(DRAFT) - Taxonomy
Species whale, bowhead
Species Id M120109
Date 26 AUG 96

TAXONOMY

NAME - whale, bowhead

OTHER COMMON NAMES - Greenland whale, Greenland right whale, Arctic right whale and Great polar whale

ELEMENT CODE -

CATEGORY - Marine Mammals

PHYLUM AND SUBPHYLUM - ,

CLASS AND SUBCLASS - ,

ORDER AND SUBORDER - ,

FAMILY AND SUBFAMILY - ,

GENUS AND SUBGENUS - Balaena,

SPECIES AND SSP - mysticetus,

SCIENTIFIC NAME - Balaena mysticetus

AUTHORITY - Linnaeus, 1758

TAXONOMY REFERENCES - 232

Taxonomy - 1 (DRAFT) - Status
Species whale, bowhead
Species Id M120109
Date 26 AUG 96

STATUS

Coded Status
Migrant
E: Federal Endangered
Subsistence
See Comments

REFERENCES FOR STATUS - 232

COMMENTS ON STATUS -
Federal: Bowhead whales are classified as endangered and are protected
under the Endangered Species Conservation Act of 1969 (PL 91-135) and Marine
Mammal Protection Act of 1972 (MMPA, PL 92-552). The NMFS (NOAA, U.S.
Department of Commerce) oversees bowhead whales for the federal government
*232*.

State: The State of Alaska has no managerial authority or responsibility
for bowhead whales *232*.

Bowhead whales are migratory. Bowhead whales apparently migrate in response
to changes in ice conditions, moving north as leads open and south before
freeze-up *232*.

The MMPA placed restrictions on the importation of marine mammal products
and allowed only Alaska Natives to take bowhead whales for subsistence and
for creating handicraft items and clothing for personal use and sale. The
MMPA and ESA allow for regulation of subsistence take if the stock is
declared depleted *232*.

Status - 1 (DRAFT) - Distribution
Species whale, bowhead
Species Id M120109
Date 26 AUG 96

DISTRIBUTION

Distribution - 1 HABITAT ASSOCIATIONS

HABITAT - MARINE

REFERENCES FOR HABITAT - 232

LAND USE -
Snow or Ice: All Classes
Water

REFERENCES FOR LAND USE - 232

NATIONAL WETLAND INVENTORY CODES

NWI NWICLS NWIMOD NWISPEC

Marine

REFERENCES FOR NWI - 232

COMMENTS ON HABITAT ASSOCIATIONS -
Ice: Bowhead whales apparently migrate in response to changes in ice
conditions, moving north as leads open and south before freeze-up. A study
noted that whales seemed to follow one another and surfaced in the same
places to breathe as they migrated north. If the ice beyond was closed,
the whales dove to search for open water, then returned to mill about and
keep the surface of the water from freezing. Although bowheads can break
through ice 22 cm thick, they are accasionally trapped in the ice. Sea ice
dampens waves from storms and makes escape from predators easier unless the
amount of open water or thin ice is restricted *232*.

Water quality: No specific information was found; however, bowheads occur
in areas of both clear and turbid water. Oil in the water may foul baleen
plates and reduce filtering efficiency *232*.

Water depth: Bowheads migrate over fairly deep water, but in summer the
"20-25 fathom whaling ground" (40-50 m water deep) was considered the most
productive. Although whales frequent both deeper and shallower water, many
are found in water about 50 m deep off the Tuktoyaktuk Peninsula in August
and September.

Water temperature: No information was found on the range of temperatures
selected or tolerated by bowhead whales *232*.

Substrate: No information was found, but bowheads feed primarily on
pelagic crustaceans, and substrate is unlikely to be of particular
importance *232*.

Acoustic properties: Although no unequivocal evidence was found on
acoustic habitat requirements, many observations of bowhead reactions to
varous types of noise have reported. The significance of the observed
behavior changes is unclear *232*.

