STATUS OF MARINE MAMMALS
IN THE EASTERN NORTH PACIFIC OCEAN
By
Karl W. Kenyon
For
Department of the Inte:dor
102 Statement Task Force B of the I'c.o 00 ('/)I Task Force on Alaskan Oil Development ('I) 0gr. LO L.· LO • 29Julyl971 I'('I) ' ('I)
I .
. i
Bureau of Sport Fisheries and Wildlife Marine Mammal Substation Naval Support Activity, Bldg. 192 Seattle, Washington 98115
Library
ARLIS. S9503 Alaska Resources Library & Information Services ·~ , Anchorage, Alaska ·. t CONTENTS
Introduction ...... * • • • • • • • • • • • • 1
Sea Otter ...... '~ ...... 1
Northern Fur Seal ...... ; ...... 6
Guadalupe Fur Seal 8
,.. Steller Sea Lion ~ •••••• ·h· 10
California..· Sea Lion • • • • • • • • • • d • • • • • • • • • • • • 13
- Harbor Seal ...... ~ ...... 14
Northern Elephant Seal •••••.• 16
The large Whales {class Cetacea) 17
( Whaling in the North Pacific Ocean (Rice 1971a) 17
Status of Species (from Rice, 1971 b)
Blue whale 10 Fin whale • 15 Sei whale •• 17 Bryde 1 s whale • • • • • 20 Minke whale . • • • . • • • • • • • • 21 Humpback whale. • • • • . • • • • . 2'2 Gray whale . . • . • . . • • • • • . . 24 Black Right whale • • 25 Bowhead whale. • • • • . • 26 Sperm whale .••• · ••• 28 Giant bottlenose whale 30
Gray Whale .•...• ...... 18 The Toothed Whales ...... 21
Porpoises and Dolphins 21
References Cited . 24 ·r ...... '-- STATUS OF MARINE MAMMALS IN THE EASTERN NORTH PACIFIC OCEAN
B-y: Kad W. Kenyon
Introduction
The purpose of this report is to summarize the best
information available, as a resource ~escription~ of marine ·
mammals in certain areas of the eastern North Pa~ific Ocean.
These areas include Prince William Sound and waters contiguous
- to shipping lanes along the coast of Southeastern Alaska and .. )
British Columbia, the inland pas sages of the Strait of Juan de
Fuca and Puget Sound and southward to Mexico. The status of
tnar~ne mammals of the Beaufort, Chukchi, and Bering Seas
is discussed separately by Ja.mes W. Brooks.
Sea Otter (Enhydra. lutris, order Carnivora) --- During the 19th centm:y the sea otter was brought to the verge of extinction throughout its range by unregulated exploitation.
·l ·.. By 1911 when survivors were afforded proteGtion under an inter- '' :! national treaty (U.S. Congress, House, 1912) a remnant colony
remained in Prince William Sound. Populations south of Kayak
Island, along the coasts of Southeastern Alaska, British Columbia,
Washington, and Oregon were by ~hen, or soon became, extirpated.
~. ~. (
~ ;_' '!/ ~,·~--;rr~·---;-:·-·" -· ··-' ··~~;...-'''--~-.,.--... ,-·~· - • ___,__. ~ c· ..
2
Protected for 60 years from exploitation, recent surveys
indicate that the Prince William Sound otter population now (1971)
numbers about 4, 000 aninutls (J. Vania and K. Schneider, pers.
comm. ). These animals are found along open coasts and protected
waters of Prince-William Sound and adjacent mainland· where
water depths (to about 180 feet) permit feeding.
Because the sea otter failed to move southward' naturally, - the State of Alaska, in 1965, undertook a program of restocking . vacant parts of the sea otter's former range. A total of 412 otters .
were translocated to Southeastern Alaska (table· 1) and, by July
1971 an additional 194 otters were liberated on the coasts -of
B·ritish Columbia, Washington, and Oregon (J. Vania and K.
Schneider, pers. comm. 1971) .
.....--Surveys in the areas of translocation reveal that many
(exact number unknown) otters survived in the new locations anC.
that young have been born in at least some locations.
A small colony that survived after 1911 on the cent:ral
California coast now numbers over 1, 000 animals. Most of this
'( '.• population is spread along about 110 miles of coast from Monterey . ·~ i ; '< Bay to Morro Bay (Peterson and Odemar, 1969). ••; ...
3 ...... Water pl)llution of any kind which, like oil, penetrates
the sea otters' soft insulating fur and causes the skin to become
wet, quickly causes death through exposure. The fur of the sea
otter is similar in function to the feathers of marine birds in
that it is dry at the base and protects the sk~ with an insulating
blanket of air from contact with water. The sea ot)er. lacks
blubber as an insulating agent. (Kenyon, 1969). -
. -~ I
.,·
-c
.·.' \ _-.:;:L ______. " . ,• -.:-;-:r-·---:-- ---.-,-·· .... ·· · -·:-':':"~r ~;-::--~--~~~:~~~ -:-;....--·~-T'~"-:"'":"1\-'t::~~..-;.r:--:;o,•,-~~ ...... ,.,.....:o-..-:;o!'l'...,,~~r ... ~~q:-T·"J·~...,-:-:--~..,...... , .... -:-..... f~---:• ... ~--~- .. - "'~ · ·· 4 Table 1. --Restocking Program
Year Location of Number of otters introduction translocated Total --·
Alaska 1965 Kahz Bay* 23 23
1966 Kahz Bay and Yakutat 30 . 30
1968 Kahz Bay 93 Yakobi Bay 30 Barrier Island 55- Biorka Island 48· Hecata Island 51 Cape Spencer ._( 25 , [30J _- .·.· - 1969 Kahz Bay 58 58 Total ]1_?'=·~
British Columbia 1969 . Near Buns by Island, . Vancouver Island 29 1970 Checleset Bay, Vancouver I. 14 . Total 43 -
Washington 1969 Pt. Grenville 29 _..-- 1970 LaPush 30 30 Total 59 .. Oregori 1970 Port Orford 29 29 139 __ _ 1971 S. of Coos Bay ·c-- Port Orford 24 63 Total. j _92-
-.. Total outside Alaska . 194
Grand total
* Chichagof Island. ·* * These otters were observed, when liberated, to be in poor c.ondition. Acbout half of those liberated off Washington were later found dead, howe~er, survivors were observed subsequently. '~ ! i' .. ,, ·- ···-·······"---.--,·.--;..,:.~~--...,~-:-,~----"·":: ____ ~----· .. ··- ·····~ -~--~·-...,--~,..,._....,.....,_~-·- ·-~-' ..., .... ~! ~so~- 1500 1300 Ma.p 1
; - Sea Otter transplant locations.
l ------··-· +------+-·--+1---+--soc
' I. ~ 1 p' A c I F I I ~-- I '! ~ 0 c E A -,- ;·1 .
..-. \~,;_-·.. ~-'·: !...... --+-----+-----t----+------1---~--+----+----+----J\., ···':: '~i . ., . '"'-',\1
t I '" . ~:('< "'\ .. -:-::·... ~-~---,_----~---,_----~----+-----~----~---30' r-"'-· .I ' ! ... I ., I 6
Northern Fur Seal (Callorhinu~ ursinus, Order Pinnipedia)
A her C. of approximately 1, 4 million fur seals (Baker,
Wilke, and Baltzo, 1970) assemble and breed on the Pribilof
Islands in summer. In fall, winter, and spring the seals mig=ate
to favored· feeding·areas in the North Pacific Ocean to as far south
as the Mexican border (Townsend, 1899; Huey, 1942; Kenyon anci . . ·, ... , Wilke, 1953; Wilke and Kenyon, 1954) .. A small b~e'eding colony · · ·' was disc'?yered on San· Miguel Island, California in 1968 (Peterson, ,
LeBoeuf, and DeLong, 1968). This colony in 1971 numbers between
.zoo and 300 breeding animals (A. M. Johnson, pers. comm. ).
