4

NOAA Technical Report NMFS 4

Management of Northern Fur'

Seals on the Pribilof

Islands, Alaska, 1786-1981

Alton Y. Rappel

April 1984

u.s. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

National Marine Fisheries Service
NOAA TECHNICAL REPORTS NMFS

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St., Washington, DC 20235.
NOAA Technical Report NMFS 4

Management of Northern Fur

Seals on the Pribilof

Islands, Alaska, 1786-1981

Alton Y Roppel

April 1984

U.S. DEPARTMENT OF COMMERCE

Malcolm Baldrige, Secretary

National Oceanic and Atmospheric Administration

John V. Byrne, Administrator

National Marine Fisheries Service

William G. Gordon, Assistant Administrator for Fisheries
The National Marine Fisheries Service (NMFS) does not approve, recommend or endorse any proprietary product or proprietary material

mentioned in this publication. No reference shall be made to NMFS, or

to this publication furnished by NMFS, in any advertising or sales promotion which would indicate or imply that NMFS approves, recommends

or endorses any proprietary product or proprietary material mentioned

herein, or which has as its purpose an intent to cause directly or indirectly

the advertised product to be used or purchased because of this NMFS

publication.
CONTENTS

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I

Russian regime 2

Human population. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Marine mammals 5

Fox............................................. 6

Marine birds 6

Marine fishes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Management by the United States 6

Herd reduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Collection of Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Harvest of males . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Harvest of females 12

Counts of adult males . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Marks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Estimates of population size. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Pup weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Mortality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Forecasts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Socioeconomic factors 21

Objections to the harvest 23

Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Literature cited 24

Figures

I. Breeding grounds and range of the northern fur seal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2. St. Paul Island, Alaska, and the rookeries and hauling grounds of the northern fur seal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3. St. George Island, Alaska, and the rookeries and hauling grounds of the northern fur seal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Tables

I. Number of fur seals harvested and skins rejected because of staginess, St. Paul Island, Alaska, August-September 1956 8

2. Limits of body length used to control the harvest of male seals, Pribilof Islands, Alaska, 1922-81 12

3. Annual quotas and numbers of females killed, Pribilof Islands, Alaska, 1954-68 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4. Actual and forecasted kills of 3- and 4-yr-old male seals and relative error of the forecast, St. Paul Island, Alaska, 1961-81 . 22

III

Management of Northern Fur Seals on the

PribilofIslands, Alaska, 1786-1981

ALTON Y. ROPPEL1

ABSTRACT

This paper includes information about the Pribilof Islands since their discovery by Russia in 1786 and the

population of northern fur seals, Callorhinus ursinus, that return there each summer to bear young and to breed.

Russia exterminated the native population ofsea otters, Enhydra lutris, here and nearly subjected the northern fur

seal to the same fate before providing proper protection. The northern fur seal was twice more exposed to extinction

following the purchase of Alaska and the Pribilof Islands by the United States in 1867. Excessive harvesting was

stopped as a result of strict management by the United States of the animals while on land and a treaty between

Japan, Russia, Great Britain (for Canada), and the United States that provided needed protection at sea. In 1941,

Japan abrogated this treaty which was replaced by a provisional agreement between Canada and the United States

that protected the fur seals in the eastern North Pacific Ocean. Japan, the U.S.S.R., Canada, and the United States

again insured the survival ofthese animals with ratification in 1957 ofthe "Interim Convention on the Conservation

of North Pacific Fur Seals," which isstill in force. Under the auspices ofthis Convention, the United States launched

an unprecedented manipulation of the resource through controlled removal during 1956-68 of over 300,000 females

considered surplus. The biological rationale for the reduction was that production of fewer pups would result in a

higher pregnancy rate and increased survival, which would, in turn, produce a sustained annual harvest of

55,000-60,000 males and 10,000-30,000 females.

Predicted results did not occur. The herd reduction program instead coincided with the beginning ofa decline

in the number of males available for harvest. Suspected but unproven causes were changes in the toll normally

accounted for by predation, disease, adverse weather, and hookworms. Depletion of the animals' food supply by

foreign fishing fleets and the entanglement offur seals in trawl webbing and other debris discarded at sea became a

prime suspect in altering the average annual harvest of males on the PribiloHslandsfrom 71,500(1940-56) to 40,000

(1957-59) to 36,000 (1960) to 82,000 (1961) and to 27,347 (1972-81). Thus was born the concept of a research control

area for fur seals, which was agreed upon by members ofthe Convention in 1973 and instituted by the United States

on St. George Island beginning in 1974. All commercial harvesting of fur seals was stopped on St. George Island

and intensive behavioral studies were begun on the now unharvested population as it responds to the moratorium

and attempts to reach its natural ceiling. The results of these and other studies here and on St. Paul Island are

expected to eventually permit a comparison between the dynamics of unharvested and harvested populations,

which should in turn permit more precise management of fur seals as nations continue to exploit the marine

resources of the North Pacific Ocean and Bering Sea.

INTRODUCTION

The northern fur seal, Callorhinus ursinus, is well known internationally for its luxurious fur and historically as a resource steeped

in controversy. The species is largely pelagic, spending much of its

life at sea in subarctic waters of the North Pacific Ocean. It resorts to

land only to bear and nurse its young and to breed. In this latter

respect, the Pribilof Islands in Alaska's Bering Sea are host to 80%

of the total estimated population of 1,800,000, with territories

belonging to the U.S.S.R. accounting for the remainder. Included

in the latter are Robben, or Tyuleni, Island in the Sea of Okhotsk, the

Commander Islands in the western Bering Sea, and several of the

KurilIslands just north of Japan. Two additional colonies containing a few thousand breed offthe coast ofsouthern California, one on

San Miguel Island and the other on nearby Castle Rock; both belong

to the United States (Fig. I).

There are five PribilofIslands, of which only three, St. Paul (Fig.

2), St. George (Fig. 3), and Sea Lion Rock (Fig. 2-Sivutch), have

rookeries and hauling grounds. Between 25,000 and 30,000 males

(mostly of ages 3 and 4 yr) are currently harvested commercially on

INational Marine Mammal Laboratory, Northwest and Alaska Fisheries Center,

National Marine Fisheries Service. NOAA. 7600 Sand Point Way N.E., Seanle, WA

98115.

St. Paul Island, and 350 males are taken annually for local use as

food on St. George Island.

The Pribilof Islands are located approximately 200 mi (322 km)

north of Unalaska in the Aleutian Islands (Fig. I). St. Paul Island

(Fig. 2) is the largest, with a total land mass of 44 mi 2 (114 km2 ).

Next in size, St. George Island (Fig. 3) with 35.5 mi 2 (92 km2 ) lies

40 mi (64 km) to the southeast. Five mi (8 km) south of St. Paul

Island lies Otter Island with an area of 0.77 mi 2 (2 km2 ) and Walrus

Island 10 mi (16 km) off St. Paul Island's northeastern cape with an

area of 0.02 mi 2 (0.05 km2 ). Sea Lion Rock (Fig. 2-Sivutch) lies

300 yd (274 m) off the southern tip of St. Paul Island and is the

smallest with 0.003 mi 2 (0.008 km2 ) (Barth 1956).

St. Paul Island once had five other rookeries in addition to the

current 14 (Fig. 2) and SI. George Island had seven instead of six

(Fig. 3). According to Elliott (1884), Nah Speel Rookery behind the

village of St. Paul contained 8,000 fur seals in 1874, Lagoon

Rookery (on the dike separating Village Cove from the Salt Lagoon)

had 37,000 animals (extinct after 1941), and Suthetunga (Kursoolah) Rookery between Antone Lake and Ridge Wall was "unworthy of survey." Little Eastern Rookery on St. George Island

contained 13,000 fur seals (extinct after 1914) and was located just

west of East Reef Rookery. During the Russian occupation, apparently in 1836, "Two small rookeries were then on the north shore of

St. Paul, near a place called 'Maroonitch'" (Elliott 1884:49). The
....

60 0011

40 00

20 00

14'1 00 16'1 OOE 176 00\1 1S6 00 136 00 116 00

Figure I.-Breeding grounds and range of the northern fur seal.

other four rookeries became extinct before 1912 but the year is not

known.

In addition to the fur seal, the northern sea lion, Eumetopias

jubatus, breeds on Walrus Island and hauls out on the other four;

Otter and St. George Islands each hosts a small breeding colony of

hair seals, Phoca sp. A few hair seals, apparently from Otter Island,

haul out on some of the exposed rocks off St. Paul Island. An

occasional walrus, Odobenus rosmarus divergens, is seen on St.

Paul and St. George Islands.

The islands of St. Paul and St. George and, to a lesser extent,

Otter, support what may be the largest marine bird colonies in the

world. On these three islands are also more than 100 species of

flowering plants, together with numerous grasses, sedges, rushes,

lichens, and mosses. Walrus Island and Sea Lion Rock are essentially barren in this respect.

The arctic blue fox, Atopex tagopus, is on all five of the Pribilof

Islands. The shrew, Sorex sp., is on St. Paul Island; the lemming,

Lemmus sp., is on St. George Island; and both islands have reindeer

(Rangifer sp.) and possibly the sea otter, Enhydra tutris, from a

transplant in the 1960's.

Much has been written about fur seals of the PribiiofIslands si nce

1867, the year in which the United States purchased Alaska from

Russia. This information has appeared in countless scientific journals, task force reports, popular magazines, and reports by various

agencies of the U.S. Federal Government, including the U.S.

Congress. Information about the Pribilof Islands before 1867 appeared in accounts by Bancroft (1886), Dall (1870), and Elliott

(1884), and publication of the book "Russian America" in 1979 by

the Soviet Union provided new information about pre-1867 Alaska,

including the Pribilof Islands. Descriptions oflife and conditions in

these islands were given; data on the human populations as well as

their utilization of fur seals and other marine mammals, plants, and

sea birds were obtained from the unpublished notes of Khlebnikov

(1979) for some of the years between 1786 and 1829.

This paper presents information from the Russian era with further

details on the management of fur seals on the Pribilof Islands, as

reported by Roppel and Davey (1965), and how the modern and

much less isolated communities of St. Paul and St. George might

now influence the fur seal resources there. Some research results are

given; however, the primary objective of the paper is to document

2

information accumulated by the author during 26 yr (1956-81) of

involvement with management of the resource and to list appropriate references to which other scientists can turn for additional

details.

RUSSIAN REGIME

According to Bancroft (1886), the Pribilof Islands were discovered by Stoorman2 Gerassim Pribylov late in the 18th century: St.

George in 1786 and St. Paul in 1787 or possibly 1786. During the

next few years, the islands underwent a succession of name changes

(Khlebnikov 1979). Called the "New Islands" at the time of discovery, they were later renamed after the company's discovery ship

"Lebedenski." The names "Zybovyi," "Northern," and, occasionally, "Fur Seal Islands" followed. Finally, they were given the name

"Pribylov Islands" in honor of their discoverer.

Human Population

The islands were uninhabited when discovered, and a labor force

was required to harvest the fur seals,3 sea otters, and arctic blue

foxes found in abundance there. This need was satisfied during the

early years by importing Aleuts from the village of Unalaska on the

Aleutian Island of the same name (Khlebnikov 1979). These people

at first "took turns" working on the Pribilof Islands, but some

eventually relocated there permanently and no longer exercised an

option to return home to Unalaska every 3 or 4 yr as they once did.

There were apparently considerable fluctuations in the number of

Aleuts on the Pribilof Islands as a result of this interisland movement. For example, in 1825 the total population of 226 humans on

the Pribilof Islands contained 189 Aleuts from Unalaska, yet 4 yr

later in 1829 only 30 of 248 persons were of this race (Khlebnikov

1979). In either case, the remainder were Russians, Indians, and

Creoles (the latter were offspring of Russian men/Aleut women

[Dmytryshyn and Crownhart- Vaughn 1979]).

'Russian for ship's mate.

'According to Khlebnikov (1979:32) "there were at least no fewer than a half million

of these animals there."
Index chart

o

I

ST. PAU L ISLAND

+

N

!.:.~::;. Killing field

::,::;;::, Rookery

Hau ling ground

Extinct rookeries:

A. Suthetunga

B. Lagoon

C. Nah Speel

D. Maroonitch

1

2

.!!J Sivutch

3

A

U

Polovina Cliffs

Potovina

()

5

o

6

Little Zapadni

Figure 2.-SI. Paul Island, Alaska, and the rookeries and hauling grounds of the northern fur seal. Sivutch is Russian for sea lion.

3
N

+

i

:::::.:: Killing field

;:;:;:;:;: Rookery

Hauling ground

Extinct rookery:

A. Little Eastern

A

"" -7 St. George rV""ge ..:: ......: ::.::... :...~: Index chart

1

Staraya Artil

2

Zapadni

4

East Cliffs

East Reef

3

Figure 3.-81. George Island, Alaska, and the rookeries and hauling grounds of the northern fur seal.

4
Up to 1818, the Pribilof Islands were a part of the Unalaska

District, but after that year administrative supervision was received

directly from New Arkhangel (now Sitka). The primary settlement

on St. Paul Island was constructed at the southeastern end where the

present village is located. There were two other but smaller settlements, one at the eastern cape and the other in the western region.

All three villages were placed near concentrations of fur seals for

convenience in harvesting and processing the skins of these animals. The only village on St. George Island was established in the

northern region. However, a small but permanent camp was located

in an outlying area west ofthe present village. Taking its name from

this camp, a nearby rookery was called Staraya Artil, literally "old

Artel" or small collective (commercial) enterprise. The Russian

Chief ofthe PribilofIslands section resided on St. Paul but annually

made a trip to St. George in the summer "to affirm business

expenses there and to census the (human) population" (Khlebnikov

1979:23). Not without considerable danger, this 40-mi crossing in

these early years was made ina large "baidara" or"skin boat" under

sail, a trip that took 7 h. There were casualties and, in at least one

instance, the island was bypassed altogether and the travelers eventually landed on one of the Aleutian Islands. Later, use of a sailing

ship from Unalaska made the journey much safer.

Marine Mammals

Four species of marine mammals were associated with the

Pribilof Islands at the time of discovery: The northern fur seal, sea

otter, northern sea lion, and walrus. Scarcely a half century passed

before the sea otter was exterminated. Khlebnikov (1979:6) wrote

"Upon discovery of the island [St. Paul] ... many sea otters were

found; now they never appear" (reference is apparently to the

1820's). He also mentioned (1979:9) that walruses appeared on

Walrus Island from time to time and that in 1821 they" ... crowded

the sea lions [on St. George Island], and this (crowded) the fur seals

on occupied places, however, the next year and thereafter, they

appeared nowhere at all." Early fur traders said that the Steller's sea

cow, Hydrodamalis gigas, was found on the Pribilof Islands in

extremely high numbers, but was later removed. According to

Khlebnikov (1979:6) " ... this information resembles a fable. This

animal had sanctuaries somewhere if it existed, but ... [they are] not

seen anywhere at all at the present time" (as of the 1820's).4

At the very beginning, the sea otter had the highest value and was

therefore the most valuable product shipped from the Pribilof Islands. The fur seal, estimated to number "no fewer than a half

million" as previously mentioned, was at that time secondary in

importance to the sea otter, and although harvested, it was apparently taken only in those places where it was most convenient

(Khlebnikov 1979). The early harvests at least were apparently of

pups, for according to Khlebnikov (1979: 14) "When the young fur

seals, having been born this year, arrive at the proper age and

approach the time for their departure from the islands, then, that is,

in the latter part of September or first of October, the drives are

begun .... Having driven the whole herd to a flatland, they separate

the sea lions, bachelors, 5 and females and accompany their return to

the sea. Young designated for killing are driven closer to the village."

'Steller's sea cow, discovered in 1741 in association with the Commander Islands,

was exterminated by 1768 (Chelnikov 1969; Scheffer 1972, 1973).

'During this period, the Russians classified males of ages 2-4 yr as subadults and

those estimated to be age 5 yr and older as adults. During their annual counts of

breeding males, U.S. scientists classify males of estimated age 7 yr and older as adults.

5

The practice of harvesting pups of both sexes during the 1700's

and early 1800's in autumn compares with the current practice of

taking primarily 3- and 4-yr-old males in late June and July and

sparing the females. At first, i.e., late 1700's and early 1800's, there

were available from St. Paul Island 50,000 to 60,000 and from St.

George Island 20,000 to 25,000 fur seals (as indicated above, the

kills were apparently of pups). The size of the annual harvest

eventually dwindled to 20,000-25,000 on St. Paul Island and

5,000-8,000 on St. George Island, a situation that led to cessation of

the kill on both islands for 3 yr (1805-7) and prompted the statement

that "The first rule is to not kill the females and bachelors, and above

all, the adult males" (Khlebnikov 1979:15). However, the kill was

resumed in 1808, and from 1786 to 1828, a total of 3,080,655 fur

seal skins had been shipped from the island (Khlebnikov 1979).6

Just when the transition from taking pups of the year to harvesting

older seals occurred is unknown. In 1822, Chief Administrator

Muravev ordered a moratorium on one rookery each October as an

emergency measure. But it was not until 1835 that the females were

spared and the kill of males was regulated (Osgood et al. 1915).

In a land far removed from the amenities of civilization, preservation of the skins of thousands of fur seals, even the relatively small

ones taken from pups, must have been a monumental task. The

Russians accomplished the nearly impossible by stretching the skins

onto wooden frames in pairs with fur against fur and flesh sides out,

then placing the "stretched" skins in a specially built drying plant

warmed with rocks under which a fire of driftwood was scantily fed

four times every 24 h to maintain slight heat. Up to 2,000 skins were

dried in 24 h on St. Paul Island (Khlebnikov 1979). This method of

preserving the skins gave way, at least under American involvement

(1867) with the Pribilof Islands and the resource, to kenching

(burying in beds of salt); the actual year the method started is

unknown. An entry in the St. Paul Island logbook for 1871 showed

that skins were salted in that year. The current practice of brining in

a saturated solution of salt began about 1951.

There was also a small industry utilizing sea lions on the Pribilof

Islands, primarily on St. George where a thousand or more were

harvested annually. The much smaller population ofsea lions on St.

