermann, B. W., and E. L. Goldsborough. 1907. The fishes of Alaska. U.S. Bur. Fish.,

Bull. 26:219-360, 144 figs.
169

Evermann, B. W., and H. B. Latimer. 1910. On a collection of fishes from the Olympic

Peninsula, together with notes on other west coast species. Proc. Biol. Soc. Wash.

23:131-140.

Evermann, B. W., and S. E. Meek. 1898. A report upon salmon investigations in the

Columbia River Basin and elsewhere on the Pacific Coast in 1896. U.S. Fish Comm.,

Bull. 17:15-84.

Evermann, B. W., and J. T. Scovell. 1896. Recent investigations concerning the redfish,

Oncorhynchus nerka, at its spawning grounds in Idaho. Proc. Indiana Acad. Sci.

1895:131-134.

Fagen, R., and W. W. Smoker. 1989. How large - capacity hatcheries can alter interannual

variability of salmon production. Fish. Res. 8:1-11.

Farley, A. L. 1979. Atlas of British Columbia. Univ. British Columbia Press, Vancouver,

B.C., 136 p.

Fish Commission of Oregon. 1967. A report on and recommendations concerning passage of

fish at Pelton and Round Butte Dams. Fish Comm. Oreg., Res. Division, Portland,

OR.

Fish and Wildlife Technical Committee (FWTC). 1970. Nooksack-Sumas Basins. In

Comprehensive study of water and related resources, Puget Sound and adjacent

waters, Appendix XI, Fish and Wildlife, p. 4.1-4.32. Puget Sound Task Force, Pacific

Northwest River Basins Commission, Vancouver, WA.

Fish Passage Center. 1996. Fish Passage Center Weekly Report 96-30, Fish Passage Center,

Portland, OR, 10 p.

Fish, F. F., and M. G. Hanavan. 1948. A report on the Grand Coulee Fish-Maintenance

Project 1939-1947. U.S. Fish Wildl. Serv. Spec. Sci. Rep. 55, 61 p.

Foerster, R. E. 1937. The relation of temperature to the seaward migration of young sockeye

salmon (Oncorhynchus nerka). J. Biol. Board Can. 3(5):421-438.

Foerster, R. E. 1944. The relation of lake population density to size of young sockeye

salmon (Oncorhynchus nerka). J. Fish. Res. Board Can. 6(3):267-280.

Foerster, R. E. 1947. Experiment to develop sea-run from land-locked sockeye salmon

(Oncorhynchus nerka kennerlyi). J. Fish. Res. Board Can. 7(2):88-93.

Foerster, R. E. 1968. The sockeye salmon, Oncorhynchus nerka. Bull. Fish. Res. Board

Can. 162, 422 p.
170

Foerster, R. E., and A. L. Pritchard. 1941. Observations on the relation of egg content to total

length and weight in sockeye salmon (Oncorhynchus nerka) and pink salmon (O.

gorbuscha). Trans. R. Soc. Can. Sect. V, Ser. 3, 35:51-60.

Folsom, W., D. Altman, A. Manuar, F. Nielsen, T. Revord, E. Sanborn, and M. Wildman.

1992. World salmon culture. U.S. Dep. Commer., NOAA Tech. Memo. NMFS-F/

SPO-3, Silver Spring, Maryland, 323 p.

Foote, C. J., and P. A. Larkin. 1988. The role of male choice in the assortative mating of

anadromous and non-anadromous sockeye salmon (Oncorhynchus nerka). Behaviour

106(1-2):43-61.

Foote, C. J., I. Mayer, C. C. Wood, W. C. Clarke, and J. Blackburn. 1994. On the

developmental pathway to nonanadromy in sockeye salmon, Oncorhynchus nerka.

Can. J. Zool. 72:397-405.

Foote, C. J., C. C. Wood, C. Clarke, and J. Blackburn. 1992. Circannual cycle of seawater

adaptability in Oncorhynchus nerka: Genetic differences between sympatric sockeye

salmon and kokanee. Can. J. Fish. Aquat. Sci. 49:99-109.

Foote, C. J., C. C. Wood, and R. E. Withler. 1989. Biochemical genetic comparison of

sockeye salmon and kokanee, the anadromous and nonanadromous forms of

Oncorhynchus nerka. Can. J. Fish. Aquat. Sci. 46:149-158.

Forrester, C. R. 1987. Distribution and abundance of sockeye salmon (Oncorhynchus nerka).

Can. Spec. Publ. Fish. Aquat. Sci. 96:2-10.

Forstall, R. L. (editor). 1969. The international atlas. Rand McNally, Chicago, 223 p.

Foskett, D. R. 1958. The Rivers Inlet sockeye salmon. J. Fish. Res. Board Can. 15(5):867-

889.

Foy, M. G., K. K. English, C. R. Steward, J. Big Eagle, and C. Huntington. 1995a. Sockeye

salmon catch, escapement, and historical abundance data. A report prepared for U.S.

Dep. Commer., Natl. Mar. Fish. Serv., Northwest Fisheries Science Center, Coastal

Zone and Estuarine Studies Division. (Available from West Coast Sockeye Salmon

Administrative Record, Environmental and Technical Services Division, Natl. Mar.

Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)
171

Foy, M. G., K. K. English, C. R. Steward, J. Big Eagle and C. Huntington. 1995b. Marine

commercial and sport catch databases with information on salmon and steelhead.

Report by Big Eagle and Associates and LGL Limited for U.S. Dep. Comm., Natl.

Mar. Fish. Serv., 45 p. plus appendices. (Available from West Coast Sockeye Salmon

Administrative Record, Environmental and Technical Services Division, Natl. Mar.

Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Fredericks, J. P., M. A. Maiolie, and S. Elam. 1995. Kokanee impacts assessment and

monitoring on Lake Pend Oreille, Idaho - Chapter 1. Kokanee impacts assessment and

monitoring on Dworshak Reservoir, Idaho - Chapter 2. Annual Progress Report:

January - December 1994. U.S. Dep. Energy, Bonneville Power Administration, Proj.

No. 94-035, Contract No. 94BII2917, 87BI35167. Portland, OR, 61 p.

French, R., H. Bilton, M. Osako, and A. Hartt. 1976. Distribution and origin of sockeye

salmon (Oncorhynchus nerka) in offshore waters of the North Pacific Ocean. Int.

North Pac. Fish. Comm. Bull. 34, 113 p.

French, R. R., and R. J. Wahle. 1954. The distribution of salmon above Rock Island Dam as

observed from stream surveys during the spawning season of 1954. U.S. Fish Wildl.

Serv., Seattle, WA, 17 p.

French, R. R., and R. J. Wahle. 1959. Biology of chinook salmon and blueback salmon and

steelhead in the Wenatchee River system. U.S. Fish Wildl. Serv. Spec. Sci. Rep. 304,

17 p.

French, R. R., and R. J. Wahle. 1960. Salmon runs - Upper Columbia River, 1956-57. U.S.

Fish Wildl. Serv. Spec. Sci. Rep. 364, 15 p.

French, R. R., and R. J. Wahle. 1965. Salmon escapements above Rock Island Dam,

1954-60. U. S. Fish Wildl. Serv. Spec. Sci. Rep. 493, 18 p.

Fryer, J. K. 1995. Columbia Basin sockeye salmon: Causes of their past decline, factors

contributing to their present low abundance, and future outlook. Ph.D. Thesis, Univ.

Washington, Seattle, WA, 274 p.

Fryer, J. K., and M. Schwartzberg. 1993. Identification of Columbia Basin sockeye salmon

stocks using scale pattern analyses in 1992. Columbia River Inter-Tribal Fish

Commission, Tech. Rep. 93-2, 35 p.

Fryer, J. K., and M. Schwartzberg. 1994. Identification of Columbia Basin sockeye salmon

stocks using scale pattern analyses in 1993. Columbia River Inter-Tribal Fish

Commission, Tech. Rep. 94-2, 39 p.
172

Fulton, L. A. 1966. Palmer Lake study, 1966. Bur. Commer. Fish., Fish-Passage Res.

Program, 8 p. (Available from West Coast Sockeye Salmon Administrative Record,

Environmental and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E.

Oregon Street, Portland, OR 97232.)

Fulton, L. A. 1970. Spawning areas and abundance of steelhead trout and coho, sockeye, and

chum salmon in the Columbia River basin -- past and present. Spec. Sci. Rep. --

Fisheries 618, 37 p. Natl. Mar. Fish. Serv., Washington, D.C.

Fulton, L. A., and R. E. Pearson. 1981. Transplantation and homing experiments on salmon,

Oncorhynchus spp., and steelhead trout, Salmo gairdneri, in the Columbia River

system: fish of the 1939-1944 broods. U.S. Dep. Commer., NOAA Tech. Memo.

NMFS F/NWC 12, 97 p.

Gangmark, H. A., and L. A. Fulton. 1952. Status of Columbia blueback salmon runs, 1951.

U. S. Fish Wildl. Serv. Spec. Sci. Rep. 74, 29 p.

Gard, R., B. Drucker, and R. Fagen. 1987. Differentiation of subpopulations of sockeye

salmon (Oncorhynchus nerka), Karluk River System, Alaska. Can. Spec. Publ. Fish.

Aquat. Sci. 96:408-418.

Gilbert, C. H. 1914. Contributions to the life history of the sockeye salmon. (No. 1) In

Report of the British Columbia Commissioner of Fisheries, 1914, p. R53-R78.

Province of British Columbia, Victoria, B.C., Canada.

Gilbert, C. H. 1918. Contributions to the life history of the sockeye salmon (No. 4). In

Report of the British Columbia Commissioner of Fisheries, 1917, p. 33-80. Province

of British Columbia, Victoria, B.C., Canada.

Gilbert, C. H. 1919. Contributions to the life history of the sockeye salmon (No. 5). In

Report of the British Columbia Commissioner of Fisheries, 1918, p. 26-52. Province

of British Columbia, Victoria, B.C., Canada.

Gilhousen, P. 1960. Migratory behavior of adult Fraser River sockeye. Int. Pac. Salmon

Fish. Comm. Prog. Rep. 7, 72 p.

Gilhousen, P. 1990. Prespawning mortalities of sockeye salmon in the Fraser River system

and possible casual factors. Int. Pac. Salmon Fish. Comm. Bull. 27, 62 p.

Gilpin, M. E., and M. E. Soulé. 1986. Minimum viable populations: Processes of species

extinction. In M. E. Soulé (editor), Conservation biology: The science of scarcity and

diversity, p. 19-34. Sinauer, Sunderland, MA.
173

Godfrey, H. 1958. A comparison of sockeye salmon catches at Rivers Inlet and Skeena

River, B. C., with particular reference to age at maturity. J. Fish. Res. Board Can.

15:331-354.

Godin, J. G. J. 1982. Migrations of salmonid fishes during early life history phases: Daily

and annual timing. In E. L. Brannon and E. O. Salo (editors), Proceedings of the

salmon and trout migratory behavior symposium, p. 22-50. School of Fisheries, Univ.

Washington, Seattle, WA.

Goldstein, L. S. 1982. Little Bear Creek stream resource inventory. Tech. Rep. WR-82-4.

METRO Water Quality Division, Municipality of Metropolitan Seattle, 51 p. plus

appendices.

Goodlad, J. C., T. W. Gjernes, and E. L. Brannon. 1974. Factors affecting sockeye salmon

(Oncorhynchus nerka) growth in four lakes of the Fraser River system. J. Fish. Res.

Board Can. 31:871-892.

Grant, W. S., G. B. Milner, P. Krasnowski, and F. M. Utter. 1980. Use of biochemical

genetic variants for identification of sockeye salmon (Oncorhynchus nerka) stocks in

Cook Inlet, Alaska. Can. J. Fish. Aquat. Sci. 37:1236-1247.

Graynoth, E. 1995. Spawning migrations and reproduction of landlocked sockeye salmon

(Oncorhynchus nerka) in the Waitaka catchment, New Zealand. N. Z. J. Mar.

Freshwater Res. 29:257-269.

Groot, C., and K. Cooke. 1987. Are the migrations of juvenile and adult Fraser River

sockeye salmon (Oncorhynchus nerka) in near-shore waters related? Can. Spec. Publ.

Fish. Aquat. Sci. 96:53-60.

Gross, H. P., W. A. Wurtsbaugh, C. Luecke, and P. Budy. 1993. Nutrient limitation of

phytoplankton in oligotrophic lakes of the Sawtooth Valley, Idaho. In C. Luecke and

W. Wurtsbaugh (editors), Part II: Limnological and fisheries investigations of

Sawtooth Valley lakes with respect to potential rehabilitation of endangered Snake

River sockeye salmon, p. 29-52. BPA Report DOE/BP-22548-1.

Gunsolus, R. T., and G. J. Eicher. 1962. Evaluation of the fish passage facilities at the Pelton

project on the Deschutes River in Oregon. Fish Comm. Oregon and Portland General

Electric Co., 133 p.

Guthrie, C. M., III, J. H. Helle, P. Aebersold, G. A. Winans, and A. J. Gharrett. 1994.

Preliminary report on the genetic diversity of sockeye salmon populations from

southeast Alaska and northern British Columbia. Alsk. Fish. Sc. Center Proc. Rep.

94-03, 109 p.
174

Hall, C. A. 1964. Shallow-water marine climates and molluscan provinces. Ecology

45(2):226-234.

Hallock, R. J., and D. H. Fry, Jr. 1967. Five species of salmon, Oncorhynchus, in the

Sacramento River, California. Calif. Fish Game 53(1):5-22.

Halupka, K. C., J. K. Troyer, M. F. Wilson, M. B. Bryant, and F. H. Everest. 1993.

Identification of unique and sensitive sockeye salmon stocks of Southeast Alaska

(Draft Manuscript). For. Sc. Lab., Pac. N. W. Res. Stat., U.S. Dep. Agr., 235 p.

Hämäläinen, A. H. E. 1978. Effects of instream flow levels on sockeye salmon fry

production in the Cedar River, Washington. Master’s Thesis, Univ. Washington,

Seattle, WA, 90 p.

Hamilton, J. A. R., and F. J. Andrew. 1954. An investigation of the effect of Baker Dam on

downstream-migrant salmon. Int. Pac. Salmon Fish. Comm. Bull. 6:1-73.

Hamilton, J. A. R., and L. Rothfus. 1963. A summary report on Lake Merwin investigations.

Wash. Dept. Fish., Olympia, WA, 40 p.

Hammond, J. P. 1886. Fish in Puget Sound. U.S. Fish Comm., Bull. 6:95-196.

Hanamura, N. 1966. Salmon of the North Pacific Ocean -- Part III. A review of the life

history of North Pacific salmon: Sockeye salmon in the far east. Int. North Pac. Fish.

Comm. Bull. 18:1-27.

Hanamura, N. 1967. Salmon of the North Pacific Ocean -- Part IV. Spawning populations of

North Pacific salmon. 1. Sockeye salmon in the Far East. Int. North Pac. Fish.

Comm. Bull. 23:1-7.

Hanson, A.J., and H. D. Smith. 1967. Mate selection in a population of sockeye salmon

(Oncorhynchus nerka) of mixed age-groups. J. Fish. Res. Board Can.