Although most of the seals taken at sea for scientific stuC.ies
in recent years ranged from 10 to 300 miles· offshore along the • ·. \ Pacific Coast (North Pacific Fur Seal Commission, 1965; 1969;
1971; H. Kajimura, pers. comm. ), many enter straits seasonally
along--- the sout::l.eastern Alaska. coast to feed on herring (Kenyon,
1955). Pelagic sealers of the 19th century took thousands of seals . -·-
on the Fairweather g·rounds high in the Gulf of Alaska and only a ... ,
few miles off Prince William Sound (Townsend, 1899) (Map 2).
During the northward migration, particularly in March, Apri~ and
May, thousands have been observed in the Gulf of Ala.ska in recent
years (Fiscus and Kajimura, 1970).· Apparently, however, or.J.y
stray individuals actually enter Prince William Sound. ·(_.
...... ,.,_ ...... ______,.,.,,,., ___ ,_,___ ,_, ___ , ______, ______·' 7
From an economic point of view the northern fur seal is
the most important pinniped jn the Pacific Ocean. The gross
income from sale of skins and by-products in fiscal 1970 was
$3,249.325. After processing expenses (Fouke Fur Co.) the
net was $2, 713, 436. By-product sales amounted to $3, 000.
The numbers of American citizens who. depend for their entire , , . annual income on the fur seal harvest are: Civil Service, Pribilof ..· - natives, 42, and nonnatives, 34; and Fouke Fur employees, about 200. In addition, seasonal worker·s during the fur seal
harvest operations include: 136 Aleuts, 35 other Alaskans, anC.
32 non-Alaskans. Thus, the total number of people employed ( full or part-time by the fur seal industry is about 479 individuals.
The effect of petroleun1 products in the marine environment
on fu,~--seals can only be inferred. Occasionally during the past
20 ·years fur seals having oil L'l their pelage and found dead on
Washington beaches have been brought to us at the Marine Mammal
Biological Laboratory. We could not determine the exact cause of
death. There is, however, no record of a fur seal on the Pribilof
Islands, where between 40, 000 and 50, 000 are taken annually,
having oil or tar in i~s pelage. This could mean that seals having i : i oil in their fur at sea do not survive to return to the Pribilofs. ,,I ·.
8
The general northward migration route of seals from 'i :. ; southern California to Unimak Pass and the areas of general
seasonal concentration are shown on map 1.
-· ·- -· -·-···-·-··---· ------·· ···------~------·-·------·-· ·------
Guadalupe Fur 'Seal {Arctocephalus philippii.- townsendi ~
·The breeding population of this seal is confined to Guadalupe
i . Island, Mexico. In 1965 the population then numbe'red about 6GO , __ ; ,_:,'! i animals {Rice, Kenyon and Lluch, 1965} and now numbers perhaps
• .,• I - 1, 000 animals. It is rarely seen north of the Mexican border on
the California Cham1el Islands.
------···------.. ( .
------
I .
. i ':. l_:·t /-· •.' 9 '~60~·. 150° 140° 1300 120° '''':f-.___:__...... -...._.,.~---_,..,.,..-..--p-.-~....,.- :~.. :--. 'l':f",_, ---,....--~----,....---.--- 6 5° '\i Map . · I ;\ -·-···-····- -- NORTHERN FUR SEAL F1 Where seals are t=l most abundant ··~- ...~ .! Monthly areas of concentration during . migration (from TownsendJ j .. < 1899) ·;~ f~----~----~----r---60° j : \. -1 ( fA··.,. ·I j j
. -- _I
,- . -
I I J I· .I -:-I .. ··-- -· . p A c F. I I~ I I I _j. -r - :·-···---. 0 v E A N February. i - I -40'
., ;,; I I-
-:...;\ I ' I - . I 10
Steller Sea Lion (Eumetopias jubatus, Order Pinnipedia)
The numbers of this sea lion were considerably reduced
by the end of the 19th century. Native people of Alaska used
their skins as boat coverings, for boots and other products, and
ate the meat {Kenyon, 1962). In addition, their hides and oil were·
taken for commercial purposes by J;he_ white man. During the 20th
century the need for sea lion pr'oducts was reduced'because other
more economically attractive materials were available .. Be-cause
- man-ca.used mortality was reduced, sea lion populations today
appear, in most areas, to be at or near the maximum attainable
within t.he e~olo~icallimits of this species r habitat. Observed
populations appear to have been stable for many yea-rs. '"'1\ttrition
.. ··.,i to the population has been primarily to control sea lions where
they interfere with fisheries.
----- .Beginning in 1964, however, an annual harvest of Steller
sea lion pup skins has been taken from rookeries, principally .),· .. ·.
in the Kodiak-Cook Inlet area. The total recorded take, 1964
through 1970, was 27,817 {average 3, 974 per year) (J. S. Vania1
pers. comm. ). Biologists of the Alaska Department of Game
regulate the harvest •
.. ,· ·!' ,,
( 11 ......
. Breeding colonies and hauling gTounds occupy isolated
... rocks and islets in Prince William Sound and along the Pacific
Coast to the Channel Islands of southern California. Population
estimates are shown in table II.
.·.I , Steller sea lions are not known to undertake regular seasonal
migrations as does the northern fur seal. N:umbers~ of animals do,
however, move northward in the Bering Sea as the ice retreats
- in summer (Kenyon and Rice, 1961). Although they generally
frequent waters within about 15 miles from shore (Fiscus and
Baines, 1966), they have been observed 70 to 85 miles from land
(~enyon and Rice, 1961).
Economically the Steller sea lion is considered by most
fishermen to be of negative value. The value of pup skins to th=
hunter,------however, has been about $10. Thus, the total haryest
since 1964 may have been valued at approximately $270, 000.
Biologists of the Alaska Department of Game estirn.ate that on a
continuing basis the economic value of the sea lion resource
should be in the range of $2 5, 000 to $40, 000 per year.
, ' ·I i Table II. Population Estimates of th-~ _Steller sea lion
Area Number* Authority
S. Calif. (Channel Islands) 100 Bartholomew (1967)
_N. Calif. {N. of Pt. Conception) 5, 2~0 Carlisle and Aplin ( 1971)
Oregon 1,000 Pearson and Verts ( 1970)
Washington 500 Kenyon and Scheffer {1959) , . British Colurn bia 12, 000 Pike and Maxwell (1958) _
Southeastern Alaska to - the· Shumagin Islands {incl. Prince William Sound** 76, 000 Mathisen ( 195 9)
Total .94,800
\ * Estimates are rounded to the nearest hundred from the
original reference.
** ~iologists of the Alaska Department of Fish and Game
estimate the Prince William Sound population at ~bout 7, 5 00 to
10, 000 animals.
I I . I !
,• .. 13 ( California Sea Lion (Zalophus californianus)
This sea lion is most abundant along the coast and among
the islands of southern California and Baja California, Mexico.
Adult and subadult males regularly c>ccur as far north as the
Sea Lion Caves, Oregon and occasionally off the Washington coast
(Kenyon and Scheffer, 1962). They have also been recorded with
some frequency at Vancouver Island, British ColurtJ.bia in past
years (Cowan and Guiguet, 1956}, and more recently a srriall
- number (24 were counted) are said to be regular winter visitors
there (Hancock, 1970).
A number of censuses have b•:.len made where this sea lion
is abundant. Odell ( 1971) says there were at least 34, 38? of then:. • on the California Channel Islands in June of 1964. Bartholomew +
(1967) says that during the past 40 Y€'ars censuses indicate an
exponential----- increase there. Our census on islands off the Pacific
·;_: coast of. Baja California indicated there were about 16, 000 California :re ~._ • I i. _sea lions there in January and February 19.6.$ (Rice, Kenyon, and _n, :·
L1uch, 19&5). ·The total population is probably in: the order of
magnitude of 35, 000 to 50, 000 and may now approach the maximum
' ... ~- size that the habitat will support.