Paul Island yielded 300-400 animals each year. 7 Primary products

from sea lions included intestines for making waterproof shirts,

throat linings for straps, bladders (use not mentioned), skin of the

flippers for shoe soles, whiskers for decorating caps and hats, and

hides for covering the baidars or "skin boats." The hides were

stacked into piles and left there for as long as a month to rot the hair,

then cleaned and stretched on stakes during the winter for drying.

The fat was saved for use in oil lamps and in the cooking fire during

shortages of driftwood, and as a medium in which to store eggs and

prevent spoilage. Young sea lions were taken in addition to the older

animals to augment the supply of food. Most of the products from

sea lions were consumed locally; however, some were shipped to

New Arkhangel.

According to Khlebnikov (1979: 16), walruses were also taken but

"Only the tusks are cut out; the meat and skin is left. However, for

"According to Khlebnikov, who mentioned difficulties in obtaining accurate data, an

additional 700,000 skins were destroyed on the islands, which mayor may not have

included 312,324 skins from the old Merculief Company rejected at Unalaska. Thus,

4,193,000 fur seals (annual average 100,(00) may have been taken during the 42-yr

period from 1786 to 1828. It seems unlikely that an annual harvest of 100,000 pups

would have depleted a herd even as small as a half million, unless half were females and

the effects of what must have been a considerable disturbance to the rookeries were

factors.

'Sea lion pups were last born on St. Paul Island (at Northeast Point) in 1957 (author's

personal observation). Kenyon (1962) documented the history ofthe sea 1ion population

on the Pribilof Islands.
some time in the past there has been no significant industry on these

islands for the walrus." Baleen was collected from beached whales.

Fox

The number of arctic blue foxes taken on the PribilofIslands each

year ranged between 1,400 and 1,800, with 1,200-1,500 coming

from the more heavily populated SI. George and the remainder from

St. Paul. Most were of the "blue" color, as opposed to the fairly rare

white phase (Khlebnikov 1979).

Marine Birds

Murres, Uria sp., and the horned, Fratercula corniculato., and

tufted, Lunda cirrhata, puffins contributed 6,000-9,000 ski:JS annually for use in making parkas. The flesh of these and other birds

was dried for consumption during the winter and the eggs of many

were collected for food (Khlebnikov 1979).

Marine Fishes

The Pacific halibut, Hippoglossus stenolepis, was much sought

for food then as now and the Pacific cod, Gadus macrocephalus,

was also taken (Khlebnikov 1979).

MANAGEMENT BY THE UNITED STATES

Following the purchase of Alaska from Russia by the United

States in 1867, the years 1868 and 1869 were" ... characterized by a

ruthless slaughter exceeding even that during early Russian ownership of the islands" (Roppel and Davey 1965:451). This practice was

stopped with the setting aside of the Pribilof Islands in 1869 as a

special reservation for the protection of the fur seals upon their

return to land in summer to bear their young and to breed.

From 1870 through 1909, two consecutive 20-yr leases for harvesting fur seals were awarded to private firms operating out of San

Francisco; the first lease was awarded to the Alaska Commercial

Company and the second to the Northern Commercial Company

(Roppel and Davey 1965). Each was mandated by contract to take

only males. Following expiration of the second 20-yr lease in 1909.

the U. S. Government assumed total responsibility for the harvest of

fur seals and the welfare of the Aleut communities of the Pribilof

Islands. The 40-yr-old policy ofsparing the females over the next 45

yr was also continued. Additionally, extensive pelagic sealing had

nearly exterminated the herd. The treaty of 1911, ratified by the

governments of Great Britain (for Canada), Japan, Russia. and the

United States protected fur seals at sea during most of this period.

Japan exercised a right as stated in the Convention and caused its

termination in October 1941. From then until 1957, the United

States and Canada maintained a provisional agreement for the

protection of fur seals in the eastern North Pacific Ocean (Roppel

and Davey 1965).

In 1957, a new treaty was ratified by Canada, Japan, the

U.S.S.R., and the United States and entered into force on 14

October of that year. A primary objective of this treaty, "Interim

Convention on the Conservation of North Pacific Fur Seals," was to

determine "what measures may be necessary to make possible the

maximum sustainable productivity of the fur seal resources so that

the fur seal populations can be brought to and maintained at the

levels which will provide the greatest harvest year after year" (U.S.

Congress, Senate 1970:74). In this connection, the United States

collected 13,845 fur seals in the eastern North Pacific Ocean and

6

Bering Sea during 1958-74 and is now cooperating with Canada in

an extensive joint analysis of data on distribution and migration of

these animals, age and growth, feeding habits, and reproduction.

These pelagic data, (Kajimura et al. 1979,R 1980;9 Lander 1980b)lO

together with those collected on the Pribilof Islands (Lander 1980a)

with respect to physiology and medicine, behavior, and population

assessment, make up the United States' contribution to the overall

data base of the North American component of the species. The

results of research carried out by the United States are periodically

published in scientific journals and are formally reported to the

Convention's North Pacific Fur Seal Commission (NPFSC) during

its annual meetings. In addition, the United States uses the information as a basis for managing the fur seal resource of the Pribilof

Islands. In addition to the above documents, Lander and Kajimura

(1980) have summarized the data on northern fur seals collected by

the U.S.S.R. and Japan in the western North Pacific Ocean.

Herd Reduction

The first intentional harvests of females on land after 1869 were

initiated in 1954 and 1955 with the taking of all females appearing in

the drives of seals from the hauling grounds that were within the

body length limits for harvesting males. These animals were used

primarily for studies of reproduction but also to provide information

on the commercial value of skins from females. According to

Kenyon (1954:31), II " ... if the COW l2 skins prove to have commercial value it will be practical and not detrimental to the fur seal herd

to continue in future sealing operations to take all cows of commercial size which appear on the killing fields." The management

decision based on the answer to this question was especially important because a forthcoming reduction in the size of the herd through

the harvesting offemales had as its ultimate objective the limiting of

pup production to 400,000 annually. The biological rationale for

this reduction was that at a lower level, survival of the young would

be enhanced and perhaps the overall pregnancy rate would increase

as the population strived to reach its natural ceiling in terms of total

number (Chapman 1961).

In return for this unprecedented manipulation of the number of

fur seals, research scientists expected an increase in the total harvest

with stabilization of year-class survival and an estimated sustained

annual yield to the harvest of 55,000 to 60,000 males and 10,000 to

30,000 females.

'Kajimura, H., R. H. Lander, M. A. Perez, A. E. York, and M. A. Bigg. 1979.

Prel iminary analysis of pelagic fur seal data collected by the United States and Canada

during 1958-1974. Unpubl. rep., 247 p. Natl. Mar. Mammal Lab., Natl. Mar. Fish.

Serv., NOAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA 98115.

9Kajimura, H., R. H. Lander, M. A. Perez. A. E. York, and M. A. Bigg. 1980.

Further analysis of pelagic fur seal data collected by the United States and Canada

during lq5~-1974. Unpubl. rep., Part I, 94 p. and Part 2.172 p. Natl. Mar. Mammal

Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA

98115. (Submitted April 1980 during the 23rd Annual Meeting in Moscow, USSR, of

the Standing Sci. Comm., North Pac. Fur Seal Comm.)

l"These data are also presented in various annual reports of fur seal investigations

and proceedings of Ihe North Pacific Fur Seal Commission meetings filed at the

National Marine Mammal Laboratory, Northwest and Alaska Fisheries Center, NMFS,

NOAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA 98115.

llKenyon, K. W. 1954. Alaska fur seal investigations, Pribilof Islands, summer of

1954. Unpubl. rep., 48 p. U.S. Dep. Inter., U.S. Fish Wildl. Serv., Bur. Commer.

Fish., Branch Wildl. Res. (Available Natl. Mar. Mammal Lab., Natl. Mar. Fish. Serv.,

NOAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA 98115.)

l'Females older than pups are also referred to as "cows," males of ages 1-6 yr are

called "bachelors," and the term "bull" is used when referring to the adult male

(estimated age 7 yr and older).
Not having harvested females in large numbers before, federal

administrators or managers of the islands and the harvest had no

guidelines to follow nor was there any information available to

suggest how, when, or where the females should or could be taken.

As a result, the early harvests of females were largely experimental.

It was already known that few females appear on the hauling

grounds before late July because most of the animals driven from

these areas in the past had been males. This and the fact that the

onset of molt or "staginess" of the skins of fur seals (sometime

during the summer) adversely affects their value in terms of a DDM

& p3 product by interfering with traditional fur processing

methodsl4 prompted managers to ask "When would be the best time

to harvest females and would it be possible to take males concurrently?"

Considering all factors known at the time, managers decided to

take all females found on the hauling grounds during the normal

harvest of males in 1956, which, in that year, was extended to 15

August. They also made plans to carry out an experimental harvest

of females in September and October of 1956 to measure the availability of these animals on the hauling grounds; furthermore the

onset of staginess would be more precisely pinpointed and thus the

time ofseason when it would no longer be profitable to take fur seals

because of it. Additional information about the development of

staginess among females was obtained between the two major

harvesti ng periods by taking 20 ofthese animals at 5-d intervals and

examining their underfur; others were removed from the sand beach

portion of Polovina Rookery in July of 1956 and 1957 (Abegglan et

al. 1956,15 195716) to test the availability of animals from this

source. These "harem raids" netted 2,983 females from eight

"drives" and exterminated that part ofPolovina Rookery, which has

not recovered to this date. Additional females were also taken

directly from portions of Reef and Northeast Point Rookeries in

1957, but the numbers were too few to have any observable effect.

Managers extended the harvest of males in 1956 from a traditional

termination date in late July to 15 August because of exceptional

survival of the 1952 and 1953 year classes and recent but rapid

increases in the numbers of idle males on the hauling grounds,

which indicated a need to reduce recruitment into the breeding

reserve. During this period, the available females taken from the

hauling grounds numbered 22,681. A 5-d harvest of females during

4-8 September in that year yielded an additional 4,807 animals, but

because 603 or 12% of these had by then become stagey and had to

be rejected as unfit for processing, plans for additional kills as late as

into October were abandoned. From the results of experimental

harvests in 1956 and 1957 (portions of three rookeries were used as

I3Dressed, dyed, machined, and finished. Each skin is subjected to a tanning process

involving the use ofoil from the fur seal itself, trimming and removal ofthe guard hairs.

The skin is also dyed and machined and finished to a thickness thin enough to permit

drawing it through a napkin ring.

I4A pelt is said to be stagey when short, new guard hairs, called "peepers" by the

trade, appear among the underfur fibers and the flesh side of the skin becomes bluish or

grayish because of new melanin (dark pigment) in the area. These short, new guard

hairs, which cannot be removed, interfere with the "lay" ofthe underfur in the finished

product.

"Abegglen, C. E., A. Y. Roppel, and F. Wilke. 1956. Alaska fur seal investigalions,

Pribilof Islands, Alaska. Reporl of field activities June-September 1956. Unpubl. rep.,

145 p. U.S. Dep. Inter., U.S. Fish Wildl. Serv., Bur. Commer. Fish., Branch Wildl.

Res. (Available NaIl. Mar. Mammal Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand

Point Way NE., Bldg. 32, Seattle, WA 98115.)

16Abegglen, C. E., A. Y Roppel, and F. Wilke. 1957. Alaska fur seal investigations,

Pribilof Islands, Alaska. Report of field aClivities June-September 1957. Unpubl. rep.,

162 p. U.S. Dep. Imer., U.S. Fish Wildl. Serv., Bur. Commer. Fish., Branch Mar.

Mammals. (Available Natl. Mar. Mammal Lab., Natl. Mar. Fish. Serv., NOAA, 7600

Sand Point Way NE., Bldg. 32. Seattle, WA 98115.)

7

sources offemales in 1957 also), and from subsequent developments

in the processing and marketing of skins from females, managers

learned that: I) It is not only dangerous for the workers but impractical to conduct harem raids because of the aggressiveness of the

territorial males, 2) females become increasingly available on the

hauling grounds and on the rookery fringes as the season progresses

beginning in late July when the organized breeding structure starts

to break up, 3) it is necessary to harvest most females in August and

September because it is not until then that they become available

from sources other than harem raids, 4) staginess becomes a problem with the skins of animals taken from early September on if they

are to be subjected to traditional DDM & F processing, 5) staginess

begins at the nose and progresses to the animal's posterior, 6) males

become stagey before females, and 7) the younger animals of both

sexes become stagey before the older seals.

Backed by years of tradition in sparing the females and with little

or no knowledge of biology or population dynamics, certain federal

managers involved with the resource and members ofthe local Aleut

communities were understandably quick to question the wisdom of

harvesting these animals. lt was emphatically noted that killing a

female not only took her life and the newly fertilized ovum within

her body, but left her pup to die from starvation on the rookery as

well. This same argument had been raised by the United States late

in the 19th century during the controversy over pelagic sealing.

Objections of the 1950's, though just as valid, nevertheless

triggered substantial resistance to the harvest of females and slowed

development of new processing methods and a badly needed market

for the skins of older females, which were "very different" from

those of males in terms of traditional quality. The situation would

have been much improved had steps been taken to correct such

deficiencies in the herd reduction program before rather than after it

commenced.

There was no particular problem with skins from the younger

females, i.e., ages 3 and 4 yr, because they had not yet entered the

formal breeding structure and were as unscarred and clean as the

skins of males of the same ages. In fact, the skins of young females

mistaken for males and taken accidentally had in the past been

included in DDM & F processing with skins from males and sold at

the same prices. However, the skins of the older females, scarred

from life on the rookery, had little to offer to an industry based on

soft luxurious furs coming from the DDM & F process. Other

problems arose because the rather large kills of females, together

with the harvest of males, severely taxed the labor force as well as

processing and storage facilities both on the Pribilof Islands and in

the Fouke Fur Company'sl7 skin processing plant in St. Louis, Mo.

lt soon became economically impractical to care for and provide

storage for thousands of skins that were unwanted for lack of a

suitable processing method and a market for the finished fur. A new

method of treating the skins of females by close shearing of fur and

guard hair was eventually to be developed under the trade name

"Lakoda." 18 This process overcame problems associated with staginess and scarring but not in time to prevent the destruction of over

I'This firm, since renamed lhe "Fouke Company," has for many years been under

contract to the Federal Government to finish the skins of fur seals taken on the Pribilof

Islands.

16The "Lakoda process," one of closely shearing the hair and fur ofthe fur seal, was

cooperatively developed in 1957 by the Federal Government (through its Marine

Mammal Biological Laboralory, now the National Marine Mammal Laboralory) and

the New Method Fur Dressing Company in San Francisco. Later, after one or more of

lhe "Lakoda" skins had been sent 10 lhe Fouke Fur Company for evaluation, S. J.

Pingree, assignor to the Fouke Fur Company, palented the shearing process (Scheffer et

al. in press).
50,000 skins, losses which appeared in official records as "skins not

utilized."

Managers formulated many courses of action during several years

of the herd reduction program on both islands to eliminate as great a

percentage as possible of the labor costs associated with "commercialization" ofthe unwanted skins from females while achieving the

planned reduction (Table I). The actual take of older, but the then

commercially worthless, females in 1958 and 1959 was minimized

to some extent by imposing an upper body length limit of 46 in (117

cm). Larger animals were to be taken in those years only if necessary to reach quotas established for taking females and reducing the

size of the herd. In the summer of 1960, however, lack of males in

expected numbers by mid-July prompted managers to seek and

obtain permission to abandon their assigned quota of 17,500

females and in its place to take only a few for research, up to 250/d

from the hauling grounds of St. Paul Island and WOld on St. George

Island. The total take of females in that year was restricted to 4,315

and concern over the welfare of the herd brought about a flurry of

photographing the rookeries for comparison with past photographs

in an attempt to learn if geographical boundaries of the breeding

areas were actually shrinking in size. Satisfied that they were not,

managers decided that during each of the next 3 yr, from 1961

through 1963, they would complete quotas established for taking

females with harvests extended into September, if necessary. The

managers received instructions from Washington, D.C., to take or

keep only those skins in 1961 that were from females with dark

whiskers, a decision that effectively prevented the processing of all

animals age 6 yr and older (both females and males through age 4 yr

have dark whiskers, age 5 yr a mixture of dark and white, and age 6

yr and older, white.

The policy ofkeeping only the dark whiskered females in 1961 led

to the discarding of nearly 70% ofthe 43,849 skins taken that year as

unfit for processing (though developed in the late 1950's, the

"Lakoda" process was not yet totally accepted by the fur trade).

Managers altered their plans for 1962 to selectively kill (on St. Paul

Island only) young females in July and August and older females in

September to demonstrate an ability to take these animals by age.

This decision followed an attempt by the Japanese contingent to

persuade the other members of the North Pacific Fur Seal Commission to permit pelagic sealing in conjunction with harvesting on

land. According to Japan's fur seal scientists, selective killing of

young females was possible at sea but not on land. The "experiment" was moderately successful in that during the early period

Table 1.-Number of fur seals harvested and skins rejected I because ofstaginess,

St. Paul Island, Alaska, August-September 1956.

Females (all ages) Males (ages 1-4 yr)

Date Harvested Rejected (o/c) Harvested Rejected ('Ic)

August

20 20 0 0 0

25 19 0 2 2 (100)

30 20 2 (10) I o ( 0)

September

4 519 101 (19) 18 Unknown

5 520 50 (10) 18 Unknown

6 399 36 ( 9) 33 28 ( 85)

7 479 97 (20) 76 66 ( 87)

8 426 85 (20) 86 76 ( 88)

13 21 6 (28) I I (100)

18 20 8 (40) I I (100)

23 12 3 (25) 10 9 ( 90)

'As unfit for further processing.

8

59% of the females taken were of ages 2-5 yr and in September 75%

were age 6 yr and older. Most of the skins from the older females

taken in 1962 were not processed, bringing the total "not utilized"

in 1961 and 1962 to more than half the total of 87,609 females

harvested during those 2 yr.

In 1963, the last of the herd reduction years, all except a few

hundred of the skins taken were kept, regardless of age. By this

time, reserves of skins held in storage on the Pribilof Islands and at

the Fouke Fur Company's plant had been depleted sufficiently to

accommodate additional skins. More importantly, the "Lakoda"

process was now gaining in importance as a method of treating the

skins of females, which were becoming increasingly valuable in a

rapidly expanding market for the product. The attitudes of federal

administrators on the islands and officials of the Fouke Fur Company were reversed almost overnight: later there was even concern

about maintaining supplies of raw skins as average values of the

"Lakodas" closely approached those of DDM & F skins.