24(9):1955-1977.

Hanson, J. M., and W. C. Leggett. 1982. Empirical prediction of fish biomass and yield.

Can. J. Fish. Aquat. Sci. 39:257-263.

Hard, J. J., R. P. Jones, M. R. Delarm, and R. S. Waples. 1992. Pacific salmon and artificial

propagation under the Endangered Species Act. U.S. Dep. Commer., NOAA Tech.

Memo. NMFS-F/NWFSC-2, 56 p.

Hartman, W. L. and R. L. Burgner. 1972. Limnology and fish ecology of sockeye salmon

nursery lakes of the world. J. Fish. Res. Board. Can. 29:699-715.
175

Hartman, W. L., and C. Y. Conkle. 1960. Fecundity of red salmon at Brooks and Karluk

lakes, Alaska. U.S. Fish. Wildl. Serv., Fish. Bull. 61:53-60.

Hartman, W. L., W. R. Heard, and B. Drucker. 1967. Migratory behavior of sockeye salmon

fry and smolts. J. Fish. Res. Board Can. 24(10):2069-2099.

Hartt, A. C. 1980. Juvenile salmonids in the oceanic ecosystem - The critical first summer.

In W. J. McNeil and D. C. Himsworth (editors), Salmonid ecosystems of the North

Pacific, p. 25-57. Oregon State Univ. Press, Corvallis, OR.

Hartt, A. C., and M. B. Dell. 1986. Early oceanic migrations and growth of juvenile Pacific

salmon and steelhead trout. Int. North Pac. Fish. Comm. Bull. 46, 105 p.

Hassemer, P. F., S. W. Kiefer, and C. E. Petrosky. 1996. Idaho’s salmon: can we count

every last one? In D. J. Stouder, P. A. Bisson, and R. J. Naiman (editors), Pacific

salmon and their ecosystems, status and future options, p. 113-125. Chapman & Hall,

New York.

Hatch, D. R., A. Wand, and M. Schwartzberg. 1992. Wenatchee River salmon escapement

estimates using video tape technology in 1991. Columbia River Inter-Tribal Fish

Commission, Tech. Rep. 92-3. 28 p.

Hayden, B. P., and R. Dolan. 1976. Coastal marine fauna and marine climates of the

Americas. J. Biogeogr. 3:71-81.

Healey, M. C. 1986. Optimum size and age at maturity in Pacific salmon and effects of

size-selective fisheries. In D. J. Meerburg (editor), Salmonid age at maturity, p. 39-52.

Can. Spec. Publ. Fish. Aquat. Sci. 89.

Healey, M. C. 1987. The adaptive significance of age and size at maturity in female sockeye

salmon (Oncorhynchus nerka). Can. Spec. Publ. Fish. Aquat. Sci. 96:110-117.

Heg, R. T. 1953. Further observations on Lake Pleasant. In Smoker, W. A., H. M. Jensen,

R. T. Heg, J. W. Fitzgerald, R. W. Williams, W. Bayliff, W. Rees, and D. R.

Johnson. Progress Report, Puget Sound Investigations, December 1952 to

February 1953. Wash. Dept. Fish. Wildl., Olympia, p. 10-12.

Heifitz, J., S. W. Johnson, K V. Koski, and M. L. Murphy. 1989. Migration timing, size, and

salinity tolerance of sea-type sockeye salmon (Oncorhynchus nerka) in an Alaska

estuary. Can. J. Fish. Aquat. Sci. 46:633-637.
176

Heiser, D. 1969. Fecundity of Cedar River sockeye salmon (Oncorhynchus nerka) 1968,

1969. Unpubl. manuscr., Wash. Dep. Fish. 7 p. (Available from West Coast Sockeye

Salmon Administrative Record, Environmental and Technical Services Division, Natl.

Mar. Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Helle, J. H., and M. S. Hoffman. 1995. Size decline and older age at maturity of two chum

salmon (Oncorhynchus keta) stocks in western North America. Can. Spec. Publ. Fish.

Aquat. Sci. No. 121, 245-260.

Henderson, H. F., R. A. Ryder, and A. W. Kudhongania. 1973. Assessing fishery potentials

of lakes and reservoirs. J. Fish. Res. Board. Can. 30:2000-2009.

Henderson, J. 1929. The non-marine Mollusca of Oregon and Washington. Univ. Colorado

Studies. 17(2):47-190.

Henderson, J. 1936. The non-marine Mollusca of Oregon and Washington -- supplement.

Univ. Colorado Studies. 23(4):251-280.

Hendry, A. P. 1995. Sockeye salmon (Oncorhynchus nerka) in Lake Washington: An

investigation of ancestral origins, population differentiation and local adaptation.

Master’s Thesis, Univ. Washington, Seattle, WA, 159 p.

Hendry, A. P., and T. P. Quinn. 1997. Variation in adult life history and morphology among

Lake Washington sockeye salmon (Oncorhynchus nerka) populations, in relation to

habitat features and ancestral affinities. Can. J. Fish. Aquat. Sci. 54:75-84.

Hendry, A. P., T. P. Quinn, and F. M. Utter. 1996. Genetic evidence for the persistence and

divergence of native and introduced sockeye salmon (Oncorhynchus nerka) within

Lake Washington, Washington. Can. J. Fish. Aquat. Sci. 53:823-832.

Henshaw, F. F., E. C. La Rue, and G. C. Stevens. 1913. Surface water supply of the United

States, 1910. Part XII. North Pacific coast. U.S. Geol. Survey Water Supply Paper

292, 685 p.

Hershberger, W. K., J. Seeb, and P. Aebersold. 1982. Genetic analysis of the sockeye salmon

(Oncorhynchus nerka) returning to Lake Ozette. Final report to Makah Tribe, 30

November 1982, 9 p. (Available from West Coast Sockeye Salmon Administrative

Record, Environmental and Technical Services Division, Natl. Mar. Fish. Serv., 525

N. E. Oregon Street, Portland, OR 97232.)

Hill, P. M. 1984. A detailed listing of the liberations of salmon into the open waters of the

State of Washington during 1983. Wash. Dep. Fish. Prog. Rep. No. 210, 369 p.
177

Hinch, S. G., M. G. Healey, R. E. Diewert, and M. A. Henderson. 1995a. Climate change

and ocean energetics of Fraser River sockeye (Oncorhynchus nerka). Can. Spec. Publ.

Fish. Aquat. Sci. No. 121, 439-445.

Hinch, S. G., M. G. Healey, R. E. Diewert, K. A. Thomson, R. Hourston, M. A. Henderson,

and F. Juanes. 1995b. Potential effects of climate change on marine growth and

survival of Fraser River sockeye salmon. Can. J. Fish. Aquat. Sci. 52:2651-2659.

Hiss, J. M., and R. C. Wunderlich. 1994. Status of kokanee salmon (Oncorhynchus nerka) in

the Lake Sutherland basin and prospects for sockeye salmon restoration. U.S. Fish

Wildl. Serv., 51 p.

Hodgins, H. O., W. E. Ames, and F. M. Utter. 1969. Variants of lactate dehydrogenase

isozymes in sera of sockeye salmon (Oncorhynchus nerka). J. Fish. Res. Board. Can.

26:15-19.

Hoines, L. 1995. Washington state statistical report 1991. Wash. Dep. Fish Wildl., Olympia,

WA, 32 p.

Houston, D. B. 1983. Anadromous fish in Olympic National Park: A status report. Natl.

Park Serv. Pacific Northwest Region, 72 p.

Houston, D. B. 1984. Anadromous fish in Olympic National Park: Status and management

considerations. In J. M. Walton and D. B. Houston (editors), Proceedings of the

Olympic wild fish conference, p. 97-111. Peninsula College, Fisheries Technology

Program, Port Angeles, WA.

Howell, P., K. Jones, D. Scarnecchia, L. LaVoy, W. Kendra, and D. Ortmann. 1985. Stock

assessment of Columbia River anadromous salmonids, Volume I: Chinook, coho,

chum and sockeye salmon stock summaries. Final report to Bonneville Power

Administration, Contract DE-A179-84BP12737, Project No. 83-335, 558 p.

Huntington, C., W. Nehlsen, and J. Bowers. 1996. A survey of healthy native stocks of

anadromous salmonids in the Pacific Northwest and California. Fisheries 21(3):6-14.

Hyatt, K. D., D. Rutherford, T. Gjernes, P. Rankin, and T. Cone. 1984. Lake enrichment

program: Juvenile sockeye unit survey guidelines. Can. Man. Rep. Fish. Aquat. Sci.

1796, 84 p.

Hyatt, K. D., and J. G. Stockner. 1985. Responses of sockeye salmon (Oncorhynchus nerka)

to fertilization of British Columbia coastal lakes. Can. J. Fish. Aquat. Sci.

42:320-331.
178

Hydrosphere Data Products, Inc. 1993. Hydrodata Regional CD-ROMs: U.S. Geological

Survey Daily values, Vols. West 1, West 2. (Available from Hydrosphere Data

Products Inc., 1002 Walnut, Suite 200, Boulder, CO 80302.)

Idaho Department of Fish and Game (IDFG). 1996. Letter to R. Gustafson, NMFS, from D.

A. Cannamela, IDFG, re. Comments on “Preliminary conclusions of the review of the

status of sockeye salmon (Oncorhynchus nerka) from Washington and Oregon under

the U. S. Endangered Species Act,” dated 11 July 1996. 1 p. plus attachment.

(Available from West Coast Sockeye Salmon Administrative Record, Environmental

and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street,

Portland, OR 97232.)

Ingram, W. M. 1948. The larger freshwater clams of California, Oregon, and Washington. J.

Entomol. Zool. 40(4):72-92.

International Pacific Salmon Fisheries Commission (IPSFC). 1972. Proposed program for

restoration and extension of the sockeye and pink salmon stocks of the Fraser River.

New Westminster, B.C., Canada, 91 p.

Ivankov, V. N., and V. L. Andreyev. 1969. Fecundity of Pacific salmon (genus

Oncorhynchus spp.). Vopr. Ikthiol. 9:80-89. [Engl. Transl. Problems in Ichthyology,

Am. Fish. Soc. 9:59-66]

Jacobs, R., G. Larson, J. Meyer, N. Currence, and J. Hinton. 1996. The sockeye salmon

Oncorhynchus nerka population in Lake Ozette, Washington, USA. Tech. Rep. NPS/

CCSOSU/NRTR-96/04, 140 p. (Available from Denver Service Center, Technical

Information Center, P. O. Box 25287, Denver, CO 80225-0287.)

James, M. C., and O. L. Meehean. 1944. Propagation and distribution of food fishes,

calendar year 1942. U.S. Fish Wildl. Serv. Statistical Digest 9, 27 p.

James, M. C., and O. L. Meehean. 1945. Propagation and distribution of food fishes,

calendar year 1943. U.S. Fish Wildl. Serv. Statistical Digest 12, 25 p.

Johnson, R. L. 1977. A management program for the Quinault sockeye salmon

(Oncorhynchus nerka, Walbaum) fishery. Master’s Thesis, Univ. Washington,

Seattle, 58 p.

Johnson, R. S. 1914. The distribution of fish and fish eggs during the fiscal year 1913.

Appendix I to the Report of the U.S. Commissioner of Fisheries for 1913, Bur. of

Fish. Doc. 794, 122 p.
179

Johnson, R. S. 1915. The distribution of fish and fish eggs during the fiscal year 1914.

Appendix I to the Report of the U.S. Commissioner of Fisheries for 1914, Bur. of

Fish. Doc. 808, 114 p.

Johnson, R. S. 1916. The distribution of fish and fish eggs during the fiscal year 1915.

Appendix I to the Report of the U.S. Commissioner of Fisheries for 1915, Bur. of

Fish. Doc. 828, 138 p.

Johnson, W. E., and C. Groot. 1963. Observations on the migration of young sockeye

salmon (Oncorhynchus nerka) through a large, complex lake system. J. Fish. Res.

Board Can. 20:919-938.

Jordan, D. S., and B. W. Evermann. 1896. The fishes of North and Middle America. U.S.

Natl. Mus. Bull. 47(Part 1), 954 p.

Jordan, D. S., and C. H. Gilbert. 1881a. Notes on the fishes of the Pacific coast of the United

States. Proc. U.S. Natl. Mus. 4:29-70.

Jordan, D. S., and C. H. Gilbert. 1881b. Observations on the salmon of the Pacific. Am. Nat.

15(3):177-186.

Kaeriyama, M., S. Urawa, and T. Suzuki. 1992. Anadromous sockeye salmon

(Oncorhynchus nerka) derived from nonanadromous kokanees: Life history in Lake

Toro. Sci. Rep. Hokkaido Salmon Hatchery 46:157-174.

Kemmerich, J. 1939. Letter to Dr. R. E. Foerster from J. Kemmerich, dated 21 June 1939

and titled, “Subject: Ozette Lake Sockeye Salmon Work.” In Miscellaneous sockeye

runs to streams in Washington, File 1510.1-1, Pacific Salmon Commission Library. 1

p. plus 4 p. attachment. (Available from Librarian, Pacific Salmon Commission, Suite

600-1155 Robson Street, Vancouver, B.C., Canada V6E 1B9.)

Kemmerich, J. 1945. A review of the artificial propagation and transplantation of the

sockeye salmon of the Puget Sound area in the state of Washington conducted by the

federal government from 1896 to 1945. Unpubl. manusc., 76 p. plus tables.

(Available from West Coast Sockeye Salmon Administrative Record, Environmental

and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street,

Portland, OR 97232.)

Kershaw, T. R. 1902. Thirteenth annual report of the state fish commissioner to the governor

of the State of Washington. Metropolitan Press, Seattle, 92 p.

Killick, S. R. 1955. The chronological order of Fraser River sockeye salmon during

migration, spawning and death. Int. Pac. Salmon Fish. Comm. Bull. 7:1- 95.
180

Killick, S. R., and W. A. Clemens. 1963. The age, sex ratio and size of Fraser River sockeye

salmon 1915 to 1960. Int. Pac. Salmon Fish. Comm. Bull. 14:1-140.

Kimsey, J. B. 1951. Notes on kokanee spawning in Donner Lake, California. Calif. Fish

Game 37:273-279.

Kirpichnikov, V. S., and I. M. Ivanova. 1977. Variation in the frequencies of the alleles of

the lactate dehydrogenase and phosphoglucomutase loci in local populations, different

age groups, and successive generations of sockeye salmon (Oncorhynchus nerka).

Sov. Genet. 13:791-799.

Kirpichnikov, V. S., G. A. Muske, A. D. Scholl-Engberts, V. M. Chernov, and S. N.

Borchsenius. 1990. Genetic structure and allele frequency dynamics in the sockeye

salmon population of Lake Dalneye, Kamchatka. Aquaculture 84:13-25.

Kline, P., and J. Younk. 1995. Research and recovery of Snake River sockeye salmon.

Annual report 1994. U.S. Dep. Energy, Bonneville Power Administration, Proj. No.

91-72, Contract No. DE-BI79-91BP21065, Portland, OR, 47 p.