; I ll . • .i . f.l
.. '\ .j,i .I ., r~: l •, 14
· Harbor Seal {Phoc~ vitulina, Order Pinnipedia)
The harbor seal is the most ubiquitous inshore pinniped
species in the North Pacific: Ocean and adjacent waters. It rar..ges
around the Pacific rim front Baja Ca~ifornia to the Chukchi Sea.
.. .. ··· and westward. It breefls in small colonies, usually on islands or
.., . sand bars throughout its range. Because the population is scattered ~ in bays and straits and alond coasts, it is difficult to census. There - are indications that where Luge and growing human populations are.. invading its habitat with buildings, boats {there are 186, 000
·.;.·; - pleasure boats in Puget So.t;md),. guns, and synthetic environmental
. poisons its numbers are dw:ndling. For example, it was estimated E. . that during the 19401 s there were "certainly no fewer tha~ 5, 000"
harbor seals in Washington Btate {Scheffer and Slipp, 1944). T:>day,
a m~ber of observations in:iicate that the Washington population
..... probably numbers no more than 2, 000 animals {Newby, 1971) .
Other population estimates are shown in Table III.
Because the economic value of the harbor seal in Alaska is
_important, the harvest is being managed by the Department of Game.
In 1970, the take of harbor seal pups was 7, 009 animals {J. Va:1ia,
pers. comm. ). The value of a skin to the hunter is about $7. SC> ' . ;.. (Jonas Bros. of Seattle, Inc., pers. comm. ). Thus, the income
from this resource in Alaska amounted to about$ 52, 500 in 197). iS;;)l • . ' . 15 l~~...... '~- . '(;, ·- Table Ill. Estimates of harbor seal populations Area Estimates
Prince William Sound and coast south to Yakutat 15, 000-20, 000 {J. Vania, pers. cornm.) *
Southeastern Alaska and coast north to Yakutat 20, 000-25, 000 (J. Vania, pers. comm. )*
British Columbia 35, 000 (Bigg, · 1969)
Washington Z, 000 {Newby, '1971)
Oregon }500 {Pearson and Verts, 1970)
California islands 500 {Bartholomew, 1967)
California coast and bayf) 1-500 {general observation, KWK)
Baja California (~. Total 74,000-84,000 *No reliable cen:"Juses have been made. These figures are educated------guesses based on the ·known kills of harbor seals in these areas during many years, ·c '·I i :_: ,. ·~ l ~ : 16 Northern Elephant Seal (Mirormga angustirostris) The elephant seal breeds on islands off the Pacific coast of northern Baja California, Mexico, the Channel Islands, and Ano Nuevo Island of California. The greatest breeding populatior: is on the Mexican islands, where a census in 1965 revealed an estimated population of about 17, 000 (Rice, Kenyon,, and Lluch., J965). In the California islands 2, 158 animals were counted in ..· February 1964 (Odell; 1971). The smaller and northernmost Ano Nuevo colony is newly established. After reviewing all available censuses, Peterson and Le Boeu£ (1·969) conclude that the total population of this se·al is about 30,_ 000 animals. This . ' pcpulation is derived from a remnant of not more than 100 animals that survived at the turn of the pre sent century. This genetically ta.."Tie. seal was subjected to unregulated exploitation, primarily for its oil, during the 19th century. The elephant seal ranges at sea far north of its breeding range. It occurs in Puget Sormd (Scheffer and Kenyon, ~- 17 63 Craddock, 1969), of£ Vancouver Island (Cowan and Guiguet, 1965} .• and one was observed off Cape Ommaney, Prince of Wales Island, Alaska, in May 196? (C. H. Fiscus, pers. comm. ). The elephant seal is rmexploited today except that a few are captured for zoos and marine aquariums. ·, l I ·?,, The Large Whales (Class Cetacea) Whaling in the North Pacific Ocean (Rice, 197la): "During the 1970 season, the nwnber of floating factories operating in the North Pacific dropped to 5, as the Soviet ship Slava ' did not operate .. Seven shore stations and a total of 72 catcher. boats .... ! I·: •· 1 .I operated in the North Pacific. .. i "The· total cat~h was 20, 469 whales. The catch of 14, 815 sperm whales. was ..ahnost the same as i:n 1969. The remainder of the cat::h included 1, 012 fin whales, 4, 503 sei whales, and 139 Bryde's whales. Catches of baleen whales were below the legal limits of ~. 453 fin whales and 5, 541 sei (including Bryde's) whales. "At the 1970 International Whaling Commission meeting, catch \ limits of 1, 308 fin whales and 4, 710 sei (including Bryde 's) wl:ale s were set for the 1971 North Pacific season. The IWC commissioners for Japan,----- the U.S.S.R., and the United States also agreed on a lL--nit of 13, 551 sperm whales. 11 Rice ( 1971 b) recently completed an exhaustive review of the historical and current literature ·on the large whales (baleen ~ales, order Mysticeti, with two exceptions) in the eastern North Pacific Ocean and summarized the available information: ·, ( STATUS OF SPECIES "The following accounts include all nine of the species o:: baleen whales t1lat occur in the eastern North Pacific, plus the two largest species of toothed whales. I have briefly summariz.ed what is known of the distribution and movements of each species, and its population size and trends. Most s·pecies of baleen whales app.ear to have a tendency to migrate .more in coastal than mid-ocean' waters, ..· so the concept of more or less discrete eastern and western North Pacific breeding stocks is r"~asonable pending further results f:rom marking programs, blood-type studies, etc. Sperm whales range widely over the oceans, and s·eparate stock units cannot be discerned until more marked animals are recovered. Blue Whale (Balaenoptera musculus) ....--"Distribution--One of the world's last remaining sizable · stocks of blue whales congregates from February to early July each year along the west coast of Baja California. The presence of blue whales in these waters was known to 19th century whaler_s, who ra.rely tried to capture them because they were too swift to pursue and .,,, , ! 10 kill with open boats and hand harpoons or bomb-lances. One of the few who tried and succeeded was Captain Scammon (1874), who wrote: "Several days trial were made in the brig Boston, in 1858, -9ff Cerrcs [= Cedros] Island, to <:apture these animals. It was in the month of July, and the sea, as :far as the eye could discern, was marked by their huge forms and towering spouts •••• "On a second voyage of the PAGE, six ofth~se immE;lnSe creatures were ~ taken by the bomb-gun and lanc_e~ off the port of San Quentin, lower .California, where the ;noderate depth of water was fav:orable for their ~ursuit. 'Large· numbers .qf ~hem were found on this ground, where they .. ..,.,..__ had been attracted by the swarms of sardines and prawns. . • /'"', t:_~ "The whales in this are:,'!. were first exploited by whalers using modern methods .. ' in the winter of 1913 and 1914~ when three catcher boats operating from the floating factory CAPELLA I killed 83 d them (T~nnessen, 1967). Ingebritsen (192'9) wrote: ---- "In 1913, I carried on whaling operations from Magdalena Bay, lower California. At the end of October the· blue whale came from the north and proceeded s9uthward along the shore. Then in April, May. and June it came northward again." "Each winter and spring season from 1924/25 to 1928/29, and again in early 1935, one or two floating factories operated inostly from Bahia Magdalena, Q but also from other points along the west coast of Mexico. Between Cabo San Lucas -(~.· .' .~ ,, :~ ' . -~ ~::.:j ..... p_._, __ -p·-.- .. ----.p--···- ·- ,--.-.. "-,.. ,.- ...--.~-- ,.....,...~- and Isla Cedros, Baja California, these expeditions took 47 to 239 blue whales each season, and a total of 989. Since then blue whales have not been exploited off Baja ( California. 