Federal Register / Vol. 72, No. 78 / Tuesday April 24, 2007 / Proposed Rules 20305 

FOR FURTHER INFORMATION CONTACT: For 

more detailed information on specific 

aspects of this rulemaking, contact 

Marilyn Goode, Office of Solid Waste, 

Hazardous Waste Identification 

Division, MC 5304P, Environmental 

Protection Agency, 1200 Pennsylvania 

Ave., NW., Washington, DC 20460, 

(703–308–8800) 

(goode.marilyn@epa.gov) or Tracy Atagi, 

Office of Solid Waste, Hazardous Waste 

Identification Division, MC 5304P, 

Environmental Protection Agency, 1200 

Pennsylvania Ave., NW., Washington, 

DC 20460, (703–308–8672) 

(atagi.tracy@epa.gov). 

SUPPLEMENTARY INFORMATION: A. 

Comment Period. We are extending the 

comment period by 30 days in response 

to requests from several stakeholders. 

B. Regulated Entities. Entities 

potentially affected by this action 

include about 4,600 facilities in 530 

industries in 17 economic sectors that 

generate or recycle hazardous secondary 

materials which are currently regulated 

as RCRA Subtitle C hazardous wastes 

(e.g., industrial co-products, byproducts, residues, unreacted 

feedstocks). About 80 percent of these 

affected facilities are classified in 

NAICS code economic sectors 31, 32, 

and 33 (manufacturing), and the 

remainder are in NAICS code economic 

sectors 21 (mining), 22 (utilities), 23 

(construction), 42 (wholesale trade), 44 

and 45 (retail trade), 48 and 49 

(transportation), 51 (information), 54 

(professional, scientific and technical 

services), 56 (administrative support, 

waste management and remediation), 61 

(educational services), 62 (health care 

and social assistance, and 81 (other 

services). About 0.65 million tons per 

year of recyclable industrial materials 

handled by these entities may be 

affected, of which the most common 

types are metal-bearing hazardous 

secondary materials (e.g., sludges and 

spent catalysts), and organic chemical 

liquids. This proposed rule, if 

promulgated, is expected to result in 

regulatory and materials recovery cost 

savings to these industries of 

approximately $107 million per year. 

Taking into account impact estimation 

uncertainty factors, this rule, if 

promulgated, could affect between 0.3 

to 1.7 million tons per year of industrial 

hazardous secondary materials handled 

by 3,600 to 5,400 entities in 460 to 570 

industries, resulting in $93 million to 

$205 million per year of net cost 

savings. More detailed information on 

the potentially affected entities, 

industries, and industrial materials, as 

well as the economic impacts of this 

rule (with impact uncertainty factors), is 

presented in the ‘‘Economics 

Background Document’’ available in the 

docket for this rulemaking. 

C. Submitting CBI. Do not submit this 

information to EPA through 

www.regulations.gov or e-mail. Clearly 

mark all information that you claim to 

be CBI. For CBI information in a disk or 

CD–ROM that you mail to EPA, mark 

the outside of the disk or CD–ROM as 

CBI and then identify electronically 

within the disk or CD–ROM the specific 

information that is claimed as CBI. In 

addition to one complete version of the 

comment that includes information 

claimed as CBI, a copy of the comment 

that does not contain the information 

claimed as CBI must be submitted for 

inclusion in the public docket. 

Information so marked will not be 

disclosed, except in accordance with 

procedures set forth in 40 CFR part 2. 

List of Subjects 

40 CFR Part 260 

Environmental protection, 

Administrative practice and procedure, 

Confidential business information, 

Hazardous waste, Reporting and 

recordkeeping requirements. 

40 CFR Part 261 

Environmental protection, Hazardous 

waste, Recycling, Reporting and 

recordkeeping requirements. 

Dated: April 13, 2007. 

Matt Hale, 

Director, Office of Solid Waste. 

[FR Doc. E7–7761 Filed 4–23–07; 8:45 am] 

BILLING CODE 6560–50–P 

DEPARTMENT OF THE INTERIOR 

Fish and Wildlife Service 

50 CFR Part 17 

Endangered and Threatened Wildlife 

and Plants; Revised 12-Month Finding 

for Upper Missouri River Distinct 

Population Segment of Fluvial Arctic 

Grayling 

AGENCY: Fish and Wildlife Service, 

Interior. 

ACTION: Notice of revised 12-month 

finding. 

SUMMARY: We, the Fish and Wildlife 

Service (Service), announce our revised 

12-month finding on a petition to list 

the upper Missouri River Distinct 

Population Segment (DPS) of fluvial 

Arctic grayling (Thymallus arcticus) as 

threatened or endangered under the 

Endangered Species Act of 1973, as 

amended (Act). After a review of the 

best available scientific and commercial 

information, we find that fluvial Arctic 

grayling of the upper Missouri River 

does not constitute a species, 

subspecies, or distinct population 

segment under the Act. Therefore, we 

find that the petition to list the upper 

Missouri River DPS of fluvial Arctic 

grayling is not warranted, and we 

withdraw the fluvial Arctic grayling 

from the candidate list. The Service 

continues to seek new information on 

the taxonomy, biology, ecology, and 

status of fluvial Arctic grayling and to 

support cooperative conservation of 

fluvial Arctic grayling in the upper 

Missouri River system. 

DATES: This finding was made on April 

24, 2007. 

ADDRESSES: The complete file for this 

finding is available for inspection, by 

appointment, during normal business 

hours, at the U.S. Fish and Wildlife 

Service, Montana Field Office, 585 

Shepard Way, Helena, MT 59601; 

telephone (406) 449–5225. Submit new 

information, materials, comments, or 

questions concerning this species to us 

at this address (Attention: Arctic 

grayling). 

FOR FURTHER INFORMATION CONTACT: 

Mark Wilson, Field Supervisor, 

Montana Field Office, at the address and 

telephone listed above. 

SUPPLEMENTARY INFORMATION: 

Species Information 

Description 

The Arctic grayling (Thymallus 

arcticus) belongs to the family 

Salmonidae (salmon, trout, charr, 

whitefishes), subfamily Thymallinae 

(graylings), and is represented by a 

single genus, Thymallus, which 

contains three other recognized species 

in addition to T. arcticus (Scott and 

Crossman 1973, pp. 301–302; Behnke 

2002, pp. 327–331). Arctic grayling have 

elongate, laterally compressed bodies 

with deeply forked tails, and adults 

typically average 254 to 330 millimeters 

(10 to 13 inches) in length. Coloration 

varies from silvery or iridescent blue 

and lavender, to dark blue (Behnke 

2002, pp. 327–328). During the 

spawning period, the colors darken and 

the males become more brilliantly 

colored than the females. A prominent 

morphological feature of Arctic grayling 

is the sail-like dorsal fin, which is large 

and vividly colored with rows of orange 

to bright green spots, and often has an 

orange border. Dark spots are often 

evident on the body towards the head 

(Behnke 2002, pp. 327–328). 


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Distribution 

Arctic grayling have a primarily 

holarctic distribution and are native to 

Arctic Ocean drainages of northwestern 

Canada and Alaska, from the Peace, 

Saskatchewan, and Athabasca River 

drainages in Alberta eastward to 

Hudson Bay and westward to the Bering 

Straits and eastern Siberia and northern 

Eurasia (Scott and Crossman 1973, pp. 