Kloempken, K. 1996. Letter to R. Gustafson, NMFS, from K. Kloempken, WDFW, re.

information request on kokanee planting records, dated 4 November 1996. 3 p.

(Available from West Coast Sockeye Salmon Administrative Record, Environmental

and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street,

Portland, OR 97232.)

Knapp, G., and T. Johnson. 1995. The Russian salmon industry, an initial review. Div. of

Trade & Development, Alsk. Dep. Commerce and Economic Development, Juneau,

AK, 62 p. (Available from Alaska Division of Trade and Development, P. O. Box

110804, Juneau, AK 99801.)

Knutzen, D. 1995. Letter to R. Gustafson, NMFS, from D. Knutzen, WDFW, re. Historical

kokanee planting records for Lake Wenatchee, Lake Pleasant, Lake Ozette, Lake

Shannon, and Baker Lake from 1981-1994, dated 17 July 1995. 1 p. plus attachment.

(Available from West Coast Sockeye Salmon Administrative Record, Environmental

and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street,

Portland, OR 97232.)

Kobayashi, T. 1980. Salmon propagation in Japan. In J. E. Thorpe (ed.) Salmon ranching, p.

91-107. Academic Press, New York.

Kolb, R. 1971. A review of Lake Washington sockeye (Oncorhynchus nerka) age and racial

characteristics as determined by scale analysis. Suppl. Prog. Rep. Mar. Fish. Invest.,

Wash. Dep. Fish., p. 1-9.
181

Konkel, G. W., and J. D. McIntyre. 1987. Trends in spawning populations of Pacific

anadromous salmonids. U.S. Fish Wildl. Serv. Tech. Rep. 9, 25 p.

Konovalov, S. M. 1975. Differentiation of local populations of sockeye salmon

Oncorhynchus nerka (Walbaum). Univ. Wash. Publ. Fish. New Ser. 6, 290 p.

[Translated by L.V. Sagen]

Konovalov, S. M. 1980. U. S. S. R.: Salmon ranching in the Pacific. In J. E. Thorpe (ed.)

Salmon ranching, p. 63-89. Academic Press, New York.

Koo, T. S. Y. 1962. Age designation in salmon. In T. S. Y. Koo (editor), Studies of Alaska

red salmon, p. 41-48. Univ. Washington Press, Seattle, WA.

Kostow, K. 1996a. Memorandum to R. Gustafson (NMFS) from K. Kostow (ODFW), dated

19 March 1996 and titled, “Subject: ODFW O. nerka hatchery records in Wallowa

and Metolius subbasins,” 18 p. (Available from West Coast Sockeye Salmon

Administrative Record, Environmental and Technical Services Division, Natl. Mar.

Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Kostow, K. 1996b. The status of salmon and steelhead in Oregon. In D. J. Stouder, P. A.

Bisson, and R. J. Naiman (editors), Pacific salmon and their ecosystems, status and

future options, p. 145-178. Chapman & Hall, New York.

Krogius, F. V. 1958. O stroenii cheshui kamchatskoi krasnoi raznykh lokalnykh stad. In

Materialy po biologii moskovo perioda zhizni dalnevostochnykh lososei, p. 52-63.

[On scale pattern of Kamchatka sockeye of different populations.] VNIRO, Moscow.

(Translated by R. E. Foerster, Fish. Res. Board Can. Transl. Ser. No. 181, 1958.)

Kyle, G. B., J. P. Koenings, and B. M. Barrett. 1988. Density-dependant, trophic level

responses to an introduced run of sockeye salmon (Oncorhynchus nerka) at Frazer

Lake, Kodiak Island, Alaska. Can. J. Fish. Aquat. Sci. 45:856-867.

Landry, M. R., J. R. Postel, W. K. Peterson, and J. Newman. 1989. Broad-scale

distributional patterns of hydrographic variables on the Washington/Oregon shelf. In

M. R. Landry and B. M. Hickey (editors), Coastal oceanography of Washington and

Oregon, p. 1-40. Elsevier, New York.

Langness, O. P. 1991. Summer chinook salmon spawning ground surveys of the Methow

and Okanogan River Basins in 1990. Confederated Tribes of the Colville Reservation,

Fish and Wildlife Dep., Rep. to Chelan County PUD, 87 p.
182

LaRiviere, M. G. 1990. 1989 Lake Ozette sockeye smolt outmigration. Progress report,

Makah Fisheries Management 90-2, 7 p. (Available from West Coast Sockeye

Salmon Administrative Record, Environmental and Technical Services Division, Natl.

Mar. Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

LaRiviere, M. G. 1991. The Lake Ozette sockeye salmon enhancement program. Makah

Fisheries Management Department, Unpubl. rep., 9 p. (Available from West Coast

Sockeye Salmon Administrative Record, Environmental and Technical Services

Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Larson, S. B. 1975. Dig the ditch: The history of the Lake Washington Ship Canal. King

County Arts Commission, King County Department of Public Works, Seattle, 48 p.

Lawson, P. W. 1993. Cycles in ocean productivity, trends in habitat quality, and the

restoration of salmon runs in Oregon. Fisheries 18(8):6-10.

Leach, G. C. 1920. The distribution of fish and fish eggs during the fiscal year 1919.

Appendix I to the Report of the U.S. Commissioner of Fisheries for 1919. Bur. Fish.

Doc. 878, 76 p.

Leach, G. C. 1922. Propagation and distribution of food fishes, 1921. Appendix IX to the

Report of the U.S. Commissioner of Fisheries for 1921. Bur. Fish. Doc. 912, 94 p.

Leach, G. C. 1923. Propagation and distribution of food fishes, 1922. Appendix XVII to the

Report of the U.S. Commissioner of Fisheries for 1922. Bur. Fish. Doc. 941,

116 p.

Leach, G. C. 1924. Propagation and distribution of food fishes, fiscal year 1923. Appendix

XIII to the Report of the U.S. Commissioner of Fisheries for 1923. Bur. Fish. Doc.

964, 108 p.

Leach, G. C. 1925. Propagation and distribution of food fishes, fiscal year 1924. Appendix

V to the Report of the U.S. Commissioner of Fisheries for 1924, p. 361-440. Bur.

Fish. Doc. 978.

Leach, G. C. 1926. Propagation and distribution of food fishes, fiscal year 1925. Appendix

V to the Report of the U. S. Commissioner of Fisheries for 1925, p. 439-500. Bur.

Fish. Doc. 999.

Leach, G. C. 1927. Propagation and distribution of food fishes, fiscal year 1926. Appendix

VI to the Report of the U. S. Commissioner of Fisheries for 1926, p. 323-384. Bur.

Fish. Doc. 1011.
183

Leach, G. C. 1928. Propagation and distribution of food fishes, fiscal year 1927. Appendix

VIII to the Report of the U.S. Commissioner of Fisheries for 1927, p. 683-736. Bur.

Fish. Doc. 1033.

Leach, G. C. 1929. Propagation and distribution of food fishes, fiscal year 1928. Appendix

VIII to the Report of the Commissioner of Fisheries for 1928, p. 339-399. Bur. Fish.

Doc. 1049.

Leach, G. C. 1930. Propagation and distribution of food fishes, fiscal year 1929. Appendix

XII to Report of the Commissioner of Fisheries for the fiscal year 1929, p. 759-823.

Bur. Fish. Doc. 1070.

Leach, G. C. 1931. Propagation and distribution of food fishes, fiscal year 1930. Appendix

XVI to Report of the Commissioner of Fisheries for the fiscal year 1930, p. 1123-

1191. Bur. Fish. Doc. 1098.

Leach, G. C. 1932. Propagation and distribution of food fishes, fiscal year 1931. Appendix

IV to Report of the Commissioner of Fisheries for the fiscal year 1931, p. 627-690.

Leach, G. C. 1933. Propagation and distribution of food fishes, fiscal year 1932. Appendix

IV to Report of the Commissioner of Fisheries for the fiscal year 1932, p. 531-569.

Leach, G. C. 1934. Propagation and distribution of food fishes, fiscal year 1933. Appendix

IV to Report of the Commissioner of Fisheries for the fiscal year 1933, p. 451-484.

Leach, G. C., and M. C. James. 1934. Propagation and distribution of food fishes, fiscal year

1934. Appendix IV to Report of the Commissioner of Fisheries for the fiscal year

1934, p. 385-417.

Leach, G. C., and M. C. James. 1936. Propagation and distribution of food fishes, fiscal year

1935. Appendix IV to Report of the Commissioner of Fisheries for the fiscal year

1935, p. 401-427. Administrative Rep. No. 22.

Leach, G. C., and M. C. James. 1937. Propagation and distribution of food fishes, fiscal year

1936. Appendix III to Report of the Commissioner of Fisheries for the fiscal year

1936, p. 349-379. Administrative Rep. No. 25.

Leach, G. C., and M. C. James. 1938. Propagation and distribution of food fishes, fiscal year

1937. Appendix IV to Report of the Commissioner of Fisheries for the fiscal year

1937, p. 461-492. Administrative Rep. No. 33.

Leach, G. C., M. C. James, and E. J. Douglass. 1939. Propagation and distribution of food

fishes, fiscal year 1938. Appendix IV to Report of the Commissioner of Fisheries for

the fiscal year 1938, p. 461-494. Administrative Rep. No. 34.
184

Leach, G. C., M. C. James, and E. J. Douglass. 1940. Propagation and distribution of food

fishes, fiscal year 1939. Appendix IV to Report of the Commissioner of Fisheries for

the fiscal year 1939, p. 555-598. Administrative Rep. No. 38.

Leach, G. C., M. C. James, and E. J. Douglass. 1941. Propagation and distribution of food

fishes, fiscal year 1940. Appendix IV to Report of the Commissioner of Fisheries for

the fiscal year 1940, p. 555-603. Administrative Rep. No. 42.

Leach, G. C., M. C. James, and E. J. Douglass. 1942. Propagation and distribution of food

fishes, fiscal year 1941. U.S. Fish Wildl. Serv. Statistical Digest No. 3, 25 p.

Leach, G. C., M. C. James, and E. J. Douglass. 1943. Propagation and distribution of food

fishes, calendar year 1941. U.S. Fish Wildl. Serv. Statistical Digest No. 6, 26 p.

Leonard, W. P., H. A. Brown, L. L. Jones, K. R. McAllister, and R. M. Storm. 1993.

Amphibians of Washington and Oregon. Seattle Audubon Society, Seattle, WA,

168 p.

Lestelle, L. and L. Workman. 1990. Proposed sockeye hatchery. Quinault Natural Resources

13(1):6-7.

Levings, C. D., D. E. Boyle, and T. R. Whitehouse. 1995. Distribution and feeding of

juvenile Pacific salmon in freshwater tidal creeks of the lower Fraser River, British

Columbia. Fish. Manage. Ecol. 2:299-308.

Levy, D. A. 1987. Review of the ecological significance of diel vertical migrations by

juvenile sockeye salmon (Oncorhynchus nerka). Can. Spec. Publ. Fish. Aquat. Sci.

96:44-52.

Lewis, S. L. 1972. Life history and ecology of kokanee in Odell Lake. Job Progress Rep.,

Project No. F-71-R-8, Oregon State Game Commission, Portland, OR, 71 p.

Linley, T. J. 1993. Patterns of life history variation among sockeye salmon (Oncorhynchus

nerka) in the Fraser River, British Columbia. Ph.D. Thesis, Univ. Washington,

Seattle, WA, 162 p.

Lorenz, J. M., and J. H. Eiler. 1989. Spawning habitat and redd characteristics of sockeye

salmon in the glacial Taku River, British Columbia and Alaska. Trans. Am. Fish. Soc.

118:495-502.

Major, R. L., and D. R. Craddock. 1962. Influence of early maturing females on reproductive

potential of Columbia River blueback salmon (Oncorhynchus nerka). U.S. Fish Wildl.

Serv., Fish. Bull. 61:429-437.
185

Major, R. L, and R. L. Mighell. 1966. Influence of Rocky Reach Dam and the temperature of

the Okanogan River on the upstream migration of sockeye salmon. U.S. Fish. Wildl.

Serv., Fish. Bull. 66(1):131-147.

Makah Fisheries Management Department (MFMD). 1995. Ozette sockeye BY 1994. Data

sheets containing length, sex, and age of sockeye salmon utilized in 1994 Ozette Lake

Makah Hatchery program. 3 p. (Available from West Coast Sockeye Salmon

Administrative Record, Environmental and Technical Services Division, Natl. Mar.

Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Makah Fisheries Management Department (MFMD). No date. Ozette sockeye. (Prepared for

1992-93 Washington State Salmon and Steelhead Stock Inventory). 2 p. (Available

from West Coast Sockeye Salmon Administrative Record, Environmental and

Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street, Portland,

OR 97232.)

Manzer, J. I., and I. Miki. 1985. Fecundity and egg retention of some sockeye salmon

(Oncorhynchus nerka) stocks in British Columbia. Can. J. Fish. Aquat. Sci. 43:1643-

1655.

Manzer, J. I., M. Wright, I. Miki, and K. D. Hyatt. 1984. Abundance, upstream migration,

age-composition and fecundity of Hobiton Lake adult sockeye salmon (Oncorhynchus

nerka), 1982. Can. Tech. Rep. Fish. Aquat. Sci. 1262, 57 p.

Margolis, L. 1963. Parasites as indicators of the geographical origin of sockeye salmon,

Oncorhynchus nerka (Walbaum), occurring in the North Pacific Ocean and adjacent

seas. Int. North Pac. Fish. Comm. Bull. 11:31-56

Margolis, L., F. C. Cleaver, Y. Fukuda, and H. Godfrey. 1966. Salmon of the North Pacific

Ocean — Part VI. Sockeye salmon in offshore waters. Int. North Pac. Fish. Comm.

Bull. 20:70 p.

Marshall, D. E., R. F. Brown, G. A. Buxton, V. D. Chahley, and D. G. Demontier. 1978.

Preliminary catalogue of salmon streams and spawning escapements of statistical area

2E (Queen Charlotte Islands). Fish. Mar. Serv. Data Rep. 72, 346 p.

Martz, M., F. Goetz, J. Dillon, and T. Shaw. 1996. Early lake life distribution of sockeye

salmon in Lake Washington [Abstract]. In Western Division American Fisheries

Society, 1996 Annual Meeting Program and Abstracts July 14-18, 1996.

McCart, P. J. 1970. A polymorphic population of Oncorhynchus nerka at Babine Lake, B. C.

involving anadromous (sockeye) and non-anadromous (kokanee) forms. Ph.D. Thesis,

Univ. British Columbia, Vancouver, B.C., 135 p.
186

McGee, J. A., and K. Truscott. 1982. Juvenile salmonid monitoring Okanogan River and

Wells Dam forebay April-May 1982. Douglas County PUD, East Wenatchee, WA.

McGee, J. A., R. Rulifson, C. Heath, and R. F. Leland. 1983. Juvenile salmon monitoring

Methow River, Okanogan River and Wells Dam forebay April-May 1983. Douglas

County PUD, East Wenatchee, WA.