11Duri..'1g our whale marking cruises we found blue whales along the entire west coast of Baja California, from 23°33' N latitude to 32°05' N latitude. We also saw two east of Isla Cerralvo on the west side of the mouth of .the Gulf of California on Fcbruar:y 8, 1966, and one moving north midway between Cabo San Lucas and the Islas 'fres Marias on February 16, 1967. ''All of the blue wh~i.les that we observed were less than 80 km from shore- so.me only 3 km. Many were in shallow water between 50 m and 200 m deep. 11 · Small numbers ·of blue whales were taken off Baja California in October, but· 0 catches were practically l1il from November through January. The catch statistics I \ and our observations show that the major influx of blue whales begins in late February, the greatest numbers are present in April, and that departure is nearly complete by ....., early July. .-- "The whereabouts of these blue whales during the remainder of the year, and ':t ·· ··· their rclat::onship to populations on whaling grounds farther north, is problematical. During the 1965 whale marking cruises, we effectively marked 49 blue· whales - 26 in February and March, and 23 in June. None of these marJ\s were recovered during the 1965 whaling season. These negative results arc inconclusive. Killing of blue whales has been banned in subsequent seasons. (:"\ \....._/ 12 ,.-:--;;..:<.·~.=-._ ·~!though the blue whales are gone from Baja California waters by late June or '- ·~' early July, they usually do not show up off central California until late Septer.:1b~r. If -. - .· ' I~~;~. -(![': they head north upon iE~aving Baja California, they must pass central California far :.· ·: ~ offshore. In May 1963, Berzin and Rovnin (1966) observed blue whales migrating north at 41" to 42" N latitude, 130" W longitude, off the coast of northern California. Catches off Vancouver Island show two peaks of abundance- in Jtme and Septe~ber. . . '!In more northerly waters, pelagic whaling has revealed three majo_r summer concentration a.reas for blue whales: (1) the eastern Gulf of Alaska, from 130" to 140" W longitude; (2) the area south of the eastern Aleutians, from 160"' to 1-80" W longitude; and :, . .~ ~ ·' . \,' (3)- the area frQm the far west~rn Aleutians to Kamchat~a, 170" to':l.60" E longitude. Catches in the eastern Aleutian area show a peak in June, whereas those in the Gulf o~ J Alaska show a peak in July .. This difference tends to support Berzin and Rovnin's (1966) hypothes-is that some of the northbound migrants turn west at about 50" N latitude and ~- ': (.•', . ~--- proceed ~ire9tly to the eastern Aleutians, while others continue north along the coast into the Gulf of Alaska. Out of 15 Japanese and Soviet·recovcrief of blue whales marked ~ '.. ; on the summer grounds, five demonstrated movement between the three major areas ~ .. _.-·· . noted above; one whale even moved from the eastern Okhotsk Sea to the Gulf of Alaska · :. {Ivashin and Rovnin, 1967; Whales Res-earch Institute, 1967). The remaining 10 whales were recovered in the area where they were marked. •From the above facts I postulate that the majority of this stock of blac whales leaves Baja California waters in May and heads north, passes central California far offshore, and arrives on the whaling grounds off Vancouver Island in June. From there 0 at least some must proceed to the ea.stcrn Aleutians or into th.c Gulf of Alaska. They -(-- ! .. 13 ; . . '(·' ----w- ·----.------·-·------·------. -~- ..... ------:'.:.·: ·r·:-,~::'f•:·•:-;-~:... :- ---· .... '-...... , ··- --. ---: ...... -- .__ •. -· • ., .• - ...... -~--.. .,~ .•. - ... -- .,. - :- , ..•. , "--~--- ...... ~ ,. i- ::·· ~- : ··- -~ ..•.,_,....,.,. --- ,; .. "• ····~---·•·?·~~...... ,·~--.,.. .. ~~~ .. .,~~---~... '"';"''"'r'-.."':""';""'~·· -- ···· ''Tl'~ ' ··~··· ~ .::J. leave the latter areas in August and pass Vancouver Island in September, central ~ . ~~- .. California in late September and October, and Baja California in October. There ·- r<¥;~ • -{'' are. no data on their movements from November through Janua.t-y, but they must be '··· either farther offshore or farther south. Our observation of a northbound animal i north of the Islas Tres Marias in February gives a little support to the second alter- l ,".! . j : i native. :'l ... I' . : j .J ''Population--The catch of blue whales off Baja California from 1924/25 to · . ' 1928/29 averaged 188 per year. The catch per unit of effort (gross nurrb er of · · I 1 .. ' , . . catcher's day's work) showed no downward trend. During the same 5-year period, blue whale catches in California, British Columbia, and Alaska ·averaged 101 per year.- Annual catches fluctuated but showed no downward trend - in fact an upward . . trend is suggested, even though effort remained about _constant. During this period 0 the population of blue whales in the eastern North Pacific as a whole apparently sus- tained aQ average kill of 289 animals per year. '.fo do this would requ·i~e a total population of about 6, 000 animals, since the recruitment can h3,rdly have been gr.eate~ .. than 0. 05 . ... .----. "Aside from this 5-year period in the late 1920's no single year's catch has :> :• .J.·-: - ever exceeded 271, except for a catch of 440 in 1963. "In 1964, Doi, Nemoto, and Ohsumi (1967) calculated that the sumner blue whale.-.<:.: . i populations on the three main pelagic whaling areas had dropped to abru t 1,420 from a post-war initial stock of about 2,430. This estimate did not include populations cast of 140° W longitude. 0 - f i 14 . - -y>-· •The above data suggest that blue whales were never very.abundant in the eastern r-. \-/' North Pacific, and their population siza has not decreased very markeclly. •Off Baja California, I have see:1 blue whales app_arently feeding on shoals of pelagic red crabs, _P~euroncodes planipes, which are often abundant in the inshore waters. Although there· is not a very marked seasonal variation in the abun.dance of these crabs' the presence of the blue whales does coincide with ,the period of greatest ...... ~rab abundance (Longhurst, 1967). If a current experimental fishery for_ red crabs should develop into a commercial ent.erprise big enough to depress crab populE.tions, ....~ .. . tt might adversely effect the population size,or movements of the blue whales. ··II S-ince this seasonal aggregation of blue whal•;!S takes-place close to tl:le over- ., ··:! ·!-'::·· ·populated ·megalopolis of southern California, it offers an opportunity for commercial_.:. ''0~·~ whale-watching cruises. Cruises to observe gray whales and seal rookeri~ are _ ·.·_: . :';,,. >. @'·~ ' ·_already a rapidly growing business in this area. It is probably_ the only pla·:::e in the . . ' world where the average citizen could have a fair chance of seeing a live blue whale - ·with a reasonable expenditure of time and money. ----- : _·- 11 Fin Whale (Balaenoptera physalus) ~·~ J. ,-·x ··~· •Distribution--The winter grounds of fin whales in the southeastern North Pacific, · . . I as elsewhere in the world, remain very poorly known. We have found fin \\ha:cs from , . r '. 15 ~ . i----~-~------····------~-- ·-· ----·---· ------.. ---~ saw none far offshore, many must spend the winter far at sea, because the number .i observed in the immediate offshor!3 waters is insufficient to account for the entire ~- eastern North Pacific population. On May 20, 196_6, Kenneth· C. Balcomb (pers •. comm.) observed 8 to 12 fih whales in the mid-Pacific at 17°54' N latitude, 158°48' W longitude, and Berzin and Rovnin (1966) reported some at 37° N latitude, 138° W longitude in February 1964. . . "In the summer fin whales range in the immediate offshore waters around the North Pacific,. from the Chukchi Sea southward along the Asian ·side. to Japan, and along . ' . the American side to southern California and scmetimes .central Baja California• . .