ANIMAL/PLANT SPECIES ASSOCIATIONS -
Ringed seal (Phoca hispida)
Arctic cod (Boreogadus saida)
Killer whale (Orcinus orca)

REFERENCES FOR SPECIES ASSOCIATIONS - 232

Habitat Associations - 1 COMMENTS ON SPECIES ASSOCIATIONS -
Ringed seals (Phoca hispida) and arctic cod (Boreogadus saida) are the
bowhead's most significant trophic competitors in the Beaufort Sea. Broad
dietary overlap is probably less important to the euryphagus ringed seal,
which eats many species of fishes and crustaceans, than to the relatively
stenophagus bowhead, which depends more on swarms of small to medium sized
zooplankton *232*.

Bowheads suffer no predation other than hunting by humans and occasional
attacks by killer whales (Orcinus orca) and have few parasites or diseases
*232*.

Habitat Associations - 2 (DRAFT) - Food Habits
Species whale, bowhead
Species Id M120109
Date 26 AUG 96

FOOD HABITS

TROPHIC LEVEL -
CARNIVORE

REFERENCES FOR TROPHIC LEVEL - 232

LIFESTAGE FOOD FOOD PART
General Crustaceans Not Specified
General Molluscs Not Specified
General Osteichthyes Not Specified
General Invertebrate Cordates Not Specified
General Malacostraca Not Specified
Juvenile Invertebrate Cordates Not Specified
General Gadiformes Not Specified
General Gasterosteiformes Not Specified
General Perciformes Not Specified

REFERENCES FOR GENERAL FOOD - 232

REFERENCES FOR JUVENILE FOOD - 232

COMMENTS ON FOOD -
Beginning in 1976, stomach content samples were taken from 20 bowhead whales
harvested by Eskimo hunters at several locations along the northern and
western Alaska coasts. Samples were taken opportunistically and represent
different seasons and locations. Approximately 56 species were found,
including 50 species of crustaceans, 3 species of molluscs, and 3 species of
fishes. Although most of the prey species (23) were gammarid amphipods, the
most frequently encountered species, in order of occurrence, were the
euphausiid, Thysanoessa raschii; the copepod, Calanus hyperboreus; and the
hyperiid amphipod, Parathemisto libellula. Organisms smaller than about 2.5
mm are not effectively retained by bowhead baleen. The largest prey
regularly consumed are 30 mm and include euphausiids, mysids, and amphipods
*232*.

Spring: Most prey species in whale stomachs were invertebrates, and most of
those were primarily benthic organisms. Benthic organisms made up a small
proportion of the overall stomach contents, however, with the exception of
five small whales taken in spring in the Bering and Chukchi seas. The
incidence of feeding during the northward migration appears to be less in
the Chukchi Sea than in the Bering. Feeding whales may be predominantly
juveniles, and their prey are mostly benthic invertebrates *232*.

Summer: Many bowheads summer in the eastern Beaufort Sea, where they
presumably feed extensively; no direct information on summer food items is
available. Whales probably feed on locally abundant food items, especially
pelagic crustaceans, during this period *232*.

Autumn: The caloric value of copepods collected in September was 1.5 times
that of the same species collected in late July and early August.
Therefore, although the autumn feeding time is short, it may be of
Food Habits - 1 (DRAFT) - Food Habits
Species whale, bowhead
Species Id M120109
Date 26 AUG 96

relatively great importance *232*.

Barter Island: Samples collected from five whales harvested near Barter
Island between 20 September and 11 October 1979 indicate that in this
area bowhead whales were feeding primarily on pelagic copepods,
euphausiids, and mysids *232*.

Barrow: Stomach samples taken from two bowhead whlaes harvested near
Point Barrow in September 1976 were almost entirely (90% of the volume)
euphausiids, with some gammarid and hyperiid amphipods. The principal
euphausiid species, (Thysanoessa raschii) was the same found in whales
taken at Kaktovik and is widely distributed in arctic waters, primarily
in the nearshore neritic zone *232*.

Winter: No data on winter foods are available *232*.

Types of Feeding Areas Used:

Summer: The eastern Beaufort Sea and Amundsen Gulf may be important feeding
areas for bowhead whales during early summer. Later, from mid July to mid
September, they move to the MacKenzie River delta region, usually staying in
water 50 m or shallower. Although no stomach samples are available from
bowheads in summer, presumed feeding behavior has been observed in these
areas.