301–302). Arctic grayling also are native 

to Pacific coast drainages of Alaska and 

Canada as far south as the Stikine River 

in British Columbia (Scott and 

Crossman 1973, pp. 301–302; Nelson 

and Paetz 1991, pp. 253–256; Behnke 

2002, pp. 327–331). Arctic grayling 

generally occur throughout their native 

range though the species is extirpated in 

some locations (Michigan) and has 

experienced local range contraction in 

others (e.g., Peace-Willison watershed in 

British Columbia (Blackman et al. (1990, 

pp. 15, 17, 34), portions of Alberta 

(Alberta Sustainable Resource 

Development (2005; pp. iv, 5–18), and 

Montana). 

In North America, two populations of 

Arctic grayling, believed to have been 

isolated by Pleistocene glaciations, have 

been recorded outside of Canada and 

Alaska (Vincent 1962, pp. 23–31). One 

population was found in streams and 

rivers of the Great Lakes region of 

northern Michigan, but those grayling 

were extirpated in the 1930s (Hubbs and 

Lagler 1949, p. 44; Scott and Crossman 

1973, p. 301). The second population 

historically inhabited watersheds in the 

upper Missouri River basin upstream of 

Great Falls, Montana (Figure 1). 

BILLING CODE 4310–55–P 


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Genetic data indicate Arctic grayling 

native to the Missouri River system 

were most likely isolated geographically 

from Hudson Bay and Arctic Ocean 

drainages by the onset of Wisconsin 

glaciation approximately 70,000 years 

ago (Redenbach and Taylor 1999, p. 32). 

Arctic grayling native to the upper 

Missouri River system are genetically 

diverged from Arctic grayling in the 

northern part of the species’ range 

(Lynch and Vyse 1979, pp. 268–270, 

275; Everett 1986, pp. 15–16, 79–80; 

Redenbach and Taylor 1999, pp. 23, 28–

29, 32–33; reviewed by Leary 2005, pp. 

1–3; reviewed by Campton 2006, pp. 5–

6), and appear to be most closely related 

evolutionarily to populations in the 

Fond du Lac area of northeastern 

Saskatchewan, Canada (Stamford and 

Taylor 2004, p. 1538). Genetic 

divergence happens when two or more 

genetic characteristics that have 

occurred naturally over time are passed 

from one generation to subsequent 

generations. Arctic grayling in the upper 

Missouri River basin are commonly 

referred to as ‘‘Montana grayling’’ and 

have been variously categorized as a 

separate species (Thymallus montanas; 

Scott and Crossman 1973, p. 301) or 

subspecies (T. arcticus montanus; 

Williams et al. 1989, p. 4), but these 

designations are of uncertain validity 

(Scott and Crossman 1973, p. 301) and 

not widely accepted (Kaya 1990, pp. 3–

4; Integrated Taxonomic Information 

System 2006). The lack of accepted 

subspecific designations is based on 

morphological similarity among 

disjunct populations (Kaya 1990, p. 4). 

Arctic grayling in the upper Missouri 

River basin currently represent the 

southern extent of the species’ range 

(Scott and Crossman 1973, pp. 301–

302), and both migratory, river-dwelling 

(fluvial) and lake-dwelling (adfluvial 

and lacustrine) populations are native to 

the upper Missouri River. For 

simplicity, the term ‘‘adfluvial’’ will be 

used to refer to all Arctic grayling 

populations associated with lakes or 

reservoirs. The migratory, stream- and 

river-dwelling form of Arctic grayling 

native to the upper Missouri River is 

hereafter referred to as ‘‘fluvial’’ Arctic 

grayling of the upper Missouri River. 

Arctic Grayling Distribution in the 

Upper Missouri River Basin 

Fluvial Arctic grayling reside in the 

Big Hole River and the lower reaches of 

connected tributaries (see Figure 1 

above). Adfluvial Arctic grayling native 

to the upper Missouri River system are 

known to reside in the Red Rock Lakes 

system, in the upper reaches of the 

Beaverhead River within the Centennial 

Valley, Montana (Vincent 1962, p. 120; 

see Figure 1 above). An indigenous 

Arctic grayling population exhibiting 

adfluvial characteristics also is present 

in the Madison River upstream from 

Ennis Reservoir (see Figure 1 above). 

The adfluvial characteristics expressed 

by the Madison River-Ennis Reservoir 

population may reflect recent 

divergence away from the presumed 

ancestral fluvial form resulting from the 

construction of Ennis Dam (Kaya 1990, 

p. 33; Kaya 1992a, p. 53). A few 

adfluvial populations found in small 

lakes within the Big Hole River system 

(in particular Miner and Mussigbrod 

Lakes; see Figure 1 above) may be 

remnant native populations derived 

from fluvial Arctic grayling from the Big 

Hole River and isolated by recent 

habitat fragmentation, but widespread 

stocking of these and other locations 

with hatchery-reared Arctic grayling 

during the 1930s–1950s (e.g., Everett 

1986, p. 4, 16; Kaya 1990, pp. 31, 75–

80) also makes it possible that these fish 

are introduced populations or that the 

existing populations are a mixture of 

native and introduced Arctic grayling. 

Ecology 

Northcote (1995) and Kaya (1990) 

reviewed the ecology of Arctic grayling 

and fluvial Arctic grayling of the upper 

Missouri River, respectively. Much of 

the information on fluvial Arctic 

grayling in the upper Missouri River 

system comes from the Big Hole River, 

Montana (see Figure 1 above), which 

contains a fluvial population. Arctic 

grayling exhibit life history and 

migratory forms present in other species 

of inland trout and charr, including 

fluvial and adfluvial. Fluvial 

populations are characterized by a cycle 

of migratory behavior over their lifespan 

between spawning, feeding, and 

overwintering habitats within rivers or 

streams (Northcote 1995, pp. 156–160). 

Fluvial Arctic grayling typically migrate 

upstream to spawn in tributary or 

mainstem river locations and 

downstream to overwintering habitats. 

Such movement patterns have been 

observed in fluvial Arctic grayling in 

Big Hole River, Montana (Shepard and 

Oswald 1989, pp. 18, 27–28). Migrations 

to feeding habitats may occur if these 

locations differ from spawning or 

overwintering habitats (Kaya 1990, pp. 

9–11). Overall, movements by fluvial 

populations within and among 

tributaries and mainstem rivers may 

cover hundreds of kilometers 

(Armstrong 1986, p. 7). Fluvial Arctic 

grayling in the Big Hole River system 

have been shown to migrate in excess of 

80 km (50 mi) between spawning, 

feeding and wintering areas (Shepard 

and Oswald 1989, pp. 18, 21; Lamothe 

and Magee 2003, pp. 7, 11, 17). 

Adfluvial Arctic grayling feed and 

overwinter in lakes, but migrate to inlet 

or outlet streams to spawn (Northcote 

1995, p. 148–149; Northcote 1997, pp. 

1030–1034). 

Age at maturity and longevity in 

Arctic grayling varies among systems 

and is probably related to growth rate, 

with populations in colder, less 

productive habitats maturing at later 

ages and having a greater lifespan 

(Northcote 1995, pp. 155–157). Fluvial 

Arctic grayling in the Big Hole River 

system typically mature at 2 years of age 

(males) or 3 years of age (females), and 

individuals older than 6 years of age are 

rare (Liknes 1981, pp. 16–18; Kaya 1990, 

pp. 18–20; Magee and Lamothe 2003, p. 

22). Arctic grayling are spring spawners. 

In Montana, Arctic grayling typically 

spawn from late April to mid-May by 

depositing adhesive eggs over gravel 

substrate without excavating a nest or 

redd (Shepard and Oswald 1989, pp. 