· ::.! "Eight fin whales that we marked in the winter (November to January] off· I• · · southern California were recovered in the sumrner (May to July) off central ,' \ whales varies from year-to-year, but a general pattern is evident. Numbers reach a -= peak in late-May or early June, after which they fall off. There is usually a second influx later in the summer, which is more prolonged and more variable-in its timing ~--·- than the early peak. . .: . .,. ' 1 Population--During their first 2 years of operation (1956 and i957) the Calif~rnia ; . ·1·1 catcher boats did not go far enough offshore to find many fin whales, ~ecausc humpb~ck ·./:"j 1 whales were so abundant closer inshore. By 1958, the increasing scarcity of the latter.· ;:~ ...... J species forced the whalers to turn their attention to fin whales. Although the catch i i .. j I fluctuated considerably from year-to-year, there was an overall downward trend in ·:~ 0 ,-· • I 16 catch per gross catcher's day's work from about 0.14 in 1958 to 1960 to about 0 •. OG in 1968 to 1970, a reduction of about 5'7% (Table 4). This figure agrees with Ohsumi, . . Shimadzu, and Doi's (1971) estimate that the entire eastern North Pacific stock of fin~ whales decreased by 55% during this period, from about 20' 000 to 9, 000 recruited .animals. This stock is well below the level of maximum sustainable yield. ''Sci Whale (Balaenoptera borealis) I. •Distribution--The winter distribution of sei whales is even more poorly known ,t than that of fin whales. We found s-ci whales widely but sparsely scattered fr:>m 35o:30' NJatitude off Point Piedras Blancas, Cl:tlifornia, south to 18°30' N, 600 km off- .. shore in the vicinity of the Islas Revillagigedo. Nowhere did we find them regularly or in any numbers. Perhaps the~majo:Fity spend the winter in far offshore waters. "'The sumrre r distribution of sei whales is similar to that of fin whales, except that they rarely go north of the Aleutian Islands. Off our coast they range south to the area west of the California Channel Islands, and we saw one at 27°13' N off Baja California. /--- ''Off central California sei whales are usually present only during the late sum~·~ mer and early autumn. In some years a few arrive in late May or June, but in most years they do not show up until eady July. . } ''One sci whale that we marked off southern California in November 1962, was 1 • f' ' killed off Vancouver Island in August 1966. Another marked in the sa:mc general area r\ in June 19G5, was killed 6GO miles off the Washington coast iJ:l July 1969. V. .I 17 &-i'- '~ •Table 4. Baleen whale catch {C), effort {E), and catch per unit of effort I~ (C/E) at California shore stations, 1956-1970 ~: <('...... · ·~r; ~~- ~ "·!.,j I • ·:l Gross number Blue F~ Sci Humpback t.; t•' ~·-.o,": of catcher's *ij,,. Year day's work c C/B c C/E c C/E c C/E 1-~- ~l:~z 1956 317 0 3 0.010 ·o 133 0.420 t ,. 1] 1957 505 0 22 ·o.o44 1 0.002 199 . 0. 3.94 .:~.t :·.t."i "7: 1958 .703 26 0. 0:37 109 0.155 2 0. 003 115- 0.164 :;! ' 1959 920 5 0.005 108 . 0-.116 37 o._p4o 14_0 0.152 .,J> L, 1960 915 1·. o. 001 138 0.151 47 o:.tl51 67 0.073 ;~., 1961 -~15 2 0.002 118 0.129 5lr 0.056 ~ 62 -0.068 1962 915 2 0.002 123 0.134 22 .0. 024 39 0.043 1963 915._ 6 0.007 17 0. 019. 96 0.105 55 C.060 -- 1964 915 .2 -0.002 148 0.'164 13 0.014 .' 27 :o. 030 1965 871 4 0.005 114 0.131 22 0.025 4 C.005 - .0. r 1966 797 42 0.053 62 0.078 ~ . \...... 1967 549 44 0.080 3 o. 005 ' .... ·" 1968 421 38 0.090 14 0.033 1969 532 31 0.058 10 0.019 1970 ~--- 368 5 o. 014. 4 0.011 --o---. ( '-- 18 "Population--As with fin whales, the California whalers made no r·eal effort to \ij(' :: \.-. take sei whales until 1959, after the humpbacks had been depleted. Since that year the sei whale catches have fluctuated more than the fin whale catches, b1.1t tltere has beerA I, a similar overall downward trend in catch per unit' of effort from 0 ... 05 in 1959 to 1961 .to 0. 02 in 1968 to 1970, a reduction of 60% (Tab~e 4). Ohsumi et al. (1971} estimated 'i '• that the eastern North Pacific sci whale stock decreased from roughly_ 50.000 to 30,000 ; ~ . . i : t recruited animals 4uring this period, but that-the stock was still at or above the levcl of maximum sustainable yield . . "Seven percent of the sci whales taken off centra4 California have been ~ccted with a unique disease that results in the progressive shedding the the baleGn plate.s· and their replacement by an abnormal papilloma-like growth. In one case, all baleen plates were missing. The epidemiology .and etiology of this disease are unknow:1, but=: 0. the collecting of two afflicted whales from one pod suggests that it is contagious • Histological studies revealed the presence of tiny granular structures .,that resemble bedsonia (Chlamvdia sp. ). Attempts by the Naval Biological Laboratory in Oakland to · ...... , isolate the causative agent were un~uccessful. The loss of such a highly specialized feeding apparatus as the baleen plates would appear to make it impossible for a whrJ.e -.-- ~ - ~ ' . . to feed. Yet none of the dis cased animals appeared emaciated and most had anchovies:"'" . -· . . , (Engraul is mordax}.' saurics (Cololabis saira), or jack mackC?rel (Trachurus symm-ctricus) in their stomachs; none had euphausiids or copepods. The ultimate effects of this disease are unknown. Because of its high incidence and severity, it might cause si?;nifi- cant mortality. Strfl.ngcly enough, this disease has never been found in sci whales else- where in the world, nor in any other species of whale, with the possible exception of an 0 Antarctic fin whale (Tomilin and Smyshlyaev, 1968). 'i. 19 !"--·; ~ • •Sci whales are also much more prone to heavy infestations of parasitic helminths ~":-'- · than are other baleen whales. The liver fluke Lecithodcsmus spinosus causes hardening _!_ ·c of the tip of the liver. The stomach worm Anisaki!:; simplex, althou~h·u~ually abundant, ~~j is not normally pathogenic. In one case, however, many worms had imradeu the liver, ~ c.'~ which was undergoing pathological degeneration. Perhaps both these helminths some- times kill the host• . llBrydc's Whale (Balaenoptera edeni) "Distribution--On the west coast of Baja California, Bryde's whales inhabit the . i!!§.hore waters from 26°12' N latitude south to Cabo San Lucas.. They also ~a:1ge all .,., across the southern end of the Gulf of California north at least as far as we went, tG · ·. · 20°40' N latitude on the western side and Mazatlan, Sinaloa, on the eastern side • .-...._ :_)~ (:-:. Robert L. Brownell (pers. comm.) found a stranded specimen in the northern gulf. . ·~· - '.· .. We saw ~few as far south as the Islas Tres Marias. 11 Bryde's whales appear to be year-round residents in these waters, as we encountered them on two cruises in June and September as well as during the winter and early spring cruises. I . "Population--pntll·recent years, Bryde's whales were not distinguishcC: from sei whales in the International Whaling Statistics. The floating factories that operated on · i' ~~!!:~ ~~ · the west coast of Mexico in 1913/14, 1924/25 to 1928/29, and 1935, reported taking 121 ''sci" whales between Bahia San Juanico, Baja California, and the Islas '!"res Marias, Nayarit. Because sei whales arc scarce in this area, whereas Bryde1s whales arc : ·j- 20 common, I believe that most if not all of the animals reported as "seP' whales were r,.-:'4 '- probably Bryde's whales. Indeed, the companies' daily catch records for 1925/26 list some of them as "Brydehval" or as "sci (Brydehval)'', and all 34 whales taken that season that were reported as sci whales in the International Whaling Statistics, were reported as Bryde's whales by Kellogg (1931) and Radcliffe (1933). ''This stock of whales has not been exploited since 1935 and may be assumed. · to be at the carrying capacity of the area. Insufficient data are available to make a quantitativ c assessment. "Minl<:e Whale {Balaenoptera acutorostrata) •Distribution-.