Autumn: Bowheads feed regularly in at least two main areas in the Alaskan
Beaufort Sea in September and October: 1) east of Barter Island to at least
the United States-Canada demarcation line (141 deg. W) and 2) east of Barrow
to Pitt Point. Feeding behavior has been observed in these areas, and
stomachs of whales taken at Barrow and Kaktovik in autumn contain food
*232*.

Factors Limiting Availability of Food: Sea ice limits the availability of
food to bowhead whales by blocking light, thus limiting productivity, and by
limiting the areas to which the whales have access. Ringed seals (Phoca
hispida) and arctic cod (Boreogadus saida) are the bowhead's most
significant trophic competitors in the Beaufort Sea. Broad dietary overlap
is probably less important to the euryphagus ringed seal, which eats many
species of fishes and crustaceans, than to the relatively stenophagus
bowhead, which depends more on swarms of small to medium sized zooplankton
*232*..

general area while feeding. Skim-feeding whales have been observed
swimming in echelon formation, staggered to the side and behind the whale at
the apex, with each whale separated by 10-50 m. At other times, bowheads
have been noted swimming abreast and parallel to one another. The largest
skim-feeding formation observed contained five individuals. Although
bowheads are basically "skimmers," they do forage near the bottom, at least
in shallow areas. Bottom-feeding whales are widely separated when they
surface, usually no closer than 300 m apart. While water-column feeding,
bowheads swim slowly at the surface, taking a series of breaths before
diving obliquely to the bottom and back to the surface. Water-column
feeding whales remain submerged longer and spend somewhat more time at the
surface between dives than do whales engaged in other activities. Although
no direct observations were found on the percentage of time spent feeding, a
study calculated that an average-sized whale would need to feed for 1,744-
2,528 of the 3.120 hours available in a typical feeding season. Assuming a
six-month feeding season, studies estimated that an average bowhead would
need to consume 1.1-4.0% of its total body weight per day *232*.

COMMENTS ON JUVENILE FOOD -
Juveniles feed mostly on benthic invertebrates *232*.

Food Habits - 3 (DRAFT) - Environment Associations
Species whale, bowhead
Species Id M120109
Date 26 AUG 96

ENVIRONMENTAL ASSOCIATIONS

G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae

LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G Turbidity: Clear water
G Turbidity: Murky water [High turbidity]
G Turbidity: Specified in Comments
G Water Depth Preference: Specified in Comments
G Water Depth Preference: 100-200 ft.
FA Water Depth Preference: Less than 1 ft.
FA Water Depth Preference: 1-5 ft.
FA Water Depth Preference: 5-10 ft.
FA Water Depth Preference: 10-25 ft.
FA Water Depth Preference: 25-50 ft.
FA Water Depth Preference: 50-100 ft.
FA Water Depth Preference: 100-200 ft.
FA Water Depth Preference: Specified in Comments
G Aquatic Habitat Zonation: Open water [pelagic zone]
G Aquatic Habitat Zonation: Specified in Comments
BA Aquatic Habitat Zonation: Open water [pelagic zone]
BA Aquatic Habitat Zonation: Specified in Comments
FA Aquatic Habitat Zonation: Specified in Comments

REFERENCES FOR ENVIRONMENTAL ASSOC_ - 232

REFERENCES FOR FEEDING ADULT ENVIRONMENTAL ASSOC_ - 232

REFERENCES FOR BREEDING ADULT ENVIRONMENTAL ASSOC_ - 232

COMMENTS ON ENVIRONMENTAL ASSOCIATIONS -
Water quality: No specific information was found; however, bowheads occur
in areas of both clear and turbid water. Oil in the water may foul baleen
plates and reduce filtering efficiency *232*.

Water temperature: No information was found on the range of temperatures
selected or tolerated by bowhead whales *232*.

Environment Associations - 1 (DRAFT) - Environment Associations
Species whale, bowhead
Species Id M120109
Date 26 AUG 96

Substrate: No information was found, but bowheads feed primarily on
pelagic crustaceans, and substrate is unlikely to be of particular
importance *232*.

