RECOVERY PLAN FOR THE BLUE WHALE

(BALAENOPTERA MUSCULUS)

Prepared by 

Randall R. Reeves, Phillip J. Clapham, 

Robert L. Brownell, Jr., and Gregory K. Silber

for the

Office of Protected Resources

National Marine Fisheries Service

National Oceanic and Atmospheric Administration

Silver Spring, Maryland

July 1998
RECOVERY PLAN FOR THE BLUE WHALE

(BALAENOPTERA MUSCULUS)

Prepared by 

Randall R. Reeves, Phillip J. Clapham, 

Robert L. Brownell, Jr., and Gregory K. Silber

for the

Office of Protected Resources

National Marine Fisheries Service

National Oceanic and Atmospheric Administration

Silver Spring, Maryland

July 1998

Approved: __________________________________________

Assistant Administrator for Fisheries

Date: __________________
i

Recovery plans identify reasonable actions which are believed to be required to recover and/or

protect endangered species. Plans are prepared by the National Marine Fisheries Service (NMFS)

and the U.S. Fish and Wildlife Service (FWS) and sometimes with the assistance of recovery

teams, contractors, State agencies, and others. This plan was prepared by Randall R. Reeves,

Phillip J. Clapham, Robert L. Brownell, Jr., and Gregory K. Silber for NMFS. Recovery plans do

not necessarily represent the views nor the official positions or approvals of any individuals or

agencies, other than those of NMFS, and they represent the views of NMFS only after they have

been approved by the Assistant Administrator for Fisheries. Objectives will only be attained and

funds expended contingent upon appropriations, priorities, and other budgetary constraints.

Approved recovery plans are subject to modification as dictated by new findings, changes in

species status, and the completion of recovery tasks described in the plan.

Literature citation should read as:

National Marine Fisheries Service. 1998. Recovery plan for the blue whale (Balaenoptera

musculus). Prepared by Reeves R.R., P.J. Clapham, R.L. Brownell, Jr., and G.K. Silber for the

National Marine Fisheries Service, Silver Spring, MD. 42 pp.
ii

ACKNOWLEDGMENTS

The preparers are grateful to Jay Barlow, John Calambokidis, and Richard Sears for providing access

to unpublished information, and also for reviewing this manuscript. Thanks are also due to Jim

Carretta, Andy Dizon, Jim Gilpatrick, Mike Payne, Wayne Perryman, and Steve Reilly for advice and

information on various subjects.

PREFACE

Congress passed the Endangered Species Act of 1973 (16 USC 1531 et seq) (ESA) to protect species

of plants and animals endangered or threatened with extinction. NMFS and the U.S. Fish and Wildlife

Service (FWS) share responsibility for the administration of the Act. NMFS is responsible for most

marine mammals including the blue whale. This Plan was written at the request of the Assistant

Administrator for Fisheries to promote the conservation of blue whales.

The goals and objectives of the Plan can be achieved only if a long-term commitment is made to

support the actions recommended here. Achievement of these goals and objectives will require the

continued cooperation of the governments of the United States and other nations. Within the United

States, the shared resources and cooperative involvement of federal, state and local governments,

industry, academia, non-governmental organizations and individuals will be required throughout the

recovery period.
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TABLE OF CONTENTS

ACKNOWLEDGMENTS .................................................... ii

PREFACE ................................................................ ii

EXECUTIVE SUMMARY ................................................... 1

I. BACKGROUND ......................................................... 2

A. Species Description and Taxonomy .................................... 2

B. Zoogeography ..................................................... 2

C. Protective Legislation ............................................... 3

II. NORTH ATLANTIC POPULATION ....................................... 4

A. Natural History .................................................... 4

1. Stocks ...................................................... 4

2. Distribution and Habitat Use. ..................................... 4

3. Feeding and Prey Selection. ...................................... 5

4. Competition. .................................................. 6

5. Reproduction. ................................................. 6

6. Natural Mortality. .............................................. 6

7. Abundance and Trends. ......................................... 6

B. Human Impacts .................................................... 7

1. Vessel interactions. ............................................. 7

a. Collisions with ships ...................................... 7

b. Disturbance by vessels ..................................... 8

2. Entrapment and Entanglement in Fishing Gear. ........................ 8

3. Habitat Degradation. ........................................... 8

4. Military Operations. ............................................ 9

5. Hunting. ..................................................... 9

III. NORTH PACIFIC POPULATION ......................................... 9

A. Natural History .................................................... 9

1. Stocks. ...................................................... 9

2. Distribution and Habitat Use. .................................... 11

3. Feeding and Prey Selection. ..................................... 12

4. Competition. ................................................. 13

5. Reproduction. ................................................ 13

6. Natural Mortality. ............................................. 13

7. Abundance and Trends. ........................................ 13
iv

B. Human Impacts .................................................. 15

1. Vessel Interactions. ........................................... 15

a. Collisions with ships ..................................... 15

b. Disturbance from vessels ................................. 15

2. Entrapment and Entanglement in Fishing Gear. ...................... 15

3. Habitat Degradation. .......................................... 15

4. Military Operations. ........................................... 16

5. Hunting. ................................................... 17

IV. RECOVERY ACTIONS AND IMPLEMENTATION ........................ 17

A. Goals and Objectives .............................................. 17

B. Stepdown Outline ................................................. 19

C. Narrative ....................................................... 20

LIST OF PERSONS PROVIDING PERSONAL COMMUNICATIONS . . . . . . . . . . . . . . . .

29

REFERENCES ........................................................... 30

APPENDIX A ............................................................ 40
1 Vessel includes every description of water craft, including nondisplacement craft

and seaplanes, used or capable of being used as a means of transportation on

water.

1

EXECUTIVE SUMMARY

The world’s stocks of blue whales, Balaenoptera musculus, were depleted by modern

whaling, and the number of blue whales in the world’s oceans is now only a small fraction of what

it was early in the 20th century. Since gaining complete legal protection from commercial whaling in

1966, some populations have shown signs of recovery; others have not been adequately monitored

to determine their status. Blue whales are listed as endangered under the Endangered Species Act.

Although the species is often found in coastal waters, blue whales are thought to occur

generally more offshore than northern right (Eubalaena glacialis) and humpback (Megaptera

novaeangliae) whales. Perhaps largely because of its offshore distribution, the blue whale seems less

prone, although not immune, to lethal entanglements in fishing gear and lethal strikes by vessels.

Moreover, its principal prey, euphausiids, are not commercially exploited on a large scale in the

Northern Hemisphere. 

Collisions with vessels, entanglement in fishing gear, reduced zooplankton production due to

habitat degradation, and disturbance from low-frequency noise are the most obvious potential indirect

threats. Thus, unlike the more piscivorous baleen whales (e.g., the humpback whale, fin whale,

Balaenoptera physalus, minke whale, B. acutorostrata, and Bryde’s whale, B. edeni), the blue whale

in the Northern Hemisphere is probably not yet competing directly with humans for prey resources.

The long-term goal of this Plan is to promote the recovery of blue whale populations so that

it becomes appropriate to remove them from the list of Endangered and Threatened Wildlife under

the Endangered Species Act. The Plan identifies measures that must be taken to protect and monitor

the recovery of blue whale populations in the North Atlantic and North Pacific oceans. The key

recommended actions of the proposed recovery program for the blue whale are to: (1) determine

population structure of blue whales, (2) estimate population size and monitor trends in abundance,

(3) identify and protect essential habitats, (4) minimize or eliminate human-caused injury and

mortality, (5) coordinate state, federal, and international actions to implement recovery efforts, (6)

determine and minimize any detrimental effects of directed vessel1 and aircraft interactions, and (7)

maximize efforts to acquire scientific information from dead, stranded, and entangled animals. Criteria

for delisting or downlisting recovering blue whale populations do not exist and developing them is

one of the recommended actions.
2

I. BACKGROUND

A. Species Description and Taxonomy

The blue whale, Balaenoptera musculus (Linnaeus 1758), is a cosmopolitan species of baleen

whale (Gambell 1979; Yochem and Leatherwood 1985; Mead and Brownell 1993). It is the largest

animal ever known to have lived on Earth: adults in the Antarctic have reached a maximum body

length of about 33 m and can weigh more than 150,000 kg. Blue whales in the Northern Hemisphere

are generally smaller than those in the Southern Ocean. True (1904), for example, concluded that

maximum body length in the North Atlantic was about 27 m (89 ft) (although a 28.1 m [92 ft] blue

whale is reported in whaling statistics from Davis Strait; R. Sears, pers. comm., October 1997). The

largest blue whales reported from the North Pacific are a female that measured 26.8 m (88 ft) taken

at Port Hobron in 1932 (Reeves et al. 1985) and a 27.1 m (89 ft) female taken by Japanese pelagic

whaling operations in 1959 (J. Gilpatrick, pers. comm., June 1998). As is true of other baleen whale

species, female blue whales are somewhat larger than males (Ralls 1976).

Blue whales are long-bodied and slender in comparison, for example, to right whales. The

dorsal fin is proportionately smaller than those of other balaenopterid whales. It is also set far back,

nearer to the tail flukes than to the middle of the body. Viewed from above, the blue whale has a

broad, flat rostrum. When a blue whale is feeding, its pleated throat and chest area expands to

accommodate the enormous intake of seawater and food. As the water is expelled and the filtered

zooplankton are swallowed, the body outline returns to its characteristically slender shape. Blue

whales have a mottled gray color pattern which appears light blue when seen through the water. The

background color can be dark gray, interrupted by irregular light gray markings, with dark gray

splotches.