In 1964, it was decided to terminate the herd reduction program

but to try to maintain the population of females at the 1963 level.

Thus, females harvested from 1964 through 1968 were considered

surplus to maintaining herd size at the level achieved by 1963.

During this period, an estimated 45,000 females were needed

annually to replace breeding animals that died of natural causes. All

above this number, usually between 9,000 and 18,000, were considered surplus.

Also, in 1964, most of the old females appearing in the drives

were allowed to escape because the new and lower level of pup

production had been achieved and the need to reduce the total

number offemales had ended. In general, only those females having

black or a mixture of black and white whiskers were taken, which

essentially restricted the kill of this sex in 1964 to those of ages 2-5

yr. The kill of females on St. Paul Island in 1965 was characterized

by a harvest selective for those with black or a mixture of black and

white whiskers; all females available on St. George Island, however, were taken regardless oftheir whisker color. In 1966, there was

essentially no commercial harvest of females on either island because managers believed that all were needed to maintain the

population at the estimated level in existence at that time. A few

were taken for research and some were killed accidentally during

the commercial harvest of males, bringing the total taken in that

year to 481. In 1967 and 1968, females believed to be in excess of the

number needed to maintain the population were again harvested.

These animals were taken without regard for age or size, and the

relative size of each rookery in terms of total population was used as

a guide in killing most ofthe animals. Special efforts were made not

to exceed quotas set for Reef and Polovina Rookeries on St. Paul

Island and for Staraya Artil Rookery on St. George Island. Because

of the extreme accessibility of females on these rookeries, they were

considerably and disproportionately overharvested during the

period of herd reduction.

Thus, the removal of 270,000 females from 1956 through 1963

and the taking of nearly 51,000 during the period of "population

maintenance" from 1964 through 1968 brought the total harvest of

this sex during the 13-yr period to well over 300,000 animals.

The impetus for reducing the number of females and, as a consequence, the number of pups born had as its primary basis historical data that showed a relationship between the size of the pup

population and survival to age 3 yr. Chapman (1961, 1964) concluded that survival to age 3 yr would be maximized with a total pup

population of about 400,000, as mentioned earlier. A level much

lower than 400,000 would recruit too few pups into the system for
maintenance of the population, whereas density dependent factors

would become operative at a higher level.

Unfortunately, the start of the herd reduction program coincided

with the beginning of a decline in the number of males available for

harvest. This development revived past objections to the removal of

females, a harvest that was now viewed by some individuals as a

direct cause of the decline in the number of young males.

There was no denying the reality of a lesser number of young

males, but there was no real nor logical explanation for a sudden and

distressing shortage of these animals beginning in the late 1950's.19

Contrary to the opinions of federal administrators on the islands and

many of the Aleut residents, it was immediately obvious that the

offspring of females harvested in 1956 could not have entered the

commercial harvest ofmales until 1959 at the earliest. Even so, only

half the pups born of the 22,680 females taken in 1956 were males,

of which 80% or more normally would be destined for death before

reaching age 3 yr in 1959. Mathematically then, those females could

not have contributed more than 2,000 young males to a harvest of

12,922 3-yr-old males ending 31 July in 1959, a number insufficient

to account for a 63% drop from a take of 34,462 the year before or

even the 39% decline from the harvest of 21,113 3-yr-old males by

31 July in 1957.

These sudden and substantial changes generated speculation

within the scientific community that some natural factor or combination of factors had become fundamentally significant-such as

predation, disease, or climatic circumstance. The hookworm, Uncinaria lucasi Stiles, identified in 1945 as a significant cause of

mortality among fur seal pups (Scheffer et al. in press), was immediately suspect. There eventually arose additional conjecture that

perhaps the invasion of foreign fishing fleets into Alaskan waters,

beginning in the mid-1950's, influenced survival through a substantial reduction of the fur seal's supply of food around the Pribilof

Islands during the nursing season and along its migration corridor

between the breeding grounds and the Aleutian Islands.

Whatever may have been the cause, managers and scientists alike

saw a 17-yr average harvest of71,500 males from 1940 through 1956

slip to one of barely over 40,000 during the next 3 yr. The harvest in

1960 declined even further to 36,000. Additional evidence that the

onset of the herd reduction program had no real relationship to the

decline in the number of males available for harvesting became

apparent with a dramatic rise in the harvest of 1961 to 82,197. The

average annual harvest of 45,000 from 1962 through 1971, though

somewhat higher than the average of 40,000 during 1957-59, was

still considerably below the average of 71,500 during 1940-56.

Clearly, one or more factors, whether natural or man-made, were

operating to adversely affect the herd and cause extreme fluctuations in year class survival and overall, a much reduced production

of young males. As a result, the NPFSC had by 1972 recognized a

need to develop a coordinated land-pelagic program and concentrate

on new avenues of research. Accordingly, the NPFSC at its annual

meeting that year discussed the desirability of collecting fur seals in

the Bering Sea between the Pribilof Islands and Unimak Pass in the

Aleutian Islands and of establishing one or more research control

'"Four-year old males normally peak in their arrival on the Pribilof Islands about

mid·July and the 3-yr-olds do so approximately 2 wk later. Thus, an extension of the

season into August in a given year increases the take of 3-yr-olds but reduces the kill of

4-yr-olds from that year class the following year. Regardless of such extensions and

their effect on the harvest, the harvest of males since 1956 has been much depressed

over what it had been previously. The decline is especially evident in the kill by year

class; 5 yr averages are 43,793 (1957·61), 36,917 (1962-66), 31,691 (1967-71), and

25,311 (1972-76). Year classes 1977 and later have not yet been totally subjected 10

harvest and are therefore not included here.

9

areas on the Pribilof Islands (North Pacific Fur Seal Commission

1973). The ultimate objective of the research at sea was to compare

feeding habits in the 1970's with those of the 1950's and 1960's

(Kajimura et al. footnotes 8, 9) to determine if there had been

changes in species of food taken (North Pacific Fur Seal Commission 1973), In 1973, the United States submitted and the NPFSC

adopted a proposal that was to provide for renewed emphasis on fur

seal research in the Bering Sea and establish all of St. George Island

as a research control area where fur seals would not be harvested for

several years (Anonymous 1973; North Pacific Fur Seal Commission 1973), The only change made in the harvest moratorium on St.

George Island since then occurred in 1976 when, beginning in that

year, a limited annual take for local use as food was permitted, The

research planned for 1973 and several subsequent years on St.

George Island was to include the collection of data on:

I) Behavior and such activity patterns of adult males as time

spent establishing and defending territories.

2) Length of nursing-feeding cycles of lactating females.

3) Distance traveled to feeding areas and time spent feeding by

lactating females.

4) Activity of pups, such as time spent nursing and average

number of nursing periods prior to leaving the island.

5) Activity patterns of adult females and young males on the

hauling grounds.

6) Changes in activity patterns of fur seals when disrupted by

research and management activities.

7) Interaction between fur seals and northern sea lions on fur seal

rookery areas.

8) Causes of death among pups before and after the expected

increase in number of males.

The United States believed it necessary to establish the research

control area on St. George Island and a moratorium on the harvest of

fur seals there because of failure of the Pribilof Islands herd to

respond as anticipated to changes in the management scheme

started in 1956. Instead of increasing, the average number of males

harvested during 1957-60 declined to 40,000 and a similar situation

with regard to the females began to develop in that by the early

1960's, fewer and fewer young females were appearing on the

hauling grounds. In order to complete quotas established for taking

females, especially during the relatively large kills of these animals

during 1961-63, managers found it increasingly necessary to "raid"

the rookeries by skimming parturient females off the inland fringes

as soon as they became available following the breakup of organized

breeding in August.

The decision to impose the harvest moratorium on St. George

Island rather than on selected rookeries of St. Paul Island and to

substantially increase the research effort there was based on several

factors. First, an analysis of tag recovery data showed that the

degree of homing to the island of birth is considerably higher than to

the individual rookery units on each. Although fur seals returning to

St. Paul Island exhibited greater homi ng tendencies in all areas than

did fur seals born on St. George Island, the collective advantages of

the latter as a research control area outweighed those of St. Paul

Island in this regard. Second, St. George Island contained 20% of

the total population ofthe Pribiloflslands or slightly less than that of

the largest rookeries on St. Paul Island (but the harvest there had

declined from 20% to II % of the total), and had four physically

discrete subpopulation units which would permit research to be

carried out on separate units and allow replication of studies.

Additionally, it would be possible to make direct counts of the
relatively small pup populations of from 8,000 to 20,000 on SI.

George Island. Moreover, access to the rookeries and hauling

grounds there was as good as or better than to those on SI. Paul

Island.

Thus, the first long-term study of behavior in the history of fur

seals on the Pribilof Islands was launched beginning in 1973.

Earlier but relatively short term studies were carried out by Bartholomew (1951,20 1953, 1959), Bartholomew and Hoel (1953),

Bartholomew and Wilke (1956), and Peterson (1965). Although IO

breeding seasons have since passed, these studies are still somewhat

in their infancy because of a need to examine the behavior and

biology of the herd at its "natural level," which will not occur until

about 1990 due to the relatively long life span of the species-17 yr

for males (Johnson 1968) and 20 yr or more for females. 21

Collection of Data

Information for studies of the population dynamics of the northern fur seal comes from several sources. Included are data on

animals harvested commercially, counts of adult males, tagging and

marking programs, estimates of the number of pups born, counts of

dead pups, and other measurements of mortality. Notes on the

development of and various features of these programs are presented

in this section.

Harvest of maIes.-The commercial harvest of males is by

necessity restricted mostly to the months of June and Jdy and

perhaps part of August because it is during this period that the males

appear on land and have yet to start their molt. Before 1930,

however, it was the practice to take seals in other months of the year

as well. These "off season" and relatively small harvests were

conducted to provide food for the people of the Pribilof Islands

(Bower 1930). After 1929, the killings for food were discontinued

(Bower 1931) and from 1930 through 1955 what is now considered a

"traditional season" prevailed, i.e., from a starting date in late June

to termination near the end of July. The need to take females under

the herd reduction program started in 1956. However, attendant

difficulties in identifying young males from females of the same

ages plus seemingly excessive numbers of adult males on the hauling grounds and rookery fringes also led to the concurrent harvesting of many males in August as well as during the regular season in

that and several subsequent years. This practice in turn led to

increasing utilization of each year class at age 3 yr, with the result

that with each passing year, progressively fewer and fewer animals

remained alive to return at age 4 yr. Managers responsible for

overseeing the harvest responded to the lack of males early in the

season22 by delaying the start of the kill to as late as 7 July (Marine

Mammal Biological Laboratory 1969) and postponing termination

several days beyond 31 July in some years from 1956 through 1968.

This seasonal shift in the period of the harvest prompted the

question of whether it was economically preferable to take fur seals

"'Bartholomew, G. A., Jr. 1951. Summary of observations made on the social and

reproductive behaviour of the Alaska fur seal during June, July, and August 1951.

Unpubl. manuscr., 3 p. U.S. Dep. Inter., U.S. Fish Wildl. Servo (Available atl. Mar.

Mammal Lab., Natl. Mar. Fish. Serv., OAA, 7600 Sand Point Way NE., Bldg. 32.

Seattle, WA 98115.)

2. A 21-yr-old animal wearing tag USA-6218 applied to it on Zapadni Rookery of St.

Paul Island in 1941 was taken there 16 August 1962. In 1981, a new known-age record

was established when a 25-yr-old nursing female wearing tag 1-7876 was seen in Reef

Rookery, SI. Paul Island . She had been tagged as a pup on North Rookery of SI. George

Island in 1956.

22As mentioned earl ier. the 4-yr-olds peak in abundance on land about 2 wk ahead of

the 3-yr-olds.

10

at age 3 yr before overwintering mortality reduced their numbers or

to take them a year later at age 4 yr after this loss had occurred. But it

was not until an analysis of average skin size and relative numerical

abundance of animals at the two ages was carried out, that it was

learned that there was little, if any, difference in economic return, at

least up to the mid-1960's (Marine Mammal Biological Laboratory

196623 ). The lesser value of the smaller 3-yr-olds was offset by their

greater abundance.

Because the managers preferred an earlier season to take advantage of summer weather (for such outdoor activities as construction

and maintenance), and because the change to a later season had

made the results ofscientific analysis of the harvest data less useful,

they opted to return to the starting and ending dates of past years.

The change back to June was made in 1967 with termination near the

end of July starting in 1969.

To decrease operating costs and provide time off for laborers

involved with the harvest, the work week on St. Paul Island was

reduced from 7 to 6 din 1967 and finally to 5 d beginning in 1977.

On St. George Island, it had been the practice for the same laborers

to not only harvest the seals each day but when finished with that

work to also process the skins. This situation was eliminated beginning in 1963 when managers changed their regime to one of harvesting the animals on Mondays, Wednesdays, and Fridays and processing the skins on alternate days. Both of these changes were possible

only because the number of animals available for harvesting had

declined from the much higher levels of former years.

Other aspects of the harvesting regime have also changed through

the years. First, it had long been the custom on the Pribiloflslands to

drive the seals from the hauling grounds to suitable killing fields

and start the harvest during the relatively cool air temperatures of

early morning24 when the grass is laden with dew to prevent overheating of the animals, undue stress, and even the deaths of some.

Thus, starting times for the drives have ranged from about 0515 h for

rookeries close to the village to 0600 h for the most distant hauling

grounds. In years of exceptionally large harvests such as in 1956,

the starting times were as much as 2 h earlier. The starting times on

SI. George Island were changed from 0515 h to 0830 h with the shift

from a 6- to a 3-d harvest week mentioned earlier. The later hour was

possible because of the relatively small kills on St. George Island,

which seldom exceeded 20% ofthe number taken on St. Paul Island.

Second, a "round" system has been followed on both islands when

harvesting the seals. The round or kill sequence on St. Paul Island

was25 and still is of5 d duration, meaning that each rookery/hauling

ground complex is visited once during the period. Thus, the total

period ofthe harvest in a given season consists ofseveral rounds. On

St. George Island, the round was only 4 d long, a number equal to

the total number of rookery/hauling ground complexes on that

island (there are six rookeries but essentially only four hauling

grounds). The 4-d round on St. George Island was changed to one of

3 d beginning in 1963 when harvesting was restricted to Mondays,

Wednesdays, and Fridays.

23Marine Mammal Biological Laboratory. 1966. Evaluation of fur seal skins by age,

sex. and method of processing. Unpubl. manuser., 29 p. U.S. Dep. Inter., U.S. Fish

Wildl. Serv., Bur. Commer. Fish., Mar. Mammal BioI. Lab. (Available Natl. Mar.

Mammal Lab., Natl. Mar. Fish. Serv., NOAA 7600 Sand Point Way NE., Bldg. 32,

Seattle, WA 9W5.)

2'Sea l drives were occasionally made the day before the harvest on Reef Rookery and

the animals held overnight in front of the village. The last such drive was made in 1950.

"Exceptions from 1967 through 1972 occurred on SI. Paul Island when managers

atlempted to maximize the kills first by inspecting the haul ing grounds then conducting

the harvest the following day from those with the most seals.
A representative of the Washington office of the Bureau of Commercial Fisheries (now the National Marine Fisheries Service)

noted, when visiting St. Paul Island in 1965, that a substantial

number of males were being rejected from the harvest, many of

which appeared to be just slightly over the upper body length limit

established for harvesting in that year. This was during an era when

field decisions concerning the harvest and even strictly biological

questions were often made by members of the Washington, D.C.,

office staff. Because of the observation, an extra 854 males were

added to the harvest in that year to test the commercial value of

"oversize" skins, many of which were of ages 4-5 yr (Roppel,

Johnson, and Chapman 1965) and of commercial quality. A nonbiological problem associated with the taking of males over a

certain body length at that stage was that their relatively large skins

could not be accommodated within the drying hoops and other

equipment used by the processing contractor. Many of these large

skins were from seals of the same ages as those normally taken and

were equal in quality and sold for higher prices (the contractor

requested, but was not granted, permission to develop new processing equipment, but instead was permitted to trim large skins to fit).

It had once been the practice to harvest seals on Sea Lion Rock

(Fig. 2-Sivutch) and such other inaccessible places as a gravel

beach just east of East Cliffs Rookery on St. George Island (Fig. 3)

and Ardiguen Rookery and an exposed reef off the western end of

Zapadni Rookery on St. Paul Island (Fig. 2). It has been many years

since seals were harvested on these areas. Firecrackers were used in

1967 and 1968 on St. Paul Island to frighten the animals off inaccessible reefs (Marine Mammal Biological Laboratory 1970a, b) and

from under cliffs and presumably to some nearby hauling ground

where they would then become available for the harvest.

According to Gentry (1981), males of harvestable ages are most

abundant on land between 1300 and 1900 h, a fact to consider with

respect to the time of day the harvest is carried out. In this connection, managers conducted three experimental harvests in 1981 on the

Polovina Rookeries of St. Paul Island during the afternoons of 23

June and 10 and 17 July. The conclusion, however, was that it would

probably never be feasible to implement a full-scale harvest in the

afternoon as opposed to a starting time of 0500 h currently in effect

because I) the seals are much more alert and aggressive later in the

day and can escape into the water with much greater ease and speed,

2) the animals would be subjected to higher ambient air temperatures and possibly death as a result of overheating, 3) the driving

and handling oflarge numbers of animals over long distances and up

steep slopes would not be possible because of 2), and 4) the sealing

crew would be resistant to such a change (Scordino 198]26).

The use of right maxillary canine teeth in determining the ages of

fur seals has been described by Scheffer (1950a) and Scheffer et al.

(in press). Bauer et al. (1964) examined the potential of using

weights of eye lenses to determine the ages of fur seals. The latter

investigators found that although the lenses did in fact grow heavier

with age, the overlapping of weights between ages precluded any

useful application of the results. Thus, the best technique so far

developed for determining the ages of fur seals is still one of

collecting, cleaning, and "reading" maxillary canine teeth. Anas

(1970) measured accuracies in assigning ages to fur seals and found

them to be within acceptable limits. The NPFSC also conducted

reader tests among member scientists, not only to measure ac-

"Scordino, J. 1981. Report on the experimental afternoon harvest of fur seals on St.