Ice: Bowhead whales apparently migrate in response to changes in ice
conditions, moving north as leads open and south before freeze-up. A study
noted that whales seemed to follow one another and surfaced in the same
places to breathe as they migrated north. If the ice beyond was closed,
the whales dove to search for open water, then returned to mill about and
keep the surface of the water from freezing. Although bowheads can break
through ice 22 cm thick, they are accasionally trapped in the ice. Sea ice
dampens waves from storms and makes escape from predators easier unless the
amount of open water or thin ice is restricted *232*.

COMMENTS ON FEEDING ADULT ENVIRONTAL ASSOC_ -
The eastern Beaufort Sea and Amundsen Gulf may be important feeding areas
for bowhead whales during early summer. Later, from mid July to mid
September, they move to the MacKenzie River delta region, usually staying
in water 50 m or shallower *232*.

Three major types of feeding behavior occur in bowhead whales: skimming,
water column feeding, and bottom feeding. Skim-feeding whales swim slowly
at the surface with the rostrum at or above the water surface and parallel
to it and the lower jaw dropped. Although bowheads are basically
"skimmers," they do forage near the bottom, at least in shallow areas.
While water-column feeding, bowheads swim slowly at the surface, taking a
series of breaths before diving obliquely to the bottom and back to the
surface *232*.

COMMENTS ON BREEDING ADULT ENVIRONMENTAL ASSOC_ -
Apparent reproductive activity was observed in an open-water lead in the
pack ice *232*.

Environment Associations - 2 (DRAFT) - Life History
Species whale, bowhead
Species Id M120109
Date 26 AUG 96

LIFE HISTORY

Reproductive Habitat: Mating probably takes place during spring migration.
Mating is the principal bowhead activity prior to ice breakup in the Bering
Strait. Apparent reproductive activity was observed in an open-water lead
in the pack ice about 32 km east of Point Barrow. Pack ice appeared to be
solid east of the immediate area, suggesting that migration was delayed
*232*.

Reproductive Seasonality: The mating season for bowheads is not well known.
Breeding occurs during the spring migration and in early summer. Presumed
breeding behavior has been observed near Point Barrow and Point Hope in
early May. Breeding activity has also been observed from March through May.
Based on sightings of young of the year, fetal lengths, and harvest of
lactating females, calving probably occurs from March to August, with a peak
in May *232*.

Reproductive Behavior: Reproductive activity has been observed only rarely
in bowhead whales because of the difficulty in observing these animals in
their natural environment. A study observed a pod of six bowheads in a lead
in the pack ice east of Point Barrow engaged in what they thought to be
reproductive activity: aggregation of several whales, flipper-touching or
twisting, one whale clasping another with its flippers, and attempted
copulation. Spring ice conditions (i.e., denser pack ice with few
open-water leads) may cause the populaton to be more aggregated than at
other times of year, increasing the number of social interactions that
eventually lead to mating. The rate of social encounters decreases steadily
from spring to autumn *232*.

Age at Sexual Maturity: Most bowhead whales harvested in recent years are
immature, making it difficult to obtain data about reproduction and sexual
maturity. All data on sexual maturity are given as a function of body
length, but there is no adequate method of aging bowheads or of correlation
body length and age *232*.

Females: A study found that all sexually mature females examined were
13-14 m in length. Another study found that 91% of all females observed
to accompanied by a calf were longer than 13.5 m *232*.

Males: A study stated that bowheads are sexually mature at 14-18 m
*232*.

Frequency of Breeding: A study concluded from indirect evidence that
bowheads calve every second year or less often. Calving intervals of two to
three years and three to five years have also been reported *232*.

Fecundity: Female bowheads normally produce only one calf; a female with
two calves is rarely observed. A study reported that 4 of 13 sexually
mature females examined wre pregnant or recently postpartum and suggested a
pregnancy rate of 0.31 *232*.

Gestation Period: Based on lengths of fetuses, neonates, and calves, as
well as assumed calving and mating periods, the gestation period is
Life History - 1 (DRAFT) - Life History
Species whale, bowhead
Species Id M120109
Date 26 AUG 96

estimated to be 13 months. Gestation periods of 9 to 13 months have been
suggested for bowheads *232*.