McHenry, M. L., D. C. Morrill, and E. Currence. 1994. Spawning gravel quality, watershed

characteristics and early life history survival of coho salmon and steelhead in five

north Olympic Peninsula watersheds. Lower Elwha S’Klallam Tribe and Makah

Tribe, Port Angeles and Neah Bay, WA, 59 p. plus appendix

McKee, B. 1972. Cascadia. The geologic evolution of the Pacific Northwest. McGraw-Hill

Book Co., New York, 394 p. [Reprinted 1992 by TechBooks, Fairfax, VA.]

McKinnell, S. 1995. Age-specific effects of sockeye abundance on adult body size of

selected British Columbia sockeye stocks. Can. J. Fish. Aquat. Sci. 52:1050-1063.

McPhail, J. D., and C. C. Lindsey. 1986. Zoogeography of the freshwater fishes of Cascadia

(the Columbia system and rivers north to the Stikine). In C. H. Hocutt and E. O.

Wiley (editors), Zoogeography of North American freshwater fishes, p. 615-637.

Wiley Interscience Publications, New York.

McPherson, S. A., and A. J. McGregor. 1986. Abundance, age, sex and size of sockeye

salmon (Oncorhynchus nerka Walbaum) catches and escapements in southeastern

Alaska in 1985. Alsk. Dep. Fish Game Tech. Data Rep. 188, 122 p.

Mesner, N., and J. Davis. 1984. Water quality in nearshore Lake Sammamish King County,

Washington: 1983 baseline monitoring report. Tech Rep. WR-85-1, Municipality of

Metropolitan Seattle, Water Quality Division, Seattle, WA, 59 p.

Miller, J. D., L. K. Brannian, and B. A. Cross. 1994. Sonar enumeration of Pacific salmon

into Nushagak River and evaluation of species composition estimates, 1992. Alsk.

Dep. Fish Game Tech. Fish. Rep. 94-06, 75 p.

Miller, R. J., and E. L. Brannon. 1982. The origin and development of life history patterns in

Pacific salmonids. In E. L. Brannon and E. O. Salo (editors), Proceedings of the

salmon and trout migratory behavior symposium, p. 296-309. School of Fisheries,

Univ. Washington, Seattle, WA.

Miller, W. H., T. C. Coley, H. L. Burge, and T. T. Kisanuki. 1990. Analysis of salmon and

steelhead supplementation: emphasis on unpublished reports and present programs.

Part 1. Report submitted to U. S. Department of Energy, Bonneville Power

Administration, Project No. 88-100, 46 p. plus appendices.
187

Millimann, R. E., and S. E. Knapp. 1970. Biology of Nanophyetus salminicola and “salmon

poisoning” disease. Advances in Parasitology, B. Dawes (ed.), Academic Press,

London, 8:1-41.

Milner, A. M., and R. G. Bailey. 1989. Salmonid colonization of new streams in Glacier Bay

National Park, Alaska. Aquacult. Fish. Manage. 20:179-192.

Minckley, W. L., D. A. Hendrickson, and C. E. Bond. 1986. Geography of western North

American freshwater fishes: Description and relationships to intracontinental

tectonism. In C. H. Hocutt and E. O. Wiley (editors), Zoogeography of North

American freshwater fishes, p. 519-613. Wiley Interscience Publications, New York.

Mitchell, S. 1980. The fish passage issue at Enloe Dam, an assessment. Wash. Dep. Ecol.,

State Water Program, Olympia, WA, 15 p.

Moberly, S. A., and R. Lium. 1977. Japan salmon hatchery review. Alsk. Dep. Fish Game,

Juneau, AK, 124 p.

Moles, A., P. Rounds, and C. Kondzela. 1990. Use of the brain parasite Mysobolus

neurobius in separating mixed stocks of sockeye salmon. Am. Fish. Soc. Symp.

7:224-231.

Monaco, M. E., T. A. Lowery, and R. L. Emmett. 1992. Assemblages of U.S. west coast

estuaries based on the distribution of fishes. J. Biogeogr. 19:251-267.

Mosley, R. A. 1995. Letter to R. Gustafson, NMFS, from R. A. Mosley, WDFW, re. Lake

Pleasant sockeye spawner data, dated 7 November 1995. 1 p. plus attachment.

(Available from West Coast Sockeye Salmon Administrative Record, Environmental

and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street,

Portland, OR 97232.)

Moser, J. F. 1899. The salmon and salmon fisheries of Alaska. Report of the Operations of

the United States Fish Commission Steamer Albatross for the year ending June 30,

1898. U.S. Government Printing Office, Washington, D.C, 178 p.

Mud Mountain Dam Fish Haul Report (MMDFHR). Seattle District, WA. U. S. Army Corps

of Engineers, 1996—. (Available through Online Internet database at http://

www.nps.usace.army.mil/fish/mmdfish.htm)

Mullan, J. W. 1986. Determinants of sockeye salmon abundance in the Columbia River,

1880’s-1982: A review and synthesis. U.S. Fish Wildl. Serv. Biol. Rep. 86(12),

135 p.
188

Murphy, M.L., K V. Koski, J. M. Lorenz, and J. F. Thedinga. 1988. Migrations of juvenile

salmon in the Taku River, Southeast Alaska. NWAFC Processed Rep. 88-31, 39 p.

Northwest and Alaska Fish. Cent., Natl. Mar. Fish. Serv., NOAA, 2725 Montlake

Blvd. E., Seattle, WA 98112.

Murphy, M. L., J. Heifetz, J. F. Thedinga, S. W. Johnson, and K V. Koski. 1989. Habitat

utilization by juvenile Pacific salmon (Oncorhynchus) in the glacial Taku River,

Southeast Alaska. Can. J. Fish. Aquat. Sci. 46:1677-1685.

Murphy, M. L., J. M. Lorenz, and K V. Koski. 1991. Population estimates of juvenile

salmon downstream migrants in the Taku River, Alaska. U.S. Dep. Commer., NOAA

Tech. Memo. NMFS-F/NWC 203, 27 p.

National Marine Fisheries Service (NMFS). 1991. Notice of policy: Policy on applying the

definition of species under the Endangered Species Act to Pacific salmon. Federal

Register [Docket 910248-1255, 20 November 1991] 56(224):58612-58618.

National Marine Fisheries Service (NMFS). 1993. Interim policy on artificial propagation of

Pacific salmon under the Endangered Species Act. Federal Register [Docket 921186-

2286, 5 April 1993] 58(63):17573-17576.

National Marine Fisheries Service (NMFS). 1994. Listing endangered and threatened species

and designating critical habitat: Initiation of status reviews for pink salmon, chum

salmon, sockeye salmon, chinook salmon, and sea-run cutthroat trout populations in

Washington, Oregon, Idaho, and California. Federal Register [I.D. 081694D, 12

September 1994] 59(175):46808-46810.

National Marine Fisheries Service (NMFS). 1996. Factors for decline: A supplement to the

Notice of determination for West Coast Steelhead under the Endangered Species Act.

NMFS Protected Species Branch, Portland, OR, 82 p. plus appendices.

National Park Service (NPS). 1995. Final environmental impact statement: Elwha River

ecosystem restoration, Olympic National Park, Washington. U.S. Dep. Interior,

Denver, CO, 674 p. (Available from United States Department of the Interior,

National Park Service, Denver Service Center-DSC-TWE, P.O. Box 25287, Denver,

CO, 80225-0287.)

Natural Resources Consultants (NRC). 1995. Artificial propagation of anadromous Pacific

salmonids: west coast sockeye salmon. Electronic database submitted to Coastal

Zone and Estuarine Studies Division, Northwest Fisheries Science Center, Natl. Mar.

Fish. Serv. Contract No. 50ABNF400128, 1.8 MB.
189

Natural Resource Council Committee on Protection and Management of Pacific Northwest

Anadromous Salmonids (NRCC). 1996. Upstream: Salmon and society in the Pacific

Northwest. National Academy Press, Washington, D.C., 452 p.

Nehlsen, W. 1995. Historical salmon and steelhead runs of the upper Deschutes River basin

and their environments. Report to Portland General Electric Company, Portland, OR,

65 p. plus references and appendices. (Available from Portland General Electric

Company, Hydro Licensing Department, Attn: Marty May, 3WTCBR04, 121 SW

Salmon St., Portland, OR 97204.)

Nehlsen, W., J. E. Williams, and J. A. Lichatowich. 1991. Pacific salmon at the crossroads:

Stocks at risk from California, Oregon, Idaho, and Washington. Fisheries 16(2):4-21.

Nei, M. 1978. Estimation of average heterozygosity and genetic distance from a small

number of individuals. Genetics 89:583-590.

Nelson, J. S. 1968. Variation in gillraker number in North American kokanee, Oncorhynchus

nerka. J. Fish. Res. Board Can. 25(2):415-420.

Nielson, R. S. 1950. Survey of the Columbia River and its tributaries - Part V. U.S. Fish

Wildl. Serv. Spec. Sci. Rep. Fish. 38, 41 p.

Northcote, T. G., and P. A. Larkin. 1956. Indices of productivity in British Columbia lakes.

J. Fish. Res. Board Can. 13(4):515-540.

Oakley, A. L., and T. E. Kruse. 1963. Occurrence of a sockeye salmon stray in an Oregon

coastal river. Oreg. Fish. Comm. Res. Briefs 9(1):68.

O’Connor, D., R. Tomsinski, S. Allen, and D. Reece. 1993. Columbia River Coordinated

Information System data catalog. U.S. Department of Energy, Bonneville Power

Administration, Portland, OR. 12 p. plus appendices.

Oglesby, R. T. 1977. Relationships of fish yield to lake phytoplankton standing crop,

production, and morphoedaphic factors. J. Fish. Res. Board Can. 34:2271-2279.

Ogura, M., Y. Ishida, and S. Ito. 1991. Growth variation of coho salmon Oncorhynchus

kisutch in the Western North Pacific. Nippon Suisan Gakkaishi 57:1089-1093.

Olsen, E. A., P. M. P. Beamesderfer, M. L. McLean, and E. S. Tinus. 1994. Salmon and

steelhead stock summaries for the Deschutes River Basin: An interim report. Oreg.

Dep. Fish Wildl., Portland, 136 p.
190

O’Malley, H. 1917. The distribution of fish and fish eggs during the fiscal year 1916.

Appendix I to the Report of the U.S. Commissioner of Fisheries for 1916. Bur. of

Fish. Doc. 837, 111 p.

O’Malley, H. 1918. The distribution of fish and fish eggs during the fiscal year 1917.

Appendix I to the Report of the U.S. Commissioner of Fisheries for 1917. Bur. of

Fish. Doc. 846, 99 p.

O’Malley, H. 1919. The distribution of fish and fish eggs during the fiscal year 1918.

Appendix I to the Report of the U.S. Commissioner of Fisheries for 1918. Bur. of

Fish. Doc. 863, 82 p.

Omernik, J. M. 1987. Ecoregions of the conterminous United States. Ann. Assoc. Am.

Geogr. 77(1):118-125.

Omernik, J. M., and A. L. Gallant. 1986. Ecoregions of the Pacific Northwest. U.S. Environ.

Protec. Agen. Rep. EPA/600/3-86/033, 39 p.

Oregon Department of Fish and Wildlife (ODFW). 1995a. Biennial report on the status of

wild fish in Oregon. Oregon Dep. Fish Wildl., Portland. 217 pp. plus 1 appendix.

Oregon Department of Fish and Wildlife (ODFW). 1995b. Oregon Game Commission

Stocking Records, Watersheds 3-6. (Available from West Coast Sockeye Salmon

Administrative Record, Environmental and Technical Services Division, Natl. Mar.

Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Orrell, R. F. 1969. Baker project sockeye artificial spawning beaches annual report 1967-

1968 season. Puget Sound Power and Light Co., Contract No. D-33347, Wash. Dep.

Fish., Olympia, WA, 14 p.

Ostergaard, E. 1996. 1995 status report: Abundance of spawning kokanee in the

Sammamish River Basin. Addendum to 1994 status report. King County Surface

Water Management Division. 22 p. plus 5 appendices. (Available from King County

Surface Water Management Division, 700 Fifth Ave., Suite 2200, Seattle, WA 98104.)

Ostergaard, E., C. Young, and K. Ludwa. 1995. Abundance of spawning kokanee in the

Sammamish River Basin. 1994 status report. King County Surface Water

Management Division. 194 p. (Available from King County Surface Water

Management Division, 700 Fifth Ave., Suite 2200, Seattle, WA 98104.)

Pacific Fisherman. 1905a. The propagation of sockeye salmon in Puget Sound: Other notes

of hatchery operation. Pac. Fisherman 3(9):15-16.
191

Pacific Fisherman. 1905b. News items from fisheries districts: Puget Sound. Pac.

Fisherman 3(9):31.

Pacific Fisherman. 1906. News items from the fisheries districts, Puget Sound, marked

sockeye for river. Pac. Fisherman 4(5):16.

Pacific Fisherman. 1915a. Will propagate sockeyes in the Samish Hatchery. Pac. Fisherman

13(4):28.

Pacific Fisherman. 1915b. Hatching sockeyes in the Samish River. Pac. Fisherman 13(9):26.

Pacific Fisherman. 1916. Deming to again aid state in Samish Hatchery. Pac. Fisherman

14(4):22.

Pacific Fisherman. 1918. Sockeyes for Samish Hatchery. Pac. Fisherman 16(7):35.

Pacific Fishery Management Council (PFMC). 1995. Vital habitat concerns. Pacific Fishery

Management Council, Portland, OR, 19 p. plus appendices.

Pahlke, K. A. 1989. Length conversion equations for sockeye, chinook, chum and coho

salmon in southeast Alaska. Alsk. Dep. Fish Game Fish. Res. Bull., 89-02, 15 p.

Pahlke, K. A., and R. R. Riffe. 1988. Compilation of catch, escapement, age, sex, and size

data for salmon returns to the Yakutat area in 1986. Alsk. Dep. Fish Game Tech. Data

Rep. 224, 151 p.

Paragamian, V. L., V. L. Ellis, and S. Andersen. 1993. Kokanee stock status and

contribution of Cabinet Gorge Hatchery, Lake Pend Oreille, Idaho, Annual Progress

Report for FY 1991. U.S. Dep. Energy, Bonneville Power Administration, Proj. No.

85-339, Contract No. DE-A179-85BP22493, Portland, OR, 73 p.

Parkhurst, Z. E. 1950a. Survey of the Columbia River and its tributaries - Part VI. Area VSnake River system from the mouth through the Grande Ronde River. U.S. Fish

Wildl. Serv. Spec. Sci. Rep. Fish. 39, 58 p.

Parkhurst, Z. E. 1950b. Survey of the Columbia River and its tributaries - Part VII. Area VISnake River system from above the Grande Ronde River through the Payette River.

U.S. Fish Wildl. Serv. Spec. Sci. Rep. Fish. 40, 95 p.

Pauley, G. B., R. Risher, and G. L. Thomas. 1989. Species profiles: Life histories and

environmental requirements of coastal fishes and invertebrates (Pacific Northwest) -

sockeye salmon. U.S. Fish Wildl. Serv., Biol. Rep. 82(11.116). U.S. Army Corps of

Engineers, TR EL-82-4, 22 p.
192

Pearcy, W. G. 1992. Ocean ecology of North Pacific salmonids. Washington Sea Grant

Prog., distributed by Univ. Washington Press, Seattle, WA, 179 p.