Paul Island in 1981. Unpubl. manuscr., II p. (Available Pribilof Islands Program,

Northwest Reg. Off., Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point Way NE.,

Seattle, WA 98115.)

11

curacies but to standardize the methods and techniques used by

scientists of different countries to determine the ages of fur seals

from canine teeth (North Pacific Fur Seal Commission 1967, 1970,

1979, 1980). The Marine Mammal Biological Laboratory (1969)

summarized the results of one reader test conducted by the NPFSC.

Abegglen (footnote 15), Roppel, Johnson, and Chapman (1965),

and the Marine Mammal Biological Laboratory (1969) discussed

sample sizes with tespect to the collection ofmaxillary canine teeth.

A beginning sample in the early 1950's of5% ofthe males harvested

was increased to 10% in 1956 to eliminate inaccuracies and variability found in the smaller sample. Kills of 100-300 males, mostly on

St. George Island, were sampled at the 20% level and those of < 100

at 30% or more to achieve representativeness. In 1966, the sample

was increased from 10 to 20% of those taken to provide better

representation of the relatively small numbers (10% or less of the

total) of 2- and 5-yr-old animals harvested.

Thus, body size, age composition, and a prescribed season became primary considerations of the managers in controlling the

harvest of males. Changes in the maximum limit of body length are

imposed to modify the utilization rate of the year classes, whereas

lengthening or shortening the season at the end ofthe kill in late July

increases or decreases the harvest of 3-yr-olds in a given year and

influences the size of the harvest of 4-yr-olds from the same year

class the following year. The results of these manipulations are

reflected most immediately in the age composition of harvested

animals as determined from annual collections of canine teeth and

several years later by changes in the number of adult males. A 20-yr

practice of counting over- or undersized males "rejected" (permitted to escape) during the harvest was abandoned at the conclusion of

the season in 1960 primarily because there was no way, short of

marking the animals, to separate seals counted once from those

counted two or more times.

As mentioned by Roppel and Davey (1965), limits of body length

for taking males were established after 1912 and applied first in 1922

to restrict the kill to males of age 3 yr. From 1922 through 1958,

these limits were a minimum of 41 in (104 cm) and a maximum of

45.75 in (116 cm), tip of nose to base of tail. At the end of the 1958

season, managers considered the number of idle males (as counted

on the hauling grounds and rookery fringes during the breeding

season) to be more than needed for recruitment into the breeding

stock and raised the maximum limit for 1959 to 46.75 in (119 cm) to

increase utilization of the year classes. The maximum in 1960 was

lowered to 45.75 in (116 cm) but raised again in 1961, this time to

47.75 in (121 cm).

The old technique of classifying harvested males by body length

to reveal age totally gave way to the new method of determining

ages from maxillary canine teeth beginning in 1962, but use of body

size as a guide in selecting males for harvesting was continued and

occasional checks were made of the lengths of harvested animals to

ensure that the workers took only those within prescribed limits. In

1962 (and all subsequent years when an actual numerical upper

length limit was imposed), the approximately l-in-Iong (2.5 cm)

tail was included in the measurement. Thus the range of 42 to 48. 75

in (107-124 cm) from tip of nose to tip of tail in effect that year was

actually equal to the range used the previous year (1961) of 41 to

47.75 in (104-121 cm), tip of nose to base of tail. The 1963 season

started with the same limits (42 to 48.75 in or 107 to 124 cm) as used

in 1962, but the maximum was removed early in July and all males

without a mane (long, silver-colored, guard hairs on the shoulders

and on the back of the neck) were taken throughout the remainder of

the season. This relaxation of control, which continued through

1968, essentially permitted the taking of all available 4-yr-olds and
(Available Natl. Mar. Mammal Lab.. Nat!' Mar. Fish. Serv.. NOAA, 7600 Sand Point

Way NE.. Bldg. 32. Seattle. WA 98115.)

Table 2.-Limits of body length used to control the harvest of male seals, Pribilof

Islands, Alaska, 1922-81.

that there was some overlapping in the body lengths of 3- and

4-yr-old fur seals. Roppel, Johnson, and Chapman (1965) demonstrated considerable overlapping in 1963 by measuring 1,005 3-

yr-old males tagged as pups in 1960. Twenty-nine percent of these

animals would have been classified as 4-yr-olds according to the

previously established age-length standards.

Li mits of body length used to control the harvests of males from

1922 through 1981 are summarized in Table 2.

ITip of nose to base of tai!.

'Tip of nose to tip oftai!. The addition of I in (2.5 em) to the limit beginning in 1962

accounted for the change in measuring from base to tip of tail, which is approximately

I in (2.5 em) in length.

3The proportion of males permitted to escape the harvest during 1973-75 was

intended to equal that during 1922-58 and in 1960, hence the return to an upper limit of

..6 in (117 em) in those 3 yr. Beginning in 1962. however. the tip of the tail, rather than

the base. was used, therefore the limit during 1973-75 should have been 47 in (119 em)

to account for the approximately I-in (2.5 em) long tail.

'Effective II July, the upper limit was raised from 47 in (119 em) to 49 in (124 em) to

increase the utilization rate.

Maximum

45.75-116

46.75-119

..5.75-116

47.75-121

48.75-124

48.75-124 to early July in

1963, thereafter in that year

and during 1964-68, all without

manes (long silver-colored

guard hairs on the shoulders

and on the back of the neck).

All without manes.

..9-124 or less

46-117 or less

47-119 or less

47-119 or less through 10 July and

49- 124 or less thereafter.

47-119 or less

49-124 or less

49- 124 or less

Body length (in-em)

41-104

41-104

.. 1-104

.. 1-104

42-107

42-107

Minimum

1969-71 None

'1972 None

'1973-75 None

"1976-77 None

11978 None

1979 None

1980 None

1981 None

Year

Harvest of females.-As mentioned earlier, few females are

available for harvesting on land until beginning in late July when

the young animals of ages 3 and 4 yr come onto the hauling grounds,

the so-called harem structure breaks up, and some of the breeding

females move to these areas from the rookeries. It has been speculated that the latter, most of which were parturient that same summer, had lost their pups through death and therefore had no particular allegiance to the rookery during the remainder of that breeding

season.

Nearly 73,000 females were sampled from the commercial harvests during 1956-68 and classified by age, reproductive condition,

body length, and vibrissal color. From this research i.t was learned

that some, but not all, of the females first give birth to pups when

4-yr-old rather than at ages 2 and 3 yr as once believed (Abegglen

and Roppel 1959), that females on the rookeries are concentrated

within the age range of 5 through 9 yr, and that most females through

age 4 yr have black vibrissae, the 5-yr-olds generally have a mixture

11922-58

11959

11960

11961

'1962

'1963-68

more than the normal number of 5- and 6-yr-olds. The minimum

limit of 42 in (107 cm) was maintained throughout the 6-yr period to

protect the 2-yr-olds.

This level of utilization continued during the next 3 yr (1969-71)

and even increased slightly through removal of the lower limit

altogether to permit the taking of all available 2-yr-olds in an effort

to learn if the total number appearing on land would be useful as a

guide in predicting the size of year class return at age 3 yr (earlier,

the lower length limit had been removed for a limited number of

days only for such studies-20 and 24 July in 1967 and 22-26 July

during 1964-66 and 1968-71). Thus, all males found on the hauling

grounds in 1969, 1970, and 1971 were taken regardless of size as

long as they did not have a mane. A minimum length limit was never

again imposed because the number of 2-yr-olds taken in uncontrolled situations was not considered excessive (the skin of the

relatively smaIl2-yr-old is of less value than the larger skin of a 3- or

4-yr-old).

In 1972, managers replaced use of the mane with 49 in (124 cm)

(tip of nose to tip oftail) as an upper limit of body length. From 1973

through 1975, the upper limit of 45. 75 in (116 cm) (rounded to 46 in

or 117 cm) used from 1922 through 1958 and in 1960 was again

imposed to increase the escapement of young males into the breeding reserve. Managers later realized that because of the change in

1962 in measuring seals to the tip rather than to the base of the tail,

they actually took animals of 45 in (114 cm) in length from 1973

through 1975 instead of 46 in (117 cm) as planned for these years.

Therefore, the upper limit in 1976 was increased to 47 in (119 cm) to

compensate for the approximately I-in-Iong (2.5 cm) tail and presumably, provide for year class escapement similar to the proportion

permitted from 1922 through 1958 and in 1960. An upper limit of 47

in (119 cm) was used again in 1977.

The 1978 season started with an upper limit of 47 in (119 cm), but

was increased to 49 in (124 cm) effective II July to reduce escapement, which managers believed had been excessive in recent years,

as indicated by growing numbers of adult males counted on the

hauling grounds' and fringes of the rookeries. Although managers

wanted to use 49 in (124 cm) again in 1979, the limit of 47 in (119

cm) was imposed because Canada would not agree to the change

without background material to justify it. This material was later

developed and a limit of 49 in (124 cm) used during 1980-81. The

effect of these changes will be evaluated in the future to determine

how they influence productivity and to ascertain whether additional

measures must be taken to produce the desired result, which is to

maximize the harvest and control the escapement of young males

into the breeding reserve.

Finally, it should be noted that the age-body length standards

established between 1913 and 1918 (Roppel and Davey 1965), but

first used in 1922 as minimum/maximum limits for harvesting seals,

indicated the 3-yr-olds as ranging up to a length of45.75 in (116 cm)

and that males within the 46 to 51.75 in (117-131 cm) range were

considered 4-yr-olds. Officials at the time recognized that there was

an overlapping of lengths of any three consecutive age classes.

Scheffer and Kenyon (195227) and Wilke (1953,28 195529) showed

"Scheffer, V. B., and K. W. Kenyon. 1952. Alaska fur seal investigations: Report of

studies on the Pribilof Islands in 1952. Unpubl. rep., 25 p. U.S. Oep. Inter., U.S. Fish

Wildl. Servo (Available Natl. Mar. Mammal Lab., Natl. Mar. Fish Serv., NOAA. 7600

Sand Point Way NE., Bldg. 32, Seattle, WA 98115.)

'·Wilke, F. 1953. Alaska fur-seal investigations. Pribilof Islands, Alaska. Summer

of 1953. Unpub!. rep., 34 p. U.S. Oep. Inter., U.S. Fish Wildl. Serv., Branch Wild!.

Res. (Available Natl. Mar. Mammal Lab., Nat!' Mar. Fish. Serv., NOAA, 7600 Sand

Point Way NE., Bldg. 32, Seattle, WA 98115.)

'"Wilke, F. 1955. Alaska fur seal investigations. Pribilof Islands, Alaska, 1955.

Unpub!. rep., 46 p. U.S. Oep. Inter.. U.S. Fish Wildl. Serv., Branch Wild!. Res.

12
of black and white, and those age 6 yr and older have white

whiskers. In addition, high proportions, e.g., 64% ofthose taken on

St. Paul Island in 1956, of the harvested females age 11 yr and older

had not produced pups in the year examined. Either their reproductive lives were completed or not all females of these ages were

producing pups each year.

Females taken on the Pribilof Islands from 1956 through 1968

were primarily from two sources-the hauling grounds30 and rookery fringes. Animals within these groups differ considerably with

respect to their pregnancy rates. According to Abegglen et al.

(l959),3J 100% of 950 rookery females had borne pups the summer

they were taken whereas only 68% of 1,414 known to have been

taken solely from hauling grounds were recently parturient. Thus,

there is no known way to determine a proper mix of females from the

various sources on land that would yield a satisfactory and usable

estimate of the true pregnancy rate. 32 The figure of 60% used over

the years has been derived from fur seals collected at sea where the

intermixing of females of various ages and reproductive conditions

is assumed to at least be more complete. Table 3 is a summary of

information on annual quotas and actual numbers of females taken

on the Pribilof Islands from 1954 through 1968 and on the source of

females killed on St. Paul Island (females were taken from the same

sources on St. George Island but this information was never documented).

In 1957 and 1958, the presence or absence of milk in the mammary glands was recorded for most females taken but found unreliable as an index of reproductive condition. Milk or milk-like fluid

was found within the mammae of nulliparous and nonpregnant

parous animals and in some instances the entire glandular tissue was

stripped from the carcass during skinning, making it impossible to

collect conclusive data one way or the other (Abegglen et al.

footnote 16, 195833).

Skins from 1,153 males and 1,609 females were collected and

marked during 1958-65 to permit identification through processing

into finished furs. Several biological attributes, particularly age and

sex, were then related to the finished grade and size of each skin

(Abegglen et al. footnotes 31 and 33, 1961;34 Roppel et al. 1963;

Roppel, Johnson, and Chapman 1965; Roppel, Johnson, Anas, and

Chapman 1965). These kinds of data were later analyzed in detail by

30Areas adjacent to the rookeries where nonbreeding fur seals congregate or where

breeding females may assemble following the deaths of their pups.

3l Abegglen. C. E., A. Y. Roppel, and F. Wilke. 1959. Fur seal investigations.

Pribilof Islands. Alaska. Report of field activities, June-September 1959. Unpubl. rep.,

132 p. U.S. Dep. Inter., U.S. Fish Wildl. Serv.. Bur. Commer. Fish .. Mar. Mammal

Res. (Available Natl. Mar. Mammal Lab., Nall. Mar. Fish. Serv.. NOAA. 7600 Sand

Point Way NE., Bldg. 32, Seattle, WA 98115.)

"True estimates of pregnancy rates from land-based samples can be calculated if

pregnancy rates such as those developed by Abegglen et al. (footnote 31) were again

obtained and combined with estimates of the number of parturient females (the

equivalent of the number of pups born) and estimates of females using the hauling

grounds, the latter to be developed from mark/recapture experiments conducted late in

the season when most nonparturient females are on the hauling grounds (R. Delong.

Wildlife Research Biologist, National Marine Mammal laboratory, Northwest and

Alaska Fisheries Center. 7600 Sand Point Way NE .. Bldg. 32, Seattle. WA 98115.

pers. commun. March 1982).

33Abegglen, C. E., A. Y. Roppel, and F. Wilke. 1958. Fur seal investigations.

Pribilof Islands, Alaska. Report of field activities, June-September 1958. Unpubl.

rep., 187 p. U.S. Dep. Inter.. U.S. Fish Wildl. Serv., Bur. Commer. Fish .. Section

Mar. Mammal Res. (Available Natl. Mar. Mammal lab., Natl. Mar. Fish. Serv..

NOAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA 98115.)

34Abegglen, C. E.. A. Y. Roppel, A. M. Johnson, and F. Wilke. 1961. Fur seal

investigations, Pribilof Islands, Alaska. Report of field activities, June-November

1961. Unpubl. rep., 148 p. U.S. Dep. Inter., V.S. Fish Wildl. Serv., Bur. Commer.

Fish., Mar. Mammal BioI. lab. (Available Natl. Mar. Mammal lab., Natl. Mar. Fish.

Serv.. NOAA, 7600 Sand Point Way NE.. Bldg. 32. Seattle. WA 98115.)

13

the Marine Mammal Biological Laboratory (footnote 23) and Scheffer and Johnson. 35.36

J. T. Fouke of the Fouke Fur Company in a letter dated 26 March

1962 had this to say about 117 skins from females of ages 2-5 yr

collected by Scheffer and Johnson (footnote 35, p. 13) for research

on quality: "The results of processing this group seem to be quite

satisfactory.... It is our feeling that if the females could be kept

within the limits of these 117, there would be no great processing

difficulties, ... Although they graded well, with a substantial

number of regulars, we believe that these skins still fall below male

grades. In other words, proportions of Fines, I's and II's (all regular

grades) run toward the II's, or the low end .. , whereas males tend in

the other direction. In large quantities these differences in size and

grade become important considerations." The fur processor (Fouke

Fur Company) also offered several reasons why the skins offemales

were generally lower in value than those from males: I) Smaller

size, 2) narrower distance between flipper holes, giving a reduced

area of fur, 3) thinner and silkier fur, and 4) more loss of fur from

trimming during the manufacturing process because of the mammae (Roppel, Johnson, and Chapman 1965).

Scheffer (1962) publ ished extensi vely on characteristics of northern fur seal fur and Scheffer and Johnson (1963) discussed the

molting process and compared differences between males and

females in this respect.

Counts of adult males,-The counts of adult males began in

1911 and have been continued since to measure recruitment of young

males into the breeding stock. They are not, however, made completely without risk to the census taker who in places must expose

himselfto the extremely aggressive behavior ofthe territorial harem

males, Conditions with respect to safety are now much improved

over what they were in 1911 when elevated structures presently

referred to as tripods and catwalks did not exist. In 1918, the census

taker experimented with a hand-held ladder perched sufficiently

high on the crest ofthe beach to permit a view ofthe water's edge for

the count (Bower 1919), This method of elevation, however, exposed the census taker to the possibility of falls to the rocks below,

especially during windy conditions which made it difficult to hold

the ladder. As a result, plans were considered for "platform walkways" in 1918, but it was not until 1921 that the first was built-on

Reef Rookery of St. Paul Island (Bower 1922). Walkways were

erected on Little Zapadni, Zapadni, and Vostochni Rookeries of St.

Paul Island, and Staraya Artil Rookery of St. George Island the

following year (Bower 1923). Construction continued through the

next several years until a reasonably full measure of safety to the

census taker was achieved in relation to the size of the fur seal

population at that time. This situation, however, changed with time

and increases in herd size so that by mid-century there had developed a need for additional tripod/catwalk construction, most of

which was accomplished in the 1960's. These structures not only

provided safety for the census taker but improved the accuracy ofthe

counts by eliminating an almost constant need to ward off aggressive males,

"Scheffer, V. B., and A. M. Johnson. 1962. Report on a sample of female sealskins

taken on SI. Paul Island, Alaska in 1961. Unpubl. manuscr., 13 p. (Available Natl. Mar.

Mammal Lab., Natl. Mar. Fish. Serv.. NOAA, 7600 Sand Point Way NE., Bldg. 32,

Seattle, WA 98115.)