- During the winter we have found minke whales widely spread all 0 the way from central California south to the Islas Revillagigedo. They ar_e most abun- dant in the vicinity of the Channel Islands off southern California. 11Iri the summer they occur from at least as far south as 26°45' N latitude off Baja California, north to the Chukchi Sea.. They are fairly common off central California, but are much more abundant in Alaskan waters. A sizable population inhabits the inside waters of Pugct Sound. "Population--A fishery for minke whales and other "small" whales has never _ been attempted in the eastern North Pacific, as it has off Norway and Jap2n. The :>· ,J I ; .:1 eastern North Pacific population of minke whales is probably at the carrying capacity, ~ 1 l but there are insufficient data for a quantitative assessment of its size or sustainable 0 yield. In recent years pelagic expeditions· in the Antarctic and one shore station in 21 South Africa have taken significant numbers of m.inke whales, because of a scarcity of larger species. of baleen whales. . The one remaining American whaling company is likewi.se considering the possibility o! fishing for minke whales. •Humpback Whale (Megaptera novaeangliae) ''_!?istribution--During the winter months~ most humpback whales congregate in warm water-s close to continental coastlines o.r oceanic islands. Their distribution at this season in the eastern North Paci~ic is well known from- the logbook records of the ' : ' . 19th century American whaleships, 'the catch records maintatncd by the floating ·~: ._.·; factories that operated off Mexico- in the 1920's and 1930's, and our observations -· during the past decade. Th~e winter grounds include three somewhat discr.cte.a~eas: ''1. The west coast of Baja California, chiefly from Isla Cedros south to Cabo San - Lucas, ru;ld around the cape at least as far north as Isla San Jos~. A few may also be found at this season farther north along the west coast as far as Ensenada, and rarely to southern California. . :·'· ''2. The mainland-- coast of west-central MeXico, from southern Sinaloa to Jalisco, especially in the vicinity of the Islas Tres Marias and Isla Isabela, Nayarit, amd Bahia Band eras, Jalisco. ., "3. The far offshore Islas Revillagigcdo, including Isla San Benedicta, Isla Socorro~ and Isla Clarion. 0 .I 22 •. 11Humpback whales also winter around the main Hawaiian Islands. I observed some off Oahu in February 1966. According to Kenneth S. Norris (pers. eomm.) tbey are regularly seen around the main islands. ' 11 In the western North Pacific, humpback whales are knowp to winter around the Marianna Islands; around the Bonin Islands; and from Oshima, Kyushu, and South Korea southwest through the Ryukyu Islands to Taiwan (Omura, 1950; Nishiwaki, 1959)~ ''Humpbacks occur all summer off centr~ -California. F.rom ther~, their sum "'·. h . mer range extends around the. entire North Pacific in the immc9iate offshore waters -..... ; ,;;.""'' -~·- r-· as far as Japan, a·ri·d north through ·the Bering Sea into the Chq~chi .Sea. ~~.\:.. . ·-~ :-::. ~i~~~ "Migration of h\lmpback whales between summer groundS ~~the eastern Aleutians..:· ~~:. . . and the winter grounds in the Ryukyu and Bonijl Islands has been ·9emonstrated ":Jy ei~~t · ~ ~~~ Japanese mark recoveries (Whales Research Institute, 1967}. Although none of the ~S I "'.~ • ·:-~~- .... humpbacks that we marked off California and Mexico from June 1963 ~o June i965, ·haq · been recovered by the end of the 1965 whaling season (after which the hunting of hump- backs was banrwd), it is probable that some of the humpbacks that winter in this area 11, ,j, . migrate far enough noa-th to mingle with the western Paqific stock on the summer grounds.' • I "Population--Because of their coastal habits, humpback whales are.pE.rUcul~rly ~· . ': · . vulnerable to exploitation by shore stations. Off Baja California, the number-of -...... - ;~ humpbacks killed per gross catcher's day's work dropped steadily from 0.41 in 1924/25.. to 0. 03 in 1928/29, a 93% reduction. Off central California, the number dropped from·· 'i '• . if: 0. 42 in 1956 to 0. 005 ~n 1965, a reduction of almost 99% (Table 4). Decreases were 8.lso :r l ~ i 0·• i. 23 •!ji apparent in the catches at the Al-1Skan shore stations that operated in pre-war years~ and at the British Columbia stations in both pre- and post-war years. By the early 1960's the only area remaining h the North Pacific where large numbers of humpbacks congregated in the summer was around the eastern Aleutians and south of the Alaska Peninsula, from 150° to 170° W longitude. ]Large pelagic catches in that area in 1S62 and 1963 reduced the population to an estimated 2,100 (Doi, Nem.oto, _and Ohsu:ni, 1967). An additional 588 humpbacks were kiHed in 1!164 and 1965. The remaining population . . ' . . probably represents the bulk of both the eastern.and western North Pacific breeding stocks. ' . . .· "We made a survey over the entire casfcrn North Pacific winter grounds between January 26 and March 15, 1965, a time of y1e~r\\hen tl).e majority of the animals -shou!d be there. ·our two vessels spent a total of 68 days cruising; we encountered only 33 · · · groups of humpbacks, totaling 102 individuals - 10 on the west coast of Baja California, • . . .. ' 65 along the coast of southern Sinaloa, Nayarit, and Jalisco, and 27 around the Islc..s .... ·- ·· Revillagigedo. More recent but less CKtensi.V'3 cruises revealed similar numbers. It is - difficult to extrapolate these counts to obtain. hn estimate of the total population on the winter grounds. Since humpbacks concentrato in coastal waters during the win"~er, 1 :~· believe that we saw a:rfairly large proportion. cJ the population. If so, the entir~ c~tcrn North Pacific stock now numbers only a few hundred individuals. ;~;; ~~ ~ "Gray Whale {Eschrichtius robustus) ./~ •Distribution--The migrations of the eastern Pacific stock of gray whales between their ~rctic sumrre r grounds and their Mexican winter grounds is well know~ and has been summarized most recently by Rice and Wolman (1971). ·I . 24 · ... "Population--In the winter of 1969/70 we estimated that the popuiation size : -!. . 0 was around 11,000, and had remained stable since 1967/68 (Rice and Wolman, 1971) • I,... {. ·r ''·'.: '', .\ The 1970/71 census yields a:u estimate almost identical with those of the preceding ··~· ...... 3 years. . i •'Black Right Whale (Ba:aena glacialis) 11 ''Distribution--The "Kodiak Ground , which encompassed the entire Gulf of Alaska from Vancouver Island to the ~astern Aleutians, was renowned in the 19th ,. , . century as one of the best areas for hunting right whales during the summer. A - '. few could be found in the southern Bering Sea and all across the North Pacific above. ~ · -50° N latitude at that season. ''Their winter grounds have been somewhat of a mystery (Scammon, 1874). In : () 1. other parts of the world, the females with calves resort' to coastal bays in the winter, ' ~·. \ • .. .:, but none have ever beez: fou~d doing so in the eastern North Pacific. Only a few right iI. whales have been found during the winter a.nd spring months off the west coast - some I as far south·as Punta Abrcojos, Baja California. L 11 Population--The 19th century AmcriQan whalers almost succeeded in completely ·· · '\ ,· i:·· I :l .• .J ·.. exterminating the right whale in the eastern North Pacific. How close they came is .-., apparent from. the fact _t.i.at, from 1905, when modern whaling methodS were introduc~ :: .. ~ .. : on th.e west coast, to 1937, when right whales were given legal protcctimi, only 24 ~~f..~:ziJ 1 killed by the whaling stations in Alaska an~- British Columbia •. Omura ct al. (H.lG9} h~~~:~,·~;1 .·.:; . f ""'I summarized recent sightings on the summer·grounds, and Pike and MacAs~ic (1969) · l .:.- ".1 .. reported several sightings off British Columbia. Rice and Fiscus (1968) reviewed the :.:' j • -.if ·:1 ..