24–25, 29; Kaya 1990, pp. 15–16). In 

general, the reproductive ecology of 

Arctic grayling is somewhat different 

from other salmonid species (trout and 

salmon) in that Arctic grayling eggs tend 

to be comparatively small (Behnke 2002, 

p. 328), and males establish and defend 

spawning territories rather than 

defending access to females (Northcote 

1995, p. 150). The time required for 

development of eggs from embryo until 

they emerge from stream gravel and 

become swim-up fry varies with water 

temperature, but averages about 3 weeks 

for Arctic grayling in the upper Missouri 

River basin (Kaya 1990, pp. 16–17). 

Small, weakly swimming fry of fluvial 

Arctic grayling prefer low velocity 

stream habitats (Kaya 1990, pp. 23–24; 

Northcote 1995, pp. 152–153). 

Arctic grayling of all ages feed 

primarily on aquatic and terrestrial 

invertebrates captured on or near the 

water surface (Northcote 1995, pp. 153–

154; Behnke 2002, p. 328). They also 

will feed opportunistically on fish and 

fish eggs (Northcote 1995, p. 154; 

Behnke 2002, p. 328). Feeding locations 

for individual fish are typically 

established and maintained through 

size-mediated dominance hierarchies 

(e.g., Hughes 1992, pp. 1994–1995). 

Although fluvial Arctic grayling may 

have specific habitat requirements 

depending on their life stage (e.g., fry) 

and ecological activity (e.g., spawning), 

individuals inhabiting streams and 

rivers often exhibit a preference for pool 

habitats (Liknes 1981, pp. 22, 28; Kaya 

1990, pp. 20–21; Lamothe and Magee 

2003, pp. 13–14, 17; Lamothe and 

Magee 2004, p. 24). Vincent (1962, pp. 

39, 42) concluded that fluvial Arctic 

grayling in Montana typically reside in 


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streams with low-to-moderate gradient 

(<4 percent) and prefer low-to-moderate 

water velocities (<60 centimeters/sec). 

Observations of fluvial Arctic grayling 

habitat use in the Big Hole River by 

Liknes (1981, p. 28) and Liknes and 

Gould (1987, p. 128) are consistent with 

these generalizations. 

Arctic grayling generally prefer cool 

or coldwater habitats (Hubert et al. 

1985, pp. 9, 14, 25, 27). Selong et al. 

(2001, p. 1032) placed Arctic grayling in 

a ‘‘coldwater’’ group of salmonids, along 

with Arctic charr and bull trout, based 

on critical thermal maximum values. 

Genetic Relationships Among Arctic 

Grayling Populations in the Upper 

Missouri River Basin 

Discussion of genetic divergence 

among Arctic grayling populations is 

complicated by the extensive hatchery 

propagation and transplantation of 

stocks from location to location (Everett 

1986, p. 40). Over 10 million grayling of 

unknown origin were stocked in the Big 

Hole River over a 30-year period from 

the 1930s to the 1950s (Kaya 1990, pp. 

31, 75–80). Everett (1986 pp. 42, 43, 47) 

concluded that the effect of grayling 

introductions on local genetics appears 

stronger in lake populations than in the 

Big Hole River. Nonetheless, the limited 

available genetic data suggest the 

presence of two or more groups—

clusters or sets of populations that are 

genetically more closely related to each 

other than they are to other populations 

of the same species—of Arctic grayling 

within the upper Missouri River that 

may not be strictly delineated by 

geography and life history (Leary 2005, 

p. 3; Campton 2006, pp. 6–9, 12). 

Inferences about genetic differences 

among Arctic grayling populations 

within the upper Missouri River basin 

are primarily based on data collected by 

Everett (1986) and Leary (1990). These 

two studies examined how a particular 

form (allele) of a protein molecule 

(allozyme) varied in frequency across 

Arctic grayling populations in Montana. 

Allozymes are gene products coded by 

DNA, so allozyme variation can be used 

to infer genetic relationships among 

populations, subspecies or species. 

Campton (2006, pp. 6, 12), in his review 

of those data, suggested the existence of 

two possible genetic groups: (a) A Big 

Hole-Madison River group that includes 

the fluvial population in the Big Hole 

River, certain populations in adjoining 

waters of the Big Hole River system 

(e.g., Bobcat, Miner, and Mussigbrod 

Lakes, and Steel Creek; see Figure 1 

above; see Everett 1986, p. 7; Leary 

1990, pp. 6–8), and fish from the 

Madison River-Ennis Reservoir; and (b) 

a Red Rock Lakes group that includes 

native adfluvial populations from the 

Red Rock and Elk Lakes system in the 

upper Beaverhead River system, and a 

number of introduced adfluvial 

populations (Agnes, Grebe, Rogers, 

Odell, and Elizabeth Lakes; see Leary 

1990, pp. 7–8) believed to be derived 

from human introductions of Red Rock 

Lakes grayling and/or associated 

hatchery stocks. The two groups (Big 

Hole-Madison and Red Rock Lakes) are 

differentiated by divergent allele 

frequencies for two allozymes (Campton 

2006, p. 6). The relative genetic 

difference between these two groups 

within the upper Missouri River basin is 

less than the difference between upper 

Missouri River Arctic grayling and 

sample populations from Alaska and 

Canada (Everett 1986, p. 80; Leary 1990, 

pp. 1, 7–8). The level of genetic 

divergence observed among populations 

within the upper Missouri River is 

consistent with what would be expected 

for populations within a geographic area 

that share a recent ancestry but have 

since diverged, as compared with the 

greater divergence observed among 

populations from different geographic 

areas or river systems that have been 

separated from each other for a much 

longer period of time (i.e., upper 

Missouri River versus Alaskan and 

Canadian populations). 

Campton (2006, p. 12) also noted that 

a few adfluvial populations of Arctic 

grayling in the Big Hole River drainage, 

including Miner Lake (see Figure 1 

above), appear to share recent ancestry 

with the mainstem Big Hole River 

fluvial population. 

Like Campton, Leary also concluded 

that Big Hole River and Madison River 

grayling samples appear to be quite 

similar (Leary 2005, p. 3). Leary’s 

interpretation of the genetic 

relationships among Miner Lake, Red 

Rock Lakes, and Elk Lake populations 

was different from Campton’s. Leary 

found Miner Lake to be very divergent 

from all the others, but also concluded 

that there was significant divergence 

between the Red Rock Lakes and Elk 

Lake samples (Leary 2005, p. 3). He 

interpreted the allozyme data to mean 

that the adfluvial samples do not appear 

to form a genetically distinct group and 

consequently concluded that the data do 

not support the premise that the fluvial 

and adfluvial life histories fall into two 

distinct genetic lineages (Leary 2005, p. 

3). Rather, he contended the data 

represent divergence among populations 

regardless of life history (Leary 2005, p. 

3). In his review, Campton (2006) 

concurred that the apparent genetic 

divergence between the two groups (Big 

Hole-Madison River and Red Rock 

Lakes) was not completely consistent 

with life histories because several 

adfluvial populations belonged to the 

Big Hole River-Madison River genetic 

group. 

An Arctic grayling population 

residing in the Sunnyslope irrigation 

canal in Teton County, Montana, is 

thought to be derived from an 

introduction into Pishkin Reservoir 

(Kaya 1990, p. 41; see Figure 1 above) 

and is not easily assigned to either of 

the two genetic groups suggested by 

Campton. These fish appear to be 

genetic outliers relative to the two other 

native genetic groups of Arctic grayling 

(Leary 1990, p. 8; Campton 2006, p. 7). 