'·Scheffer, V. B.. and A. M. Johnson. 1963. Report on a sample of sealskins taken on

SI. Paul Island. Alaska in 1962. Unpubl. manuscr., 8 p (Available Natl. Mar. Mammal

lab .. Natl. Mar. Fish. Serv.. NOAA. 7600 Sand Point Way NE.. Bldg. 32. Seattle, WA

98115.)
Table 3.-Annual quotas and numbers' of females killed, Pribilof Islands, Alaska, 1954:68.

Source

(St. Paul Island Actual

Year only) Quota harvest Remarks

1954 Hauling ground All avai lable during 540 For research (all taken on

the kill of males St. Paul Island)

1955 Hauling ground All available during 641 For research (all taken on

the kill of males St. Paul Island)

1956 Hauling ground 30.000 27 ,599 Took all 41 in (104 em)

Rookery (.. harem or longer in body length

raids")

1957 Hauling ground 50,000 47,414 Took all 41 in (104 em)

Rookery (.. harem or longer in body length

raids")

1958 Haul ing ground 30,000 31,102 Took all 46 in (117 em)

or less in body length

1959 Hauling ground 50,000 28,064 Took all 46 in (I 17 em)

or less in body length

1960 Haul ing ground 17,500 4.315 Commercial harvest discontinued mid-July; research kills

only thereafter

1961 Hauling ground 43,750 43,849 Kept skins from young, dark

Rookery rri nge whiskered females only

1962 Hauling ground 43,750 43,760 Selective for young females

Rookery fringe July and August-most from

hauling grounds; took older

females in autumn from rookery fringes and hauling

grounds; kept female skins

with dark whiskers only

1963 Hauling ground 43,750 43,860 Kept all skins except 976

Rookery fringe

1964 Haul ing ground 9,('00-18,000 16,452 Kept all skins-Lakoda

Rookery fringe process becoming valuable

1965 Hauling ground 9,000-18,000 10,432 Kept all ski ns except a few

1966 Hauling ground None 391 Took 330 for research and

killed 61 accidentally

1%7 Hauling ground 10,000 10,094 Kept most ski ns

1968 Hauling ground 13,000 13,335 Kept most skins

'Preseason statements or figures established for the harvesting of fur seals.

The counts have traditionally been made near mid-July when

most ofthe females have arrived and given birth to their pups. Adult

males were not counted on either of the PribiJof Islands in 1942

because of the threat ofWorid War II and evacuation ofthe people on

16 June of that year to the safety of abandoned cannery (St. Paul

residents) and mine (St. George residents) buildings on Funter Bay

in southeastern Alaska, nor on St. George Island in 1956 because of

a lack of interisland transportation.

Two classes of males, harem and idle, have been recorded each

year since 1911. By definition, a harem male is one that is defending

a territory containing one or more females (or pups)Y The idle

37A territorial male with only one or two females may be miselassihed if those

females are at sea. However, the presence of pups within a territory identifies the adult

14

males are estimated to be age 7 yr and older and mayor may not

have territories.

From 1911 through 1958, the counts were made by a succession of

managers associated with what is now called the Pribilof Islands

Program. This responsibility was transferred in 1959 to what is now

the National Marine Mammal Laboratory.

male there as one with females. Although the term "harem" has been used over the

yea" to describe what to the casual observer appears to be individual breeding units

within each rookery, the harem concept cannot be applied to the behavior of fur seals in

the true sense of the word. In reality, the territorial male does not "collect" females, but

rather the groups" ... result more from the gregariousness of the females than from the

efforts of the 'harem master' " (Peterson 1968:36).
Beginning in 1966 and continuing through 1974, the classifications of adults were expanded to include four kinds of idle males and

one corresponding to harem males as follows:

Idle Males.-Class I Shoreline-Full-grown males without

females but apparently with establisi;ed territories at the high tide

mark. Most of these animals are of estimated age 10 yr and older.

Class 2 Territorial without females-Full-grown males without

females (or pups) but with established territories on the rookery.

Most of these animals are also approximately age 10 yr and older.

Class 4 Back fringe-Males with neither females nor territories

that are found along the inland fringe of the rookery.. Most of these

animals are partly grown at estimated ages 7, 8, and 9 yr (Johnson

1968). Class 5 Hauling ground-Males with neither females nor

territories that are found on traditional hauling grounds. Most of

these males are partly grown at estimated ages 7, 8, and 9 yr.

Harem Male.-Class 3 Territorial with females-Full-grown

males with one or more females (or pups) and establ ished territories

on the rookery. Most of these animals are age 10 yr and older

(Johnson 1968).

Since 1975, classes 1and 4 have been combined with class 5 into a

single count because it was found that although there was no

problem in identifying the animals belonging to classes 1 and 4,

there was no useful application of the results. Classes 2 and 3 were

continued as is, so that there are now classes 2, 3, and 5.

The following summarizes the classifications of adult males used

from 1911 to the present:

1911-65-2 classifications, harem and idle

1) Harem = territorial with one or more females (or pups)

2) Idle = territorial with neither females nor pups and all nonterritorial estimated to be age 7 yr and older.

1966-74-5 classifications as listed above (1,2,3,4, and 5)

I) Class 3 = harem male classification used from 1911 to 1965

2) Classes 1,2,4, and 5 = idle male classification used from 1911

to 1965

1975 to present-3 classifications (2, 3, and 5)

I) Class 3 = harem male classification used from 1911 to 1965

2) Classes 2 and 5 = idle male classification used from 1911 to

1965.

In 1966, each rookery (except Ardiguen on St. Paul Island and

East Reef on St. George Island) was divided into numbered sections

containing approximately 100 harem (Class 3) males (more or less

than 100 in certain places where prominent natural boundaries

existed). Sectioning the rookeries has since made the counts easier

and possibly more accurate.

From 1967 through 1980, the adult males were also counted in late

June when most of the females had yet to arrive and disturbance to

the rookery is much less. Preliminary comparisons of the counts in

June and July indicate a strong correlation between the two, but a

decision has not been made as to the possibility of changing to the

early count without sacrificing comparability of data collected since

1911.

The only detailed counts available by rookery from 1911 through

1965 are those that might exist in the form of field records. Beginning in 1966, the counts by rookery section have been recorded in

the annual reports of fur seal investigations on file at the National

Marine Mammal Laboratory.

Marks.-Fur seals of both sexes have been marked by various

15

methods and for different reasons on the Pribilof Islands since 1870

(Scheffer 1950b; Roppel and Davey 1965). However, the most ambitious marking program ever carried out there was one involving

863,584 pups over a span of 36 yr from 1940 through 1975, with

about 80% of the marks applied to animals on St. Paul Island and

20% to those on St. George Island. There were only five seasons

during this period when pups were not marked on a large scale.

Information obtained from returns of these animals to the commercial harvest at ages 2-5 yr since 1940 was intended primarily for use

in studies of growth and migration patterns as well as making

estimates of the number of pups born from marked to unmarked

ratios. An additional benefit came from the marking program

through the accumulation of information on the degree to which fur

seals tend to return to their island and rookery of birth (Marine

Mammal Biological Laboratory 1969).

The use oftags to mark pups was largely experimental up to about

1950 with respect to size, type, and metal content (Kenyon 1949;38

Scheffer 1950b). Tags of Monel Metal manufactured according to

certain specifications (Abegglen et al. 196039) were eventually

found to be most suitable and were used to mark the pups beginning

in 1949, each of which was also given a checkmark for use in

identifying the animal at an older age should its tag become lost.

Checkmarks were made by removing part of a flipper.

Tagging was not without its disadvantages, many of which surfaced early in the program. Scientists working with fur seals of the

Pribilof Islands eventually realized that tag-caused mortality, tag

loss as well as overlooked tags and checkmarks potentially could

all combine to produce inflated estimates of the number of pups

born (Abegglen et al. footnote 31; Roppel et al. 1963).

In his studies of the problem on St. Paul Island, Keyes (1962,40

196641 ) pointed to overexertion and stress as possible causes of

mortality among pups driven to suitable tagging sites, as well as

infection from attachment of the tags themselves and impairment of

limb function as a result of improper placement. Abegglen et al.

(footnote 39) reexamined the carcasses ofseveral hundred harvested

seals on St. Paul Island and found that 6% ofthe available 1,691 tags

and checkmarks (a notch, slit, hole, or other mark made on a seal

flipper to ensure recognition of an animal that had lost its tag-such

marks were used without tags during 1969-75) had been overlooked

during the recovery process. Improperly applied checkmarks,

which were difficult or impossible to identify at the ages of harvest,

appeared most frequently among those overlooked. Because of

uncertainties about the recovery of all available checkmarks from

seals that had lost their tags, the NPFSC proposed that the United

States double tag some of its pups in 1958 to determine rates of tag

loss. Thus, 5,000 were so treated in that year (Abegglen et al.

footnote 33).

"Kenyon, K. W 1949. Report on the tagging of fur seal pups. SI. Paul Island,

Alaska, season of 1949. UnpubL manuscr., 14 p. U.S. Dep. Inter., U.S. Fish WildL

Serv., Branch WildL Res. (Available NatL Mar. Mammal Lab., NatL Mar. Fish. Serv.,

NOAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA 98115.)

'"Abegglen, C. E., A. Y. Roppel, and F. Wilke. 1960. Alaska fur seal investigations,

Pribilol Islands, Alaska. Report of field activities, June-October 1960. UnpubL rep.,

165 p. U.S. Dep. Inter., U.S. Fish WildL Serv., Bur. Cammer. Fish., Mar. Mammal

BioI. Lab. (Available NatI. Mar. Mammal Lab., NatL Mar. Fish. Serv., NOAA, 7600

Sand Point Way NE., Bldg. 32, Seattle, WA 98115.)

4°Keyes, M. C. 1962. Mortality among fur seal pups, SI. Paul Island, Alaska, 15

August to 10 September 1962. Unpubl. rep., 24 p. U.S. Dep. Inter., Bur. Cammer.

Fish., Mar. Mammal BioI. Lab. (Available NatI. Mar. Mammal Lab., NatL Mar. Fish.

Serv., OAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA 98115.)

41Keyes, M. C. 1966. Research in fur seal mortality, SI. Paul Island, Alaska, 19July

to 3 September 1965. UnpubL rep., 97 p. U.S. Dep. Inter., Bur. Cammer. Fish., Mar.

Mammal BioI. Lab. (Available Natl. Mar. Mammal Lab., NatL Mar. Fish. Serv.,

OAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA 98115.)
Marking effort and size of the labor force used to carry out the

program was reduced beginning in 1963 with the belief that devotion of more time to each pup would result in gentler handling and

better placement of the tags with attendant lower mortality among

the animals involved (Roppel, Johnson, and Chapman 1965). Even

so, information obtained from the recoveries of these animals and

from the double tagging experiment of 1958 led to additional doubt

as to the validity of data based on returns. Thus, beginning in 1969,

scientists were prompted to abandon the application of tags altogether in favor of physical marks only (Marine Mammal Division

197642 ). This program. in turn, was abolished in 1975, partly

because of known disadvantages, but primarily because the United

States adopted the view that the recoveries of marked animals were

too few for solving questions with respect to the intermixture of

seals of different origins on land and at sea and, also, because a new

and improved method of estimating the number of pups born had by

then been developed.

Regardless of how the pups are marked, mid-September or later

seems to be the best time of the season for doing so, apparently

because the animals are larger and older and better able to withstand

fright and the stress of handling. Because of a growing suspicion

that perhaps the survival of these animals would be improved if

tagged later in the season (as they had at various times since 1945),

half of the pups marked on St. Paul Island in 1963 and 1964 were

tagged in August and half in mid-September. As predicted, the

recovery rate in the harvest 3 and 4 yr later for tags applied to pups in

September was significantly higher than for those applied in August

(Marine Mammal Biological Laboratory 1970a).

Evidence that marking and even handling of the pups actually

affects growth rates first appeared in 1962 when a weighing program

started in 1957 with a different objective was modified to include

three weighings a month apart, the first about I wk after tagging.

The results showed that tagging causes an immediate loss of weight

among tagged pups but that this loss is at least partially overcome 2

mo later (Roppel et al. 1963). Additional data followed when it was

learned that tagged and checkmarked pups weighed less than untagged and unmarked pups each year from 1957 through 1965. In

1965, untagged pups marked by removal of part of the hind flipper

also weighed less than pups given no marks at all. These discoveries

were carried further in 1966 by means of an experiment that involved shearing patches of fur from the rumps of 800 pups (small

groups of pups were driven as short a distance as possible and held

in three-sided barricades for shearing) then weighing samples of

sheared (handled) and unsheared (unhandled) animals 13 dafter

marking. Again, pups driven a few yards and sheared, while held on

the ground, weighed less than did those that were not handled in any

way (Marine Mammal Biological Laboratory 1969).

In addition to the pups, several hundred yearling fur seals and

males of ages 2-4 yr were marked during 1961-71 on St. Paul Island

because ofthe potential of these programs in producing information

on mortality at sea (Abegglen et al. footnote 34; Roppel et al. 1963).

Tagging of yearlings was begun in 1961 by Peterson43 and continued

by the staff ofthe Marine Mammal Biological Laboratory in following years mostly because of the reason just given but also because

"Marine Mammal Division. 1976. Fur seal investigations. 1975. Unpubl. rep., 115

p. U.S. Dep. Commer., Natl. Oceanic Atmos. Admin .. Natl. Mar. Fish. Serv.,

Northwest Fish. Cent.. Mar. Mammal Div. (Available Natl. Mar. Mammal Lab.. Natl.

Mar. Fish. Servo NOAA. 7600 Sand Point Way NE.. Bldg. 32. Seatl;e. WA 98115.)

"Peterson. R. S. 1962. Report and analysis of yearling recoveries and tagging, St.

Paul Island, 1961. Unpubl. manuscr.. 19 p. U.S. Dep. Inter.. U.S. Fish Wildl. Serv..

Bur. Commer. Fish .. Mar. Mammal BioI. Lab. (Available Natl. Mar. Mammal Lab..

Natl. Mar. Fish Serv., NOAA, 7600 Sand Point Way NE.. Bldg. 32. Seattle. WA 98115.)

16

the only previous comprehensive study of this element of the herd

was conducted by Wilke and Banner (1941).44 Over 5,000 fur seals

presumed to be yearlings were double tagged during the 7-yr period

ending with 1967 and nearly 3,000 males of ages 2-4 yr were so

treated in 1966 and 1967. Relative size of the animals, color of the

pelage, and behavior and appearance were used in combination to

identify yearlings from older seals in 1961. Beginning in 1962, body

length was found superior as a guide in selecting yearlings and was

used thereafter. Only those females 95 cm or less and males 100 cm

or less were considered yearlings (Roppel et al. 1963). In all cases

true ages of the yearlings (and males of ages 2-4 yr) were determined after the fact from maxillary canine teeth collected from

survivors subsequently taken in the harvest (Marine Mammal

Biological Laboratory 1970a).

Gentry (1979,45 1981) marked and branded juvenile males for

studies of land-sea movements as did Griben (1979) to obtain

information on interisland (St.Paul - St.George) movements of

these animals.

Estimates of Population Size.-Until 1896, estimates of population size were based on density and areal measurements. According to Jordan (1898, footnote 46), Captain Charles Bryant, a Government agent detailed to the Pribilof Islands in 1869 to investigate

the condition of the herd, made the first attempt at enumerating the

seals on the basis ofspace occupied by animals, not including pups.

Smithsonian artist/naturalist Henry Wood Elliott arrived in 1872, as

an agent ofthe Treasury Department, to study the herd. His estimate

of pup production and of the numerical size of other elements of the

total herd was based on an average of2 ft2 (0.2 m2) of rookery space

occupied by every seal whether adult male, female, or pup (Elliott

1884). When applied to total rookery area as computed by himself

and added to an estimate of the number of nonbreeding animals,

Elliott was convinced that all classes of animals totaled no less than

4,500,000 in each of the years 1872-74. It was generally believed at

the time that conservation measures as practiced by the Russians

following their near annihilation of the herd by the early 1800's had

by 1867 returned the population to its pre-discovery level. Even so,

a total population of 4,500,000 (breeding and nonbreeding seals

included) was discounted by Jordan (1898) as not necessarily based

on sound scientific facts and measurements. In this connection, I

once had the opportunity to view one of Elliott's original water

colors depicting seal life on Lukanin Rookery of St. Paul Island in

which he had virtually covered the entire slope and top of the hill

behind this breeding ground with fur seals. Had this been true

historically, the exposed rocks most assuredly would have been

worn smooth by the overland movement of thousands of seals

throughout the centuries. This was not so. Those rocks were and

still are as rough as the day they were formed, a fact that lends

credence to the contentions of Jordan that Elliott's estimates were

grossly exaggerated. In 1886, George R. Tingle, then Treasury

Agent on St. Paul Island, also disagreed with Elliott's estimate in

"Wilke, E, and A. H. Banner. 1941. Recovery of branded yearlings. Unpubl.

manuscr., 5 p. U.S. Dep. Inter.. Bur. Commer. Fish .. Mar. Mammal BioI. Lab.

(Available Natl. Mar. Mammal Lab., Natl. Mar. Fish. Serv.. NOAA, 7600 Sand Point

Way NE., Bldg. 32, Seattle. WA 98115.).

"'Gentry. R. L. 1979. Land-sea movements ofjuvenile males. In Fur Seallnvestigations. 1978. Unpubl. rep.. 84 p. Natl. Mar. Mammal Lab.. Natl. Mar. Fish. Serv..

NOAA. 7600 Sand Point Way NE.. Bldg. 32. Seattle. WA 98115.

"David StarrJordan, President of Stanford University, headed a special commission

authorized and funded by the U.S. Congress to document the depleted condition of

the herd and the cause of its threatened destruction with studies undertaken in 1896

and 1897.
that he considered the space assigned by the latter to the individual

animal as too small. He therefore reduced his own estimate of

breeding seals and young by one-fourth to 4,768,430, a figure

which nevertheless exceeded Elliott's estimate of 3,193,420 for the

same group by 1,575,010 animals (nonbreeding seals were not

included in either estimate).