Studies of intraspecific variability have led to the designation of three subspecies (Rice 1977):

B. m. musculus in the Northern Hemisphere; the somewhat larger B. m. intermedia from the

Antarctic; and B. m. brevicauda, the so-called "pygmy" blue whale, a significantly smaller and

morphologically distinct form found in the subantarctic zone of the southern Indian Ocean and

southwestern Pacific Ocean (Ichihara 1966). There is also a "resident" population of blue whales (of

unknown taxonomic status) in the northern Indian Ocean from the Gulf of Aden east at least to the

Bay of Bengal. This population was named Balaenoptera indica by Anderson (1879). Some of the

uncertainty regarding the blue whale’s conservation status, as a species, resides in the problem of

distinguishing among the subspecies and populations. Obviously, when the current numbers of all

three subspecies are combined, the total world population of blue whales is larger than if one refers

only to the numbers of one subspecies or population.

B. Zoogeography

Although the populations of blue whales were severely depleted by whaling, no evidence is

available to suggest that this exploitation resulted in a major change in their distribution during

modern times. Possible exceptions are in the eastern North Atlantic (Christensen et al. 1992a) and
3

western North Pacific (Forney and Brownell 1997; see below). It is assumed that blue whale

distribution is governed largely by food requirements and that populations are seasonally migratory.

Poleward movements in spring allow the whales to take advantage of high zooplankton production

in summer. Movement toward the subtropics in the fall allows blue whales to reduce their energy

expenditure while fasting, avoid ice entrapment in some areas, and engage in reproductive activities

in warmer waters of lower latitudes.

Separate summaries of natural history and human impacts are provided in this Plan for blue

whales in the North Atlantic and North Pacific oceans. However, since management needs in the two

ocean basins are similar, the Plan treats the two areas together when summarizing conservation efforts

and recommended actions.

C. Protective Legislation

Blue whales were only occasionally hunted by the sailing-vessel whalers of the 19th century

(e.g., see Scammon 1874). The introduction of steam power in the second half of that century made

it possible for boats to overtake the large, fast-swimming blue whales and other rorquals; yet it

remained for deck-mounted harpoon cannons to be developed for killing and securing them on an

industrial scale. Most of the technology for "modern" whaling was available by the early 1870s, and

factory ships were added in the early 20th century (Tønnessen and Johnsen 1982). Thus, from the

turn of the century until the mid-1960s, blue whales from various stocks were intensively hunted in

all the world’s oceans.

Blue whales were protected in portions of the Southern Hemisphere beginning in 1939. In

1955 they were given complete protection in the North Atlantic under the International Convention

for the Regulation of Whaling; this protection was extended to the Antarctic in 1965 and the North

Pacific in 1966 (Gambell 1979; Best 1993). The protected status of North Atlantic blue whales was

not recognized by Iceland until 1960 (Sigurjónsson 1988).

Blue whales are protected under both the Endangered Species Act (ESA) (as an endangered

species) and the Marine Mammal Protection Act (MMPA). The IUCN Red List of Threatened

Animals (Baillie and Groombridge 1996) lists three geographical populations of blue whales, as

follows: Antarctic stock as "endangered," North Pacific stock as "low risk, conservation dependent,"

and North Atlantic stock as "vulnerable." The pygmy blue whale is classified as "data deficient"

meaning that, although it may be threatened, too little is known to decide how it should be listed.

Only a few illegal kills of blue whales have been documented in the Northern Hemisphere,

including three at Canadian east-coast whaling stations during 1966-69 (Mitchell 1974), some at

shore stations in Spain during the late 1950s to early 1970s (Aguilar and Lens 1981; Sanpera and

Aguilar 1992), and at least two by "pirate" whalers in the eastern North Atlantic in 1978 (Best 1992).

Some illegal whaling by the USSR also occurred in the North Pacific (Yablokov 1994); it is likely that

blue whales were among the species taken by these operations, but the extent of the catches is not

known.
4

II. NORTH ATLANTIC POPULATION

A. Natural History

1. Stocks. Gambell (1979) identified ten putative stocks of blue whales in the world’s oceans,

including two (western and eastern) in the North Atlantic. This distinction has been adopted by others

(e.g., Best 1993); however, no rigorous discussion of blue whale stock boundaries has occurred in

the International Whaling Commission (IWC) (Donovan 1991), and hypotheses regarding stock

structure in this species have yet to be tested with molecular or other pertinent analyses.

Murray and Hjort (1912: 714) cited the finding of American-made bomb lances in two blue

whales killed in the Barents Sea as evidence that these animals had "migrated" between there and the

coast of North America. However, this conclusion did not take into account the fact that an American

whaler had shot experimental bomb lances into "hundreds" of blue whales off Iceland during the

1860s (see Schmitt et al. 1980: 101-113). One of three blue whales photo-identified off West

Greenland in July-August 1988 had been photographed in the Gulf of St. Lawrence in August 1984

and August 1985 (Anon. 1990). This suggests that blue whales in Davis Strait and the Gulf of St.

Lawrence belong to the same population. On the basis of catch timing and trends, Jonsgård (1955)

argued that the blue whales hunted along the coasts of Newfoundland and Labrador belonged to the

same stock as those hunted in Davis Strait as far north as Disko Island. Blue whales photo-identified

on the Scotian Shelf and in the Gulf of Maine were also photo-identified in the St. Lawrence (Wenzel

et al. 1988; Sears et al. 1990).

Sigurjónsson and Gunnlaugsson (1990a; following Jonsgård 1955; Christensen 1955) inferred

from catch data and trends in sightings off Iceland that blue whales occur in "relatively discrete

feeding populations." This concept of "feeding substocks" is generally accepted as applying to

humpback whales in the North Atlantic (Katona and Beard 1990) and may be appropriate for blue

whales as well, as originally suggested by Jonsgård (1955). 

Previous assumptions about stock identity of blue whales were recently called into question

by acoustic evidence from the North Atlantic. Acoustic tracking of individual blue whales has led to

speculation that they may range over the entire ocean basin (Clark 1994). This could mean that the

blue whales of the North Atlantic comprise a single panmictic stock (a concept anticipated by

Thompson 1928). However, genetic analyses are required to elucidate this issue.

2. Distribution and Habitat Use. The overall range of blue whales in the North Atlantic

extends from the subtropics north to Baffin Bay and the Greenland Sea (Jongsård 1955; Yochem and

Leatherwood 1985). The species was regularly hunted from land stations in Newfoundland and

Labrador, the Gulf of St. Lawrence, West Greenland, Iceland, Norway, Ireland, and the islands of

Shetland, the Hebrides and the Faroes (True 1904; Thompson 1928; Sergeant 1953, 1966; Jonsgård

1955, 1977; Kapel 1979; Sigurjónsson and Gunnlaugsson 1990a).
5

Blue whales are rare in the shelf waters of the eastern United States. Occasional sightings of

individuals have been made off Cape Cod, Massachusetts, in summer and fall (Wenzel et al. 1988).

Farther north in Canadian waters, a few sightings have been made on the Scotian Shelf (CETAP

1982, Sutcliffe and Brodie 1977), and two blue whales were sighted in August 1995 in the lower Bay

of Fundy (newspaper reports). A stranding at Ocean City, Maryland, in October 1891 (True 1904)

is the southernmost confirmed record on the east coast. Several records (pre-1970) of blue whale

strandings in the Gulf of Mexico (J. G. Mead, pers. comm., 27 October 1997) suggest occasional

straying into that area. A large blue whale was killed at Cristobal, Panama, in the Caribbean Sea

entrance to the Panama Canal in January 1922 (Harmer 1923).

In the 1960s, whalers regularly observed blue whales on the Scotian Shelf from May to

November, with most sightings between July and October (Sutcliffe and Brodie 1977). Off the

northern Newfoundland and southern Labrador coasts, including the Strait of Belle Isle, catches were

made mainly in June and July (Jonsgård 1955; Sergeant 1953, 1966).

Blue whales are present in the Gulf of St. Lawrence for most of the year (records are for

March to February according to R. Sears, pers. comm., October 1997), but most leave by early winter

to avoid ice entrapment and do not return until the ice breaks up in spring. Two peaks or pulses of

sightings occur in most years along the north shore of the Gulf: one in April to early June, the other

from August into at least late October (R. Sears, pers. comm., August 1995). Blue whales are

especially common along the north shore during the summer and fall feeding season, with a peak in

sightings from June to November (Sears et al. 1987; R. Sears, pers. comm., October 1997) Whaling

records suggest that the occurrence of blue whales is seasonal in most areas, but the lack of whaling

effort during the period from late fall to spring may explain the lack of records in those seasons (e.g.,

see Thompson 1928). 

In the Gulf of St. Lawrence, individual blue whales rarely spend more than about ten days in

a particular area, and they have been described as "very nomadic, with generally low local resident

times" (Sears et al. 1990). Four individuals were documented to have traveled more than 400 km in

a two-week period during the summer and fall (Sears et al. 1990). However, some individuals have

been documented as remaining in the same area for a month or more (R. Sears, pers. comm., August

1995). The main sighting areas are off the Gaspé Peninsula, along the Quebec north shore of the Gulf,

around Anticosti Island, and in the St. Lawrence River estuary to as far upriver as Tadoussac (R.

Sears, pers. comm., October 1997). 

The paucity of sightings during recent surveys along the coasts of Finnmark and on the banks

west of Bear Island and Svalbard, where blue whales were common in the late 1800s and early 1900s,

has been interpreted to mean that the historic distribution and migratory pattern of the species in the

eastern North Atlantic may have changed (Christensen et al. 1992a). However, it could also indicate

depletion of the population by whaling.

3. Feeding and Prey Selection. Based on stomach content analysis, the food of blue whales

in the North Atlantic has been reported to consist entirely of “krill,” i.e., relatively large euphausiid
6

crustaceans (Jonsgård 1955; Sergeant 1966; Christensen et al. 1992b). The species Thysanoëssa

inermis and Meganyctiphanes norvegica are particularly important in the eastern North Atlantic

(Hjort and Ruud 1929; Christensen et al. 1992b). The species T. raschii and M. norvegica are said

to represent important food sources of blue whales in the Gulf of St. Lawrence, based on

observations of feeding whales and sampling of the nearby water column (Sears et al. 1987). Some

other prey species, including fish and copepods, have been mentioned in the literature (e.g., see the

review by Kawamura 1980), but these are not likely to contribute significantly to the diet of blue

whales. Sears et al. (1987) suggested that the whales’ apparent preference for the 100 m contour

during daylight hours along the north shore of the Gulf of St. Lawrence is explained by krill

concentrations found regularly at depths of 90-120 m.