Overall, both Campton and Leary 

observe that: (a) Fluvial Arctic grayling 

from the Big Hole River are genetically 

different from native adfluvial Arctic 

grayling in Red Rock Lakes based on 

observed differences in allozyme allele 

frequencies even if the genetic 

divergence between these populations 

appears to be low (average Nei’s genetic 

distance of the cluster containing these 

populations equals 0.0132 (Leary 1990, 

pp. 1,8)); (b) the existing genetic data do 

not strongly support the hypothesis that 

the fluvial form of Arctic grayling in the 

upper Missouri River represents a 

unique genetic lineage, because it is 

genetically similar to adfluvial 

populations in Miner Lake and in the 

Madison River (Leary 2005, pp. 3–4; 

Campton 2006, p. 12); and (c) the low 

allozyme variability in upper Missouri 

River Arctic grayling samples results in 

a weak dataset for resolving ancestries 

among recently diverged populations 

(Leary 2005, pp. 3–4; Campton 2006, p. 

10). The Service views Campton’s and 

Leary’s conclusions about the ancestral 

relationships among Arctic grayling 

populations in the upper Missouri River 

as tentative, given the inherent 

limitations of the existing genetic data. 

However, it is the best available 

scientific information at this time. 

Further investigations with more 

variable genetic markers, such as 

microsatellite DNA, may clarify genetic 

relationships (Campton 2006, pp. 10, 

14). 

Heritable, Behavioral Differences 

Between Fluvial and Adfluvial Arctic 

Grayling in the Upper Missouri River 

Basin 

Arctic grayling exhibit at least two life 

histories in the upper Missouri River 

system—a river-dwelling fluvial form 

and a lake-dwelling adfluvial form. Life 

history variation in salmonid fishes 

(trout and salmon) may or may not be 

related to genetic differentiation (e.g., 

Fausch and Young 1995, p. 365). 

However, experiments designed to 

determine whether behavioral 


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differences were due to genetic or 

environmental influences found that the 

behavioral differences between fluvial 

and adfluvial Arctic grayling in 

Montana were heritable. In tests of 

swimming behavior of young-of-year 

Arctic grayling raised in common 

conditions in captivity, progeny of 

fluvial Big Hole River fish behaved 

significantly differently, on average, 

than adfluvial progeny from Red Rock 

Lakes and Madison River-Ennis 

Reservoir populations (Kaya 1989, 1991; 

Kaya and Jeanes 1995). The Big Hole 

River progeny exhibited a greater 

tendency to hold position in flowing 

water (Kaya and Jeanes 1995, pp. 453–

456). Because the test fish from the Big 

Hole River population were progeny of 

parents reared in a non-fluvial 

environment, retention of this rheotactic 

behavior (behavior in response to 

flowing water) was taken as evidence 

that such behavior has a genetic 

(heritable) basis (Kaya and Jeanes 1995, 

p. 456), consistent with conclusions of 

previous investigations (Kaya 1989, pp. 

474, 478–479; Kaya 1991, pp. 53, 55–

58). 

Expression of rheotactic 

characteristics in Arctic grayling also 

can be influenced by ontogeny, or the 

developmental history of an individual 

(in this case, time from emergence from 

gravel as fry until maturity; Kaya 1991, 

pp. 53, 55–57), and environmental 

conditions, such as time of day (Kaya 

1989, p. 56), light intensity (Kaya 1989, 

p. 478; Kaya 1991, p. 56), or water 

temperature (Kaya 1989, p. 478). 

However, the collective results are 

nonetheless consistent with the 

hypothesis that heritable, behavioral 

differences in the test populations exist 

between the fluvial and adfluvial 

populations and those associated with 

lakes or reservoirs. 

Adfluvial Arctic grayling repeatedly 

introduced into rivers have failed to 

establish viable populations (Kaya 

1992b, pp. 12–14). Adaptive divergence 

and lack of ecological exchangeability 

between life history types are among the 

factors that may have contributed to 

these failures (Campton 2006, p. 13). 

However, introductions of fluvial 

grayling into other rivers within the 

native range have not been successful 

either, so success may be due to other 

factors (e.g., habitat degradation or 

competition with nonnative fish (Kaya 

1992b, pp. 10–12, 60)). In general, life 

history expression in salmonid species 

can be flexible, and Arctic grayling 

exhibit variation in migratory behavior 

across the range of the species 

(Northcote 1997, p. 1030). Geography 

may be a stronger determinant of 

ancestral relationships than life history 

for Arctic grayling. Native Arctic 

grayling populations within the upper 

Missouri River basin may be similar 

based on genetics, because they reside 

in the same river basin and presumably 

share a recent evolutionary ancestry 

(Campton 2006, p. 12), while at the 

same time expressing different life 

histories in response to local habitat 

conditions. 

Previous Federal Action 

The Service initiated a status review 

for the Montana Arctic grayling 

(Thymallus arcticus montanus) through 

a notice of review published on 

December 30, 1982 (47 FR 58454). In 

that notice, Montana Arctic grayling was 

designated a Category 2 species, which 

included taxa for which information in 

possession of the Service at that time 

indicated that proposing to list the 

species as Endangered or Threatened 

was possibly appropriate, but for which 

substantial data were not currently 

available to biologically support a 

proposed rule (47 FR 58454). We 

received a petition, dated October 2, 

1991, from the Biodiversity Legal 

Foundation and George Wuerthner on 

October 9, 1991. The petition requested 

that the ‘‘fluvial Arctic grayling’’ be 

listed as an endangered species 

throughout its historic range ‘‘in the 

conterminous United States.’’

We published a notice of a 90-day 

finding in the January 19, 1993, Federal 

Register (58 FR 4975). In that 90-day 

finding we found that the petitioners 

presented substantial information 

indicating that listing the fluvial Arctic 

grayling of the upper Missouri River, in 

Montana and northwestern Wyoming, 

may be warranted. We also found that 

because the Michigan population of 

Arctic grayling is extinct and, therefore, 

by definition cannot be listed, the 

finding would address only the fluvial 

population of the Arctic grayling in the 

upper Missouri River drainage. 

On July 25, 1994, we published a 

notice of a 12-month petition finding in 

the Federal Register concluding that 

listing the fluvial Arctic grayling 

indigenous to the upper Missouri River 

was warranted but precluded by other 

higher priority listing actions (59 FR 

37738). This finding stated that the 

Service viewed adfluvial Arctic grayling 

as not under consideration in the 

Service’s finding as it was believed to be 

a distinct population from the fluvial 

Arctic grayling. This 1994 status review 

identified the fluvial form of Arctic 

grayling in the upper Missouri River 

drainage as a DPS based on its 

geographic isolation and behavioral 

distinctiveness (59 FR 37738–37741, 

July 25, 1994). This status review 

occurred prior to the finalization of the 

Service and the National Marine 

Fisheries Service’s joint DPS policy in 

1996 (61 FR 4722, February 7, 1996). 

Since 1994, and based on the best 

available information and the 

assessment that we conduct during our 

candidate review process, we have 

continued to preliminarily recognize the 

fluvial Arctic grayling of the upper 

Missouri River as a DPS, and has 

maintained it as a candidate species 

through the annual Candidate Notice of 

Review. In 2004, the Service elevated 

the listing priority number of the fluvial 

Arctic grayling to 3 (69 FR 24881, May 

4, 2004) because the abundance of the 

remnant population in the Big Hole 

River declined substantially and 

reestablishment efforts had not yet 

produced self-sustaining populations 

elsewhere in the upper Missouri River. 