Peterman, R. M. 1984. Density-dependent growth in early ocean life of sockeye salmon

(Oncorhynchus nerka). Can. J. Fish. Aquat. Sci. 41:1825-1829.

Peterman, R. M. 1985. Patterns of interannual variation in age at maturity of sockeye salmon

(Oncorhynchus nerka) in Alaska and British Columbia. Can. J. Fish. Aquat. Sci.

42:1595-1607.

Peven, C. M. 1987. Downstream migration timing of two stocks of sockeye salmon on the

Mid-Columbia River. Northwest Sci. 61(3):186-190.

Pfeifer, B. 1978. Evaluation of the natural reproduction of kokanee (Oncorhynchus nerka

Walbaum) in Lake Stevens, Washington, as related to the lake limnology and basin.

Master’s Thesis, Univ. Washington, Seattle, WA, 328 p.

Pfeifer, B. 1992. Fisheries investigations of Lakes Washington and Sammamish — 1980-

1990. Part V. Wild cutthroat and kokanee in Lakes Washington and Sammamish

(draft document). Wash. Dep. Game. 210 p. (Available from West Coast Sockeye

Salmon Administrative Record, Environmental and Technical Services Division, Natl.

Mar. Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Phinney, L. A., and P. Bucknell. 1975. A catalog of Washington streams and salmon

utilization, Vol. 2: Coastal region. R. W. Williams (editor), Wash. Dep. of Fish.,

Olympia, WA. 477 p. plus appendices.

Poe, P. H., and O. A. Mathisen. 1981. Distances from sea and elevation of important sockeye

salmon spawning grounds. Univ. Wash. Fish. Res. Inst. Circular No. 81-1,

23 p.

Pratt, D. C., and E. D. Jewell. 1972. The 1971 Lake Washington sockeye tagging study final

report. Wash. Dep. Fish., Olympia, WA. 34 p.

Professional Resource Organization-salmon (PRO-Salmon). 1994. Petition for a rule to list

nine Puget Sound salmon populations as threatened or endangered under the

Endangered Species Act and to designate critical habitat. Petition to the U.S. National

Marine Fisheries Service, March 1994, 86 p.

Quinault Indian Nation (QIN). 1981. 1981 preseason management report for spring and

summer fisheries on the Quinault and Queets Rivers. Harvest Management Section,

Quinault Fisheries Division, 82 p. (Available from West Coast Sockeye Salmon

Administrative Record, Environmental and Technical Services Division, Natl. Mar.

Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)
193

Quinault Indian Nation (QIN). 1995a. Computer disk submitted by Quinault Indian Nation

(computer files titled “sizenage.txt” and “blueback.zip”) containing data on sockeye

salmon collected in in-river fishery on Quinault and Queets Rivers (species, river,

date, statistical week, sex, weight, length, freshwater age, saltwater age from 1971 to

1993). (Available from West Coast Sockeye Salmon Administrative Record,

Environmental and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E.

Oregon Street, Portland, OR 97232.)

Quinault Indian Nation (QIN). 1995b. Artificial propagation records submitted to the

Administrative Record for sockeye salmon. (Available from West Coast Sockeye

Salmon Administrative Record, Environmental and Technical Services Division, Natl.

Mar. Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Quinault Indian Nation (QIN). 1995c. Draft preseason management report for spring and

summer fisheries in the Quinault River for 1995. Harvest Management Section,

Quinault Fisheries Division, Taholah, WA, 11 p.

Quinn, T.P. 1980. Evidence for celestial and magnetic compass orientation in lake migrating

sockeye salmon fry. J. Comp. Physiol. 137:243-248.

Quinn, T.P. 1981. Compass orientation of juvenile sockeye salmon (Oncorhynchus nerka).

Ph.D. Thesis, Univ. Washington, Seattle, WA, 89 p.

Quinn, T.P. 1985. Homing and evolution of sockeye salmon (Oncorhynchus nerka). In M.

A. Rankin (editor), Migration: Mechanisms and adaptive significance. Contrib. Mar.

Sci. (Suppl.) 27:353-366.

Quinn, T.P., and D. J. Adams. 1996. Environmental changes affecting the migratory timing

of American shad and sockeye salmon. Ecology 77:1151-1162.

Quinn, T. P., A. P. Hendry, and L. A. Wetzel. 1995. The influence of life history trade-offs

and the size of incubation gravels on egg size variation in sockeye salmon

(Oncorhynchus nerka). Oikos 74:425-438.

Quinn, T. P., C. C. Wood, L. Margolis, B. E. Riddell, and K. D. Hyatt. 1987. Homing in

wild sockeye salmon (Oncorhynchus nerka) populations as inferred from differences

in parasite prevalence and allozyme allele frequencies. Can. J. Fish. Aquat. Sci.

44:1963-1971.

Quistorff, E. 1954a. Notes on stream observations - Baker River: September 9-12, 1954.

Wash. Dep. Fish., Olympia, WA, 7 p. (Available from West Coast Sockeye Salmon

Administrative Record, Environmental and Technical Services Division, Natl. Mar.

Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)
194

Quistorff, E. 1954b. Notes on stream observations - Baker River: September 17-22, 1954.

Wash. Dep. Fish., Olympia, WA, 5 p. (Available from West Coast Sockeye Salmon

Administrative Record, Environmental and Technical Services Division, Natl. Mar.

Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Quistorff, E. 1954c. Notes on stream observations - Baker River: September 28 - October 2,

1954. Wash. Dep. Fish., Olympia, WA, 8 p. (Available from West Coast Sockeye

Salmon Administrative Record, Environmental and Technical Services Division, Natl.

Mar. Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Quistorff, E. 1955. A preliminary report on the Puget Sound Power and Light Company,

Baker River fisheries survey project September, 1954 - December, 1954. Puget Sound

Power and Light and Wash. Dep. Fish., Olympia, WA, 5 p. (Available from West

Coast Sockeye Salmon Administrative Record, Environmental and Technical Services

Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Quistorff, E. 1959. Sockeye spawning beach, Baker Lake: The problem confronted and

accomplishments to date, 1959. Wash. Dep. Fish., Olympia, WA, 8 p. (Available

from West Coast Sockeye Salmon Administrative Record, Environmental and

Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street, Portland,

OR 97232.)

Quistorff, E. 1966. Floating salmon smolt collectors at Baker River dams. Wash. Dep. Fish.

Fish. Res. Pap. 2(4):39-52.

Raleigh, R. F. 1967. Genetic control in the lakeward migrations of sockeye salmon

(Oncorhynchus nerka) fry. J. Fish. Res. Board Can. 24:2613-2622.

Rathbun, R. 1900. A review of the fisheries in the contiguous waters of the state of

Washington and British Columbia. Report of the Commissioner for the year ending

June 30, 1899, U. S. Comm. Fish and Fisheries 25:251-350.

Ravenel, W. de C. 1901. Report on the propagation and distribution of food-fishes. Report

of the Commissioner for the year ending June 30, 1900, U. S. Comm. Fish and

Fisheries 26:25-118.

Ravenel, W. de C. 1902. Report on the propagation and distribution of food-fishes. Report

of the Commissioner for the year ending June 30, 1901, U. S. Comm. Fish and

Fisheries 27:21-110.

Rawson, D. S. 1952. Mean depth and the fish production of large lakes. Ecology 33(4):513-

521.
195

Regenthal, A. F. 1955. Report on the test of a ski-jump spillway. Wash. Dep. Fish.,

Olympia, WA. 8 p.

Rensel, J. 1995. Water quality and sockeye salmon rearing in Lake Osoyoos during 1994.

Draft Report of Rensel Associates, Arlington, WA. to Douglas County PUD, East

Wenatchee, WA. (As quoted by Chapman et al. 1995).

Rice, S. D., R. E. Thomas, and A. Moles. 1994. Physiological and growth differences in

three stocks of underyearling sockeye salmon (Oncorhynchus nerka) on early entry

into seawater. Can. J. Fish. Aquat. Sci. 51:974-980.

Ricker, W. E. 1937. Physical and chemical characteristics of Cultus Lake, British Columbia.

J. Biol. Board Can. 3(4):363-402.

Ricker, W. E. 1938. “Residual” and kokanee salmon in Cultus Lake. J. Fish. Res. Board

Can. 4(3):192-218.

Ricker, W. E. 1940. On the origin of kokanee, a fresh-water type of sockeye salmon. Trans.

R. Soc. Can., Ser. 3, 34(5):121-135.

Ricker, W. E. 1950. Cyclic dominance among the Fraser River sockeye. Ecology 31:6-26.

Ricker, W. E. 1959. Additional observations concerning residual sockeye and kokanee

(Oncorhynchus nerka). J. Fish. Res. Board Can. 16(6):897-902.

Ricker, W. E. 1966. Salmon of the North Pacific Ocean - Part III. A review of the life

history of North Pacific salmon. 4. Sockeye salmon in British Columbia. Int. North

Pac. Fish. Comm. Bull. 18:59-70.

Ricker, W. E. 1972. Hereditary and environmental factors affecting certain salmonid

populations. In R.C. Simon and P.S. Larkin (editors), The stock concept in Pacific

salmon, p. 19-160. H. R. MacMillan Lectures in Fisheries, Univ. British Columbia,

Vancouver, B.C., Canada.

Ricker, W. E. 1982. Size and age of British Columbia sockeye salmon (Oncorhynchus

nerka) in relation to environmental factors and the fishery. Can. Tech. Rep. Fish.

Aquat. Sci. 1115, 117 p.

Ricker, W. E. 1995. Trends in the average size of Pacific salmon in Canadian catches. Can.

Spec. Publ. Fish. Aquat. Sci. No. 121, 593-602.

Ricker, W. E. 1997. Cycles of abundance among Fraser River sockeye salmon

(Oncorhynchus nerka). Can. J. Fish. Aquat. Sci. 54:950-968.
196

Riggs, L. A. 1990. Principles for genetic conservation and production quality. Report to

Northwest Power Planning Council, Portland, OR.

Robertson, A. 1922. Further proof of the parent stream theory. Trans. Am. Fish. Soc. 51:87-

90.

Robison, B. D. 1995. Genetic relationships between maternal lineages of sympatric

anadromous and resident forms of Oncorhynchus nerka determined through PCR

RFLP analysis of mtDNA. Master’s Thesis, Univ. Idaho, Boise, ID, 53 p.

Rogers, D. E. 1980. Density-dependent growth of Bristol Bay sockeye salmon. In W. J.

McNeil and D. C. Himsworth (editors), Salmonid ecosystems of the North Pacific, p.

267-283. Oregon State Univ. Press, Corvallis.

Rogers, D. E. 1987. The regulation of age at maturity in Wood River sockeye salmon

(Oncorhynchus nerka). Can. Spec. Publ. Fish. Aquat. Sci. 96:78-89.

Rogers, D. E., and G. T. Ruggerone. 1993. Factors affecting marine growth of Bristol Bay

sockeye salmon. Fish. Res. (Bethesda) 18:89-103.

Rohlf, F. J. 1993. NTSYS-pc. Numerical taxonomy and multivariate analysis system.

Exeter Software, Setauket, N.Y. (Software program).

Roppel, P. 1982. Alaska’s salmon hatcheries 1891-1991. Alaska Historical Commission

Studies in History 20, Natl. Mar. Fish. Serv., Portland, OR, 299 p.

Roukhlov, F. N. 1982. The role of salmon production and the perspectives of its

development in the Sakhalin Region. In B. R. Metcalfe and R. A. Neve (editors),

Proceedings of the North Pacific aquaculture symposium, August 18-21, 1980,

Anchorage, AK, p. 99-103. Alaska Sea Grant Program, Univ. Alaska, Fairbanks.

Publ. 82-2.

Rounsefell, G. A. 1957. Fecundity of North American Salmonidae. U.S. Fish. Wildl. Serv.,

Fish. Bull. 57:451-468.

Rounsefell, G. A. 1958a. Anadromy in North American Salmonidae. U.S. Fish. Wildl.

Serv., Fish. Bull. 58:171-185.

Rounsefell, G. A. 1958b. Factors causing decline in sockeye salmon of Karluk River,

Alaska. U.S. Fish. Wildl. Serv., Fish. Bull. 58:83-169.

Rounsefell, G. A., and G. B. Kelez. 1938. The salmon and salmon fisheries of Swiftsure

Bank, Puget Sound, and the Fraser River. U.S. Bur. Fish., Bull. 49:693-823.
197

Royal, L. A., and A. Seymour. 1940. Building new salmon runs, Puget Sound sockeye

salmon plantings show varying degrees of success. Prog. Fish - Cult. (Memo I-131)

52:7 p.

Ruggles, C. P. 1966. Juvenile sockeye studies in Owikeno Lake, British Columbia. Can.

Fish. Cult. 36:3-21.

Russell, R. B., D. L. Bill, and W. A. Bucher. 1989. Salmon spawning ground surveys in the

Bristol Bay area, 1988. Alsk. Dep. Fish Game Regional Information Rep., 2K88-14.

Rutherford, D. T., C. C. Wood, and J. R. Candy. 1988. Stock assessments and biological

investigations of kokanee (Oncorhynchus nerka) in Cowichan Lake, British Columbia.

Can. Manuscr. Rep. Fish. Aquat. Sci. 1995, 35 p.

Rutherford, D. T., C. C. Wood, K. D. Hyatt, L. Margolis, T. E. McDonald, B. E. Ridell, and

R. E. Withler. 1992. Biological characteristics of coastal populations of sockeye

salmon (Oncorhynchus nerka) in British Columbia. Can. Tech. Rep. Fish. Aquat. Sci.

1849, 47 p.

Rutherford, D. T., C. C. Wood, A. L. Jantz, and D. R. Southgate. 1994. Biological

characteristics of Nass River sockeye salmon and their utility for stock composition

analysis of test fisheries. Can. Tech. Rep. Fish. Aquat. Sci. 1988, 65 p.

Rutter, C. 1904. Natural history of the quinnat salmon. A report of investigations in the

Sacramento River, 1896-1901. U.S. Fish. Comm., Bull. 22:65-141.

Ryder, R. A. 1965. A method for estimating the potential fish production of north-temperate

lakes. Trans. Am. Fish. Soc. 94:214-218.

Schaefer, M. B. 1950. A study of the spawning populations of sockeye salmon in the

Harrison River system, with special reference to the problem of enumeration by means

of marked members. Ph.D. Thesis, Univ. Washington, Seattle, WA, 383 p.

Schaefer, M. B. 1951. A study of the spawning populations of sockeye salmon in the

Harrison River system, with special reference to the problem of enumeration by means

of marked members. Int. Pac. Salmon Fish. Comm. Bull. 4, 207 p.

Scheffer, V. B., and R. J. Robinson. 1939. A limnological study of Lake Washington. Ecol.

Monogr. 9:95-143.