4. Competition. The question of whether blue whales are food-limited in the Northern

Hemisphere has not been addressed. All baleen whale species that are sympatric with the blue whale

eat euphausiids to some extent and are, therefore, potential competitors (Nemoto 1970). However,

there is currently little or no direct evidence for interspecific competition involving blue whales

anywhere (Clapham & Brownell 1996), and it seems unlikely that resource competition would be an

important factor in preventing the recovery of blue whale stocks. The high mobility of blue whales

should enable them to take advantage of transitory concentrations of prey over a very large area.

5. Reproduction. The gestation period is approximately 10-12 months, and blue whale calves

are nursed for about 6-7 months. Most reproductive activity, including births and mating, takes place

in the winter season. Weaning probably occurs on, or en route to, the summer feeding areas. The

average calving interval is probably two to three years. The age at attainment of sexual maturity is

uncertain but is thought to be 5-15 years (Mizroch et al. 1984; Yochem and Leatherwood 1985).

Only nine blue whales classified as “calves” were observed during 19 seasons of observations

along the north shore of the Gulf of St. Lawrence (R. Sears, pers. comm., October 1997). Either blue

whale populations are segregated in such a way that lactating females reside mainly in areas other

than those in which observations have been made, or weaning occurs prior to their arrival in these

areas, or (as suggested by R. Sears, pers. comm., October 1997) relatively few calves are being

produced by this population.

6. Natural Mortality. Little is known about natural mortality of blue whales in the North

Atlantic. Ice entrapment is known to injure and kill some blue whales, particularly along the

southwest coast of Newfoundland during late winter and early spring (Beamish 1979; Sergeant 1982).

Scarring on the dorsal surface of some whales in the St. Lawrence is thought to be from contact with

ice (Sears et al. 1987, 1990). Two blue whales in the Gulf of St. Lawrence bore rake-like markings

assumed to be from the teeth of killer whales (Orcinus orca) (Sears et al. 1990), but no direct

evidence of predation on blue whales has been reported from this area.

7. Abundance and Trends. No good estimates of pre-exploitation population size are available.

Sergeant (1966) guessed that approximately 1,500 blue whales were present in eastern Canadian

waters when modern whaling began there in 1898, based on cumulative catches between 1898 and
7

1915. Allen (1970) used a less direct approach to infer an eastern Canadian population in 1903 of

somewhat more than 1,100. All authors have agreed that the western North Atlantic stock of blue

whales was severely depleted by the time that legal protection was introduced in 1955. This is also

true of the stock(s) in the eastern and central North Atlantic (Jonsgård 1955). Klinowska (1991),

citing FAO (1978) and Yochem and Leatherwood (1985), suggested that about 15,000 blue whales

inhabited the North Atlantic when whaling began. This estimate may be too high. Regardless, it

should be treated skeptically in the absence of a detailed explanation of how it was derived.

Mitchell (1974) judged from "cumulative sightings recorded by whale catchers" (see Sutcliffe

and Brodie 1977) and his own surveys that the population of blue whales in the western North

Atlantic during the late 1960s and early 1970s was in the "very low hundreds, at most."

More than 320 individual blue whales had been photo-identified in the Gulf of St. Lawrence

from 1979 to the summer of 1995 (Sears et al. 1990; R. Sears, pers. comm., August 1995). The total

number of photo-identified individuals for eastern Canada and New England was 352 through autumn

1997 (R. Sears, pers. comm., October 1997). Exploratory analysis of the photo-identification data

from this region determined that they could not be used for a mark-recapture (i.e., sight-resight)

population estimate (Hammond et al. 1990).

Sighting data from whaling vessels operating off the west and southwest coasts of Iceland

have been interpreted as demonstrating a trend of increase, at about five percent per year, in the

number of blue whales since the late 1960s (Sigurjónsson and Gunnlaugsson 1990a). This increasing

trend is considered to apply specifically to the whale population in these waters, and not necessarily

to the North Atlantic as a whole. An estimate of 442 blue whales in Icelandic waters (no CV

calculated) was presented by Gunnlaugsson and Sigurjónsson (1990), based on the results of a

shipboard survey in June-July 1987. These authors referred to the estimate as "a probable upper

bound for the abundance of this species in the survey area" (p. 577). Elsewhere, however, the same

authors, citing Gunnlaugsson and Sigurjónsson (1990), indicated that the blue whale population in

Icelandic and neighboring waters "may number at least in the high hundreds" (Sigurjónsson and

Gunnlaugsson 1990a: 548). Christensen et al. (1992a) suggested that surveys in 1989, once fully

analyzed, would produce an estimate greater than 1,000 for Icelandic waters (see Sigurjónsson and

Gunnlaugsson 1990b). There is no current estimate for the number of blue whales in eastern North

Atlantic waters. As of autumn 1997, 32 individuals had been photo-identified in Icelandic waters (R.

Sears, pers. comm., October 1997).

B. Human Impacts

1. Vessel interactions.

a. Collisions with ships

Blue whales are at least occasionally injured or killed by ship collisions. A juvenile male blue

whale was reportedly struck and killed by a commercial vessel in March 1998 and was carried on the
8

bow of the ship into Narragansett, Rhode Island. The necropsy indicated that death occurred as a

result of a ship strike, including bone fractures at several locations along one side of its body.

Most of one fluke of an individual in the western North Atlantic catalog was missing,

apparently having been amputated by a ship’s propeller (Sears et al. 1987, 1990). Deep gashes in the

caudal peduncle are also assumed to have been made by the propellers of large ships. At least 9

percent of the whales in the Gulf of St. Lawrence have injuries or scars attributed to contact with

ships (Sears et al. 1990); another estimate has been provided of 25% (n=355) of the blue whales in

the Gulf of St. Lawrence bearing vessel contact scars (R. Sears, pers. comm., October 1997). The

St. Lawrence Seaway has heavy ship traffic during the time of year when blue whales are relatively

abundant there.

b. Disturbance by vessels

Since the early 1980s, blue whales have been among the main attractions for whalewatching

along the north shore of the Gulf of St. Lawrence and in the St. Lawrence estuary. Although no direct

evidence is available to demonstrate that persistent close approaches by tour boats have a negative

effect on the whales, there is concern about such a possibility. The Canadian Government has a "code

of ethics" for whalewatching; also, according to the Marine Mammal Regulations under the Canadian

Fisheries Act, it is illegal to "disturb" whales (Fisheries and Oceans 1995). There is no whalewatching

that targets blue whales along the eastern seaboard of the United States. Blue whales have been

observed occasionally, however, during whalewatching cruises in the Gulf of Maine (Wenzel et al.

1988). 

2. Entrapment and Entanglement in Fishing Gear. At least one blue whale found dead in the

Gulf of St. Lawrence in recent years apparently died from the effects of entanglement in fishing gear

(R. Sears, pers. comm., August 1995). A blue whale was observed on Stellwagen Bank, north of

Cape Cod, Massachusetts in August 1987 trailing fishing gear, including what appeared to be a

lobster pot buoy, from one pectoral fin (D.K. Mattila, pers. comm., February 1998).

The lack of more evidence that blue whales become entrapped or entangled in fishing gear in

the western North Atlantic may be due to incomplete reporting. In addition, the large size of the

animals makes it more likely that blue whales will break through nets, or carry gear away with them.

In the latter case, undetected mortality may result from starvation due to interference with feeding,

as sometimes occurs in humpback and northern right whales.

3. Habitat Degradation. At least some of the areas used by North Atlantic blue whales (e.g.,

the St. Lawrence River and Gulf) have been degraded by acoustic and chemical pollution. However,

no specific evidence is available to describe or quantify the impacts of this degradation on the blue

whale population. R. Sears (pers. comm., October 1997) reported having evidence that blue whales

from the St. Lawrence River estuary carry substantial body burdens of chemical contaminants,

including PCB’s and pesticides such as DDT. However, the data have not been published.
9

4. Military Operations. There is currently no evidence to indicate that military activities in the

North Atlantic have had an impact on blue whales. However, concern about the potential for injury

or disturbance to blue whales (and other cetaceans) influenced the siting and timing of Canadian shipshock trials on the Scotian Shelf in November 1994 (see Reeves and Brown 1994). A monitoring

program was undertaken by the Canadian Department of Defense to ensure that whales were clear

of the area during the blasting, and no direct effects on blue whales were documented (R. Sears, pers.

comm., August 1995).

5. Hunting. Deliberate killing has had a severe effect on the status of blue whales in the North

Atlantic (Jonsgård 1955). At least 11,000 were taken (all whaling areas, combined) from the late 19th

to mid 20th centuries (Sigurjónsson and Gunnlaugsson 1990a).

Blue whales are not known to have been subjected to hunting anywhere in the western North

Atlantic since the 1960s. Whalers who hunt humpback whales in the Lesser Antilles under the

aboriginal exemption in the IWC Schedule (and other cetaceans, including sperm whales, Physeter

macrocephalus, and pilot whales, Globicephala macrorhynchus) apparently do not see or attempt

to take blue whales (cf. Price 1985). Similarly, the "aboriginal subsistence" whaling off the coasts of

Greenland legally involves only fin and minke whales (B. physalus and B. acutorostrata, respectively)

at present, and only humpback whales have been reported as having been taken illegally in recent

years (e.g., see Anon. 1993). Blue whales were not reported as taken from Icelandic shore stations

after 1960, but at least three "fin" whales landed in Iceland during the 1980s were fin-blue whale

hybrids (Spilliaert et al. 1991; Árnason et al. 1991). Another fin-blue whale hybrid was killed by a

Spanish whaling operation in 1984 (Bérubé and Aguilar 1998). Currently, Norwegian whaling

operations target only minke whales, and the commercial whaling stations in Iceland, Spain, and the

Portugese islands of the Azores and Madeira remain officially closed.