-·;· -~ I'",,, . ~ 25 l,. 1 .··. '•· ,.;·, ... . , . :~~.·~~~.41.: .... ;,1.. __ ... ~ .. ·~·~·~-~··---·--·-~- ~-· ... - .",o,•-·····-'-0• •-·••--• • ooo o •M·· ... _:__ •• ;.••• ·- ... o• status of right whales in the southeastern North Pacific. The lack of any additional sightings sirice then further confirms our opinion that this stock numbers only. a few ) individuals and has not noticeably increased in the.past 35 years. ''J}owhead Whale (Balaena mysticctus) '· •Distribution--Bowheads spend the winter in the loose, southern edge of the pack ice, which usually extends across the central Bering Sea from Kuskokwim Bay, Alaska, west-southwest t4l the northern shores of the Kamchatka Peninsula, USSR. ' ~ ·- ~ . .-~- "As soon as the ice north of the Bering Strait pegins to break up in the spring, the whales migrate northward through thf; open leads. Many follow the shore lead (between the· fast ice and the pack ice). T'h.e first whales pass Point Hope, Alaska. in ~arly April, and Point Barrow in late Ap:r.il. In the summer they are distributed in ' . ) the shallow waters of the northern Bering Sea, the Chukchi Sea, and the Beaufort Sea east to about Banks Island. During the autumn freeze-up, they retreat south of·the Bering Strait• .. ---· ''Population-":'American whaling ships first went through Bering Strait into tlfe Arctic.Oc<,,hl' 1848. From 1868 on, tho Arctic Ocean was the pri!lcipal resort of .. the North P~ic fleet. In 1870, tM fleet reached a peak of 53 vessels that took about . . • '487 bowh~d whales (estimated on the basis of whalebone production). Starting in 1884., many shore whaling stat!ons were established in northwestern Alaska by white men who employed Eskimos. Many writers have stated, without documentation, that the bowhead whale population was greatly reduced during this period. The statistics show that dnrhg the peak of the fishery, from 1868 to 1884, the catch per vessel fluctuated but showed no ) .. :·: ,,: ~:;<·~{~~*' 2G ~·-···"-·. -·-···· -·- ~'-'·--·--···--··-··--··· downward trend. An estimated average of 219 whales was killed each year {excluding 1871 and 1876, when most of the fleet was lost in the ice). If the population was stable, ") the fishery mortality could hardly have exceeded 5%, so the population may have been . . , around 4, 000 or 5, 000. The fishery collapsed when the bottom fell out of the whaletxme market after 19.09. 1 ~tThe maritime Eskimos of Arctic Alaska have hunted bowhead whales for perhap$ 50 centuries~ Today the Eskimos living in the villagc.c; of Point Hope, Barrow, and Wainwright hunt wha.fcs each year during Aprrl an~ May. Te~iorary camps trans ported by dog sled are established at the edge of. the fast ice. The whales are chased ..· in easily transportable skin-covered umiaks, about 6. 6 m long, propelled with P.adcUes. The only major innovation since prehistoric times is the adoption of darting-guns and ~- shoulder-guns which fire bomb-lances. Formerly, bone-headed harpoons were used."'_ ') An annual ayerage of about 10 bowheads are killed and recovered. For each whale '· - ,,i recovered about three or four are struck and lost; some of these may die, so the total number of whales killed off Alaska is probably about 20 per year. Bowheads are rarely i. r killed off Siberia (Zimushko, 1969). Catch statistics for Barrow since 1928, compiled by Maher and Wilimovsky (1963), and for Point Hope since 1890, compiled by the late Don C. Foote (pers. comm.) give no indication that the population size has changed during this century. These facts imply a minimum population of about 400. · ~· . ••Each year between early April and early ~iune, between 100 and 200 whales are observed migrating past Point Hope and Barrow. The highcst_rate of migration that I observed was at Point narrow on May 11, 1962, \Vhcn 25 whales passed during the 23- j hour pericd from 0030 to 2330 hours. These cou~l.ts are made only during periods when 27 ,,. \\.1 41.1 l\11 111; iiiii¥11Ai41ii iii ilii&ihi\1 i '<---- ·----~=~ -- ~ .... ;..: the whaling camps are occupied; whaling is suspended when the shore lead closes, at~.d when it becomes more than 2 km wide. In the early part of the whaling season, it may 0 be too dark to see whales during the midnight hours, but often they can be heard blowing. Many more whales pass too far offshore to be seen from the fast ice. Pilots flying for the Arctic Research Laboratory at. Barrow told me that they have seen bowheads in leads and polynyas as far as 80 km offshore in May. The number of whale~ obser;ed from the whaling camps is thus only a small proportion of the total population. 1'§perm Whale (Physeter catodon) ''Distribution--During the winter sperm whales are scattered across the entire North Pacific below 40° N latitude. From November i;hrough April we have frequenby encountered breeding schools over the continental slope off the coast of California .... from 33° to 38° N latitude. South of California, except for two large bulls·at Isla Guadalupe, we encountered sperm whales only in the area south of Cabo San Lucas and west of the Islas Tres Marias. Many were taken the Jear round in the latter area in the 19th century, but we found only a fe-n, all males. Th,~ old records also indicate that the ----- area around the main Hawaiian Islands was a year rotnd concentration area. II During the summer, sperm whales may be fou.:1ci anywhere in the North Pacific. The area of greatest population density extends fromthe southwestern Bering Sea and northern Gulf of Alaska south to 50° N latitude, dippin:; to below 40° N latitude on the ··---American coas+.,. · Oth-er major summer grounds·lic between 25° and 35° N latitude-from 180° longitude west to Japan, and thence northward along the entire Asiatic coast. 'J 28 EI!l!££&1&JDB&m. - -· -·- ·----·'...,_·-···-;;-·"- ·- ···-·--"--·····- .. m~~l ~·; " ". "The summer range of the population that \Vintcrs off California is indicated '.·· by the recqvcry of three whales that were marked off southern California in January. J These included a male taken off northern California in JWlc, an animal of unknown se.X off Washington in, JWle, and a female in the western Gulf of Alaska in April. ' 11 0n the whaling grounds off· central California sperm whales arc common from early April until the middle of June, reaching a peak in mid-May. They arc again common from the end of August to the middle of Novembe·r, reaching a peak in mi6- September. Very few are present in mid-summer. We found p.o sperm whales between t San Francisco and Bahia Magdalena during cruises in May, Jtme, and September. The ·.· - two annual peaks of abundance suggest that the whales are moving north through the whaling grotmds pff San Francisco in the spl}.ng, and are returning south in the autumri. ''Japanese and Soviet mark recoveries reveal considerable longitudinal dispersaf •.' J of sperm whales. The mating season extends from late winter to late sum:zp.er, so a female might mate almost anywhere within her ye~round range. Furthermore, the -. ...:., harem bulls apparently do not remain long in a particular breeding school. These facts suggest that all North Pacific sperm whales comprise one pan:mictic population. 6 PopuJ;ation--During their first 5 y·ears of operation (195f>··19Gl), the California whaling stations took sperm whales only when they could not find baleen whales. In 1962, there was a sharp rise in the price of sperm oil, and baleen whales were bccom- ming less common, so the whalers expended more effort on sperm whales. Since the data are inadequate to determine the number of catcher's day's work spent hunting sperm whales, I have used simply the catch per vessel per season as a mcat!urc of the 0 29 il~:}\.}:((·:> . w~~~ _12. 6 from 1961 to 1965. Thereafter it () mean body length of legal-sized males in the catch. dropped from 44.0 ft in 1956 to 1960 to 39. 