Natural Factors Influencing Populations: Bowheads suffer no predation other
than hunting by humans and occasional attacks by killer whales (Orcinus
orca) and have few parasites or diseases. Bowheads may occasionally be
caught in ice and die. Mortality rates are not known *232*.

Human-related Factors Influencing Populations: A summary of possible
impacts form human-related activities includes: barriers to movement,
physical and behavioral (e.g., structures); chronic debilitation due to
ingestion or contact with petroleum or petroleum products; chronic
debilitation due to ingestion or contact with chemicals; collision with
vehicles or structures; harassment, passive; harvest, change in level;
interference with intraspecies communication; interference with reproductive
behavior; interruption of ongoing behavior: alarm, flight; and prey base,
alteration of *232*.

Ringed seals (Phoca hispida) and arctic cod (Boreogadus saida) are the
bowhead's most significant trophic competitors in the Beaufort Sea. Broad
dietary overlap is probably less important to the euryphagus ringed seal,
which eats many species of fishes and crustaceans, than to the relatively
stenophagus bowhead, which depends more on swarms of small to medium sized
zooplankton *232*.

Feeding Behavior: Three major types of feeding behavior occur in bowhead
whales: skimming, water column feeding, and bottom feeding. Another
behavior, bubbleblowing, has been associated with feeding, although its
function is uncertain. The relative frequency of feeding behavior types
changed from year to year; the distribution of prey probably dictates
bowhead movements and behaviors in the Beaufort Sea in summer. Skim-feeding
whales swim slowly at the surface with the rostrum at or above the water
surface and parallel to it and the lower jaw dropped. Whales occasionally
skim-feed alone but more commonly are observed in groups of 2 to 10
individuals. In these cases, each group covers an area of about 10 km2.
The groups are separated from each other by 10-20 km and remain in the same
general area while feeding. Skim-feeding whales have been observed
swimming in echelon formation, staggered to the side and behind the whale at
the apex, with each whale separated by 10-50 m. At other times, bowheads
have been noted swimming abreast and parallel to one another. The largest
skim-feeding formation observed contained five individuals. Although
bowheads are basically "skimmers," they do forage near the bottom, at least
in shallow areas. Bottom-feeding whales are widely separated when they
surface, usually no closer than 300 m apart. While water-column feeding,
bowheads swim slowly at the surface, taking a series of breaths before
diving obliquely to the bottom and back to the surface. Water-column
feeding whales remain submerged longer and spend somewhat more time at the
surface between dives than do whales engaged in other activities. Although
no direct observations were found on the percentage of time spent feeding, a
study calculated that an average-sized whale would need to feed for 1,744-
2,528 of the 3.120 hours available in a typical feeding season. Assuming a
six-month feeding season, studies estimated that an average bowhead would
need to consume 1.1-4.0% of its total body weight per day *232*.
Life History - 2 (DRAFT) - Life History
Species whale, bowhead
Species Id M120109
Date 26 AUG 96

LIFE HISTORY CODES -
Foraging Strategy: Filtering
Breeding/Spawning Season: March
Breeding Spawning Season: April
Breeding/Spawning Season: May
Breeding/Spawning Season: June
Breeding/Spawning Season: July
Breeding/Spawning Season: August
Average Number of Offspring/Reproductive Effort: 1
Average Number of Offspring/Reproductive Effort: 2
Gestation/Incubation Period: Greater than 8 months
Parental Care of Young: Female

REFERENCES FOR LIFE HISTORY- 232

Life History - 3 (DRAFT) - Management Practices
Species whale, bowhead
Species Id M120109
Date 26 AUG 96

MANAGEMENT PRACTICES

RESULT MANAGEMENT PRACTICE

Adverse Migration barriers
Beneficial Regulating commercial harvest levels
Beneficial Controlling pollution [thermal, chemical, physical]
Existing Regulating harvest of species being described
Beneficial Prohibiting harvest of species being described
Beneficial Restricting/regulating human disturbance of populations
Beneficial Other management practices [specified in comments]
Adverse Other management practices [specified in comments]
Existing Other management practices [specified in comments]