III. NORTH PACIFIC POPULATION

A. Natural History

1. Stocks. Little information has been available for evaluating stock differences of blue whales

in the North Pacific. Although Gambell (1979) suggested that there were three stocks in the North

Pacific - west, central, and east, the IWC has considered there to be a single panmictic stock in this

ocean basin (Donovan 1991; also see Best 1993). A blue whale tagged in the Okhotsk Sea under the

"Discovery" tagging program was reported as having been killed in waters east of Kodiak Island

(Ivashin and Rovnin 1967). If this record is reliable, it indicates that considerable trans-oceanic

movement occurs at least occasionally, and that North Pacific subpopulations may not be entirely

discrete.

Rice (1974) hypothesized that blue whales from Baja California, Mexico, migrated far

offshore to feed near the eastern Aleutians or in the Gulf of Alaska and returned to feed in California

waters. However, he recently concluded, based on the presence of rare epizoites on blue whales
10

which were not found on other species known to migrate north, that the California population is

separate from that in the Gulf of Alaska and eastern Aleutians (Rice 1992). This latter view is

supported by the recent work of Calambokidis et al. (1995) and by length frequency analysis

(Gilpatrick et al. 1996). The agreement between estimates of abundance calculated from line-transect

surveys off California (Barlow 1995) and from sight-resight (photo-identification) data from

California (Calambokidis and Steiger 1995) provides further support to the hypothesis that the blue

whales off Mexico and California belong to a different stock from those in Alaskan waters. If whales

observed off California in summer were merely migrating to Alaska, the sight-resight estimates are

likely much higher than those derived from line-transect surveys.

Whaling catch data indicate that animals believed to belong to the central stock (as defined

by Gambell 1979) feed off the Aleutian Islands in summer. The prime period for blue whale catches

(made in various years between 1912 and 1939) was June through August (Reeves et al. 1985).

"Discovery" tag returns indicate that this population ranges further to the east, with movements from

the Gulf of Alaska to the Aleutian Islands, and from off Vancouver Island to the Gulf of Alaska

(Omura and Ohsumi 1964; Ohsumi and Masaki 1975; Ivashin and Rovnin 1967). Migratory

destinations of whales in this region are largely unknown, although it is possible that sightings of blue

whales in offshore waters north of the Hawaiian Islands reflect the winter range of this stock (Berzin

and Rovnin 1966). Blue whale calls detected by seafloor-mounted hydrophone arrays approximately

500 km offshore from Astoria, Oregon, in August 1990 (McDonald et al. 1995) and blue whales

sighted off the southern Oregon coast in 1996 (J. Barlow, unpublished data) are of unknown stock

origin.

In the western North Pacific, blue whales have been found offshore from Kamchatka and the

Kuril Islands (Russia) in summer to Japanese waters in winter (Nishiwaki 1966; Ohsumi and Wada

1972; Fujise et al. 1995, 1996). Forney and Brownell (1997) analyzed locations of catches and length

frequency data for blue whales taken in the North Pacific by both shore stations and pelagic

operations from 1929-1965. They concluded that the western stock is separate from the population

that was exploited in the Aleutian Islands area (the central stock). Furthermore, the virtual

disappearance of blue whales from the area off southern Japan where they were heavily exploited

(Kasaharu 1950) suggests that this area may have hosted another population that was largely separate

from that found off northern Japan and Kamchatka.

Another major area of concentration for blue whales is in the eastern tropical Pacific Ocean

around the Costa Rican Dome, where sightings have been recorded throughout the year. It is not

clear whether this represents a single year round population or alternating seasonal use of the region

by two (or more) populations (Reilly and Thayer 1990).

In conclusion, whaling and sighting data suggest the existence of at least five subpopulations

of blue whales in the North Pacific, with an unknown degree of mixing among them: (i) southern

Japan (which appears to have been virtually extirpated by whaling); (ii) northern

Japan/Kurils/Kamchatka; (iii) Aleutian Islands (the central stock, which may winter in deep water

north of Hawaii); (iv) eastern Gulf of Alaska; and (v) California/Mexico. The relationship between
11

any of these sub-populations and the whales that occur around the Costa Rican Dome is unclear.

2. Distribution and Habitat Use. The range of the blue whale is known to encompass much

of the North Pacific Ocean, from Kamchatka to southern Japan in the west, and from the Gulf of

Alaska and California south to at least Costa Rica in the east. The species is found primarily south

of the Aleutian Islands and the Bering Sea (Nishiwaki 1966; Reeves et al. 1985). Small numbers have

been observed as far north as the Chukchi Sea (Yochem and Leatherwood 1985; Rice 1986), but the

reliability of these reports have been questioned (D. W. Rice, pers. comm., September 1997). The

only (presumably) reliable sighting report of this species in the vicinity of the Hawaiian Islands is that

of Berzin and Rovnin (1966), who noted that blue whales were observed from scientific research

vessels about 400 km northeast of Hawaii in January 1964. Recordings of blue whale calls off Oahu

and Midway (Northrop et al. 1971; Thompson and Friedl 1982) provide additional evidence that they

occur within several hundred km of these islands (see Barlow et al. 1997). 

Overall, it is clear that this species inhabits and feeds in both coastal and pelagic environments.

Blue whales are frequently found on the continental shelf (e.g., in areas off the California coast,

Calambokidis et al. 1990; Fiedler et al. 1998) and also far offshore in deep water (e.g., in the

northeastern tropical Pacific, Wade and Friedrichsen 1979).

Knowledge concerning distribution and movement varies with area. The species appears to

undertake seasonal movements in many places. Summer feeding concentrations were exploited by

pelagic whalers in three areas (Rice 1974): (i) the eastern Gulf of Alaska between 130EW and

140EW, (ii) south of the eastern Aleutians between 160EW and 180EW, and (iii) from the far western

Aleutians to Kamchatka, between 170EE and 160EE. It is noteworthy that, while the second of these

three areas was documented to have relatively large concentrations of blue whales in the 1970s

(Berzin and Vladimirov 1981), the species appears rare there today, suggesting that illegal and

unreported whaling depleted the population (Stewart et al. 1987; Forney and Brownell 1997). Blue

whales were also taken in May-October from shore stations on the eastern Aleutians and Kodiak

Island through the 1930s (Reeves et al. 1985; Brueggeman et al. 1985).

In the western North Pacific, blue whale catches from shore stations were made off the

southern portion of the main Japanese islands in winter, off Hokkaido in spring and early summer,

and in summer off Kamchatka, the Kurils and the western Aleutians (Kasaharu 1950). This pattern

could be interpreted as evidence of a seasonal progression northward, but the lack of blue whales off

southern Japan today suggests that the animals of this region constituted a separate stock that has

been extirpated. Japanese pelagic operations in the North Pacific took blue whales between 1952 and

1965, with the largest catches along the south side of the Aleutians (Ohsumi and Wada 1972).

Blue whales were taken off the west coast of Baja California as early as the mid-19th century

(Scammon 1874). Extensive catches were made by factory ships operating in 1913/1914, from 1924

to 1930, and in 1935 (Rice 1974; Tønnessen and Johnsen 1982). The timing varied, but whalers found

few whales from December through February. A similar pattern has been observed in recent years

(Sears 1990; Calambokidis et al. 1990; Calambokidis 1995). Ingebrigtsen (1929) reported that blue
12

whales appeared off the Baja California coast "from the north" in October and traveled southward

along the shore, returning north in April, May, and June. It is possible that the migratory destination

of these whales was the Costa Rican Dome, which shows a seasonal increase in sightings in winter

(Reilly and Thayer 1990).

Recently, some blue whales have been seen along the west coast of Baja California between

March and July (Gendron and Zavala-Hernàndez 1995). They are first observed in Monterey Bay,

around the Channel Islands, and in the Gulf of the Farallons in June and July (Calambokidis et al.

1990; Calambokidis 1995). They are fairly widespread and unpredictable in their areas of

concentration from August to November. Individuals have been shown to move among the Gulf of

the Farallons, Monterey Bay, and Point Arena, California, within years. Also, some of the whales that

spend the summer and fall (August-October) off the California coast migrate to Mexican waters,

where they have been re-identified by photographs in spring (March-April) (Calambokidis et al.

1990).

As noted below, there is evidence for blue whale distributional shifts related to prey

abundance and oceanographic conditions. The appearance of numerous blue whales off the Farallon

Islands is noteworthy in light of their rarity in that region prior to the late 1970s (Calambokidis et al.

1990). Similarly, shore-based whaling data from Moss Landing and Trinidad, California, for the

period 1919-26 indicate that the species was (unlike today) extremely uncommon in this region

(Claphamet al. 1997). Calambokidis (1995) concluded that such changes in distribution reflect a shift

in feeding from the more offshore euphausiid, Euphausia pacifica, to the primarily neritic euphausiid,

Thysanoëssa spinifera.

3. Feeding and Prey Selection. Blue whales off California and elsewhere in the North Pacific

are said to prey mainly on Euphausia pacifica, and secondarily on the somewhat larger species

Thysanoëssa spinifera (Rice 1986). However, recent studies in the coastal waters of California have

found blue whales feeding primarily on the latter (Schoenherr 1991, Kieckhefer et al. 1995, Fiedler

et al. 1998).