On May 31, 2003, the Center for 

Biological Diversity and Western 

Watersheds Project (collectively 

plaintiffs) filed a complaint in United 

States District Court in Washington, DC 

(1:03-cv-01110), challenging the 

Service’s continuing ‘‘warranted but 

precluded’’ determination for fluvial 

Arctic grayling contained in the 2002 

Candidate Notice of Review (67 FR 

40657, June 13, 2002). Plaintiffs filed an 

amended complaint on July 22, 2004, 

challenging the Service’s failure to use 

its emergency listing authority to protect 

the fluvial Arctic grayling under the Act 

(16 U.S.C. 1531 et seq.). The litigation 

with plaintiffs was settled in August 

2005. In this settlement agreement, the 

Service agreed that on or before April 

16, 2007, it shall submit for publication 

in the Federal Register a final 

determination made pursuant to the Act 

as to whether or not the ‘‘Montana 

fluvial Arctic grayling’’ is an 

endangered or threatened species. 

During the evaluation of the petition, 

the Service considered the term 

‘‘Montana fluvial Arctic grayling’’ as 

synonymous with ‘‘fluvial Arctic 

grayling of the upper Missouri River.’’

In this finding, as in the past, the fluvial 

form of the indigenous Arctic grayling 

from the upper Missouri River drainage 

in Montana and Wyoming is referred to 

as the fluvial Arctic grayling. This 

revised 12-month finding is being 

published as a final listing 

determination in accordance with the 

settlement agreement. 

Distinct Vertebrate Population Segment 

Pursuant to the Act, we must consider 

for listing any species, subspecies, or, 

for vertebrates, any DPS of these taxa if 

there is sufficient information to 

indicate that such action may be 

warranted. The petition we received 


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concerns a potential DPS of fluvial 

Arctic grayling. Under our Policy 

Regarding the Recognition of Distinct 

Vertebrate Population Segments (61 FR 

4722, February 7, 1996) (known as the 

DPS Policy), three elements are 

considered in a decision regarding the 

status of a possible DPS as endangered 

or threatened under the Act. These 

factors are applied similarly for 

additions to the Lists of Endangered and 

Threatened Wildlife and Plants (Lists), 

reclassification, and removal from the 

Lists. They are: (1) Discreteness of the 

population segment in relation to the 

remainder of the species to which it 

belongs; (2) the significance of the 

population segment to the species to 

which it belongs; and (3) the population 

segment’s conservation status in relation 

to the Act’s standards for listing (i.e., is 

the population segment, when treated as 

if it were a species, endangered or 

threatened?). Discreteness refers to the 

isolation of a population from other 

members of the species, and we evaluate 

this based on specific criteria that are 

also contained in the DPS Policy and are 

listed below. If the population segment 

is determined to be discrete, then we 

evaluate significance by using the 

available scientific information to 

determine the population segment’s 

importance to the taxon to which it 

belongs. If we determine that a 

population segment is discrete and 

significant, we subsequently evaluate it 

for endangered or threatened status 

based on the Act’s standards. 

Discreteness 

Under our DPS Policy, a population 

segment of a vertebrate species may be 

considered discrete if it satisfies either 

one of the following conditions: (1) It is 

markedly separated from other 

populations of the same taxon as a 

consequence of physical, physiological, 

ecological, or behavioral factors. 

Quantitative measures of genetic or 

morphological discontinuity may 

provide evidence of this separation; or 

(2) It is delimited by international 

governmental boundaries within which 

differences in control of exploitation, 

management of habitat, conservation 

status, or regulatory mechanisms exist 

that are significant in light of section 

4(a)(1)(D) of the Act. 

The subject of this DPS evaluation is 

the fluvial Arctic grayling of the upper 

Missouri River. In response to a 

petition, the fluvial Arctic grayling was 

the subject of a status review by the 

Service in 1994, which identified Arctic 

grayling indigenous to the Big Hole and 

Madison Rivers as elements of a fluvial 

DPS in the upper Missouri River (59 FR 

37738–37741, July 25, 1994). However, 

this status review occurred prior to the 

finalization of the Service and the 

National Marine Fisheries Service’s 

joint DPS policy in 1996 (61 FR 4722, 

February 7, 1996). Since 1994, and most 

recently in 2004 and 2005, the Service 

reviewed the available information 

concerning the taxonomic status of the 

species in relation to the DPS policy and 

again preliminarily determined that the 

fluvial Arctic grayling of the upper 

Missouri River was a valid DPS (Service 

2004, 2005). This DPS evaluation 

considers the information used in the 

previous assessments as well as a 

solicited review (Campton 2006) and 

unsolicited review (Leary 2005) of the 

available genetic data for Arctic grayling 

in Montana. 

(1) Fluvial Arctic Grayling Are Discrete 

as a Consequence of Physical Features 

Fluvial arctic grayling native to the 

upper Missouri River are ‘‘markedly 

separated’’ from other grayling, both 

those in Canada and Alaska, and from 

the adfluvial form in the Missouri River 

drainage because of physical and 

reproductive isolation. Fluvial actic 

grayling are geographically disjunct and 

reproductively isolated from 

populations inhabiting Arctic Ocean 

and Hudson Bay drainages in Canada 

and Alaska (Scott and Crossman 1973, 

p. 301). Arctic grayling in the upper 

Missouri River are reproductively 

isolated from their nearest conspecifics 

by at least 800 kilometers (km) (500 

miles (mi)) (Nelson and Paetz 1991, p. 

255) and have been separated from 

Arctic Ocean populations for perhaps 

70,000 years as a result of glacial 

activity (Lynch and Vyse 1979, p. 263; 

Redenbach and Taylor 1999, p. 32). This 

long period of reproductive isolation 

coupled with genetic drift and 

environmental selection pressures has 

resulted in genetic differences between 

Arctic grayling from the Missouri River 

and elsewhere based on analyses of 

allozymes and mitochondrial DNA 

(Lynch and Vyse 1979, pp. 263, 268, 

275; Everett and Allendorf 1985, pp. 22–

23, 26; Everett 1986, pp. 79–80; 

Redenbach and Taylor 1999, p. 23; 

reviewed by Campton 2006, pp. 5–6; 

reviewed by Leary 2005, pp. 1–3). 

Fluvial and adfluvial Arctic grayling 

within the upper Missouri River basin 

are ‘‘markedly separated’’ from each 

other as a result of physical features. 

The fluvial form was once widespread 

in the upper Missouri River basin, but 

the adfluvial form was native only to the 

Red Rocks Lakes and possible Elk Lake 

in the headwaters of the Beaverhead 

River (Kaya 1990). Extant populations of 

native fluvial and adfluvial Arctic 

grayling within the upper Missouri 

River are reproductively isolated, and 

the available genetic data are consistent 

with the hypothesis of two genetic 

groups of Arctic grayling (the Big Hole—

Madison River and Red Rock Lakes 

genetic groups) within the upper 

Missouri River (Leary 2005, p. 3; 

Campton 2006, pp. 6–9, 12) 

(2) Fluvial Arctic Grayling Are Not 

Discrete as a Consequence of 

Physiological Features 

We do not believe that fluvial Arctic 

grayling are discrete because of unique 

or different physiological 

characteristics. Lohr et al. (1996) 

examined the thermal tolerance of 

juvenile fluvial Arctic grayling from the 

Big Hole River to elevated temperatures 

in laboratory tests. However, grayling 

from the Big Hole River did not appear 

to be more tolerant of warm stream 

temperatures than grayling from Alaska 

(Lohr et al. 1996, p. 937). 

Arctic grayling from the upper 

Missouri River tend to grow more 

quickly than individuals from northern 

populations (Northcote 1995, pp. 156–

157). However, experimental data are 

lacking that permit these differences to 

be attributed to environmental versus 

genetic influences. 