7 ft in 1968 to 1970. This decrease in the availability of adult males off .California agrees with Ohsumi, Shimadzu, andDoi's (1971) calculation that the recruited '.'.· .· stock of male spe~s in the entire northern North Pacific dropped fre>m 134, 000 in 1964 ....- to 64,000 in 1970. ''From 1956 through 1965, only 18% of the sperm whales killed off California ~ were females. From 1966 through 1970, when special scientific permits allowed the taking of animals shorter than the legal minimum length, 53% of the catch was females . . In the,No~th Pacific as a whole, females make up about 25% of the catch, and the number taken has ne\rer been as high as the estimated sustainable yield (Ohsumi et al., 1971) • ... :) "Giant 'Bottlenose Whale (Berardius bairdi) 11 Distribution--This species is endemic to the North Pacific. It ranges. from St. Matthew Island in the Bering Sea south in the eastern Pacific to 32°30' N latitude o..ff southern California, and in the western Pacific to 34°001 N off Japan. "Seasonal movements are poorly understood. California catches suggest iwc peaks of abundance - in July and October. Off British Colmnbia, tlYe majority have been killed in August. ,.·' uThirteen of 15 (87%) taken off California were males. Likewise,off British Columbia, 92% of those killed were males (Pike and MacAskie, 19G9), and in most i) areas of Japan males predominate in the catch (Omura et al., 1956). Since females 30 .. -' ------______,. ______... ______-----~-...... ______..___ 1..-.; __ ..... ___...... ~-~ .... --····- -··-·-·-····.. -'··--~--- •••• ~-- ...... :- ~;--~----·----·-·-- .. . , ...... - ---~ ·-- ... _ .. ''Table 5. Male sperm whale catch, effort, catch per unit of effort, and mean body length, at California shore stations, 1956-1970 J . Catch of male Number of Whales per Mean body Season sperm whales1 catcher boats catcher boat length (ft)2 1956 9 2 4.5 43.2 1957 14 3 4.7 44.4 1958 8 4 2.0 45.7 1959 17 5 '.3.4 42.6 1960 14 5 2.8 44.7 1961 59 5 .11.8 42.0. ~ 1962 46 5 9.2 41.4 '~ 1963 .. · 75 5 15.0 41.4 1964 54 5 10.8 39.6 1965 82 5 16.4 --~- 40.8 .-: 1966 37 5 7.4. 40.5 ..,. 1967 29 3 9.7 41.1 :) 1968 23 3 7.7 38.7 1969 21 3 7.0 40.4 1970 20 3 6.6 40.1 1Excluding--- whales taken on special scientific permits, 1966 to 1970. 2 Excluding whales leas than 35 ft long taken on special scientific permits, .but including whales longer than 34ft taken out-of-season on·permits. ) 31 ,. : /~ ''. \" . : ... ' :21~~~.. ~~-~-..· .. - .:..:.-_ .... ,_ ... ··-·-··- ... --~--- .. average larger than males, the preponderance of males in the catches in certain areas suggests a partial goographical segregation of the sexes. "Population--Although bottlenose whales are regularly encou~tered off central California, they are not common there. Because of their relatively small size, whalers in the eastern North Pacific rarely bother to kill them. Only 15 were taken off California from 1956 to 1970, and 29 off British Columbia from 1953 .to 1967.'~ ... ..·'• , .. · ... • ) ... ~· . ( '. 32 • ~ • I I .I I Ll iiEli&E &Lid£& . ··' 18 Gray whale (Eschrichtius robustus, Order Cetacea) The gray whale migrates ann~ally b~tween its winter (December to March) calving lagoons in Baja California, Mexico, and its summer (May to October) feeding grounds in the northern Bering, Chukchi, and Beaufort_ Seas. While on migration the majority of whales follow the coastline within a few miles of shore . (Rice and Wolman, 1971) (see Map 3 ).- Counts of migrating gray whales as they move southward ..· past California have been cond;~cted by biologists during many seasons beginning in the 1950's. The counts were nearly identical during 1969, 1970, and 1971, indicating that the population remained. ) stable at about 10~ 000 to 11, 000 whales during that period (Rice, 1971). Because the gray whale remains near shore it is particularl_y vulnerable to whaling. By 1900 it was nearly extinct, but the stock partialiy recovered and 933 Wei'je ;recorded a~ taken in the 34-year period, 1913 through 1946. In ;:, 946 complete protection from commercial whaling was given 7:Jy the International Whaling Commission and it riow appears that the stock may have attained its natural maximum size. 19 The possible potential economic value of this resource may be calculated: the 1970 price of whale meat was about lOi/lb, for oil Si/lb, and for meal 7i/lb. The mean weight of these products per whale from 29 southbound gray whales was: oil, 16, 665 lb; meal, 15, 066 lb; and meat, 10, 337 lb {computed ~ from Rice and Wolman, 1971, p. 36). Thus the total mean value of a whale was about $3, 420. .!!_ 400 whales could be taken annually as a sustained crop, the total ann:1al value of this resource w"ould be about $1, 368, 000. I . .! I . , . . I II 1." l _JIL .. I .a .I. . a·~ .. ~.·. : .... . :·. . ·.. ·. ·.... '• . . . _.:.·.:··.. . . : ...:·~~ .... . .· I 1 .. A c I F I l .. / - J 0 c E A N j. 21 ~-, fa . The Toothed Whales (Class Cetacea) ·.... ·.: Porpoises and Dolphins (Order Odontoceti) The species which occur in the eastern North Pacific Ocean within 100 miles of shore and between the Mexican border and , Prince William Sound are listed below~ Although their abundance ,.· is unknown, general observations indicate that in this area and in . . , the aggregate they number at least in the tens of thousands, and more probably in the hundreds of thousands. The sperm whale is the only extensively commercially used species (see Whaling). . . The smaller species are not utilized except tha.t a few individuals of certain species are valuable as exhibits in aquariums (for lj.sting ~ ~ J and othex data see Lucas, 1970}, and as experimental animals in -research on diving maxnmals (for example see Elsner, 1969; Norris, 1969) . ...----· Information on the distribution by season and area of these d .. ' .~ ~ cetaceans is only partially known (see Norris and Prescott, 1961; ... l :: Fiscus and Niggol, 1965) .. During Bureau of Sport Fisheries and Wildlife surface and aerial surveys, which inclt..:ided 1 /24th of the area, of Prince William Sound from 25 Feb.ruary to 7 March 1971, five species of cetaceans were observed and a total of about 3, 540 individuals were estimated to be in.the area (table IV). ;I' IJI 22 Toothed whales, Porpoises, and Dolphins founq in the eastern North Pacific Ocean (Rice and Scheffer, 1968) Bottle-nosed dolphin {Tursiops truncatus) White-headed grampus; gray grampus; Risso's dolphin (Grampus griset:.s) North Pacific white-sided dolphin (Lagenorhynchu~ Qbliquidens) Common dolphin; saddleback dolphin (Delphinus delphis) Northern right-whale dolphin (Lissodelphis borealil) Broad-beaked dolphin; many-toothed blackfish (Peponocephala electra) False killer whale (Pseudorca crassidene) Common pilot whale; common blackfish; pothead whale (Globicepha:.a melaena) Killer whale (Orcinus orca) Harbor porpoise. (Phocoena phocoena) Dall porpoise; y.rhite-flanked porpoise (Phocoenoides dalli) Sperm whale (Physeter catodon) Pygmy sperm whale {Kogia breviceps) Bering Sea beaked whale (Me soplodbn stejnegeri) Arch-beaked whale- (Mesoplodon carlhubbsi) ? (Mesoplodon ginkgodens) Dense-beaked whale (Me soplodon densirostris) North Pacific giant bottle-nose whale (B~~rardius ba~.rdi) ,_) 23 0 Table IV. --Observations of cetaceans in 1 /24th of the area of Prince William Sound and estimated totals present 1 (observed ~urn ber x 24) Total Estimated Species seen total Little piked whale (Balaenoptera acutorostrata) 1 20 Pilot whale (Globicephala melaena)} 81 I 1, 900 Dall Porpoise (Phocoenoide s dalli) ..· Killer whale (Orcinus orca) 10 200 Harbor porpoise (Phocoena phocoena} 1 20 Porpoise (unidentified) 57 l, 400 ~ Total 150 3,540 J ':1\ :..is) .... ·...:-··~·..:~~ ' 24 REFERENCES CITED Bartholomew, G. A. 1967. Seal and sea lion populations of the California Islands. 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