The species Thysanoëssa inermis, Thysanoëssa longipes, Thysanoëssa raschii, and

Nematoscelis megalops have also been listed as prey of blue whales in the North Pacific (Kawamura

1980; Yochem and Leatherwood 1985). Although some stomachs of blue whales have been found

to contain a mixture of euphausiids and copepods or amphipods (Nemoto 1957; Nemoto and

Kawamura 1977), it is likely that the copepods and amphipods were consumed adventitiously or

incidentally. One exception to their near-total dependence on euphausiid prey is that blue whales have

been observed feeding on pelagic red crabs, Pleuroncodes planipes, off Baja California (Rice 1974,

1986), although these observations have not been confirmed by subsequent observations or other

analyses (e.g., fecal analysis). Reports that they feed on small schooling fish and squid in the western

Pacific (Mizue 1951; Sleptsov 1955) have been interpreted as suggesting that the preferred

zooplankton are less available there (Nemoto 1957). Between February and April, blue whales in the

Gulf of California, Mexico, have been observed feeding on euphausiid surface swarms (Sears 1990)

consisting mainly of Nyctiphanes simplex engaged in reproductive activities (Gendron 1990, 1992).
13

Sears (1990) regarded Nyctiphanes simplex as the principal prey of blue whales in the region, and

results from recent fecal analyses confirmed this assertion (Gendron and Del Angel-Rodriguez 1997).

However, this phenomenon appears to be strongly influenced by the occurrence of El Niño Southern

Oscillation (ENSO) events (Gendron and Sears 1993).

4. Competition. As in the North Atlantic, the trophic interactions of blue whales with other

krill consumers are not well understood. The comments in Section II.A.4 apply here as well.

5. Reproduction. No differences in the reproductive biology of blue whales in the North

Pacific and North Atlantic are known or suspected. Thus, the general comments in Section II.A.5

apply here as well.

Blue whales accompanied by young calves have been observed often in the Gulf of California

from December through March, and thus at least some calves may be born in or near the Gulf (Sears

1990). Therefore, this area is probably an important nursing and calving area for the species. One

female that was seen with a calf in March 1988 was resighted in March 1990 with another (Sears

1990), supporting the general belief that females of this species give birth in alternate years (Lockyer

1984).

Observations of females with calves off California occur primarily in June and July.

Photogrammetric observations of small whales in late summer support the idea that weaning occurs

at approximately six months of age (J. Gilpatrick, pers. comm., May 1997).

6. Natural Mortality. A well-documented observation of killer whales attacking a blue whale

off Baja California proves that blue whales are at least occasionally vulnerable to these predators

(Tarpy 1979). A high proportion of the blue whales in the Gulf of California bear injuries or rake-like

scars that are the result of encounters with killer whales (Sears 1990), although the extent to which

such attacks are fatal is unknown. Unlike in the western North Atlantic, injury or suffocation from

ice entrapment is not known to be a factor in the natural mortality of blue whales in the North Pacific.

7. Abundance and Trends. With the exception of the population that summers off California,

there are no reliable estimates of abundance for blue whales in the North Pacific. 

A reported total of 9,500 blue whales were killed by commercial whalers in the North Pacific

between 1910 and 1965 (Ohsumi and Wada 1972). This includes at least 1,378 taken by factory ships

off California and Baja California between 1913 and 1937 (Rice 1992), and 48 taken by land-based

whalers off central California between 1958 and 1965 (Rice 1974).

From a crude analysis of catch statistics and whaling effort, Rice (1974) concluded that the

population of blue whales in the eastern North Pacific (Baja California to Alaska) was large enough

to sustain an average kill of 289 per year from 1924/25 to 1928/29. Assuming an annual net

recruitment rate of about 0.05, he reasoned that the initial (1924) population size would have had to

be about 6,000 whales; this contrasts with the "initial stock size" of 4,900 for the entire North Pacific
14

estimated by Omura and Ohsumi (1974). Rice (1974) guessed that the total population of blue whales

in the eastern North Pacific in the early 1970s was 2,000 or less. However, Rice’s calculations

assumed the existence of a single blue whale population in the eastern North Pacific, an assumption

which recent findings strongly suggest is not correct.

Although they have been cited as abundance estimates (e.g., by Wade and Gerrodette 1993),

the figures for blue whales in the North Pacific published by Omura and Ohsumi (1974) and by Wada

(1975) were actually indices of abundance based on sightings from Japanese whaling catcher boats.

The data were not collected or analyzed in the same ways as those from more recent sighting cruises,

nor did the area of coverage include several well-known centers of blue whale abundance in the North

Pacific (cf. Wada 1975, Figures 1-2, compared with Reilly and Thayer 1990, Figures 1, 3). It is

therefore not possible to evaluate trends by comparing the Japanese “indices” from the 1960s and

1970s with the more recent abundance estimates from sighting cruises and photo-identification

studies. Similarly, a widely cited figure of 1,600 blue whales (e.g., Gambell 1979) was based on data

derived from a combination of very different methods and first presented in an unreviewed,

unpublished manuscript (by Ohsumi and Wada). This estimate must be considered unreliable.

Russian scientists inferred from sightings made during whaling and research cruises in the

1970s that blue whale numbers were increasing throughout the North Pacific, with a particular

concentration in the offshore area between 37EN-45EN and 177EE-150EW (Berzin and Vladimirov

1981). Berzin and Vladimirov (1981) estimated a pre-exploitation population size of 5,000 and a

present size of 1,400-1,900, but they gave no details of how these figures were derived. An aerial

survey of the former Akutan whaling grounds around the eastern Aleutians in 1984 produced no

sightings of blue whales, suggesting that the population remained severely depleted (Stewart et al.

1987). In the early 1980s blue whales in the North Pacific were thought to be at about one-third of

the historical carrying capacity stock size (1,600 out of 4,900; Mizroch et al. 1984), but in view of

the many uncertainties, this estimate must likewise be considered questionable. Also, no blue whales

were sighted during a marine mammal survey south of the Aleutian Islands in 1994 (Forney and

Brownell 1997).

More than 700 individual blue whales had been photo-identified in Californian and Mexican

coastal waters through 1993 (Calambokidis 1995). Ship surveys of the eastern tropical Pacific during

1986-1990 resulted in an estimate of 1,415 (95% CI 1,078-2,501) blue whales in that area (Wade and

Gerrodette 1993). A ship survey at the same time of year off the California coast in 1991 produced

an estimate of 2,250 (CV=0.38) for this area (Barlow 1995). Barlow (1997) reported a revised

estimate of 1,927 (CV=0.16) based on a weighted average of data from 1991, 1993, and 1996

surveys off the California coast. Another estimate is available for the Mexico/California stock from

mark-recapture analyses: 2,038 (CV=0.33) based on photographs of left sides and 1,997 (CV=0.42)

based on right sides (Calambokidis and Steiger 1995). The best estimate of the California/Mexico

stock, calculated as the average of the line-transect and mark-recapture estimates, weighted by their

variances, is 2,134 (CV=0.27). By combining this estimate with that from the eastern tropical Pacific,

the total eastern North Pacific population south of Oregon can be estimated at about 3,500 whales.

Given our current view of stock structure within the North Pacific, this figure almost certainly does
15

not include all of the whales that feed in summer off Alaska and British Columbia (and possibly also

Washington and Oregon).

The abundance of blue whales along the California coast has clearly been increasing during

the past two decades (Calambokidis et al. 1990; Barlow 1994; Calambokidis 1995). The magnitude

of this increase is considered too large to be explained by population growth alone, and it is therefore

assumed that a shift in distribution has occurred. The evident scarcity of blue whales in areas of

former abundance (e.g., Gulf of Alaska and near the Aleutian Islands; see Calambokidis et al. 1990)

suggests that the increasing trend does not apply to the species’ entire range in the eastern North

Pacific.

B. Human Impacts

1. Vessel Interactions.

a. Collisions with ships

Ship strikes were implicated in the deaths of at least four and possibly six blue whales off

California between 1980 and 1993 (Barlow et al. 1995; Barlow et al. 1997). The average number of

blue whale mortalities in California attributed to ship strikes was 0.2 per year from 1991-1995

(Barlow et al. 1997). Further mortalities of this nature probably have occurred without being

reported. Several of the whales photo-identified off California had large gashes on the dorsal body

surface that were thought to have been caused by collisions with vessels (Calambokidis 1995).

b. Disturbance from vessels

In most years since the mid 1980s, blue whales have been commonly found during summer

and early fall in nearshore waters along the coast of southern California, especially around the

Channel Islands. Thus, some whalewatching focused on blue whales has developed in recent years,

notably in the Santa Barbara Channel where the species has occurred with regularity in July and

August. Sporadic whalewatching on blue whales occurs in winter off Baja California. Whalewatching

has no known impact on this species. Major shipping lanes pass through, or near, whalewatching

areas, and underwater noise produced by commercial ship traffic may have a much greater impact

than that produced by whalewatching. However, little is known about whether, or how, vessel noise

affects blue whales.

2. Entrapment and Entanglement in Fishing Gear. No definite evidence of blue whales being

taken in fishing gear in the North Pacific is available. Heyning and Lewis (1990) made a crude

estimate that about 73 rorquals were killed annually in the offshore southern California drift gillnet

fishery during the 1980s, and at least some of these could have been blue whales. Heyning and Lewis

suggested that most whales killed by offshore fishing gear do not drift far enough to strand on

beaches or to be detected floating in the nearshore corridor where most whalewatching occurs. Thus,

the lack of documentation of blue whale entanglements should not be interpreted to mean that none
16

occur. The drift gillnet fisheries for swordfish and sharks off California and Baja California represent

a potential threat to blue whales of the Mexico/California stock. Observer coverage in such fisheries

was relatively low in the past (Barlow et al. 1995) but increased to 10-18 percent in 1991-1995

(Barlowet al. 1997). In the observed fisheries, no blue whale mortalities were documented. However,

entanglement rates may be underestimated inasmuch as blue whales may break through or carry away

fishing gear, perhaps suffering unrecorded subsequent mortalities.

3. Habitat Degradation. The planktivorous diet of blue whales makes them less susceptible

than piscivorous baleen whales to the accumulation of organochlorine and metal contaminants in their

tissue. In any event, there is no reason to suspect that levels of these substances in any baleen whales

are presently high enough to cause toxic or other effects (O’Shea and Brownell 1994), although

possible long-term or transgenerational impacts are unstudied.