(3) Fluvial Arctic Grayling Are Not 

Discrete as a Consequence of Ecological 

Features 

The Arctic grayling of the upper 

Missouri River represent the only 

natural example of the taxon inhabiting 

an Atlantic Ocean drainage (via the 

Missouri and Mississippi Rivers and 

Gulf of Mexico). All other wild 

populations of Arctic grayling inhabit 

drainages of the Arctic Ocean, Hudson 

Bay, or north Pacific Ocean (USFWS 

2005, p. 10). However, fluvial Arctic 

grayling of the upper Missouri River 

basin are not discrete from adfluvial 

Arctic grayling of the upper Missouri 

River basin as a consequence of 

ecological features as they exist within 

a common drainage. 

(4) Fluvial Arctic Grayling Are Discrete 

as a Consequence of Behavioral 

Features 

Under historical conditions within 

the upper Missouri River basin, native 

fluvial and adfluvial populations of 

Arctic grayling spawned in different 

locations (Vincent 1962, pp. 98–121; 

Kaya 1990, pp. 24–30; Kaya 1992a, pp. 

47–53). Homing behavior to natal (birth) 

habitats that is typically expressed by 

Arctic grayling (e.g., Carl et al. 1992, p. 

245) would presumably result in the 

reproductive isolation of historical 

fluvial and adfluvial populations even if 

occasional exchange was possible. In 


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addition, genetic differences between 

the extant fluvial population in the Big 

Hole River and the native adfluvial 

population in Red Rock Lakes (e.g., 

Everett 1986, pp. 79–30; Leary 1990, pp. 

7–8) are consistent with reproductive 

isolation between those populations 

based on observed differences in 

allozyme allele frequencies. 

Fluvial and adfluvial Arctic grayling 

do not appear to represent distinct 

lineages based strictly on life histories 

within the upper Missouri River system 

(e.g., Leary 2005, p. 3; Campton 2006, p. 

12); there are clearly some heritable 

differences in juvenile swimming 

behavior among fluvial Arctic grayling 

and the native adfluvial populations in 

terms of rheotactic response to flowing 

water (Kaya 1989, pp. 474, 478–479; 

Kaya 1991, pp. 53, 55–58; Kaya and 

Jeanes 1995, pp. 453–456). These 

differences in behavior are sufficient to 

satisfy the discreteness criterion of the 

DPS policy. 

On the basis of the available 

information, we conclude that the 

fluvial Arctic grayling of the upper 

Missouri River drainage is discrete from 

other populations of the same taxon as 

a consequence of physical and 

behavioral factors. Since a population 

segment of a vertebrate species may be 

considered discrete if the first factor is 

met (marked separateness), we need not 

address the second factor (delimitation 

by an international boundary). 

Therefore, we considered the potential 

significance of this discrete population 

to the remainder of the taxon. 

Significance 

If a population segment is determined 

to be discrete, the Service considers the 

available scientific evidence of its 

significance to the taxon to which it 

belongs. Our policy states that this 

consideration may include, but is not 

limited to, the following: 

(1) Persistence of the discrete 

population segment in an ecological 

setting unusual or unique for the taxon; 

(2) Evidence that loss of the discrete 

population segment would result in a 

significant gap in the range of the taxon; 

(3) Evidence that the discrete 

population segment represents the only 

surviving natural occurrence of a taxon 

that may be more abundant elsewhere as 

an introduced population outside its 

historic range; or 

(4) Evidence that the discrete 

population segment differs markedly 

from other populations of the species in 

its genetic characteristics. 

A population segment needs to satisfy 

only one of these criteria to be 

considered significant. Furthermore, the 

list of criteria is not exhaustive; other 

criteria may be used, as appropriate. 

(1) Fluvial Arctic Grayling Do Not 

Persist in an Ecological Setting Unusual 

or Unique for the Taxon 

As discussed above, Arctic grayling 

generally occur throughout their native 

range in the holarctic region of Canada 

and Alaska to eastern Siberia and 

northern Eurasia (Scott and Crossman 

1973, pp. 301–302). In our 2005 

candidate assessment, we asserted that 

the fluvial Arctic grayling of the upper 

Missouri River persist in an ecological 

setting unusual or unique for the taxon 

as they represent the only natural 

example of the taxon inhabiting an 

Atlantic Ocean drainage via the 

Missouri and Mississippi Rivers and 

Gulf of Mexico. We noted that all other 

wild populations of Arctic grayling 

inhabit drainages of the Arctic Ocean, 

Hudson Bay, or north Pacific Ocean 

(USFWS 2005, p. 10). However, as 

established above, we now note that 

adfluvial Arctic grayling also persist in 

the upper Missouri River drainage. Our 

prior finding did not take these fish into 

account in its discussion of ecological 

setting. Because both the fluvial and 

adfluvial forms are found in the upper 

Missouri drainage, we cannot find that 

the population persists in an ecological 

setting unique or unusual to the taxon 

as a whole. 

Further, existence of the species in a 

different drainage, or different rivers 

and lakes, from those grayling found in 

Canada and Alaska is not necessarily 

evidence of a unique ecological setting. 

Arctic grayling in the neararctic region 

are found in the same habitat type as 

those in Montana. Grayling inhabit clear 

water streams, rivers, and lakes. 

Riverine populations depend on large 

streams, deep pools of small streams, or 

spring-fed reaches that are not 

completely frozen in winter for 

overwinter survival. Populations not 

associated with lakes are found in both 

Alaska and Montana (Hubert 1985, p. 1). 

For this reason also, we find that fluvial 

Arctic grayling do not persist in an 

ecological setting unique or unusual for 

the taxon. 

(2) The Loss of the Fluvial Arctic 

Grayling Would Not Result in a 

Significant Gap in the Range of the 

Taxon 

Loss of the fluvial Arctic grayling in 

the upper Missouri River, when 

considered in relation to grayling 

throughout the remainder of the nearctic 

region, would mean the loss of a small 

percentage of the entire range of the 

taxon. Due to the broad geographic 

range of Arctic grayling, the gap in the 

range of Arctic grayling resulting from 

the loss of fluvial Arctic grayling in the 

upper Missouri River basin would not 

result in a significant gap in the range 

of the taxon as a whole. 

In our 2005 candidate assessment, we 

asserted that the loss of the fluvial 

Arctic grayling of the upper Missouri 

River would result in a significant gap 

in the range of the taxon as these fish 

are the only extant fluvial grayling 

population in the contiguous United 

States and represent the southernmost 

extent of the species (USFWS 2005, p. 

10). However, the Ninth Circuit Court 

has rejected this argument as a 

misconstruction of this criterion in the 

case of National Association of Home 

Builders v. Norton, 340 F. 3d 835, 852 

(9th Cir. 2003) concerning the cactus 

ferruginous pygmy-owl (Glaucidium 

brasilianum cactorum) (70 FR 44551, 

August 3, 2005). The Court found that 

in designating a DPS under the DPS 

policy, we must find that a discrete 

population is significant to the taxon as 

a whole, not to the United States. 

Therefore, we have determined, based 

on the information available to the 

Service, the loss of the fluvial Arctic 

grayling in the upper Missouri River 

would not result in a significant gap in 

the range of the species on the basis of 

the significance of the Montana 

population to the species as a whole. 

(3) Fluvial Arctic Grayling Do Not 

Represent the Only Surviving Natural 

Occurrence of the Taxon 

This criterion from the DPS policy 

does not apply to the fluvial Arctic 

grayling in the upper Missouri River 

because it is clearly not a population 

segment representing the only surviving 

natural occurrence of a taxon that may 

be more abundant elsewhere as an 

introduced population outside its 

historic range. Consequently, this 

population of grayling is not significant 

according to this standard. 