Other investigators of herd size followed with equally questionable results, including Elliott again in 1890. In its day, the estimate

that most likely represented the best numerical level of breeding

seals and young was that offered by Jordan (1898). His method was

to count all of the harems on all of the rookeries at the peak of the

breeding season and then to multiply that figure by the average

harem size counted on some typical rookery space. 47 In doing so,

Jordan (1898, vol. I, p. 98) suggested that there were" ... a total of

262,850 'breeding seals and young' at one time or another on the

rookeries of the Pribilof Islands during the past season [1897]."

Because the nonbreeding animals were not necessarily available for

counting, he was forced to theorize their numerical strength, which,

when added to the above figure, brought his estimate of total herd

size to 402,850 in that year.

In 1914, Wilfred H. Osgood of the Field Museum of Natural

History in Chicago, Ill., Edward A. Preble, Bureau of Biological

Survey in the Department of Agriculture, and George H. Parker,

Harvard University, were engaged by the Department of Commerce

and detailed to the Pribilof Islands for the purpose of investigating

the Alaskan fur seals and related questions. Prior to their investigation, Osgood et al. (1915:27) " ... found that unpublished charts

showing the number and approximate position of the harems on

each rookery had been made in 1912 and again in 1913 by Special

Investigator G. A. Clark. These charts showed the contours of the

topography as surveyed by the United States Coast and Geodetic

Survey and also indicated the position of the rocks on which conspicuous numbers were painted at the time of the survey." In their

historical account of the scientific study of the Alaskan fur seal,

Scheffer et al. (in press) mentioned that these numbers were painted

on the rocks in 1897 and that they "have been renewed at intervals

down to the present [year]." They also stated that there were numbered (and lettered) camera stations, although those of the 1890's

were not "exactly those in use today." The rookeries (on St. Paul

Island) were last photographed (by Ford Wilke and Alton Roppel)

from some of these "stations" in 1960.

Total counts of pups were made on all rookeries from 1912

through 1916 and in 1922, and additionally on a few rookeries

during 1917-21 and in 1924 (Lander 1980a). By inference and in

conjunction with such other actual counts as those ofthe adult males

(described later), estimates were made of all classes of fur seals.

The counts of pups were abandoned after 1922 because their

number had by then become too large for an accurate census on all

but four relatively small rookeries. Instead, an annual increase of

8%, the rate observed between 1912 and 1922, was used up to about

1940. Several years later, however, it was learned that use of this

method was in error because the actual rate had diminished to < 8%

per year after 1930.

A new technique for estimating year-class size was developed

beginning in 1941 with the use of metal tags to mark 12,000 pups in

that year on St. Paul Island. This relatively large-scale marking

program, interrupted by World War II and resumed in 1947, was

used into the 1960's to determine the number of pups born from

"The herd had by this time been considerably reduced in size through pelagic

sealing and was correspondingly much easier to work with in terms of determining

numerical leveb of the various components.

17

tagged to untagged ratios among harvested males. Tagged and

untagged ratios were also used to estimate the total size of the herd

and develop a life table for males and females (Kenyon footnote II).

The first attempt at enumerating fur seals on the Pribilof Islands

through the use of aerial photography came in 1938 when Administrative Superintendent Harry J. Christoffers took motion and still

pictures of a few of the rookeries from aU. S. Coast Guard aircraft.

Scheffer followed in 1945 with additional photographs from a U.S.

Navy PBY airplane. According to Kenyon (1951):" neither experiment produced useful results. The year 1948 saw the first complete

coverage of all fur seal rookeries with photographs from a U.S. Fish

and Wildlife Service twin-engine aircraft (Kenyon 194849). During

1947-49, Scheffer and Kenyon (1948, 5U 195051 ) suspended a camera

from a tethered balloon over Northeast Point Rookery of St. Paul

Island, also for the purpose of obtaining photographs for counting

seals. Wilke and Kenyon (1951)52 reported on the use of a U.S. Navy

helicopter in 1951 from which to take a few photographs. From the

results, Kenyon (footnote 52) concluded that as a photographic

platform the helicopter showed promise. Complete coverage of all

rookeries occurred again in 1967 when the Bureau of Commercial

Fisheries (now the National Marine Fisheries Service) contracted

with the Bureau of Land Management to take photographs, with

Alton Roppel aboard as adviser and observer (unpublished material

on file, Northwest and Alaska Fisheries Center, National Marine

Mammal Laboratory). The results of this latter venture were generally superior to the foregoing experiments in that they were useful in

del ineati ng boundaries of the rookeries; however, they were, for the

most part, equally unsatisfactory for determining numerical abundance of the animals.

In 1950, Kenyon began preliminary trials with what he called

"rapid field estimates of living pups" and in 1951 produced an

estimate oftotal year-class strength based on this method (Kenyon et

al. 1954). From a suitable vantage point, observers simply estimate

the number of pups on the rookery before them. The method has the

advantage of speed: 5,000-10,000 pups can be estimated per hour.

In using this technique a second and final time in 1954, however,

Kenyon (footnote 11, p. (7) stated that "Their value is questionable

because of their highly subjective nature."

The most satisfactory of all the methods so far developed for

estimating the number of pups, regardless of numbers, has been one

involving marking then sampling living animals for marked/

unmarked ratios (Chapman and Johnson 1968), to which must be

added the count of dead pups to arrive at the total number born. This

type of program superceded a marklrecapture technique used on the

"Kenyon, K. W. 1951. Aerial photography of fur seals from a Navy helicopter.

Unpubl. manuscr., 4 p. U.S. Dep. Inter., U.S. Fish Wildl. Servo (Available Natl. Mar.

Mammal Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point Way NE.. Bldg. 32.

Seattle, WA 98115.)

"Kenyon. K. W. 1948. Preliminary report of aerial photography offur seal breeding

areas on the Pribilof Islands, July 14-15. 1948. Unpubl. manuscr.. 6 p. (Available Natl.

Mar. Mammal Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point Way NE.. Bldg.

32. Seattle, WA 98115.)

'·Scheffer, V. B., and K. W. Kenyon. 1948. Research on the Alaska fur seal herd.

1948. Unpubl. rep., 49 p. U.S. Dep. Inter.. U.S. Fish Wildl. Servo (Available Natl.

Mar. Mammal Lab., Natl. Mar. Fish. Serv., OAA. 7600 Sand Point Way NE.. Bldg.

32. Seattle, WA 98115.)

'lScheffer, V. B., and K. W. Kenyon. 1950. Research on the Alaska fur seal herd in

1949. Unpubl. rep .. 24 p. U.S. Dep. Inter., U.S. Fish Wildl. Servo (Available Natl.

Mar. Mammal Lab., Natl. Mar. Fish Serv., NOAA, 7600 Sand Point Way NE.. Bldg.

32. Seallle, WA 98115.)

"Wilke, E. and K. W. Kenyon. 1951. Alaska fur seal investigations. Pribilof

Islands. Summer of 1951. Unpubl. rep .. 25 p. U.S. Dep. Inter.. U.S. Fish Wildl. Servo

(Available NaIl. Mar. Mammal Lab., Natl. Mar. Fish, Serv., NOAA, 7600 Sand Point

Way NE., Bldg, 32, Seattle, WA 98115,)
Pribilof Islands for several years. It is superior in that it permits an

estimate of year-class strength during the summer of birth rather

than 4-5 yr later when the animals are harvested and eliminates most

or perhaps all of the problems associated with the latter. The mark/

recapture program was a key element used by Kenyon et al. (1954)

in producing an estimate of the total population.

The marking/sampling program, which was developed on SI.

Paul Island, first used pups that had been given tags as usual in 1960

and 1961. The objective of the small-scale study in 1960 was to test

the feasibility of the technique in producing satisfactory estimates

of year-class size. As followed in that year, the procedure was first to

complete the total tagging program, wait a few days for tagged and

untagged animals to intermix, then count approximately 25 pups at

each of 14 stations on Zapadni Reef Rookery and 17 stations on Little

Polovina Rookery and record the number tagged within each sample

(Abegglen et al. footnote 39). This technique was repeated on three

rookeries in 1961 and expanded in that year to include a modified

version that was carried out on all rookeries of SI. Paul Island. The

latter technique also employed the use of tagged pups, but with this

difference: Successive groups of pups were rounded up along the

length of each rookery, then 100 in each were driven between two

observers who recorded the number tagged (Abegglen et al. footnote 34).

There were three known disadvantages associated with either

version of the tagging/sampling program. First, large-scale tagging

of pups was necessarily carried out on certain areas of the rookeries

where the animals were most abundant, which produced "Iumping

effects" within the population and consequently within the samples.

Thus, samples of counted pups were heavily saturated with marked

animals in and around the areas of tagging but were without marked

individuals elsewhere. Second, pups with tags attached to their

flippers were difficult to identify because the tags were next to the

ground and the animals tended to crowd closely together, behavior

that obscured this type of mark from view by the observer. Finally,

loss of unclinched tags or the deaths of some of the marked animals

produced inflated estimates.

The most promising of the two methods tried in 1960 and 1961

was the counting of groups of25 pups along transect lines systematically distributed throughout each rookery (Roppel et al. 1963).

These transects were permanently marked with steel stakes in J966

(Marine Mammal Biological Laboratory 1969). The primary advantage of this method was that about 500 pups/man-hour could be

sampled compared with only 200/man-hour using sample sizes of

100. For this reason, the smaller sample size was used throughout

the rookeries on SI. Paul Island in 1962. Still, it had all of the

disadvantages as outlined above.

In 1963, known disadvantages of the program were eliminated by

marking the pups through shearing guard hair from the heads to

expose the light-colored underfur and by randomizing the marking

and sampling efforts (Chapman and Johnson 1968; Roppel et al.

1963). The new mark not only was not susceptible to loss as were the

tags but was also highly visible during the counts. The latter advantage, however, was not totally satisfactory at first because the

observers tended to begin their counts with pups marked in this

fashion, which renders them extremely conspicuous. To eliminate

selection for marked and perhaps unmarked pups, persons making

the census were instructed to begin each count at a fixed object such

as a log, rock, or dead animal and then count the nearest 25 pups and

record the number marked within the group.

The only known and proven way w check the accuracy of estimates of pup production based on shearing/sampling is to make

total counts of the living animals, which in terms of current herd

18

size is possible only on the smallest rookeries. The first check was

made in 1964 with counts on three small rookeries and an isolated

section of a fourth. Estimates based on shearing/sampling varied

from -4% to + 17% of the counts on the three rookeries and +26%

of the number counted on the isolated section (Roppel, Johnson,

Anas, and Chapman 1965), with a mean of +5% for all four. The

estimate was 91 % of the count on these same rookeries in 1965

(Roppel et al. 1966) and 105% in 1966 (Marine Mammal Biological

Laboratory 1969). Total counts of pups were made on some, but not

all, of these small rookeries in following years as well.

The shearing/sampling program and other methods used to estimate the number of pups born on the Pribilof Islands have been

fully analyzed by York and Kozloff (1979),53 who suggested that

the shearing/sampling program may be selective for younger pups, i.e.,

they are still totally on land and available for marking whereas some

of the older pups are venturing into the water at the time ofshearing

(Kozloff 198]54). York and Hartley (1981) concluded from their

study that 62,300 or 70% of the 89,000 decline in the number of

female pups born on SI. Paul Island (224,000 during 1950-56 to

135,000 by 1962) can be traced directly to the herd reduction

program for females in effect on that island beginning in 1956. Their

analysis does not explain the remaining 30% decline. In another

analysis, however, Eberhardt (1981) discussed density dependence

combined with the effect of harvesting females. Lander (l980a)

gave estimates of pup production from 1912 through 1979 for the

Pribilof Islands.

A preliminary study of the weights of sheared and unsheared

pups in 1980 supports the results of previous experiments tha't

showed that male pups are significantly heavier than female pups

and that there are major differences in pup weights between

rookeries. In addition, sheared pups weighed less than unsheared

pups (Kozlofffootnote 54). The effect ofthese weight differences, if

any, on estimates of pup production need further study.

Pup Weights.-Fur seal pups were weighed annually on St. Paul

Island from 1957 through 1971 in an effort to learn whether average

body weights in autumn vary from one year class to another and, if

so. what influence these differences might have on survival at sea.

The animals were weighed on about the same dates each year, i.e.,

late August-early September, and on the same rookeriesNortheast Point, Polovina, Reef, and Zapadni Reef. Subsequent

correlations of pup weights with numerical returns of the year

classes to the harvests (Marine Mammal Biological Laboratory

197255 ) and with body weights and lengths of harvested animals

(Abegglen et al. footnote 39) were of little or no value in predicting

survival based on average body conditions of pups in autumn.

As with large-scale marking of pups, the weighing of these

animals was expedited when carried out in parts of the rookeries

with relatively large concentrations of pups. As a result, and because weighing each year followed tagging, many of the pups so

handled were also tagged. This fact was recorded as well. As

"York, A. E., and P. Kozloff. 1979. Estimation of numbers of fur seal pups born on

St. Paul Island. Unpubl. manuscr., 27 p. Natl. Mar. Mammal Lab., Natl. Mar. Fish.

Serv., NOAA, 7600 Sand Point Way E., Bldg. 32, Seattle. WA 98115.

"Kozloff, P. (editor). 1981. Fur seal investigations, 1980. NWAFC Processed Rep.

~1-2, 96 p. Natl. Mar. Mammal Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point

Way E., Bldg. 32, Seattle, WA 98115.

''-'Marine Mammal Biological Laboratory. 1972. Fur seal investigations, 1971. Unpubl. rep., 132 p. U.S. Dep. Commer., Natl. Oceanic Atmos. Admin., Natl. Mar. Fish.

Serv., Northwest Fish. Cent., Mar. Mammal Div. (Available Natl. Mar. Mammal Lab.,

Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point Way E., Bldg. 32, Seattle, WA

98115.)
previously discussed, it was later discovered that the tagged pups of

both sexes weighed significantly less than the untagged animals.

Mortality .-Furseals die of many causes but at different rates at

various stages of their life cycle. Most losses, some of which have

been documented by Scheffer (1950c), occur at sea; Lander (1975,

1979) described a method of determining natural mortality in northern fur seals and analyzed its influence on the size ofthe commercial

harvest.

Mortality following birth of the pups begins on the breeding

grounds, where multiple hemorrhage-perinatal complex (hemorrhage of internal organs "around birth," especially of the liver)

emaciation syndrome (malnutrition from varied causes), hookworm disease, microbial infections, and trauma account for most of

the deaths (Doyle 1957;56 Engle et al. 1980;57 Keyes 1964,58 1965,

footnote 59, 1966 (footnote 41), 1971, footnote 60, 1972,61 1973;62

Anonymous 1969, 1970a, b; Lander 1980a; Lyons 1963). In past

years, 20% « 10% in most years since 1963) or more of the

newborn pups died from various causes during the summer of birth

(Baker et al. 1970).

Little information has been collected on causes of death at sea;

however, sharks and killer whales are presumed to account for some

mortality with disease and starvation of pups playing a prominent

but unmeasured role. Bychkov (1967) summarized the views of

several scientists with respect to the relationship of the killer whale

to mortality of fur seals together with his own observations and

concluded that " ... it may be assumed that the fur seals do not

constitute a substantial portion of the killer whales' diet; while

procuring their food, the killer whales do not hunt them regularly,

and attack them very seldom, even though such opportunities are

present." There is little or no direct information available on the

impact of sharks on the fur seal.

Another source of mortal ity among the pups is predation by foxes

and northern sea lions. On three occasions, foxes were observed to

attack living pups, severely injuring them (Marine Mammal Division footnote 42); studies of predation by sea lions on St. George

"Doyle, L. P. 1957. Investigation of death losses in fur seal pups on St. Paul Island,

Alaska, June 28 to August 15,1957. Unpubl. rep., 10 p. U.S. Fish Wildl. Serv., Bur.

Sport Fish. Wildl., Mar. Mammal BioI. Lab., Seattle, Wash. (Available Natl. Mar.

Mammal Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point Way NE., Bldg. 32,

Seattle, WA 98115.)

57Engel, R. M., R. H. Lander, A. Y. Rappel, P. Kozloff, J. R. Hartley, and M. C.

Keyes. 1980. Population data, collection procedures, and management of the northern

fur seal, Callorhinus ursinus, of the Pribilof Islands, Alaska. NWAFC Processed Rep.

80·11,212 p. Natl. Mar. Mammal. Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand

Point Way NE., Bldg. 32, Seattle. WA 98115.

"Keyes, M. C. 1964. Research in fur seal mortality, St. Paul Island, Alaska, 8 July

to 24 September 1963. Unpubl. rep., 140 p. U.S. Dep. Inter., Bur. Commer. Fish., Mar.

Mammal BioI. Lab. (Available Natl. Mar. Mammal Lab., Natl. Mar. Fish. Serv.,

NOAA, 7600 Sand Point Way NE., Seattle, WA 98115.)

"Keyes, M. C. 1965. Research in fur seal mortality, St. Paul Island, Alaska, 6July to

24 August 1964. Unpubl. rep., 48 p. U.S. Dep. Inter., Bur. Commer. Fish., Mar.

Mammal BioI. Lab. (Available Natl. Mar. Mammal Lab., Natl. Mar. Fish. Serv.,

NOAA, 7600 Sand Point Way NE., Seattle, WA 98115.)

.oKeyes, M. C. 1971. Pathology (of fur seals). In Fur seal investigations, 1970.

Unpubl. rep., 155 p. U.S. Dep. Inter., Bur. Commer. Fish., Mar. Mammal BioI. Lab.

(Available Natl. Mar. Mammal Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point

Way NE., Bldg. 32, Seattle, WA 98115.)

'IKeyes, M. C. 1972. Pathology (of fur seals). In Fur seal investigations, 1971.

Unpubl. rep., 132 p. U.S. Dep. Inter., Bur. Commer. Fish., Mar. Mammal BioI. Lab.

(Availa!]le Natl. Mar. Mammal Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point

Way NE., Bldg. 32, Seattle, WA.)

"Keyes, M. C. 1973. Pathology (of fur seals). In Fur seal investigations, 1972.

Unpubl. rep., 93 p. Northwest Fish. Cent., Mar. Mammal Div. (Available Natl. Mar.

Mammal Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point Way NE., Bldg. 32,

Seattle, WA 98115.)

19

Island suggest that mortality from this cause may be significant

(Marine Mammal Division footnotes 42,63).