Anthropogenic noise may affect blue whales. Short-term changes in the behavior of a blue

whale, interpreted as possibly a "startle response," were observed in the southern Indian Ocean during

the experimental transmission of low-frequency, high-intensity underwater sounds (Bowles et al.

1994). Concern has been expressed about the potential impacts on blue (and other) whales of a more

extensive study involving underwater sound transmission (Acoustic Thermometry of Ocean Climate,

ATOC) in the North Pacific (Schmidt 1994). Studies of the responses of several whale species to the

ATOC signal at Pioneer Seamount off Half Moon Bay is being concluded. Preliminary analysis shows

that whales observed during trials were distributed slightly farther from the source when it was

activated compared to when it was not. No other changes in behavior or distribution were observed.

4. Military Operations. Ship shock trials were conducted by the U.S. Navy approximately 90

miles southwest of San Nicolas Island, California, in late June 1994. Associated monitoring activities

detected two blue whales in the vicinity, causing a relocation of the trials to an area nine miles from

the animals (J. Carretta, pers. comm., June 1997). 

A study to assess the impact of loud low-frequency active sonar signals by the U.S. Navy is

underway. The Navy has completed a three-phase research program as the basis for an Environmental

Impact Statement (EIS) on their Low-Frequency Active (LFA) sonar system. Phase I focused on the

effects of the LFA signal on foraging blue whales in California, phase II focused on the effects on

migrating gray whales off California, and phase III focused on its effects on breeding humpback

whales off Hawaii. The EIS planning and writing are underway, and the draft EIS is expected to be

completed in late 1998 or early 1999.

In addition to the potential effects from sonar and other sounds and from ordnance drops

associated with training activities, military traffic contributes to the overall problem of vessel traffic

(see above).

5. Hunting. As indicated above, there is no doubt that hunting had a severe impact on blue

whales in the North Pacific. Areas of former abundance, notably off Japan and the Aleutian Islands,

are currently host to very few blue whales (Stewart et al. 1987; Miyashita et al. 1995), strongly
17

suggesting that whaling gravely depleted the populations concerned.

According to Yablokov (1994), citing Zemsky and Shazhinov (1982), "It was ... well known

in the Soviet Union that blue whales continued to be killed [in the Southern Hemisphere] after they

were protected by the IWC." Details of these illegal kills have been reported recently (Zemsky et al.

1995a, 1995b). Although Yablokov (1994) stated that Russia also made illegal catches in the North

Pacific from both land stations and pelagic operations, no information on these takes has been

published. If these unreported catches included large numbers of blue whales, they would almost

certainly have had a significant negative impact on the recovery of the species in this region.

IV. RECOVERY ACTIONS AND IMPLEMENTATION

Given the similar management and research needs involved, the North Atlantic and North

Pacific blue whale populations are treated together in this section rather than separately. Accordingly,

the summary of conservation efforts and recommended actions given below is applicable to both

oceanic populations, except where indicated. 

No whaling (either “aboriginal subsistence” or commercial) for blue whales occurs at present.

Moratoria on the deliberate killing of blue whales have been in force for several decades, and these

have undoubtedly had a positive effect on the species’ conservation. The threat of renewed

commercial whaling was one of the primary factors in the decision to add blue whales to the list of

Endangered and Threatened Wildlife. For now, and presumably for the foreseeable future, this threat

is not likely to recur.

The regulation of whalewatching activities in the River and Gulf of St. Lawrence, Canada (see

above), and to a much lesser extent in the northeastern United States, can be viewed as providing

some benefits to blue whales. There are currently no whalewatching or vessel approach regulations

in U.S. or Mexican waters except those explicitly directed at protecting North Atlantic right whales

in U.S. waters. Whale watching guidelines have been issued by NMFS for other endangered species

and there are general prohibitions on harassment of marine mammals.

A. Goals and Objectives

The overall long-range goal of this Recovery Plan is to promote recovery of blue whale

populations to levels at which it becomes appropriate to downlist them from endangered to

threatened status, and ultimately to remove them from the list of Endangered and Threatened

Wildlife, under the provisions of the ESA. The Act defines an "endangered species" as "any species

which is in danger of extinction throughout all or a significant portion of its range." A "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."

The primary purpose of the Plan is to identify a set of actions that will minimize or eliminate
18

effects from human activities that are detrimental to the recovery of blue whale populations.

Immediate objectives are to identify factors that may be limiting the populations and actions necessary

to allow the populations to increase.

Since blue whales move freely across international borders, it is not reasonable to confine

recovery efforts to U.S. waters, and this Plan stresses the importance of a multi-national approach

to blue whale protection. The Plan recognizes limits imposed by the national nature of protective

legislation; however, as demonstrated by recent work on humpback whales (Palsbøll et al. 1997),

considerably more information becomes available for management of human activities affecting whale

populations when actions are taken based on biological rather than political divisions, and through

international cooperation leading to research and conservation at oceanic rather than national levels.

Tasks required to achieve the objectives of this Plan are listed in the step-down outline below.
19

B. Stepdown Outline

Items in this outline are not in order of priority. Priorities are identified in Appendix A.

1.0. Determine Stock Structure of Blue Whale Populations Occurring in U.S. Waters and

Elsewhere.

1.1 Determine stock structure of blue whales using genetic analyses.

1.2 Assess daily and seasonal movements and inter-area exchange, using telemetry.

2.0. Estimate the Size and Monitor Trends in Abundance of Blue Whale Populations.

2.1 Conduct surveys to estimate the size and monitor trends in abundance of populations.

2.2 Conduct annual independent photo-identification surveys.

2.3 Maintain existing blue whale photo-identification catalogs and sighting databases, and

establish others as required.

2.4 Promote international efforts to estimate abundance and investigate stock structure of

blue whales in non-U.S. waters.

3.0. Identify and Protect Habitat Essential to the Survival and Recovery of Blue Whale

Populations.

3.1 Promote action to protect areas of importance in U.S. waters. 

3.2 Promote action to protect known areas of importance in foreign waters.

3.3 Improve knowledge of blue whale feeding ecology.

3.4 Improve knowledge of the characteristics of important blue whale habitat, and of how

blue whales use such habitat.

4.0. Reduce or Eliminate Human-caused Injury and Mortality of Blue Whales.

4.1 Identify areas where ship collisions with blue whales might occur, and areas where

concentrations of blue whales coincide with significant levels of maritime traffic or pollution.

4.2 Identify and implement methods to reduce ship collisions with blue whales.

4.3 Reduce or eliminate injury and mortality caused by fisheries and fishing gear.
20

4.4 Conduct studies of environmental pollution that may affect blue whale populations and

their habitat.

5.0. Minimize Detrimental Effects of Directed Vessel Interactions with Blue Whales.

5.1 Investigate the potential effects of whale watching on blue whales.

5.2 Implement appropriate protective measures on any such activities which may be

detrimental to blue whales.

6.0. Maximize Efforts to Acquire Scientific Information from Dead, Stranded, and

Entangled Blue Whales.

6.1 Improve and maintain the system for reporting dead or entangled blue whales.

6.2 Improve and maintain existing programs to collect data from dead blue whales.

7.0. Coordinate State, Federal, and International Efforts to Implement Recovery Actions

for Blue Whales.

7.1 Designate an implementation coordinator to facilitate Recovery Plan implementation.

7.2 Identify, at an appropriate time, representatives of the scientific community, private,

state, and federal agencies (and international agencies where applicable) to periodically review

and update this Recovery Plan.

7.3 Support a continued international ban on commercial hunting and other directed lethal

take of blue whales, and encourage international efforts to detect and prevent illegal whaling.

8.0. Establish Criteria for Deciding Whether to Delist or Downlist Blue Whales.

8.1 Establish criteria for delisting or downlisting blue whale populations.

C. Narrative

Data collected through any research identified in this Plan should be analyzed and reported

in a timely manner. Reports should be thoroughly referenced and follow standards of organization

to facilitate comparison with other reports. As much as possible, data should be presented in peerreviewed journals and other open publications to ensure that research programs benefit from regular

peer commentary.

To the maximum extent possible, ongoing and future data collection should be done such that

recent data can be compared with historical data. Studies may need to be conducted to calibrate
21

results from newly developed techniques with those obtained by previous methods. Data analyses

should examine trends over time and attempt to correlate observed changes with physical, biological,

or human-induced changes in the environment.

1.0. Determine Stock Structure of Blue Whale Populations Occurring in U.S. Waters and

Elsewhere.

Existing knowledge of the population structure of blue whales is insufficient, and a more

comprehensive understanding is essential to developing effective strategies to promote recovery.

1.1 Determine stock structure of blue whales using genetic analyses.

A comprehensive program of biopsy sampling of blue whales should be implemented

that focuses on current and historically important blue whale habitat in both U.S. waters and

elsewhere. Ideally, this would be a collaborative multi-national effort with standardized

sampling protocols. Using the resulting samples, population structure can be investigated

through analyses of mitochondrial and nuclear DNA. In addition, the sexual composition of

each population should be assessed through molecular determination of the sex of all sampled

whales. All biopsy samples should be preserved in such a way that the accompanying blubber

can be utilized for contaminant analyses (item 4.4 below). The genetics work should be

complemented by a thorough review of existing data (from whaling catches and other

sources) on inter-area differences in morphology and meristics of blue whales. An ancillary

objective of genetic studies might be to evaluate genetic variability within populations or

stocks of blue whales. A comparative approach, examining differences in genetic variability

between recovering versus non-recovering groups of blue whales, could prove informative.

1.2 Assess daily and seasonal movements and inter-area exchange, using telemetry.

Telemetry studies (notably those using satellite-monitored radio tags) should be

conducted to gather information on patterns and ranges of daily and seasonal movement of

individual blue whales. These studies also have the potential to address the question of

exchange between subpopulations.

2.0. Estimate the Size and Monitor Trends in Abundance of Blue Whale Populations.

Estimation of abundance, and of trends in abundance, is vital to assessing the recovery of blue

whale populations, yet reliable data for such estimation exist only for the California/Mexico

population (see III.A.7, above). Given the known range of the blue whale, a multinational effort is

essential to achieve this goal.