(4) Fluvial Arctic Grayling in the 

Missouri River Drainage Do Not Differ 

Markedly in Genetic Characteristics 

From Adfluvial Populations in the 

Missouri River Drainage 

As noted above, analyses of allozymes 

and mitochondrial DNA show genetic 

divergence between Arctic grayling in 

the upper Missouri River and Arctic 

grayling in Canada and Alaska (Lynch 

and Vyse 1979, pp. 263, 268, 275; 

Everett and Allendorf 1985, pp. 22–23, 

26; Everett 1986, pp. 79–80; Redenbach 

and Taylor 1999, p. 23; reviewed by 

Campton 2006, pp. 5–6; reviewed by 

Leary 2005, pp. 1–3) and appear to be 

most closely related evolutionarily to 

populations in northeastern 


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Saskatchewan, Canada (Stamford and 

Taylor 2004, p. 1538). 

In addition, fluvial Arctic grayling 

from the Big Hole River are genetically 

different from native adfluvial Arctic 

grayling in Red Rock Lakes based on 

observed differences in allozyme allele 

frequencies (Campton 2006, p. 6). 

However, the relative genetic difference 

between these two groups within the 

upper Missouri River basin is less than 

that between upper Missouri River 

Arctic grayling and sample populations 

from Alaska and Canada (Leary 1990, 

pp. 1, 7–8). 

Resolving ancestries among recently 

diverged upper Missouri River Arctic 

grayling populations is difficult due to 

the low allozyme variability among 

samples (Leary 2005, pp. 3–4; Campton 

2006, p. 10). In this case, although 

allozyme data from 39 loci are available 

from these populations, only 2 of the 

loci analyzed were generally variable 

among them (Everett 1986; Leary 1990; 

Leary 2005, p. 3). Information from only 

two loci may cause chance similarities 

or differences and require cautious 

interpretation (Leary 2005, p. 3). 

Likewise, the paucity of genetic 

variation detected by Redenbach and 

Taylor (1999, p. 27) in their restriction 

enzyme analysis of mtDNA of upper 

Missouri River basin Arctic grayling 

precludes making any inferences about 

genetic similarities or differences among 

the upper Missouri River populations 

sampled except that they all appear to 

share a common maternal lineage (Leary 

2005, p. 4). The level of genetic 

divergence observed among populations 

within the upper Missouri River is 

consistent with what would be expected 

for populations within a geographic area 

that share a recent ancestry (Campton 

2006, p. 12). 

Discerning genetic divergence among 

Arctic grayling populations is further 

complicated by the extensive hatchery 

propagation and transplantation of 

stocks, as discussed above (Everett 1986, 

p. 40). The Service does not regard the 

introduced, lake-dwelling grayling to be 

part of the indigenous upper Missouri 

River fluvial Arctic grayling population 

(59 FR 37739, July 25, 1994). However, 

widespread stocking of hatchery-reared 

Arctic grayling in the Big Hole River 

system and other locations (e.g., Everett 

1986, pp. 4, 16; Kaya 1990, pp. 31, 75–

80) makes it possible that some fish are 

introduced populations or that the 

existing populations are a mixture of 

native and introduced Arctic grayling. 

We find that, based on the genetic 

information currently available, the 

fluvial Arctic grayling of the upper 

Missouri River drainage do not differ 

markedly from adfluvial populations of 

the species in their genetic 

characteristics such that they should be 

considered biologically or ecologically 

significant based simply on genetic 

characteristics. Biological and ecological 

significance under the DPS policy is 

always considered in light of 

Congressional guidance (see Senate 

Report 151, 96th Congress, 1st Session) 

that the authority to list DPSs be used 

‘‘sparingly’’ while encouraging the 

conservation of genetic diversity. 

Conclusion on DPS 

Under section 3 of the Act and our 

implementing regulations at 50 CFR 

424.02, a ‘‘species’’ is defined to include 

any species or subspecies of fish, 

wildlife, or plant, and any distinct 

population segment of any vertebrate 

species which interbreeds when mature. 

Our implementing regulations provide 

further guidance on determining 

whether a particular taxon or 

population is a species or subspecies for 

the purposes of the Act: ‘‘The Secretary 

shall rely on standard taxonomic 

distinctions and the biological expertise 

of the Department and the scientific 

community concerning the relevant 

taxonomic group’’ (50 CFR 424.11). As 

noted above, Arctic grayling in the 

upper Missouri River basin have been 

classified into separate species and 

subspecies, but these designations are 

not widely accepted. Therefore, we do 

not consider the subject of this petition 

to constitute a distinct species or 

subspecies. 

The 1994 status review identified the 

fluvial form of Arctic grayling in the 

upper Missouri River drainage as a DPS 

based on its geographic isolation and 

behavioral distinctiveness (59 FR 37738, 

July 25, 1994). On the basis of the best 

available information, we continue to 

conclude that the fluvial Arctic grayling 

of the upper Missouri River drainage is 

‘‘markedly separated’’ from all other 

populations of the same taxon as a 

consequence of physical and behavioral 

factors. Consequently, the Service 

concludes that the petitioned entity is 

discrete according to the 1996 DPS 

policy. However, on the basis of the four 

significance criteria in the 1996 DPS 

Policy, the Service is unable to conclude 

at this time that the petitioned entity is 

significant. Therefore, we find that the 

fluvial Arctic grayling of the upper 

Missouri River does not qualify as a 

distinct population segment under the 

Act. 

Significant Portion of the Range 

Pursuant to the Act and our 

implementing regulations, a species 

may warrant listing if it is threatened or 

endangered in a significant portion of its 

range. However, the petition did not 

request that we determine whether the 

grayling was threatened or endangered 

in a significant portion of its range. 

Rather, it asked that we list the fluvial 

Arctic grayling in the U.S. as an 

endangered species. Consistent with the 

petition, our previous petition findings 

have uniformly addressed possible 

listing in the context of whether the 

fluvial Arctic grayling in Montana 

constitutes a DPS, and therefore a 

‘‘species’’ under the Act. As discussed 

above, we have now determined that the 

fluvial Arctic grayling is not a DPS. 

Thus, we have disposed of the question 

raised by the petition: we have no 

obligation under the Act to address the 

separate question of whether the fluvial 

Arctic grayling in Montana constitutes a 

significant portion of the range of some 

of the entire grayling species, or some 

valid but currently undefined DPS. If 

the Service determines in the future that 

the grayling is threatened or endangered 

in a significant portion of its range, we 

will add the species to the candidate list 

and propose its listing. However, that 

would be a future action. Because the 

petition and our prior finding were with 

respect to a DPS, and we have found 

that there is not a valid DPS, we do not 

need to address significant portion of 

the range at this time. 

Finding 

On the basis of the discussion 

presented in this document, we find 

that the fluvial Arctic grayling of the 

upper Missouri River does not qualify as 

a distinct population segment. As a 

result, we find that the petition to list 

the fluvial Arctic grayling of the upper 

Missouri River is not warranted. Based 

on this determination, we withdraw the 

fluvial Arctic grayling of the upper 

Missouri River from the candidate list. 