Schultz, L. P., and A. C. DeLacy. 1935-1936. The fishes of the American northwest. A

catalogue of the fishes of Washington and Oregon, with distributional records and a

bibliography. J. Pan-Pacific Res. Inst. 10:365-380 and Mid. Pac. Mag. 48:63-78, 127-

142, 211-226, 275-290.
198

Schultz, L. P., and Students. 1935. The breeding activities of the little redfish, a landlocked

form of the sockeye salmon, Oncorhynchus nerka. Journ. Pan-Pacific Res. Inst.

10:67-77.

Scofield, N. B. 1916. The humpback and dog salmon taken in San Lorenzo River. Calif.

Dep. Fish Game Fish Bull. 2(1):41.

Scott, D. 1984. Origin of the New Zealand sockeye salmon, Oncorhynchus nerka

(Walbaum). J. Roy. Soc. N. Z. 14:245-249.

Seale, A. 1895. List of fresh-water fishes collected in the vicinity of Seattle, Washington, by

Edwin C. Starks. Proc. Calif. Acad. Sci., Ser. 2, 5(2):852-854.

Seeb, J., and L. Wishard. 1977. Lake Washington sockeye study, p. 26-36. In J. Seeb and L.

Wishard, The use of biochemical genetics in the management of Pacific salmon

stocks: genetic marking and mixed fishery analysis. Final Rep., Wash. Dep. Fish.,

Serv. Contr. No. 792.

Seiler, D., and L. E. Kishimoto. 1996. Annual report 1995 Cedar River sockeye salmon fry

production evaluation program. Wash. Dep. Fish Wildl., Olympia, WA, 9 p. plus

figures and tables.

Semko, R. S. 1954. Zapasy zapadnokamchatskikh lososei i ikh promyslovoe ispolzovanie.

Isvestiia Ttikhookeanskovo Nauchno-issledovatelskovo Instituta Rybnovo

Khoziaistvai. [The stocks of West Kamchatka salmon and their commercial

utilization] Okeanografii (Vladisvostok) 41:3-109. (Transl. by R. E. Foerster, Fish.

Res. Board Can. Transl. Ser. No. 30, 1960.)

Shaklee, J. B., J. Ames, and L. LaVoy. 1996. Genetic diversity units and major ancestral

lineages for sockeye salmon in Washington. Chapter E (Tech. Rep. RAD 95-02/96) In

C. Busack and J. B. Shaklee (editors), Genetic diversity units and major ancestral

lineages of salmonid fishes in Washington, Tech Rep. RAD 95-02. Wash. Dep. Fish

Wildl., Olympia, Wash., 37 p. plus figures and appendices.

Shaklee, J. B., D. C. Klaybor, S. Young, and B. A. White. 1991. Genetic stock structure of

odd-year pink salmon, Oncorhynchus gorbuscha (Walbaum), from Washington and

British Columbia and potential mixed-stock fisheries applications. J. Fish. Biol.

39(A):21-34.

Sharr, S., C. Peckham, and G. Carpenter. 1988. Catch and escapement statistics for Copper

River, Bering River, and Prince William Sound, 1986. Alsk. Dep. Fish Game Tech.

Fish. Rep. 88-17, 254 p.
199

Shepard, B. G., and B. A. Inkster. 1995. Sockeye and kokanee fry migration study Okanagan

River above Osoyoos Lake, 1994. Ministry of Environm., Lands, and Parks,

Okanagan Fish. Sect., Fish. Project Rep. OK-18, Penticton, B.C., Canada. (As cited by

Chapman et al. 1995)

Shepard, M. P., C. D. Shepard, and A. W. Argue. 1985. Historic statistics of salmon

production around the Pacific Rim. Can. Manuscr. Rep. Fish. Aquat. Sci. 1819, 297 p.

Simon, R. C., J. D. McIntyre, and A. R. Hemingsen. 1986. Family size and effective

population size in a hatchery stock of coho salmon (Oncorhynchus kisutch). Can. J.

Fish. Aquat. Sci. 43:2434-2442.

Slaney, T. L., K. D. Hyatt, T. G. Northcote, and R. J. Fielden. 1996. Status of anadromous

salmon and trout in British Columbia and Yukon. Fisheries 21:20-35.

Slauson, M. C. 1976. Renton - from coal to jets. Renton Historical Society, Renton, WA.

183 p.

Smith, M. W. 1940. The Puyallup - Nisqually. Columbia Univ. Press, New York, 336 p.

Smith, R. L. 1983. Physical features of coastal upwelling systems. Wash. Sea Grant Tech.

Rep. WSG 83-2, Wash. Sea Grant, Seattle, 34 p.

Smirnov, A. I. 1975. The biology, reproduction and development of the Pacific salmon. Izd.

Mosk. Univ., p. 1-355. [Fish. Res. Board Can. Transl. Ser. No. 3816, 1976]

Smoker, W. A., H. M. Jensen, R. T. Pressey, R. T. Heg, and J. W. Fitzgerald. 1952. Special

fresh water surveys, Lake Pleasant and Upper and Lower Lake Creeks, Clallam

County. In Puget Sound Investigations, April 1952 to June 1952. Wash. Dept. Fish.

Wildl., Olympia, WA, p. 18-23.

Sneath, P. H. A., and R. R. Sokal. 1973. Numerical taxonomy. W. H. Freeman & Co., San

Francisco, CA, 573 p.

Sneva, J. 1997. Final Lake Pleasant sockeye age estimates, 1994-1996, submitted to NMFS,

by J, Sneva, Washington Department of Fish and Wildlife, 5 May 1997. 5 p. and

Additional Lake Pleasant sockeye spawner age data, submitted to NMFS, by J, Sneva,

Washington Department of Fish and Wildlife, 5 June 1997. 1 p. (Available from

West Coast Sockeye Salmon Administrative Record, Environmental and Technical

Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street, Portland, OR

97232.)

Sokal, R. R., and F. J. Rohlf. 1981. Biometry. 2nd ed. W. H. Freeman & Co., San

Francisco, CA, 859 p.
200

Sprague, G. 1996a. Baker sockeye terminal runsize. Histogram, footnotes, and data tables

sent to Dr. M. Schiewe, NMFS, from G. Sprague, Washington Department of Fish and

Wildlife, dated 6 June 1996. 6 p. (Available from West Coast Sockeye Salmon

Administrative Record, Environmental and Technical Services Division, Natl. Mar.

Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Sprague, G. 1996b. Data tables and unpublished reports on Baker Lake sockeye salmon

submitted to NMFS, by G. Sprague, Washington Department of Fish and Wildlife, 17

December 1996. (Available from West Coast Sockeye Salmon Administrative

Record, Environmental and Technical Services Division, Natl. Mar. Fish. Serv., 525

N. E. Oregon Street, Portland, OR 97232.)

Stanford, L. M. 1942. Preliminary studies in the biology of the Snake River. Ph.D. Thesis,

Univ. Washington, Seattle, WA, 119 p.

Steer, G. J., and K. D. Hyatt. 1987. Use of a run timing model to provide in-season estimates

of sockeye salmon (Oncorhynchus nerka) returns to Barkley Sound, 1985. Can.

Tech. Rep. Fish. Aquat. Sci. 1557, 39 p.

Stickney, A. E., and L. McDonald. 1977. Squak Slough 1870-1920. Early days on the

Sammamish River Woodinville-Bothell-Kenmore. Friends of the Bothell Library,

Bothell, WA. 266 p.

Stober, Q. J., and A. H. Hämäläinen. 1979. Cedar River sockeye salmon fry emigration.

Univ. Wash. Fish. Res. Inst. FRI-UW-7917. 52 p.

Stober, Q. J., and A. H. Hämäläinen. 1980. Cedar River sockeye salmon production. Univ.

Wash. Fish. Res. Inst. FRI-UW-8016. 59 p.

Stockner, J. G. 1987. Lake fertilization: The enrichment cycle and lake sockeye salmon

(Oncorhynchus nerka) production. Can. Spec. Publ. Fish. Aquat. Sci. 96:198-215.

Stockner, J. G., and T. G. Northcote. 1974. Recent limnological studies of Okanagan Basin

lakes and their contribution to comprehensive water resource planning. J. Fish. Res.

Board Can. 31:955-976.

Stockner, J. G., and K. S. Shortreed. 1978. Limnological survey of 35 sockeye salmon

(Oncorhynchus nerka) nursery lakes in British Columbia and the Yukon Territory.

Fish. Mar. Serv. Tech. Rep. 827, 47 p.

Stockner, J. G., and K. S. Shortreed. 1979. Limnological studies of 13 sockeye salmon

(Oncorhynchus nerka) nursery lakes in British Columbia, Canada. Fish. Mar. Serv.

Tech. Rep. 865, 125 p.
201

Stockner, J. G., and K. S. Shortreed. 1983. A comparative limnological survey of 19 sockeye

salmon (Oncorhynchus nerka) nursery lakes in the Fraser River system, British

Columbia. Can. Tech. Rep. Fish. Aquat. Sci. 1190, 63 p.

Stockner, J. G., K. S. Shortreed, E. A. MacIsaac, and B. Nidle. 1993. The limnology of

Kitlope Lake: A cold, glacially-turbid sockeye salmon (Oncorhynchus nerka) nursery

lake. Can. Tech. Rep. Fish. Aquat. Sci. No. 1909, 35 p.

Storm, J. M., D. Chance, J. Harp, K. Harp, L. Lestelle, S. C. Sotomish, and L. Workman.

1990. Land of the Quinault. P. K. Capoeman (editor), Published by Quinault Indian

Nation, Taholah, WA, 316 p.

Swan, G. A., L. K. Timmee, R. N. Iwamoto, L. C. Stuehrenberg, E. E. Hockersmith, B. L.

Iverson, and B. P. Sandford. 1994. Wells Dam radio-telemetry study, 1992. U.S.

Dep. Commer., Natl. Oceanic Atmos. Admin., Natl. Mar. Fish. Serv., Northwest Fish.

Sci. Cent., Seattle, WA, 70 p.

Swofford, D. L., and R. B. Selander. 1981. BIOSYS-1: a FORTRAN program for the

comprehensive analysis of electrophoretic data in population genetics and systematics.

J. Hered. 72:282-283.

Taft, A. C. 1937. A red salmon (Oncorhynchus nerka) taken in the Klamath River. Calif.

Fish Game 23(2):178.

Taylor, E. B. 1991. A review of local adaptation in Salmonidae, with particular reference to

Pacific and Atlantic salmon. Aquaculture 98:185-207.

Taylor, E. B., and C. J. Foote. 1991. Critical swimming velocities of juvenile sockeye

salmon and kokanee, the anadromous and non-anadromous forms of Oncorhynchus

nerka (Walbaum). J. Fish Biol. 38:407-419.

Taylor, E. B., C. J. Foote, and C. C. Wood. 1996. Molecular genetic evidence for parallel life

history evolution within a Pacific salmon (sockeye salmon and kokanee,

Oncorhynchus nerka). Evolution 50:401-416.

Technical Advisory Committee (TAC). 1991. Sockeye. In Columbia River fish management

plan: 1991 All species review. Technical Advisory Committee, U.S. v. Oregon.

(Available from Environmental and Technical Services Division, Natl. Mar. Fish. Srv.,

525 N.E. Oregon Street, Portland, OR 97232.)
202

Technical Advisory Committee (TAC). 1994. Biological assessment of the impacts of

anticipated 1995 winter, spring, and summer season Columbia River and tributary

fisheries on listed Snake River salmon species under the Endangered Species Act.

U.S. v. Oregon Technical Advisory Committee, Portland, Oregon. (Available from

Environmental and Technical Services Division, Natl. Mar. Fish. Serv., 525 N.E.

Oregon Street, Portland, OR 97232.)

Teuscher, D, and D. Taki. 1996. Snake River sockeye salmon habitat and limnological

research, Annual Report 1995. U.S. Dep. Energy, Bonneville Power Administration,

Proj. No. 91-71, Contract No. DE-B179-91BP22548. Portland, OR, 135 p. plus figure

and tables.

Teuscher, D., D. Taki, W. A. Wurtsbaugh, C. Luecke, P. Budy, H. P. Gross, and G. Steinhart.

1994. Snake River salmon habitat and limnological research annual report: 1993.

U.S. Dep. Energy, Bonneville Power Administration, Proj. No. 91-71, Contract No.

DE-BI79-91BP22548, Portland, OR, 133 p. plus appendices.

Teuscher, D, D. Taki, W. Wurtsbaugh, C. Luecke, P. Budy, and G. Steinhart. 1995. Snake

River sockeye salmon habitat and limnological research, Annual Report 1994. U.S.

Dep. Energy, Bonneville Power Administration, Proj. No. 91-71, Contract No. DEB179-91BP22548, Portland, OR, 85 p. plus figures and tables.

Thompson, G. G. 1991. Determining minimum viable populations under the Endangered

Species Act. U.S. Dep. Commer., NOAA Tech. Memo. NMFS F/NWC-198, 78 p.

Thompson, R. B., and D. F. Tufts. 1967. Predation by Dolly Varden and northern squawfish

on hatchery-reared sockeye salmon in Lake Wenatchee, Washington. Trans. Am.

Fish. Soc. 96:424-427.

Thompson, R. E. 1981. Oceanography of the British Columbia coast. Can. Spec. Publ. Fish.

Aquat. Sci. 56, 291 p.

Thomson, B. L., S. K. Bachen, and R.D. Goruk. 1988. An historical overview of the

Owikeno Lake (Rivers Inlet, Statistical Area 9) fall sockeye salmon escapement

surveys 1971-1987. Can. Data Rep. Fish. Aquat. Sci. 711, 69 p. plus appendices.

Thomson, B. L., and R.D. Goruk. 1988. An historical overview of the Docee River

enumeration program 1963-1987. Can. Data Rep. Fish. Aquat. Sci. 702, 8 p. plus

appendices.

Thorgaard, G. H., P. Spruell, S. A. Cummings, A. S. Peek, and E. L. Brannon. 1995. Mixed

DNA fingerprint analysis differentiates sockeye salmon populations. In J. L. Nielsen

(editor), Evolution and the aquatic ecosystem: defining unique units in population

conservation. Am. Fish. Soc. Symp. 17:295-303.
203

Tierney, E. 1997. Letter to R. Gustafson, NMFS, from E. Tierney, Quileute Natural

Resources, re. Lake Pleasant sockeye survey data, dated 8 April 1997. 1 p. plus

attachment. (Available from West Coast Sockeye Salmon Administrative Record,

Environmental and Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E.

Oregon Street, Portland, OR 97232.)

Titcomb, J. W. 1904. Report on the propagation and distribution of food-fishes. Report of

the Commissioner for the year ending June 30, 1902, U. S. Comm. Fish and Fisheries

28:22-110.

Titcomb, J. W. 1905. Report on the propagation and distribution of food fishes. Report of

the Commissioner for the year ending June 30, 1903, U. S. Comm. Fish and Fisheries

29:29-74.

Toner, R. C. 1960. Appendix A: A study of some of the factors associated with the

reestablishment of blueback salmon (Oncorhynchus nerka) into the upper Wallowa

River system. In Thompson, R. N. and J. B. Haas (editors), Environmental survey

report pertaining to salmon and steelhead in certain rivers of eastern Oregon and the

Willamette River and its tributaries. Part 1. Survey reports of eastern Oregon rivers,

p. A1-A46. Oreg. Fish Comm., Res. Division, Clackamas, OR.