The advent of extensive foreign fisheries in the Bering Sea and

North Pacific Ocean in the 1950's provided additional causes of

death among the fur seals. Direct losses as a result of these fisheries

come from an incidental take of fur seals. Fukuhara (\974)64 estimated this catch of fur seals by the Japanese salmon mothership

fishery (which uses gill nets) to range between 3,500 and 3,750

annually. Nishiwaki65 estimated the total incidental take offur seals

to be 7,000 annually. In her extensive analysis of the problem, Jones

(1980)66 estimated incidental takes of from 500 to nearly 8,000 fur

seals each year during 1975-79, depending upon the amount of gear

fished. An even greater cause of death attributable to high-seas

fisheries, however, may be the entanglement of fur seals in scrap

trawl webbing and other synthetic material discarded by mariners at

sea. The incidence of animals so entangled increased annually from

75 or 0.15% of 50,229 fur seals harvested on St. Paul Island in 1967

to 211 or 0.72% of 29,148 taken in 1975 (Lander 1980a; Kozloff

footnote 54). If extrapolated to the total Pribi lof Islands population

of fur seals (estimated by Johnson (\975) at 1.2 million and by

Lander (1981) at 1.25 million), the minimum annual number of

animals entangled ranged from about 1,800 to 9,000 annually during the 9-yr period. This estimate is probably conservative because

an unknown but additional number offur seals may have succumbed

at sea due to the effects of discarded material around their necks

(Fowler 1982).67

Fur seals apparently have a penchant for investigating floating

debris and putting their heads through circular objects. In the late

1940's and in the 1950's, a few males of harvestable size occasionally appeared on the hauling grounds ofthe Pribilof Islands wearing

rubber rings around their necks. The origin of these rings, which

apparently caused little or no immediate damage to the animal

because of their elasticity, was never determined, although it was

surmised that perhaps each had originally served to reinforce the

mouth of a waterproof rubber bag. Scheffer and Kenyon (footnote

50) learned of the possibility that the bags were used by the Japanese

for aerial delivery of food and water during the latter years of World

War II.

Of much more serious concern has been the aforementioned

incidence of entanglement in scrap trawl webbing and uncut plastic

bands used on fishing boats and other marine vessels to strap

bundles of new netting, crates, etc. In a study of plastic litter on the

beachs of Amchitka Island in Alaska, Merrell (1980: 175) accumulated evidence during a 3-yr survey to indicate that "Under conditions of large fisheries and attendent accidental loss and deliberate

dumping of discarded plastic fishing gear, marine litter accumulates

at a rate that exceeds theoretical estimates." Trawl webbing headed

63Marine Mammal Division. 1975. Fur seal investigations, 1974. Unpubl. rep., 125

p. U.S. Dep. Commer., Natl. Oceanic Atmos. Admin., Natl. Mar. Fish. Serv.,

Northwest Fish. Cent., Mar. Mammal Div. (Available Natl. Mar. Mammal Lab., Natl.

Mar. Fish. Serv., NOAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA 98115.)

'4Fukuhara, F. 1974. Estimated mortality of seabirds, fur seals, and porpoise in

Japanese salmon drift net fisheries and sea lions in the Eastern Bering Sea trawl fishery.

Unpubl. manuscr., 10 p. (Available Natl. Mar. Mammal Lab., Natl. Mar. Fish. Serv.,

NOAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA 98115.)

"M. Nishiwaki, University of the Ryukyus, Shuri, Naha City, Okinawa 903 Japan,

pers. commun. to Lander and Kajimura in 1976.

••Jones, L. L. 1980. Estimates of the incidental take of northern fur seals in Japanese

salmon gill nets, 1975-1976. Unpubl. manuscr., 15 p. Natl. Mar. Mammal Lab., Natl.

Mar. Fish. Serv., NOAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA 98115.

"Fowler, Charles W. 1982. Interactions of northern fur seals and commercial

fisheries. Unpubl. manuscr., 30 p. atl. Mar. Mammal Lab., atl. Mar. Fish. Serv.,

OAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA 98115.
his list in terms of weight, and strapping material was third numerically.

Once encircled about the neck of a fur seal, these nonelastic and

extremely durable materials are prone to remain there indefinitely or

until death of the animal. If anything, they tend to work their way

over the posteriorly sloping guard hair and become even further

entrenched with no possibility of removal except by the hand of

man. With time and growth of the animal, the material deeply

girdles the neck into the flesh. Death may come to the wearer very

early, not from infection and perhaps choking as certainly would be

the case later, but from impairing the animal's ability to swim and to

catch food. Some of the fur seals appearing on the breeding grounds

have massive amounts of trawl webbing about their necks.

Convinced that entanglement (principally in polypropylene trawl

webbing) was definitely a factor of considerable importance in the

survival of fur seals at sea, the NPFSC carefully reviewed the

subject at several of its annual meetings (North Pacific Fur Seal

Commission 1971, 1974, 1976-80) and instructed its members to

develop posters and written material for distribution to their respective fishing industries in an attempt to explain this dilemma and

persuade fishermen to delay disposal of their waste until they reach

port. Whether the distribution of posters was wholly or even partly

the cause of a decline beginning in 1976 in the number of entangled

fur seals harvested on St. Paul Island will probably never be known.

In that year, however, the proportion dropped to 0.44% from a high

of 0.72% in 1975. The following year saw an even further decline to

0.35% and from 1978 through 1980 the average was 0.45%. Enactment of the U.S. Magnuson Fishery Conservation and Management

Act of 1976, which established a 200-mi (322 km) fishery conservation zone in which foreign fishing vessels are controlled may also

have been a factor in the decline.

Although polypropylene trawl webbing has no national markings, it is assumed to be of Japanese or Soviet origin because trawl

fishing in the North Pacific Ocean and Bering Sea has been primarily by vessels ofthese two nations (Merrell 1980). Another aspect of

the trawl web story is that the U.S.S.R. has used polyethylene

netting, which sinks. This fact gives rise to the question of whether

fur seals also become entangled in debris on the bottom. Problems

associated with entanglement have been described and the data

summarized by Fiscus and Kozloff (1972),68 Sanger (1974),69 Bigg

(1979),7° Kozloff (1979),7' and Fowler (footnote 67).

The only direct measure of the mortality of fur seals is through

counts of dead animals when they are on the breeding grounds. The

most important 72 of these has been the partial and total counts of

dead pups on the PribilofIslands in various years following acquisition of these lands by the United States in 1867. Counts during the

early 1900's, which were usually made in conjunction with censuses

"Fiscus, C. H.. and P. Kozloff. 1972. Fur seals and fish netting. I" Marine Mammal

Biological Laboratory. Fur seal investigations. 1971, Appendix E, 1'.124·132. Unpubl.

rep. U.S. Del'. Commer.. NatI. Oceanic Atmos. Admin .. NatI. Mar. Fish. Servo

(Available Natl. Mar. Mammal Lab.. Natl. Mar. Fish. Serv.. OAA. 7600 Sand Point

Way NE.. Bldg. 32, Seattle, WA 98115.)

·'Sanger, G. A. 1974. On the effect of fish net scraps and other oceanic debris on

northern fur seals. Unpubl, manuscr.. 4 p. (Available Natl. Mar. Mammal Lab., NaIl.

Mar. Fish. Serv.. NOAA. 7600 Sand Point Way NE., Bldg. 32, Seattle. WA 98115.)

'''Bigg, M. 1979. Incidence of adult northern fur seals entangled in debris on 51. Paul

Island, 1978. Unpubl. man user.. 5 p. Dep. Fish Environ .. Fish Mar. Serv., Resour.

Servo Br" Pac. BioI. Stn., Nanaimo. B.C., Canada.

71 Kozloff, P. 1979. Fur seals entangled in fishing debris and other materials. Unpubl.

manuscr., 5 p. Natl. Mar. Mammal Lab., Natl. Mar. Fish. Serv.. NOAA, 7600 Sand

Point Way NE., Bldg. 32, Seattle, WA 98115.

72Dead fur seals of both sexes that are older than pups are also counted each year and

their canine teeth collected for studies of age at death. These numbers are relatively

small.

20

of the living pups in late July and early August, tended to produce

underestimates of mortality, This was not learned until 1951 when it

was demonstrated that it is not until 15-20 August that the death rate

on land declines to insignificance. These dates have since been

reconfirmed. 73

In an effort to reduce the amount of time needed to make total

counts of dead pups and to eliminate much of the disturbance

associated with this activity, sample areas were established on all

except the four smallest rookeries on St. Paul Island in 1956

(Abegglen et aI., footnote 15). Each of these areas contained approximately 30% of the total number of dead pups on a given

rookery. Although records were kept for several years of the number

of dead pups counted within the study areas for comparison with

total counts made during those same years, the study areas were

never used alone as a basis for estimating the total number of dead

pups.

In 1966, the rookeries on the Pribilof Islands were subdivided

into numbered sections containing approximately 100 harem males

each to facilitate the counting of adult male fur seals and the

distribution of marking effort during surveys to estimate the

number of live pups. Since that year, the dead pups have also been

counted by section to determine if there are relationships between

pup mortality and such factors as density of harem males.

An unknown number of dead pups are not "seen" during the

count each year due to removal by foxes, gulls, the heavy surf

generated by storms, and through advanced decomposition of those

born early in the season which makes identification difficult or

impossible, and simply because the counters inadvertently overlook

some ofthe dead pups as they work their way through each rookery,

An attempt has been made to account for dead pups overlooked

during the counts by increasing the actual number counted by 5% in

the various reports. Abegglen et al. (footnote 39, p. 49) checked the

validity of the 5% addition by reexamining Morjovi Rookery immediately after the count and found that 5.9% had been overlooked.

According to their report, "This agrees closely with the standard 5

percent addition, though the number of dead pups missed would

probably vary from none on sand or [cobblestone] beaches to many

on boulder beaches. For example, during the 'clearing off' of dead

pups on Zapadni Reef Rookery, [boulders and cobblestone] 10

percent were overlooked. On Little Polovina Rookery, [sand and

cobblestone] a negligible number were missed during the [removal

of dead pups].... The surface of Morjovi Rookery varies from sand

to [cobblestone]."

Other possible causes of mortality among fur seals at sea, besides

starvation, are the increasing amounts and kinds of pollutants added

to the marine food chain by man. According to Klein and Goldberg

(1970), 4,000-5,000 tons of mercury are contributed annually by

man to the environment in addition to the 5,000 tons of this element

transferred to the oceans by continental weathering. In their

research on fur seals, Anas (1974), Anas and Wilson (1970a, b), and

Anas and Worlund (1975) analyzed samples of liver, muscle, brain,

and kidney tissue not only for mercury but for other heavy metals

such as lead, cadmium, and arsenic as well as organochlorine

pesticides. General results were that the levels of mercury were

much higher in liver than in other tissues, that this element was

significantly correlated with age, and that pesticides were found in

every sample examined. The relationship of these pollutants to

mortality of fur seals, however, has not yet been identified.

"R. Gentry, Wildlife Research Biologist, National Marine Mammal Laboratory,

Northwest and Alaska Fisheries Center. 7600 Sand Point Way NE" Bldg. 32, Seattle,

WA 98115. pers. commun. November 1981.
Forecasts.-It should be mentioned at the outset that forecasts of

the size of the commercial harvest of male fur seals on the Pribilof

Islands were never intended to be anything more than that.

Nevertheless, many persons, including some closely involved with

fur seals, have come to look upon the forecasts as quotas, such as

those that were in effect from 1870 through 1909 and again from

1918 through 1923. Quotas have not been established since 1923,

except for females during 1956-68 (Roppel and Davey 1965).

Forecasts of the returns of male seals started in 1960 when D. G.

Chapman, through a contract between the Marine Mammal Biological Laboratory (now the National Marine Mammal Laboratory) of

the Bureau of Commercial Fisheries and the University of Washington, was asked to predict the size of the commercial harvest in 1961.

These forecasts have essentially been attempts to estimate the survival of the year classes to ages 3 and 4 yr so as to better enable

managers to plan for materials, equipment, and the off-island labor

force needed to take and process the skins. Success in forecasting

requires reasonably accurate information on: I) Number of pups

born, and 2) mortality of pups on land, and annual mortality

between the time they leave the rookeries in November of the

summer of birth and their return at ages 3 and 4 yr.

Major obstacles to success in predicting year-class returns have

been variability in mortality and lack of adequate data for estimating losses at sea, which have a much greater influence on the

magnitude of returns than do those that occur on land. Forecasts of

the kill have been reasonably accurate and useful when based on

year classes with average survival, but of no practical value for

those with extreme variations in numerical levels. Such predictions,

therefore, are of little or no use unless these extremes can be

estimated with accuracy.

Forecasts of the return of 4-yr-olds have been based on the kill of

3-yr-olds the previous year, mean air temperature on St. Paul Island

for 12 mo preceding birth of the year class,74 weights of pups in

autumn, number of pups born, counts of dead pups and harem

males, and estimates of yearling males. Most of these factors have

also been examined with respect to forecasting the return of 3-

yr-olds.

The kill of 3-yr-olds should be a good basis for estimating the

return of the year class a year later at age 4 yr. However, this

indicator has suffered certain inaccuracies as a result of changes in

termination dates of the kill and variations in the time of arrival on

land of the 3-yr-olds.

Forecasts of the kill at age 3 yr have been even more difficult and

uncertain because the number available on land at age 2 yr as a basis

for making predictions is relatively small, at least during the traditional period of the harvest in July.

A potential indicator of the number of males surviving their first

winter at sea is the number of yearling seals that come ashore in

uutumn. Problems encountered in the use of this measurement

include: 1) Difficulty in marking an adequate number of yearling

male seals, 2) relatively small kills the following year of 2-yr-old

males that had been tagged as yearlings, and 3) bias should tagged

animals be killed more frequently than those without tags.

74Hookworm larvae were once thought to overwinter in rookery soil and Infect the

fDllowing year class of pups through their flippers and that perhaps weather had some

influence over the number of these larvae, the degree to which the pups were infected,

and death rates (Abegglen et al. footnotes 31, 33). It has since been learned that

free-living hookworm larvae do in fact penetrate the flippers. This occurs predominantly in August by larvae produced by the pups themselves. Mortality of pups from

hDokworm disease, however, is actually caused from 3rd stage larvae passed from

mother to pup through the milk, and overwintering of larvae is unimportant (Lyons

1963).

21

Mean air temperature in the year preceding birth of a year class,

weights of pups in autumn, number of pups born, and counts ofdead

pups are all collected before the year class suffers a substantial part

of its losses. Therefore, if the factors that influence survival at sea

cannot be measured, data collected on land have little value for

forecasting.

Erratic management ofthe seal kill on land has at various times in

the past also contributed to (he difficulty in making useful forecasts.

There have been few good reasons for varying the termination date

of the kill. The onset of molt is not known to cause problems

through any extensive variations from year to year (Scheffer and

Johnson footnote 36) and unless future studies indicate otherwise,

there is no real financial advantage in emphasizing utilization of the

year classes at age 3 rather than age 4 yr (Marine Mammal Biological Laboratory footnote 23). The only known reasons for varying

the termination date of the harvest are: I) The possibility of an

exceptionally large survival of a year class, making it necessary to

take more at age 3 yr, 2) significant variation in timing of the returns

of 3-yr-olds, 3) a rather dubious need to take additional 2-yr-olds,

even if available, as a way to improve the forecast of the kill the

following year at age 3 yr, and 4) to increase (or decrease) recruitment of males into the breeding reserve.

The actual and forecasted returns of male seals during 1961-81 are

presented in Table 4, and methodologies used in making these

predictions are on file in various annual reports of fur seal investigations and other documents at the National Marine Mammal

Laboratory, Northwest and Alaska Fisheries Center. Also on file is a

summary of estimation procedures developed by Chapman (1975) 75

as a background paper for the 19th meeting of the NPFSC in 1976.

Socioeconomic Factors

Fur seals of the Pribilof Islands are subject to disturbance from

various groups of people, including tourists, Coast Guard personnel, research scientists, photographers, and the Aleuts. Officially,

the rookeries, hauling grounds, and certain parts of adjacent

beaches are closed to all but authorized persons each summer from I

June through 15 October. Regardless, several changes have in the

past and undoubtedly will in the future contribute to some disruption of these animals on their breeding grounds.

Located in an extremely remote part of the world, the Pribilof

Islands were once seldom viewed by anyone other than federal

officials and the people who lived there or landed to work with the

fur seals. 76 Construction of a runway and the beginning of air

service to the islands in the 1950's, however, opened the way to

tourism, an industry that in its infancy brought only 5-6 sightseers

weekly and perhaps as many as 100 to St. Paul Island during an

entire summer. Now promoted commercially as part of their overall

tourist package, Alaska Tour and Marketing Services, Inc., annually brings in up to 1,000 people interested in marine birds and fur

seals. St. George Island may be added to Alaska Tour and Marketing

Services' list of tourist attractions; however, the existing runway on

St. George Island is suitable only for small twin-engine aircraft.

Two studies were started on St. George Island in 1981, one on the

feasibility of extending the runway to accommodate four-engine

"Chapman, D. G. 1975. Methods of torecasting the kill of males on the Pribilof

Islanos. Unrubl. manuscr.. 10 p. (Available Natl. Mar. Mammal Lab., Natl. Mar. Fish.

Serv., NOAA. 7600 Sand P"II11 Way NE., Bldg. 32, Seattle, WA 98115.)

"All other visitors to the islands were required to have permits issued under the

authority of a succession of federal agencies begi I1I1l11g with the Treasury Department in

1869. The permit system was in effect from that year to about 1964, at which time;\ was

abolished.
Table 4.- Actual and forecasted kills of 3- and 4-yr-old male seals and relative aircraft and another on the impact of these aircraft and tourism on

error [error = (forecast - actual)/forecastj ofthe forecast, St. Paul Island, Alaska, the fur seals there.