REFERENCES FOR BENEFICIAL MANAGEMENT PRACTICES - 232

REFERENCES FOR ADVERSE MANAGEMENT PRACTICES - 232

REFERENCES FOR EXISTING MANAGEMENT PRACTICES - 232

COMMENTS ON MANAGEMENT PRACTICES -
Human-related Factors Influencing Populations: A summary of possible
impacts form human-related activities includes: barriers to movement,
physical and behavioral (e.g., structures); chronic debilitation due to
ingestion or contact with petroleum or petroleum products; chronic
debilitation due to ingestion or contact with chemicals; collision with
vehicles or structures; harassment, passive; harvest, change in level;
interference with intraspecies communication; interference with reproductive
behavior; interruption of ongoing behavior: alarm, flight; and prey base,
alteration of *232*.

POPULATION MANAGEMENT HISTORY

Summary of Harvest: During the commercial whaling period (1848-1914), over
18,000 bowheads were killed, and at least 16,000 were taken by Yankee
whalers. The western arctic stock was depleted quickly; two-thirds of the
total Yankee harvest was taken within the first two decades of whaling. By
1914, commercial take of bowheads ended because of the decline of the
bowhead population and the collapse of the whalebone and whale-oil markets.
Between 1910 and 1969, the annual catch dropped sharply; records indicate
that 704 bowheads were taken, for an average take of 11.7 whales per year.
The harvest jumped: from 1970 through 1977, a total of 259 whales were
landed, with an average of 32.4 per year. Beginning in 1978, the annual
harvest quota has been set by the International Whaling Commission (IWC) and
has ranged from 14 to 18 whales landed *232*.

Period of State Authority: The State of Alaska has never had managerial
authority or responsibility for bowhead whales *232*.

Period of Federal Authority and International Agreements: Bowhead whales
have been completely protected from commercial whaling since 1946 by the
International Convention for the Regulation of Whaling, the same act that
Management Practices - 1 (DRAFT) - Management Practices
Species whale, bowhead
Species Id M120109
Date 26 AUG 96

set up the IWC. In 1969, the Endangered species conservation Act (ESA, PL
91-135) placed the bowhead under further protection and ended all
nonsubsistence whaling by the United States. The MMPA placed restrictions on
the importation of marine mammal products and allowed only Alaska Natives to
take bowhead whales for subsistence and for creating handicraft items and
clothing for personal use and sale. The MMPA and ESA allow for regulaton of
subsistence take if the stock is declared depleted. Rather than go through
the lengthy hearing process to set up regulations under those laws, the
United States proposed to the IWC a yearly quota system of whales struck and
whales landed. The first quotas took effect in 1978; enforcement was through
the Whaling Convention Act. At the same time (1978), the Alaska Eskimo
Whaling Commission (AEWC) was organized *232*.

Current Population Management: In 1981, NMFS entered into a two-year
cooperative agreement with the AEWC for cooperative bowhead whale
management. An amendment to the cooperative agreement, passed in July 1982,
extends the agreement through 1987. The IWC sets overall quotas, usually
for a block of several years. NMFS and AEWC then determine, through annual
negotiations, the number of whales that may be struck in each year; if they
are unable to agree in a particular year, the quota from the previous year
applies *232*.

Management Objectives: The AEWC Management Plan provides for the following:
enforcement powers held by the AEWC; definitions of permissible whaling
equipment and methods; registration of each Eskimo whaling captain in
Alaska; requirement of reporting all whaling occurences, strikes, landings,
or accidents; establishing the level of harvest in conjunction with NMFS and
setting the level of fines for infractions; supporting bowhead and weapons
research *232*.

Management Considerations: Research is continuing on more efficient and
humane methods of whale harvest and reducing the number of whales struck and
lost *232*.

Management Practices - 2 (DRAFT) - References
Species whale, bowhead
Species Id M120109
Date 26 AUG 96

References

232 * State of Alaska Department of Fish, and Game. 1986. Alaska
Habitat Management Guide: Life Histories and Habitat
Requirements of Fish and Wildlife. (ed.). Alaska Department of
Fish and Game Juneau, Alaska:763.

References - 1