Tschaplinksi, P. J., and K. D. Hyatt. 1990. Abundance, migration timing, and biological

characteristics of sockeye salmon (Oncorhynchus nerka) returning to Henderson Lake,

Vancouver Island during 1988. Can. Tech. Rep. Fish. Aquat. Sci. 1758, 82 p.

Tschaplinksi, P. J., and K. D. Hyatt. 1991. A comparison of population assessment methods

employed to estimate the abundance of sockeye salmon (Oncorhynchus nerka)

returning to Henderson Lake, Vancouver Island during 1989. Can. Tech. Rep. Fish.

Aquat. Sci. 1798, 101 p.

Tufts, D. F., and D. R. Craddock. 1963. Spawning escapement of Columbia River sockeye

salmon (Oncorhynchus nerka), 1962. U.S. Fish and Wildl. Serv. Processed Rep.,

Seattle, WA, 17 p.

Tyler, R. W., and T. E. Wright. 1974. A method of enumerating blueback salmon smolts

from Quinault Lake and biological parameters of the 1974 outmigration. Final report

to Quinault Tribal Council, Fisheries Research Institute, Univ. Washington, FRI-UW74-14. 29 p.

U.S. Bureau of Fisheries (USBF). 1905-1921. Reports of the U.S. Commissioner of

Fisheries for the fiscal years 1904-1920. Washington, D.C., various pages.

U.S. Bureau of Fisheries (USBF). 1906. The propagation and distribution of food fishes

during 1905. Bur. of Fish. Doc. 602, 64 p.
204

U.S. Bureau of Fisheries (USBF). 1907. The distribution of food fishes during the fiscal year

1906. Bur. of Fish. Doc. 613, 78 p.

U.S. Bureau of Fisheries (USBF). 1909. The distribution of fish and fish eggs during the

fiscal year 1908. Bur. of Fish. Doc. 644, 93 p.

U.S. Bureau of Fisheries (USBF). 1910. The distribution of fish and fish eggs during the

fiscal year 1909. Bur. of Fish. Doc. No. 728, 103 p.

U.S. Bureau of Fisheries (USBF). 1911. The distribution of fish and fish eggs during the

fiscal year 1910. Bur. of Fish. Doc. 740, 112 p.

U.S. Bureau of Fisheries (USBF). 1913. The distribution of fish and fish eggs during the

fiscal year 1912. Bur. of Fish. Doc. 770, 108 p.

U.S. Bureau of Sport Fisheries and Wildlife (USBSFW). 1971. Sockeye fishery

investigations on the Quinault River system. U.S. Dep. Interior, Bur. Sport Fish.

Wildl., Division Fish. Services, Spec. Rep., Tumwater, WA, 5 p. plus figures and

tables.

U.S. Department of Commerce (USDOC). 1968. Weather atlas of the United States

(Originally titled: Climate atlas of the United States). [1975 reprint of 1968 edition

published by U.S. Environmental Data Service and Gale Research Co., Detroit, MI,

262 p.]

U.S. Environmental Protection Agency (USEPA). 1974. The relationships of phosphorus and

nitrogen to the trophic state of Northeast and North Central lakes and reservoirs.

Working Paper No. 23. National Eutrophication Survey, Corvallis, OR.

Utter, F. 1995. Letter from F. Utter (Univ. of Washington, School of Fisheries) to C. Pevan

(Chelan County PUD), re. Preliminary results of investigations of genetic variation in

1994 sockeye salmon collections from the Mid-Columbia River, dated 30 November

1995. 3 p. plus 3 tables and 1 fig. (Available from West Coast Sockeye Salmon

Administrative Record, Environmental and Technical Services Division, Natl. Mar.

Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Utter, F., P. Aebersold, J. Helle, and G. Winans. 1984. Genetic characterization of

populations in the southeastern range of sockeye salmon. In J. M. Walton and D. B.

Houston (editors), Proceedings of the Olympic wild fish conference, p. 17-31.

Fisheries Technology Program, Peninsula College, Port Angeles, WA.

Utter, F. M., and H. O. Hodgins. 1970. Phosphoglucomutase polymorphism in sockeye

salmon. Comp. Biochem. Physiol. 36:195-199.
205

Utter, F., G. Milner, G. Stahl, and D. Teel. 1989. Genetic population structure of chinook

salmon, Oncorhynchus tshawytscha, in the Pacific Northwest. Fish. Bull., U.S.

87:239-264.

Valentine, J. W. 1966. Numerical analysis of marine molluscan ranges on the extratropical

northeastern Pacific shelf. Limnol. Oceanogr. 11:198-211.

Varnavskaya, N. V. 1984. Distribution of lactic acid dehydrogenase and

phosphoglucomutase gene frequencies in populations of Kamchatka sockeye salmon

(Oncorhynchus nerka Walb.) preferring different types of spawning grounds. Sov.

Genet. 20:81-87.

Varnavskaya, N. V., V. S. Varnavskii, I. I. Vetsler, and K. Yu. Nepomnyashchii. 1988.

Features of spatial genetic differentiation of populations of blue-black salmon

(Oncorhynchus nerka Walbaum) in lakes Nachiki, Dvukhyurtochnoe, Dal’nee and

Blizhnee (Kamchatka). Sov. Genet. 24:505-512.

Varnavskaya, N. V., C. C. Wood, and R. J. Everett. 1994a. Genetic variation in sockeye

salmon (Oncorhynchus nerka) populations of Asia and North America. Can. J. Fish.

Aquat. Sci. 51(Suppl. 1):132-146.

Varnavskaya, N. V., C. C. Wood, R. J. Everett, R. L. Wilmot, V. S. Varnavsky, V. V.

Midanaya, and T. P. Quinn. 1994b. Genetic differentiation of subpopulations of

sockeye salmon (Oncorhynchus nerka) within lakes of Alaska, British Columbia, and

Kamchatka, Russia. Can. J. Fish. Aquat. Sci. 51(Suppl. 1):147-157.

Velsen, F. P. J. 1980. Embryonic development in eggs of sockeye salmon, Oncorhynchus

nerka. Can. Spec. Publ. Fish. Aquat. Sci. 49:1-19.

Vernon, E. H. 1957. Morphometric comparison of three races of kokanee (Oncorhynchus

nerka) within a large British Columbia Lake. J. Fish. Res. Board Can. 14(4):573-598.

Waknitz, F. W., G. M. Mathews, T. Wainwright, and G.A. Winans. 1995. Status review for

mid-Columbia River summer chinook salmon. NOAA Tech. Memo. NMFS-NWFSC22, 80 p.

Waltemyer, D. L. 1994. Age, sex and size composition of chinook, sockeye, coho, and chum

salmon returning to Upper Cook Inlet, Alaska in 1991. Alsk. Dep. Fish Game Tech.

Fish. Rep. 94-11, 95 p.

Wampler, P. L. 1980. Instream flow requirements of the lower North Fork, South Fork and

mainstem Skokomish River. U.S. Fish Wildl. Serv., Fisheries Assistance Office,

Olympia, WA, 54 p.
206

Waples, R. S. 1991a. Pacific salmon, Oncorhynchus spp., and the definition of “species”

under the Endangered Species Act. Mar. Fish. Rev. 53(3):11-22.

Waples, R. S. 1991b. Genetic interactions between hatchery and wild salmonids: lessons

from the Pacific Northwest. Can. J. Fish. Aquat. Sci. 48(Suppl. 1):124-133.

Waples, R. S., P. B. Aebersold, and G. A. Winans. In press. Population genetic structure and

life-history variability in Oncorhynchus nerka from the Snake River Basin. Final

report of research. U.S. Dep. Energy, Bonneville Power Administration, Proj. No. 93-

066, Contract No. DE-A179-93BP05326.

Waples, R. S., O. W. Johnson, and R. P. Jones, Jr. 1991. Status review for Snake River

sockeye salmon. U.S. Dep. Commer., NOAA Tech. Memo. NMFS F/NWC-195,

23 p.

Waples, R. S., and D. J. Teel. 1990. Conservation genetics of Pacific salmon. I. Temporal

changes of allele frequency. Cons. Biol. 4:144-156.

Ward, F. J. 1952. Egg counts as a means of identifying the races of Fraser River sockeye

salmon. Bachelor’s Thesis, Dep. of Zool., Univ. British Columbia, Vancouver, B. C.,

48 p.

Ward, F. J., and P. A. Larkin. 1964. Cyclic dominance in Adams River sockeye salmon. Int.

Pac. Salmon Fish. Comm. Prog. Rep. 11, 116 p.

Ward, H. B. 1929. Further studies on the influence of a power dam in modifying conditions

affecting the migration of the salmon. Proc. Nat. Acad. Sci. 15:56-62.

Ward, H. B. 1930. Some responses of sockeye salmon to environmental influence during

fresh-water migration. Ann. Mag. Nat. Hist. (10) 6:18-36.

Ward, H. B. 1932. The origin of the landlocked habit in salmon. Proc. Nat. Acad. Sci.

18:569-580.

Warner, E. 1996. Lake Washington sockeye smolt lengths. E-mail to R. Gustafson, NMFS,

from E. Warner, Muckleshoot Indian Tribe, dated 22 January 1997. 1 p. (Available

from West Coast Sockeye Salmon Administrative Record, Environmental and

Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street, Portland,

OR 97232.)
207

Warner, E. 1997. Letter to R. Gustafson, NMFS, from E. Warner, Muckleshoot Indian Tribe

Fisheries Department, re. Muckleshoot Indian Tribe comments on the draft sockeye

status review, dated 30 January 1997. 3 p. (Available from West Coast Sockeye

Salmon Administrative Record, Environmental and Technical Services Division, Natl.

Mar. Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Washington Department of Fish and Wildlife (WDFW). 1996. Letter to M. Schiewe, NMFS,

from R. Lincoln, Assistant Director, Fish Management Program, Washington

Department of Fish and Wildlife, dated 12 July 1996. 3 p. plus appendix. (Available

from West Coast Sockeye Salmon Administrative Record, Environmental and

Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street, Portland,

OR 97232.)

Washington Department of Fisheries (WDF). 1973. Review draft. Fisheries resources in

southwest Washington. Southwest Washington river basins study. Wash. Dep. Ecol.,

Olympia, WA, 151 p.

Washington Department of Fisheries (WDF). 1974. 1974 fisheries statistical report, p. 108-

110. State Printing Plant, Olympia, WA.

Washington Department of Fisheries (WDF), Washington Department of Game (WDG), and

United States Bureau of Fisheries (USBF). 1938. A report on the preliminary

investigations into the possible methods of preserving the Columbia River salmon and

steelhead at the Grand Coulee Dam. Wash. Dep. Fish, Olympia, WA, 120 p.

Washington Department of Fisheries (WDF), Washington Department of Wildlife (WDW),

and Western Washington Treaty Indian Tribes (WWTIT). 1993. 1992 Washington

State salmon and steelhead stock inventory (SASSI). Wash. Dep. Fish Wildl.,

Olympia, WA, 212 p. plus 5 regional volumes.

Washington Department of Fisheries and Game (WDFG). 1916a. Twenty-forth and twentyfifth annual reports of State Fish Commissioner to the Governor of the State of

Washington April 1, 1913, to March 31, 1915. Wash. Dep. Fish. Game, Olympia,

WA, 171 p.

Washington Department of Fisheries and Game (WDFG). 1916b. First and second annual

reports of the chief game warden to the Governor of the State of Washington June 12,

1913 to February 28, 1915. Wash. Dep. Fish. Game, Olympia, WA, 58 p.

Washington Department of Fisheries and Game (WDFG). 1917. Twenty-sixth and twentyseventh annual reports of State Fish Commissioner to the Governor of the State of

Washington April 1, 1915, to March 31, 1917. Wash. Dep. Fish. Game, Olympia,

WA, 196 p.
208

Washington Department of Fisheries and Game (WDFG). 1918. Third and fourth annual

reports of the state game warden to the Governor of the State of Washington March 1,

1915 to February 28, 1917. Wash. Dep. Fish. Game, Olympia, WA, 78 p.

Washington Department of Fisheries and Game (WDFG). 1919. Fifth and sixth annual

reports of the state game warden to the Governor of the State of Washington March 1,

1917 to February 28, 1919. Wash. Dep. Fish. Game, Olympia, WA, 99 p.

Washington Department of Fisheries and Game (WDFG). 1920. Twenty-eighth and twentyninth annual reports of State Fish Commissioner to the Governor of the State of

Washington April 1, 1917, to March 31, 1919. Wash. Dep. Fish. Game, Olympia,

WA, 174 p.

Washington Department of Fisheries and Game (WDFG). 1921a. Seventh and eighth annual

reports of the state game warden to the Governor of the State of Washington March 1,

1919 to February 28, 1921. Wash. Dep. Fish. Game, Olympia, WA, 143 p.

Washington Department of Fisheries and Game (WDFG). 1921b. Thirtieth and thirty-first

annual reports of State Fish Commissioner to the Governor of the State of Washington

April 1, 1919, to March 31, 1921. Wash. Dep. Fish. Game, Olympia, WA, 302 p.

Washington Department of Fisheries and Game (WDFG). 1923. First biennial report 1921-

1922. Wash. Dep. Fish. Game, Olympia, WA, 174 p.

Washington Department of Fisheries and Game (WDFG). 1924. Thirty-second and thirtythird annual reports of State Supervisor of Fisheries for the period from April 1, 1921,

to March 31, 1923. Wash. Dep. Fish. Game, Olympia, WA, 114 p.

Washington Department of Fisheries and Game (WDFG). 1928. Thirty-sixth and thirtyseventh annual reports of State Department of Fisheries and Game, Division of

Fisheries, for the period from April 1, 1925, to March 31, 1927. Wash. Dep. Fish.

Game, Olympia, WA, 218 p.

Washington Department of Fisheries and Game (WDFG). 1930. Thirty-eighth and thirtyninth annual reports of State Department of Fisheries and Game, Division of Fisheries,

for the period from April 1, 1927, to March 31, 1929. Wash. Dep. Fish. Game,

Olympia, WA, 121 p.

Washington Department of Fisheries and Game (WDFG). 1932. Fortieth and forty-first

annual reports of State Department of Fisheries and Game, Division of Fisheries, for

the period from April 1, 1929, to March 31, 1931. Wash. Dep. Fish. Game, Olympia,

WA, 150 p.
209

Wayne, W. W. 1961. Fish handling facilities for Baker River Project. J. Power Division,

Proc. Amer. Soc. Civil Engineers 87(PO3):23-54.

Weitkamp, D., and J. Neuner. 1981. Juvenile salmonid monitoring Methow River, Okanogan

River and Wells Dam forebay. Doc. No. 82-0113-001D2, review draft prepared for

Douglas County PUD, East Wenatchee, WA.

Weitkamp, L. A., T. C. Wainwright, G. J. Bryant, G. B. Milner, D. J. Teel, R. G. Kope, and R.