Although no further action will result 

from this finding, we request that you 

submit new information concerning the 

taxonomy, biology, ecology, and status 

of the Arctic grayling of the upper 

Missouri River system to the Montana 

Field Office (see ADDRESSES below) 

whenever it becomes available. We will 

accept additional information and 

comments from all concerned 

governmental agencies, the scientific 

community, industry, or any other 

interested party concerning this finding; 

and will reconsider this determination 

in the event of new information as 

appropriate. The Service continues to 

strongly encourage cooperative 

conservation and restoration of fluvial 

Arctic grayling in the upper Missouri 

River. 


jlentini on PROD1PC65 with PROPOSAL
20314 Federal Register / Vol. 72, No. 78 / Tuesday April 24, 2007 / Proposed Rules 

References 

A complete list of all references cited 

herein is available upon request from 

the Montana Field Office, U.S. Fish and 

Wildlife Service (see ADDRESSES). 

Author 

The authors of this finding are 

biologists in Region 6 of the U.S. Fish 

and Wildlife Service. 

Authority 

The authority for this action is the 

Endangered Species Act of 1973, as 

amended (16 U.S.C. 1531 et seq.). 

Dated: April 13, 2007. 

H. Dale Hall, 

Director, Fish and Wildlife Service. 

[FR Doc. E7–7484 Filed 4–23–07; 8:45 am] 

BILLING CODE 4310–55–P 

DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric 

Administration 

50 CFR Part 648 

[Docket No. 070409081–7081–01; I.D. 

032907A] 

RIN 0648–AS22 

Magnuson-Stevens Fishery 

Conservation and Management Act 

Provisions; Fisheries of the 

Northeastern United States; Summer 

Flounder, Scup, and Black Sea Bass 

Fishery Management Plan; 

Amendment 14 

AGENCY: National Marine Fisheries 

Service (NMFS), National Oceanic and 

Atmospheric Administration (NOAA), 

Commerce. 

ACTION: Proposed rule; request for 

comments. 

SUMMARY: NMFS proposes regulations to 

implement Amendment 14 to the 

Summer Flounder, Scup, and Black Sea 

Bass Fishery Management Plan (FMP) 

developed by the Mid-Atlantic Fishery 

Management Council (Council). The 

proposed measures include a plan to 

rebuild the scup stock from an 

overfished condition to the level 

associated with maximum sustainable 

yield, as required by the MagnusonStevens Fishery Conservation and 

Management Act (Magnuson-Stevens 

Act). This action also proposes to allow 

the regulations concerning the Gear 

Restricted Areas (GRAs) to be modified 

through framework adjustments to the 

FMP. The intended effect of this change 

would improve the timing of developing 

and implementing modifications to the 

GRAs. 

DATES: Comments must be received by 

5 p.m. local time, on May 24, 2007. 

ADDRESSES: You may submit comments 

by any of the following methods: 

• E-mail: FSBAmendment14Proposed 

Rule@noaa.gov. Include in the subject 

line the following identifier: 

‘‘Comments on Amendment 14 

Proposed Rule (Scup Rebuilding Plan).’’

• Federal e-rulemaking portal: http:/ 

www.regulations.gov 

• Mail: Patricia A. Kurkul, Regional 

Administrator, NMFS, Northeast 

Regional Office, One Blackburn Drive, 

Gloucester, MA 01930. Mark the outside 

of the envelope: ‘‘Comments on 

Amendment 14 Proposed Rule (Scup 

Rebuilding Plan).’’

• Fax: (978) 281–9135 

Copies of Amendment 14 and of the 

draft Environmental Assessment, 

preliminary Regulatory Impact Review, 

and Initial Regulatory Flexibility 

Analysis (EA/RIR/IRFA) are available 

from Daniel T. Furlong, Executive 

Director, Mid-Atlantic Fishery 

Management Council, Room 2115, 

Federal Building, 300 South New Street, 

Dover, DE 19901–6790. The EA/RIR/ 

IRFA is also accessible via the Internet 

at http://www.nero.noaa.gov. 

FOR FURTHER INFORMATION CONTACT: 

Michael P. Ruccio, Fishery Policy 

Analyst, (978) 281–9104. 

SUPPLEMENTARY INFORMATION: On August 

18, 2005, NMFS notified the Council 

that the scup (Stenotomus chrysops) 

stock had been designated as overfished 

and that, within 1 year of that notice, an 

amendment or proposed regulations for 

the scup fishery to end overfishing and 

to rebuild the stock must be prepared in 

accordance with the Magnuson-Stevens 

Act. In response, the Council has 

developed, and submitted for Secretarial 

review, Amendment 14 to propose two 

actions: (1) A 7–year plan to rebuild the 

scup stock from an overfished condition 

to a level associated with maximum 

sustained yield (Bmsy), as required by the 

Magnuson-Stevens Act; and (2) an 

administrative change to the regulations 

on framework adjustments. 

Background 

The scup stock was determined to be 

overfished in 1998 when the 

Sustainable Fisheries Act (SFA) 

amendments to the Magnuson-Stevens 

Act were implemented. The Council 

developed and proposed Amendment 

12 (64 FR 16891, April 7, 1999) to 

rebuild the scup stock in accordance 

with the provisions outlined in the SFA. 

The Council proposed in Amendment 

12 that the management measures in 

place to rebuild the scup fishery, 

established by Amendment 8, were 

adequate under SFA guidelines. NMFS 

disagreed, and the rebuilding plan 

proposed in Amendment 12 was 

disapproved on April 28, 1999. 

Following the disapproval, the 

management measures previously 

implemented by Amendment 8 

remained in place for the scup fishery. 

In years subsequent to the disapproval 

of Amendment 12, the scup stock 

exhibited signs of recovery. The 

Northeast Fisheries Science Center 

(NEFSC) spring survey index 3–year 

average value for 2001–2003 indicated 

that scup spawning stock biomass (SSB) 

had increased to 3.31 kg/tow, above the 

minimum biomass threshold (1/2 Bmsy) 

of 2.77 kg/tow. The scup stock was no 

longer considered overfished, although 

the 35th Stock Assessment Review 

Committee (SARC 35) indicated that the 

status of the stock with respect to 

overfishing could not be evaluated. 

Although the condition of the scup 

stock was improving, the stock had not 

yet been rebuilt, as required by the 

Magnuson-Stevens Act, to the Bmsy

proxy rebuilding target of 5.54 kg/tow. 

In 2005, the NEFSC 3–year SSB index 

value decreased to 0.69 kg/tow, 

indicating that the stock was again 

below the minimum biomass threshold 

(1/2 Bmsy) and considered overfished. 

NMFS formally notified the Council of 

the overfished status of the scup stock, 

thus initiating the Magnuson-Stevens 

Act requirement that the Council 

develop regulations or an amendment to 

the FMP to rebuild the scup stock to the 

Bmsy proxy level. The rebuilding plan 

implemented by such regulations or 

amendment must achieve the rebuilding 

target within 10 years to comply with 

the Magnuson-Stevens Act. In response, 

the Council has developed, and 

submitted for Secretarial review, 

Amendment 14. 

Proposed Scup Rebuilding Plan 

Under Amendment 14, a constant 

fishing mortality rate (F) of 0.10 would 

be applied each year during a 7–year 

rebuilding time period. Under this 

approach, the NEFSC 3–year SSB index 

value for the rebuilding period ending 

December 31, 2014, is projected to be 

5.96 kg/tow, approximately 8 percent 

above the Bmsy proxy rebuilding target 

(5.54 kg/tow). 

Applying a constant F=0.10 for 7 

years is projected to achieve the 

required stock rebuilding to comply 

with the Magunuson-Stevens Act; 

however, because scup is a relatively 

data poor stock and uncertainty exists 

around estimates of fishing mortality, 

stock size, and discards, Amendment 14 

contains additional criteria to be 


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