2.1 Conduct surveys to estimate the size and monitor trends in abundance of populations.

Surveys using line-transect and photo-identification methods should be conducted to
22

assess abundance in present or historic blue whale habitat. In U.S. waters, this includes the

entire west coast and the Aleutian Islands region. Collaborative multinational efforts with

standardized sampling protocols should be developed to integrate such studies with others

conducted off Mexico, Canada (both Pacific and Atlantic coasts) and areas more remote from

U.S. waters. Knowledge derived from the population structure studies outlined above would

be used to assist in interpretation of the results of this work. Because of the relatively long

generation time of blue whales, and the time scales on which environmental factors affecting

their distribution may operate, programs to monitor trends in blue whale abundance must be

long-term efforts. 

2.2 Conduct annual independent photo-identification surveys.

Photographic identification of individual blue and other large whales has proven to be

a valuable tool for estimating abundance, determining vital rates, investigating population

structure, and studying a variety of other aspects of biology and behavior. A long-term

collaborative photo-identification effort in the California/Mexico region has yielded

considerable information on this population. The continuation of such surveys is very

important to the monitoring of this stock. In addition, international efforts to support photoidentification studies in other blue whale habitats should be encouraged. The photoidentification studies would also complement the continued maintenance of photoidentification catalogs (item 2.3, below).

2.3 Maintain existing blue whale photo-identification catalogs and sighting databases, and

establish others as required.

The three existing blue whale photo-identification catalogs include blue whales

identified (i) off California, Mexico and adjacent regions; (ii) in the western North Atlantic,

with an emphasis on the Gulf of St. Lawrence; and (iii) in waters of Baja California including

inshore and offshore areas of both coasts of the Peninsula. Continued support for these

catalogs is essential to improving knowledge of the status and basic biology of this species.

When other concentrations of blue whales are located during the survey work recommended

above, as many animals as possible should be photo-identified and new regional catalogs

established. A network should also be formed to examine inter-area movements of

individually identified blue whales to increase knowledge of population structure, and to

integrate the results of genetic and sex-determination analyses with photo-identification

studies.

Centralization of these databases would promote efficiency in addressing questions

related to occurrence and habitat use. Sighting data would complement information from

photo-identification catalogs and other sources.

2.4 Promote international efforts to estimate abundance and investigate stock structure of

blue whales in non-U.S. waters.
23

As noted above, a multinational collaborative scientific effort will be required for

understanding blue whale population structure and abundance at oceanic scales. Effective

conservation and recovery of the species can occur only if this broad-scale approach is taken.

3.0. Identify and Protect Habitat Essential to the Survival and Recovery of Blue Whale

Populations.

Some areas are known to be important habitat for blue whales; others may be discovered

during the course of the studies recommended above. Protection of these areas is essential to

population recovery.

3.1 Promote action to protect areas of importance in U.S. waters.

Areas of known importance include the waters off California and, historically, the

Alaska/Aleutian Island region, although as noted above, blue whales may no longer be

abundant in the latter region. The U.S. east coast does not appear to be a region of

importance to blue whales; only occasional sightings and strandings are reported there.

It is also important to identify and protect other habitats essential to the survival and

recovery of blue whales. Identification of such habitat would be accomplished using

information gained from studies conducted under item 3.4 below.

3.2 Promote action to protect known areas of importance in foreign waters 

Efforts should be made to encourage the governments of Canada, Mexico, and other

relevant countries to protect blue whale habitat, and to join multi-national efforts of this

nature. In Canada, areas important to blue whales include the Gulf of St. Lawrence, coastal

waters of Newfoundland, the Scotian Shelf in the North Atlantic, and the eastern Gulf of

Alaska in the North Pacific. In Mexico, the waters of Baja California, particularly the

southwestern portion of the Gulf of California where nursing, feeding, and probably calving

occurs, are clearly of great importance to many eastern North Pacific blue whales, including

whales that spend part of the year in U.S. waters. Other areas of known importance (past or

present) include the waters of Costa Rica, Iceland, Norway, Japan, and the Russian Far East.

3.3 Improve knowledge of blue whale feeding ecology.

Studies designed to improve knowledge of blue whale prey type, dietary requirements,

and energetics are needed for a better understanding of both habitat use and recovery

potential. This is particularly true in light of the blue whale’s nearly total dependence on

euphausiids, which makes it vulnerable to environmental or other catastrophes resulting in

major declines in krill abundance. An avenue of research that could be pursued is to compare

features of areas where blue whales appear to be recovering (e.g., Iceland, California/Mexico)
24

with areas where they seem not to be (e.g., off Norway, south of the Aleutian Islands). A

testable hypothesis might be that populations with slow recovery rates feed on pelagic

aggregations of euphausiids, which tend to be less dense and more patchy than those in

nearshore areas, on which the strongly recovering blue whale populations feed (D. Croll and

B. Tershy, pers. comm., August 1997).

3.4 Improve knowledge of the characteristics of important blue whale habitat, and of how

blue whales use such habitat.

Characterization of habitat used by blue whales is essential to identifying other

potentially important areas, and to future assessments of the health of the environments on

which blue whales depend. Such characterizations would include prey type and abundance,

and associated oceanographic features. Studies to determine interannual variability in habitat

characteristics, and in blue whale habitat use, are important components of such work. The

end-goal should be to develop a predictive framework for identifying other potentially

important blue whale habitat.

4.0. Reduce or Eliminate Human-caused Injury and Mortality of Blue Whales.

Vessel strikes and entanglement in fishing gear are known to kill and injure blue whales. The

frequency and significance to the population need to be studied. Implementation of appropriate

measures designed to reduce or eliminate such problems are essential to recovery.

4.1 Identify areas where ship collisions with blue whales might occur, and areas where

concentrations of blue whales coincide with significant levels of maritime traffic or pollution.

Research on the frequency with which shipping-related mortalities occur in blue

whales is desirable, given that mortalities from this source are known, and others have almost

certainly gone unrecorded. Studies to quantify the volume and type of shipping traffic in areas

known to be important to blue whales are also required. This task will be assisted by efforts

to improve detection and reporting of blue whale mortalities (item 6.1 below).

4.2 Identify and implement methods to reduce ship collisions with blue whales.

The practicality and effectiveness of measures to reduce ship strike mortalities should

be assessed.

4.3 Reduce or eliminate injury and mortality caused by fisheries and fishing gear.

If observations from fishery observer programs, whalewatching vessels, researchers,

or other sources indicate that entanglement represents a serious threat to the recovery of blue

whales, actions should be taken to reduce or eliminate deaths from this cause.
25

4.4 Conduct studies of environmental pollution that may affect blue whale populations and

their habitat.

Baleen whales (including blue whales) generally have lower levels of contaminants

than odontocetes. However, nothing is known about the effects of pollutants on blue whales,

notably regarding long-term impacts, transgenerational effects, and impacts on prey resources.

Studies should be conducted to improve knowledge of these topics, and to examine related

issues such as metabolic pathways, and effect of sex, age, reproductive condition and

geographic origin on contaminant burdens. Biopsy samples collected under item 1.1 will be

usable for much of this work. Studies should also be conducted to examine the impact on blue

whales or blue whale habitat of point-source and other types of pollution, including lowfrequency noise.

5.0. Minimize Detrimental Effects of Directed Vessel Interactions with Blue Whales.

An active whalewatching industry targeting blue whales has already developed in California,

yet the impact of such activities is unknown. Excessive directed activity (whether from commercial

vessels, private boats or aircraft) could potentially disrupt vital behavior such as feeding or nursing.

5.1 Investigate the potential effects of whale watching on blue whales.

Studies should be conducted to assess the effects of directed vessel and aircraft

interactions on blue whale behavior. 

5.2 Implement appropriate protective measures on any such activities which may be

detrimental to blue whales.

If the studies recommended in item 5.1 indicate that certain types or numbers of boat

or aircraft approaches adversely affect blue whales, appropriate measures should be

developed and implemented.

6.0. Maximize Efforts to Acquire Scientific Information from Dead, Stranded, and

Entangled Blue Whales.

Assessments of the causes and frequency of mortality (either natural or anthropogenic) are

extremely important to understanding blue whale population dynamics and the threats that may

impede recovery. However, the discovery of a blue whale carcass in circumstances in which it can

be examined closely is a rare event. Accordingly, efforts to detect and investigate blue whale

mortalities should be made as efficient as possible. Live entanglements of blue whales are rarely

observed, but better reporting might provide rescue opportunities.

6.1 Improve and maintain the system for reporting dead or entangled blue whales.
26

In order to optimize detection and reporting of dead blue whales (whether stranded

or observed at sea), the Large Whale Recovery Program coordinator should work with

representatives of local, state and federal agencies, private organizations, and regional and

national stranding networks to facilitate efficient observer coverage and information

exchange. In addition, prompt reporting of live entanglements might provide opportunities

for disentanglement rescue teams to release whales or remove gear being towed.

6.2 Improve and maintain existing programs to collect data from dead blue whales.

Each blue whale carcass represents an opportunity for scientific investigation of the

cause of mortality, as well as of numerous other questions relating to the biology of the

species. Delays in attempts to secure or examine a carcass can result in the loss of valuable

data, or even of the carcass itself. Stranding network coordinators and the implementation

coordinator should work with relevant agencies, organizations, and individuals to ensure that,

when a blue whale carcass is reported and secured: (i) necropsy is performed as rapidly and

as thoroughly as possible by qualified individuals selected to gather information regarding

cause of death; (ii) samples are taken and optimally preserved for studies of genetics,

toxicology, pathology, histology, and other subjects; and (iii) funding is available to rapidly

notify and transport appropriate experts to the site and to distribute tissue samples to

appropriate locations for analysis or storage. In addition, the implementation coordinator

should work with stranding networks and the scientific community to develop and maintain

lists of tissue samples requested by various qualified individuals and agencies, and ensure that

these samples are routinely collected from each carcass and stored in appropriate locations

or distributed to appropriate researchers for analysis. It is recognized that extensive

development of stranding networks has already taken place along much of the U.S. coastline.