S. Waples. 1995. Status review of coho salmon from Washington, Oregon, and

California. U.S. Dep. Commer., NOAA Tech. Memo. NMFS-NWFSC-24, 258 p.

Welch, E. B., T. Wiederholm, D. E. Spyridakis, and C. A. Rook. 1977. Nutrient loading and

trophic state of Lake Sammamish, Washington. In Seyb, L. and K. Randolph (eds.)

North American project — A study of U. S. water bodies, p. 301-320. U.S.

Environmental Protection Agency, Environmental Research Laboratory - Corvallis,

EPA-600/3-77-086.

Wendler, H. O., and G. Deschamps. 1955. The salmon fisheries of Washington’s coastal

rivers and harbors. Wash. Dep. of Fish., Olympia, WA. 33 p. (Available from West

Coast Sockeye Salmon Administrative Record, Environmental and Technical Services

Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street, Portland, OR 97232.)

Westley, R. E. 1966. Limnological study of Merwin, Upper Baker, and Lower Baker

Reservoirs. Res. Division, Wash. Dep. Fish., Summary Rep. Olympia, WA, 206 p.

Wilcock, J. A. 1993. Salmon catch and escapement statistics for Copper River, Bering

River, and Prince William Sound, 1989. Alsk. Dep. Fish Game Tech. Fish. Rep. 93-

07, 152 p.

Wilcox, W. A. 1898. Notes on the fisheries of the Pacific coast in 1895. Report of the

Commissioner for the year ending June 30, 1896, U. S. Comm. Fish and Fisheries

22:575-659.

Wilderness Society. 1993. The living landscape, Vol. 2: Pacific salmon and federal lands.

Bolle Center for Forest Ecosystem Management, 87 p.

Williams, I. V. 1987. Attempts to re-establish sockeye salmon (Oncorhynchus nerka)

populations in the Upper Adams River, British Columbia, 1949-1984. Can. Spec.

Publ. Fish. Aquat. Sci. 96:235-242.

Williams, R. W., R. M. Laramie, and J. J. Ames. 1975. A catalog of Washington streams and

salmon utilization, Vol. 1, Puget Sound region. Wash. Dep. Fish., Olympia, WA.

926 p.
210

Willoughby, C. 1889. Indians of the Quinaielt (sic) Agency, Washington Territory.

Smithsonian Institution Annul Report of the Board of Regents for the year ending June

30, 1886, p. 267-282. U.S. Government Printing Office, Washington, D.C. (Available

from West Coast Sockeye Salmon Administrative Record, Environmental and

Technical Services Division, Natl. Mar. Fish. Serv., 525 N. E. Oregon Street, Portland,

OR 97232.)

Wilmot, R. L., and C. V. Burger. 1985. Genetic differences among populations of Alaskan

sockeye salmon. Trans. Am. Fish. Soc. 114:236-243.

Winans, G. A., P. B. Aebersold, S. Urawa, and N. V. Varnavskaya. 1994. Determining

continent of origin of chum salmon (Oncorhynchus keta) using genetic stock

identification techniques: status of allozyme baseline in Asia. Can. J. Fish. Aquat.

Sci. 51 (Suppl. 1):95-113.

Winans, G. A., P. A. Aebersold, and R. S. Waples. 1996. Allozyme variability of

Oncorhynchus nerka in the Pacific Northwest, with special consideration to

populations of Redfish Lake, Idaho. Trans. Am. Fish. Soc. 205:645-663.

Withler, R. E. 1985. Ldh-4 allozyme variability in North American sockeye salmon

(Oncorhynchus nerka) populations. Can. J. Zool. 63:2924-2932.

Withler, R. E. 1988. Genetic consequences of fertilizing chinook salmon (Oncorhynchus

tshawytscha) eggs with pooled milt. Aquaculture 68:15-25.

Wolcott, E. E. 1961. Lakes of Washington, Vol. 1, Western Washington. Water Supply

Bulletin No 14. Water Resources Division, Wash. Dep. Conservation, Olympia, WA,

618 p.

Wood, C. C. 1995. Life history variation and population structure in sockeye salmon. In J.

L. Nielsen (editor), Evolution and the aquatic ecosystem: defining unique units in

population conservation. Am. Fish. Soc. Symp. 17:195-216.

Wood, C. C., and C. J. Foote. 1990. Genetic differences in the early development and growth

of sympatric sockeye salmon and kokanee (Oncorhynchus nerka), and their hybrids.

Can. J. Fish. Aquat. Sci. 47:2250-2260.

Wood, C. C., and C. J. Foote. 1996. Evidence for sympatric genetic divergence of

anadromous and non-anadromous morphs of sockeye salmon (Oncorhynchus nerka).

Evolution 50:1265-1279.

Wood, C. C., N. B. Hargreaves, D. T. Rutherford, and B. T. Emmett. 1993. Downstream and

early marine migratory behaviour of sockeye salmon (Oncorhynchus nerka) smolts

entering Barkley Sound, Vancouver Island. Can. J. Fish. Aquat. Sci. 50:1329-1337.
211

Wood, C. C., G. T. Oliver, and Rutherford, D.T. 1988. Comparison of several biological

markers used for stock identification of sockeye salmon (Oncorhynchus nerka) in

northern British Columbia and southeast Alaska. Can. Tech. Rep. Fish. Aquat. Sci.

1624, 44 p.

Wood, C. C., B. E. Riddell, and D. T. Rutherford. 1987a. Alternative juvenile life histories

of sockeye salmon (Oncorhynchus nerka) and their contribution to production in the

Stikine River, northern British Columbia. Can. Spec. Publ. Fish. Aquat. Sci. 96:12-

24.

Wood, C. C., B. E. Riddell, D. T. Rutherford, and K. L. Rutherford. 1987b. Variation in

biological characters among sockeye salmon populations of the Stikine River with

potential application for stock identification in mixed-stock fisheries. Can. Tech. Rep.

Fish. Aquat. Sci. 1535, 61 p.

Wood, C. C., B. E. Riddell, D. T. Rutherford, and R. E. Withler. 1994. Biochemical genetic

survey of sockeye salmon (Oncorhynchus nerka) in Canada. Can. J. Fish. Aquat. Sci.

51(Suppl. 1):114-131.

Wood, C. C., D. T. Rutherford, and S. McKinnell. 1989. Identification of sockeye salmon

(Oncorhynchus nerka) stocks in mixed-stock fisheries in British Columbia and

Southeast Alaska using biological markers. Can. J. Fish. Aquat. Sci. 46:2108-2120.

Woodey, J. C. 1966. Sockeye salmon spawning grounds and adult returns in the Lake

Washington watershed, 1965. Master’s Thesis, Univ. Washington, Seattle, WA, 101

p.

Woodey, J. C. 1972. Distribution, feeding, and growth of juvenile sockeye salmon in Lake

Washington. Ph.D. Thesis, Univ. Washington, Seattle, WA, 174 p.

Wunderlich, R. C., B. D. Winter, and J. H. Meyer. 1994. Restoration of the Elwha River

ecosystem. Fisheries 19(8):11-19.

Young, S. F. 1997. Data tables for sockeye salmon collected for genetic stock inventory,

submitted to NMFS, 16 December 1996, 11 January 1997, 29 April 1997, and 23 May

1997 by S. F. Young, Washington Department of Fish and Wildlife, Olympia, WA,

8 p., 3 p., and 6 p.

Youngs, W. D., and D. G. Heimbuch. 1982. Another consideration of the morphoedaphic

index. Trans. Am. Fish. Soc. 111:151-153.

Zhadin, V. I. 1965. Mollusks of fresh and brackish waters of the U.S.S.R. Keys to the fauna

of the U.S.S.R., No. 46 [Transl. by A. Mercado]. Israel Program for Scientific

Translations, Jerusalem, 368 p.
212
213

APPENDIX A - GLOSSARY
214

GLOSSARY

age

Age is based on counts and measurements of annual rings on scales or otoliths (a

calcareous “earstone” found in the internal ear of fishes). Several notation styles have been

developed to designate age (Koo 1962). In this review the European notation style is used.

Freshwater age is generally separated from saltwater age by a period (.); for example, the age

of a fish which spent 2 winters in fresh water (not counting the incubation period) and 2 years

in saltwater would be represented as age 2.2.

allele

An allele is an alternate form of a gene (the basic unit of heredity passed from parent

to offspring). By convention, the “100 allele” is the most common allele in a population and

is the reference for the electrophoretic mobility of other alleles of the same gene. Other

genetic terms used in this document include allozymes (alternate forms of an enzyme

produced by different alleles and often detected by protein electrophoresis); dendrogram (a

branching diagram, sometimes resembling a tree, that provides one way of visualizing

similarities between different groups or samples); gene locus (pl. loci; the site on a

chromosome where a gene is found); genetic distance (D) (a quantitative measure of genetic

differences between a pair of samples); and introgression (introduction of genes from one

population or species into another). See also DNA and electrophoresis.

artificial propagation

See hatchery.

Biological Review Team (BRT)

The team of scientists from National Marine Fisheries Service formed to conduct the

status review.

DNA (deoxyribonucleic acid)

DNA is a complex molecule that carries an organism’s heritable information. The two

types of DNA commonly used to examine genetic variation are mitochondrial DNA

(mtDNA), a circular molecule that is maternally inherited, and nuclear DNA, which is

organized into a set of chromosomes. See also allele and electrophoresis.

electrophoresis

Electrophoresis refers to the movement of charged particles in an electric field. It has

proven to be a very useful analytical tool for biochemical characters because molecules can be

separated on the basis of differences in size or net charge. Protein electrophoresis, which

measures differences in the amino acid composition of proteins from different individuals, has

been used for over two decades to study natural populations, including all species of

anadromous Pacific salmonids. Because the amino acid sequence of proteins is coded for by

DNA, data provided by protein electrophoresis provide insight into levels of genetic

variability within populations and the extent of genetic differentiation between them. Genetic
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techniques that focus directly on variation in DNA also routinely use electrophoresis to

separate fragments formed by cutting DNA with special enzymes (restriction

endonucleases). See also allele and DNA.

epilimnion

The upper region of a thermally stratified lake, above the thermocline, and generally

warm and well oxygenated.

escapement

The number of fish that survive to reach the spawning grounds or hatcheries. The

escapement plus the number of fish removed by harvest form the total run size.

evolutionarily significant unit (ESU)

A “distinct” population of Pacific salmon, and hence a species, under the Endangered

Species Act.

hatchery

Salmon hatcheries typically spawn adults in captivity and raise the resulting progeny

in fresh water for release into the natural environment. In some cases, fertilized eggs are

outplanted (usually in “hatch-boxes”), but it is more common to release fry (young juveniles)

or smolts (juveniles that are physiologically prepared to undergo the migration into salt

water). The fish are released either at the hatchery (on-station release) or away from the

hatchery (off-station release). Releases may also be classified as within basin (occurring

within the river basin in which the hatchery is located or the stock originated from) or out-ofbasin (occurring in a river basin other than that in which the hatchery is located or the stock

originated from).

The broodstock of some hatcheries is based on adults that return to the hatchery each

year; others rely on fish or eggs from other hatcheries, or capture adults in the wild each year.

hypolimnion

The lower zone of a thermally stratified lake, below the thermocline, and usually

depleted in oxygen during summer stagnation.

IHN

Infectious Hematopoietic Necrosis; a viral disease endemic to salmonid fishes of the

Pacific Coast of North America that can cause high mortality in 3-week to 6-month-old fish.

.

jacks

Male salmon that return from the ocean to spawn one or more years before full-sized

adults return. For sockeye salmon in Oregon, Washington, and southern British Columbia,

jacks are 3 years old (age 1.1), having spent only one winter in the ocean, in contrast to more

typical sockeye salmon that are age 1.2, 1.3, 2.2 or 2.3 on return.
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jills

Female salmon that return from the ocean to spawn one or more years before full-sized

adults return. For sockeye salmon in Oregon, Washington, and southern British Columbia,

jills are 3 years old (age 1.1), having spent only one winter in the ocean, in contrast to more

typical sockeye salmon that are age 1.2, 1.3, 2.2 or 2.3 on return.

kokanee

The self-perpetuating, nonanadromous form of O. nerka that occurs in balanced sexratio populations and whose parents, for several generations back, have spent their whole lives

in fresh-water.

morphoedaphic index (MEI)

The most widely used index of potential fish production in lakes. A metric expression

of the MEI is derived by dividing a lake’s total dissolved solids (mg/L), or its conductivity, by

its mean depth in meters.

polymorphic

Having more than one form (e.g., polymorphic gene loci have more than one allele).

principal component analysis (PCA)

A statistical technique that attempts to explain variation among several (n) variables in

terms of a smaller number of composite independent factors called principal components.

These principal components are represented by eigenvectors, or the perpendicular axes of

central trend that pass through the clouds of points represented in n-dimensional space. The

matrix of eigenvectors and the matrix of correlations of independent variables are used with

linear algebra to calculate the equations describing the principal components that account for

the greatest amount of the variation expressed in the original variables. Principal component

one (PC1) is defined as a linear combination of the n variables that accounts for more of the

variance in the data than any other linear combination of variables. Second (PC2) and

subsequent components are defined as linear combinations that account for residual variance

after the effect of the first (and subsequent) component(s) is removed from the data. PC

values or “scores” are calculated for each individual and subjected to statistical analysis.

resident sockeye salmon

The progeny of anadromous sockeye salmon parents that spend their adult life in

freshwater and are observed together with their anadromous siblings on the spawning

grounds.

river kilometer (RKm)

Distance, in kilometers, from the mouth of the indicated river. Usually used to

identify the location of a physical feature, such as a confluence, dam, waterfall, or spawning

area.
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smolt

verb- The physiological process that prepares a juvenile anadromous fish to survive

the transition from fresh water to salt water.

noun- A juvenile anadromous fish that has smolted.

spawner surveys

Spawner surveys utilize counts of redds (nests dug by females in which they deposit

their eggs) and fish carcasses to estimate spawner escapement and identify habitat being used

by spawning fish. Annual surveys can be used to compare the relative magnitude of spawning

activity between years. Surveys are conducted on a regular basis on standard stream

segments, groups of which form a spawner index, and are occasionally conducted on

supplemental stream segments (those that are not part of the standard surveying plan).

Strait of Georgia

The body of water separating the southern portion of Vancouver Island and the British

Columbia mainland. The strait extends from Cortes Island and Desolation Sound in the north

to the San Juan Islands in the south.

Strait of Juan de Fuca

The body of water separating the southern portion of Vancouver Island and the

Olympic Peninsula in Washington. The strait extends from the Pacific Ocean east to the San

Juan and Whidbey Islands.

thermocline

That layer of water in a lake in which the temperature changes 10

C with each meter

increase in depth.

west coast sockeye salmon

For the purposes of this document, west coast sockeye salmon are defined as sockeye

salmon originating from fresh waters of Washington, Oregon, and British Columbia.
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APPENDIX C - LIFE HISTORY TRAIT INFORMATION
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APPENDIX D - RECORDS OF HATCHERY OUTPLANTS
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APPENDIX E - SUMMARY OF WEST COAST SOCKEYE

SALMON STATUS
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