Existing protocols should be maintained indefinitely and improved where necessary to meet

the requirements listed above.

Rapid detection of blue whale carcasses, and notification and transport of qualified

personnel, are vital to ensuring that the maximum amount of information is obtained.

Adequate funding is imperative.

7.0. Coordinate State, Federal, and International Efforts to Implement Recovery Actions

for Blue Whales.

A coordinated approach to the tasks identified in this Plan would greatly facilitate their

completion. Establishment of a team charged with coordinating state and federal efforts to implement

the Plan, and with pursuing international cooperative efforts, is highly desirable. Liaison between the

team and the lead agency would be the responsibility of a designated individual from the latter body.

7.1 Designate an implementation coordinator to facilitate Recovery Plan implementation.

Many of the tasks identified in this Plan would best be accomplished by an
27

implementation coordinator or coordinators with responsibility for overseeing the various

aspects of the recovery plan process. Tasks include developing (with appropriate input from

others) and administering research contracts, participating in interagency consultations under

the ESA, and helping to develop, evaluate, and implement protection measures.

7.2 Identify, at an appropriate time, representatives of the scientific community, private,

state, and federal agencies (and international agencies where applicable) to periodically review

and update this Recovery Plan.

As the Plan is implemented, new information will be obtained and the priorities of the

Recovery Plan will accordingly require periodic review and revision. Representatives of the

relevant agencies and the scientific community should be appointed to review and revise the

Plan every five years for the first 15 years of implementation, and every ten years thereafter.

This schedule would, of course, be subject to change in the event of resumed whaling for blue

whales or the occurrence of an environmental catastrophe causing significant blue whale

mortality.

7.3 Support a continued international ban on commercial hunting and other directed lethal

take of blue whales, and encourage international efforts to detect and prevent illegal whaling.

The international ban on the hunting of blue whales has been vital to recovery efforts.

In light of the continued low abundance of blue whales in most areas, continuation of this ban

is essential. While there is currently no known illegal whaling of blue whales, it is important

that international efforts to detect any future infractions be supported.

8.0. Establish Criteria for Deciding Whether to Delist or Downlist Blue Whales.

Development of scientifically defensible criteria for eventual downlisting or delisting of any

endangered species is an essential part of recovery plan implementation. However, any application

of such criteria requires good information about the discreteness of populations, population sizes and

trends in abundance, and the nature and magnitude of threats; thus, the criteria cannot be reasonably

developed prior to the acquisition of such information.

8.1 Establish criteria for delisting or downlisting blue whale populations.

A de/downlisting criteria workshop should be convened at such time as the

implementation team judges that sufficient information has been gained about blue whales to

develop such criteria. The workshop should include representatives of relevant agencies as

well as acknowledged experts on blue whales and individuals with expertise in scientific and

statistical fields essential to the success of the workshop.
28

LIST OF PEOPLE PROVIDING PERSONAL COMMUNICATIONS

James V. Carretta, National Marine Fisheries Service, Southwest Fisheries Science Center, P.O. Box

271, La Jolla, CA 92038-0271

Donald A. Croll, Division of Natural Sciences, University of California, Santa Cruz, Santa Cruz, CA

95064

James W. Gilpatrick, National Marine Fisheries Service, Southwest Fisheries Science Center, P.O.

Box 271, La Jolla, CA 92038-0271

David K. Mattilla, Center for Coastal Studies, P.O. Box 826, Provincetown, MA 02657

James G. Mead, National Museum of Natural History, Smithsonian Institution, 10th and Constitution

Avenues, NW, Washington, D.C. 20560

Dale W. Rice, National Marine Mammal Laboratory, National Marine Fisheries Service, 7600 Sand

Point Way, NE, Seattle, WA 98115

Richard Sears, Mingan Island Cetacean Study, 285 Green Street, St. Lambert, Quebec, Canada J4P

IT3

Bernie R. Tershy, Division of Natural Sciences, University of California, Santa Cruz, Santa Cruz, CA

95064
29

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39

APPENDIX A

Blue Whale Recovery Plan Implementation Schedule and Cost Estimates

An implementation schedule is used to direct and monitor implementation and completion of recovery

tasks. Priorities in column 3 of the following implementation schedule are assigned as follows:

Priority 1 - An action that must be taken to prevent extinction or to identify those actions

necessary to prevent extinction.

Priority 2 - An action that must be taken to prevent a significant decline in population

numbers or habitat quality, or to prevent other significant negative impacts

short of extinction.

Priority 3 - All other actions necessary to provide for full recovery of the species.

This implementation schedule prioritizes individual tasks to emphasize their importance in the

recovery effort. The priority system and the criteria for each priority is based on an established

NMFS policy (55 CFR 24296). It should be noted that even the highest priority tasks within a plan

are not given a Priority 1 ranking unless they are actions necessary to prevent extinction. Therefore,

some plans will have no Priority 1 tasks. In general, Priority 1 tasks only apply to a species facing a

high magnitude of threat. This allows NMFS to set priorities for allocation of available resources

among different recovery plans.

Funding is estimated according to the number of years necessary to complete the task once

implementation has begun. The provision of cost estimates is not meant to imply that appropriate

levels of funding will necessarily be available for all blue whale recovery tasks. Also, identification

of cost estimates does not assign responsibility for providing support to NMFS or any other agency

or group. The costs associated with the various recovery tasks listed below are for those to be

implemented in U.S. waters only. Costs associated with promotion of international action have not

been estimated.
y p

PLAN TASK 

1.0 DETERMINE STOCK STRUCTURE 

1.1 Determine stock structure of blue whales using genetic 

analysis 

1.2 Assess daily and seasonal movements and inter-area exchange 

using telemetry 

2.0 ESTIMATE POPULATION SIZE AND MONITOR 

TRENDS IN ABUNDANCE 

2.1 Conduct surveys to estimate the size and monitor trends in 

abundance of populations 

2.2 Conduct annual independent photo-identification surveys 

2.3 Maintain existing blue whale photo-identification catalogs 

and sighting databases, and establish others as required 

2.4 Promote international efforts to estimate abundance and 

investigate stock structure of blue whales in non-U.S. waters 

3.0 IDENTIFY AND PROTECT HABITATS ESSENTIAL 

TO BLUE WHALE SURVIVAL AND RECOVERY 

3.1 Promote action to protect areas of importance in U.S. waters 

3.2 Promote action to protect known areas of importance in 

foreign waters 

Priority 

2 

2 

2 

2 

3 

2 

2 

3 

Task 

Duration 

5 years 

3 years 

5 years 

5 years 

ongoing 

ongoing 

ongoing 

ongoing 

Fiscal Year Costs 

FY 1 

8 

90 

260 

50 

60 

* 

* 

- 

FY 2 

8 

90 

e 

130 

50 

60 

FY 3 

3 

90 

50 

60 

I 

(thousands 

FY 4 

3 

50 

50 

of $) 

FY 5 

3 

260 

50 

50 
Blue Whale Recovery Plan Implementation Schedule 

PLAN TASK 

3.3 lmprove knowledge of blue whale feeding ecology 

3.4 lmprove knowledge of the characteristics of important blue 

whale habitat, and of how blue whales use such habitats 

4.0 REDUCE OR ELIMINATE HUMAN-CAUSED INJURY 

AND MORTALITY 

4.1 Identify areas where ship collisions with blue whales might 

occur, and in areas where concentrations of blue whales 

coincide with significant levels of maritime traffic or 

pollution 

4.2 Identify and implement methods to reduce ship collisions 

with blue whales 

4.3 Reduce or eliminate injury and mortality caused by fisheries 

and fishing gear 

4.4 Conduct studies of environmental pollution that may affect 

blue whale populations and their habitat 

5.0 MINIMIZE DETRIMENTAL EFFECTS OF DIRECTED 

VESSEL INTERACTIONS 

5.1 Investigate the potential effects of whale watching on blue 

whales 

5.2 Implement appropriate protective measures on any such 

activities which may be detrimental to blue whales 

Priority 

3 

3 

2 

2 

2 

2 

3 

3 

FY 1 

75 

100 

I 

I 

20 

Task 

Duration 

2 years 

1 year 

2 years 

ongoing 

ongoing 

2 years 

1 year 

ongoing 

(thousands 

FY 4 

of $) 

FY 2 FY5 

7 5 

30 

20 

FY 3 

30' 

20 
PLAN TASK 

* No direct costs associated with this task. 

6.0 MAXIMIZE EFFORTS TO ACQUIRE SCIENTIFIC 

INFORMATION FROM DEAD, STRANDED, AND 

ENTANGLED BLUE WHALES 

6.1 Improve and maintain the system for reporting dead or 

entangled blue whales 

6.2 Improve and maintain existing programs to collect data 

from dead blue whales 

7.0 COORDINATE STATE, FEDERAL, AND 

INTERNATIONAL EFFORTS TO IMPLEMENT 

RECOVERY ACTIONS 

7.1 Designate an implementation coordinator to facilitate 

Recovery Plan implementation 

7.2 Identify representatives of the scientific community, 

private, state, and federal agencies (and international 

agencies where applicable) to periodically review and 

update this Recovery Plan 

7.3 Support a continued international ban on commercial 

hunting and other directed lethal take, and encourage 

international efforts to detect and prevent illegal whaling 

8.0 ESTABLISH CRITERIA FOR DELISTTNG OR 

DO WNLISTING 

8.1 Establish criteria for delisting or downlisting blue whale 

populations 

Fiscal Year Costs 

Priority 

2 

2 

3 

3 

1 

2 

FY 1 

10 

* 

* 

Task 

Duration 

2 years 

2 years 

2 years 

ongoing 

2 years 

FY 2 

10 

FY 3 

15 

25 

(thousands 

FY 4 

2 5 

of $) 

FY 5 

15