1961-81. Early tourists to St. Paul were largely on their own with respect to

Age (yr) moving about the island. The servicing airline provided occasional

3 4 Total transportation and a few visitors rented vehicles from local resiNumber Error (Cle) Number Error ('If) umber Error ('10) dents, but most walked everywhere they went. Later, federal man1961 agers assumed some responsibility for the tourists in the form of

Actual 29,523 12,4~~ 42,011 transportation and a driver/guide to supply information. At the same

Forecast 34.500 14 13,500 48,000 12 time, the servicing airline asked each of its passengers to complete a 1962 questionnaire designed to produce information that would assist it

Actual 25,098 13,422 38,520

Forecast 36.000 30 11,000 -22 47,000 18 and the Federal Government in a bid to help the tourists realize the

1963 most from dollars spent. Finally, Alaska Tour and Marketing SerActual 11,596 12,283 23,879 vices put a bus on St. Paul Island for transporting its customers to

Forecast 30,000 61 15,000 18 45,000 47 places of interest, and federal managers constructed one "blind" on 1964 Little Zapadni Rookery and another on Gorbatch Rookery in 1976

Actual 22.203 10,509 32,712 from which tourists and others could observe fur seals in safety Forecast 24,000 7 13,000 19 37,000 12

1965 without disturbing the animals. From 1963 through 1975, people

Actual 12,126 9,838 21,964 wishing to view fur seals at close range were taken to an observation

Forecast 26,000 53 13,000 24 39,000 44 hut on Kitovi Rookery (Amphitheater) where they caused some 1966 disruption among the animals when they wandered away from the

Actual 25,535 12,156 37,691 hut. Forecast 26,000 2 14,000 13 40,000 6

1967 Construction of a Coast Guard loran station on St. Paul in the late

Actual 26,991 11,785 38,776 1950's brought an additional 20 people to this island on a year-round

Forecast 27,500 2 14,300 18 41,800 7 basis, Many of them "beachcomb" as a recreational outlet, and in

1968 some instances have run seals into the sea from areas closed to the

Actual 18,706 13,279 31 ,9~5 public. In an effort to eliminate or at least minimize this problem, Forecast 22,000 15 13,000 -·22 35,000 9

1969 managers have erected appropriately worded signs along access

Actual 17,826 10,565 28,391 roads and at various points on the beaches and now patrol all of the

Forecast 23,600 24 18,300 42 41,900 32 rookeries and hauling grounds one to four times daily from about

1970 mid-June to mid-August each summer.

Actual 22,176 11,548 33,724 Before 1962, the people of the Pribilof Islands were paid a token

Forecast 27,800 20 1/,600 0 39,400 14 wage supplemented by furnished housing and utilities and such dole

1971 as surplus military clothing and footwear. In that year, however, the Actual 12,888 12,503 25,391

Forecast 18,000 28 13,000 4 31,000 18 workers began receiving a full day's pay for a full day's work

1972 comparable with that paid others in similar occupations elsewhere

Actual 15,024 14,932 29,956 in Alaska. Among other material possessions, their new-found Forecast 19,600 23 16,000 7 35,600 16 wealth translated into various kinds of vehicles which in turn gave 1973 the people mobility about the island never before enjoyed. The Actual 16,337 10,800 27,137

Forecast 16,700 2 13,200 18 29,900 9 effect has been one of access to all parts ofthe islands, including the

1974 fur seal rookeries. Visible as a result of this access has been a certain

Actual 14,652 15,533 30,185 amount of destruction to the landscape, particularly from fourForecast 13,000 -13 9,600 -62 22,600 -34 wheel drive units and motorbikes, Not so visible has been distur1975 bance to the fur seals, indicated indirectly by the occasional appear- Actual 15,186 10,76R 25,954 ance of fresh tire tread marks on or along certain rookeries and Forecast 16,000 16,000 33 32,000 19

1976 hauling grounds during the closed period mentioned earlier. InActual 13,397 8,050 21,447 creased mobility, especially among those too young to drive, and

Forecast 17,100 22 11,000 27 28,100 24 additional potential for disturbance of the fur seals has come with

1977 development of a local motorbike rental business. Installation of

Actual 16,476 9,421 25,~97

gates across roads leading to the rookeries in the 1960's proved to be Forecast 15,700 - 5 11,000 14 26,700

1978 an unworkable and a locally unpopular solution to the problem,

Actual 13,752 8,955 22,707 mostly because large areas without fur seals beyond or near concenForecast 15,100 9 10,200 12 25,300 10 trations of these animals were also closed to use in summer.

1979 A large number of independent scientists have carried out re- Actual 15,245 7,918 23,163

Forecast 15,500 2 10,600 25 26,100 II search on various aspects of fur seal biology in recent years, Univer1980 sity professors, postgraduate students, and members of the ScienActual 13,157 g,lg3 21,340 tific Committee of the NPFSC have participated. Some disruption Forecast 17,700 26 g,400 3 26,100 I~ of rookery Iife has been necessary because of a need to capture fur

1981 seals for use as subjects of research and because of construction and Actual 14.224 6,714 20,938

Forecast 16,700 15 9,300 28 26,000 19 use of long catwalks to enhance certain kinds of research.

All years Another possible source of disturbance to the fur seals is profesActual 372,118 231,650 603,768 sional photographers. Fortunately, most or all of these people in the Forecast 45~,5oo 19 265,000 13 723,500 17

past have been interested in filming the animals under completely

22
natural conditions. It is not inconceivable, however, that some

photographers in the future will want or attempt to take "action"

shots, which in most situations must be created through disturbance. The adult males are normally given to boundary displays

rather than actual fighting unless excited by the presence of humans.

During the summer of 1980, a two-man team from Seattle experimentally fished for Korean horse hair crab, Erimacrus izenbeckii, off St. Paul Island; in 1981, the Tanadgusix Corporation (a local

subsidiary of the Alaskan Aleut Corporation) began fishing halibut

commercially. Both operations would benefit from construction of a

small boat harbor on St. Paul Island, a subject that has been given

considerable thought for several years and for which a draft environmental impact statement has been developed (U.S. Army

Corps ofEngineers 198F7). So far as is known, the fur seals will not

in any way be affected should a harbor be developed at the site now

contemplated. However, the protection afforded boats by it may

cause a local increase in vessel traffic with unknown consequences

to these animals.

Objections to the Harvest

Periodically since the late 1960's, the fur seal of the Pribilof

Islands received considerable attention from animal protection

groups because of their attempts to stop the harvest on the grounds

that it is an inhumane78 use of the resource. Organizations actively

opposed to the harvest were the Humane Society of the United

States, Fund for Animals, Friends of Animals, and Greenpeace.

The International Society for the Protection of Animals, and World

Federation for the Protection of Animals were primarily interested

in the humaneness of the kill. The activities of the first four groups

have been especially intense each time the Convention has come up

for renewal. In this connection, for example, a dozen people,

including one U.S. Congressman and two national television network crews, observed the harvest on St. Paul Island in 1979.

Federal managers responded to pressure and publicity brought to

bear b/ these groups with studies of the effectiveness of traditional

and alternate methods of stunning and killing the animals, and for

several seasons since 1972 have util ized the services of a succession

of volunteer veterinarians to observe the harvest to ensure that it was

as humane and stress-free for the animals as possible.

The first of the studies was by a veterinary pathologist from the

University ofCambridge, England, who was also a representative of

the World Federation for the Protection of Animals. Simpson (1968)

observed the rounding up of the seals and the harvest, and conducted postmortem examinations of animals on the killing fields

and at the byproducts plant where the carcasses were ground and

frozen for mink food. Of 1,121 carcasses examined, 21 (1.9%) did

not have fractured crania and those without punctured hearts totaled

38 (3.4%).79 However, the thorax of every seal had been opened, a

condition that would lead very rapidly to death from collapse of the

lungs and respiratory failure. The conclusions were that none of the

seals had been skinned while still alive, that the mechanics of the

harvest were reasonably humane, and that the traditional method of

"u.S. Army Corps of Engineers, Alaska District. 1981. Harbor feasibility report,

St. Paul Island, Alaska. Unpubl. manuscr., 244 p. U.S. Army Corps Eng., Alaska

Dist., P.O. Box 7002, Anchorage, AK 99510.

"First objections into the early 1970's were primarily ofquestioning the humaneness

of the killing techniques. After the studies listed were carried out the major emphasis

for stopping the harvest changed to one of questioning the moral issue of killing wild

animals for profit and luxury skins.

79The procedure then and now is to first stun the animal with a blow to the head, then

open the chest with a knife and puncture the heart to reduce blood pressure to zero.

23

stunning by club followed by myocardial puncture is probably the

best method of euthanasia considering all of the factors.

In 1968, the Bureau of Commercial Fisheries (now the National

Marine Fisheries Service) organized a five-man team of mixed

biological professions and one member of the Humane Society of

the United States to experiment with alternative methods of killing

fur seals and to review the entire seal harvesting operation (U. S.

Department of the Interior 19688°). The team employed several

forms of euthanasia including carbon dioxide, electricity, shooting,

stunning, and concussion bolts as well as drugs and tranquilizers.

They concluded that none of the methods tested were adaptable to

harvesting fur seals at that time. However, the members did recommend several changes that would improve conditions for driving the

animals from the hauling grounds to the killing fields and reduce

stress on the animals. The panel suggested that the length of the

drives be shortened, 81 that the drive paths be improved by removing

surface rocks and filling depressions to prevent crowding and

pileups of the animals, that seals unsuitable for harvesting be

rejected as soon as possible along the drive path, that where possible

the animals be driven around rather than over obstacles, and that at

least two relief stunners be available to provide rest periods, which

in turn should result in greater accuracy in stunning the animals and

eliminate the need for multiple blows.

Because the Humane Society of the United States suggested

further investigations involving carbon dioxide and nitrogen asphyxiation, the Federal Government contracted with the Virginia

Mason Research Center, Seattle, Wash., to carry out experiments on

surgically instrumented seals. The objective was to compare the

effectiveness of hypoxic atmospheres of COz and Nz' the drug

succinylcholine chloride, and the traditional method. Spencer et al.

(1971) concluded that the two experimental methods took five to

eight times longer to kill than did manual stunning and exsanguination.

In 1971, the National Oceanic and Atmospheric Administration

invited six veterinary medical doctors, members of the American

Veterinary Medical Association's panel on euthanasia, to evaluate

the humaneness of harvesting fur seals and make recommendations

for the future. Specific objectives were to: I) Observe current

methods of slaughter from roundup until death occurred and skinning was completed and to assess for humaneness, and 2) suggest

research which might lead to more humane methods of euthanasia or

methods which might be equally humane but more aesthetically

acceptable. With respect to the roundups and drives, the group

observed that although obstructions existed in the drive paths in the

form of rocks, the seals were accustomed to traveling over this type

of terrain on the rookeries. The members also agreed that distances

over which the animals were driven were reasonable and did not

constitute inhumane treatment. The current method of slaughter,

i.e., manual stunning followed by exsanguination, was considered

painless, humane euthanasia, a fact that has been overwhelmin2"l"

supported by tourists who viewed the kills and reported their feelings in questionnaires routinely handed out by the servicing airline.

The panel did, however, suggest that the aesthetics of the operation

could be improved by: I) Shifting the collection of genital organs (a

byproduct in demand as an aphrodisiac) from the killing field to the

ROU .S. Department of the Interior, Bureau ofCommerical Fisheries. 1968. Report of

the task force to study alternate methods of harvesting fur seals. St. Paul Island, Alaska.

Unpubl. rep., 41 p. (Available Natl. Mar. Mammal Lab., Natl. Mar. Fish. Serv.,

NOAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA 98115.)

RI New access roads and extensions of old ones to shorten the drives were constructed

during 1970-71.
byproducts plant, 2) speeding removal of carcasses and skins from

the places of harvest, and 3) constructing panels on both sides of the

outside portion of the "turkey line" on which the carcasses were

suspended at the byproducts plant for processi ng (Veterinary Panel

1971"2). The intent of the panel was to shield from public view these

three parts of the harvesting operation.

Finally, Battelle Columbus Laboratories were contracted by the

National Marine Fisheries Service in 1972 to carry out research on

"Concept scrutiny, prototype development, and field evaluation of

improved fur seal slaughtering techniques." In a final analysis, their

report stated, "the [seal] club emerges as the best technique for

stunning fur seals on a mass harvest basis." However, the scientists

conducting these studies saw two objections to the club: Aesthetics

and inaccurate blows; they felt that a reduction in the number of

inaccurate blows should help to improve the aesthetics. Accordingly, the group" recommended that a serious analysis of the clubbing approach be undertaken to determine desirable qualities for

fabrication of a 'super club' " (Williams et al. 1973"3).

Keys (1980)"4 summarized the activities of these various groups

in a background paper submitted to the NPFSC at its 23rd meeting.

ACKNOWLEDGMENTS

Special thanks are due several staff members of the National

Marine Mammal Laboratory for their review of the manuscript.

Current members include M. F. Tillman, C. F. Fowler, P. Kozloff,

M. C. Keyes, A. York, R. L. DeLong, and G. A. Antonelis. Former

members include F. Wilke, G. Y. Harry, C. H. Fiscus, R. H. Lander,

A. M. Johnson, K. W. Kenyon, and V. B. Scheffer. Reviews by W.

Kirkness and J. Scordino, Pribilof Islands Program, are also gratefully acknowledged, as are those of D. G. Chapman, Center for

Quantitative Science, University of Washington, and M. A. Bigg,

Fisheries and Marine Service, Canada. T. C10cksin provided considerable assistance with the references. Typists: D. C. Roppel, M.

Wood, and J. Waychoff.

LITERATURE CITED

ABEGGLEN, C. E., and A. Y. ROPPEL.

1959. Fertility in the northern fur seal, 1956-57. J. Wildl. Manage. 23:75-81.

A AS, R. E.

1970. Accuracy in assigning ages to fur seals. J. Wildl. Manage. 34: 844-852.

1974. Heavy metals in the northern fur seal, Callorhinl/s l/rsinl/s, and harbor

seal, Phom Vill/lilla richardi. Fish. Bull., U.S. 72:133-137.

ANAS, R. E.. and A. 1. WILSON, Jr.

1970a. Organochlorine pesticides in nursing fur seals. Pestic. Manit. J.

3: 198-200.

1970b. Organochlorine pesticides in nursing fur seal pups. Pestic. Manit. J.

4:114-116.

ANAS, R. E. and O. O. WORLUNO.

1975. Comparison between two methods ofsubsampl ing blubber of northern fur

seals for total DDT plus PCB's. Pestic. Manit. 1. 8:261-262.

"Veterinary Panel. 1971. Preliminary report of the veterinary panel evaluating

humaneness of the northern fur seal harvest in the Pribilof Islands. Unpubl. manuscr.,

14 p. Prepared for Natl. Mar. Fish. Serv., Washington, O.c. (Available Natl. Mar.

Mammal Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point Way NE., Bldg. 32,

Seattle, WA 981/5.)

"Williams, R. A., C. R. Hassler, J. O. Helmer, and K. E. Hughs. 1973. Final

research report on concept scrutiny, prototype development, and field evaluation of

improved fur seal slaughtering techniques. Unpubl. manuscr., 46 p. Banelle, Columbus Lab., Columbus, Ohio. (Available Natl. Mar. Mammal Lab., Natl. Mar. Fish.

Serv., NOAA, 7600 Sand Point Way NE., Bldg. 32, Seattle, WA 98115.)

"Keyes, M. C. 1980. Summary of humane slaughter activities in connection with

the annual fur seal harvest conducted by the United States. Unpubl. manuscr., 7 p. Natl.

Mar. Mammal Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point Way NE., Bldg.

32, Seattle, WA 981/5.

24

ANONYMOUS.

196Y. Mortality. III Fur seal investigations, 1966, p. 6-12. U.S. Fish Wildl.

Serv., Spec. Sci. Rep. Fish. 584.

1970a. Mortality. III Fur Seal investigations, 1967, p. 7-10. U.S. Fish Wildl.

Scrv., Spec. Sci. Rep. Fish. 597.

1970b. Causes of seal pup mortality. III Fur seal investigations, 1968, p.

7-11. U.S. Oep. Commer., NOAA, Natl. Mar. Fish. Serv., Spec. Sci. Rep.

Fish. 617.

1973. Appendix O. Coordinated Pribilof Islands-Bering Sea Research Proposal. Fed. Regist. 38(149):20599-20601.

BAKER, R. C., F WILKE, and C. H. BALT/.O.

1970. The northern fur seal. U.S. Fish Wildl. Serv., Circ. 336, 22 p.

BANCROFT, H. H.

1886. History of Alaska, 1730-1885. III The works of Hubert Howe Bancroft.

Vol. 33,775 p. A. L. Bancroft and Co., San Franc.

BARTH, T. F. W.

1956. Geology and petrology of the Pribilof Islands, Alaska. U.S. Geol. Surv.

Bull. 1028-F, 160 p.

BARTHOLOMEW, GA., .1r

1953. Behavioral factors affecting social structure in the Alaska fur seal.

Trans. 18th North Am. Wildl. Conf. 1953:481-502.

1959. Mother-young relations and the maturation of pup behaviour in the Alaska

fur seal. Anim. Behav 7:163-171.

BARTHOLOMEW, G. A., Jr., and P. G. HOEL.

1953. Reproductive behavior of the Alaska fur seal, Callorhil1l/S l/rsilll/S. J.

Mammal. 34:417-436.

BARTHOLOMEW, G. A., and F. WILKE.

1956. Body temperature in the northern fur seal, Callorhil1l/s l/rsilll/s. J.

Mammal. 37:327-337.

BAUER, R. D., A. M. JOHNSON, and V. B. SCHEFFER.

1964. Eye lens weight and age in the fur seal. J. Wildl. Manage. 28:374-376.

BOWER, W. T.

1919. Alaska fisheries and fur industries in 1918. Rep. U.S. Comm. Fish.,

1918, append. 7, 128 p. (Doc. 872.)

1922. Alaska fishery and fur-seal industries in 1921. Rep. U.S. Comm. Fish.,

1922, append. 10,85 p. (Doc. 933.)

1923. Alaska fishery and fur-seal industries in 1922. Rep. U.S. Comm. Fish.,

1923, append. 4_ 118 p. (Doc 951.)

1930. Alaska fishery and fur-seal industries in 1929. Rep. U.S. Comm. Fish.,

1930, append. 10:205-339. (Doc. 1086.)

1931. Alaska fishery and fur-seal industries in 1930. [U.S.] Bur. Fish., Admin.

Rep. 2, 108 p. (Another source is Rep. U.S. Comm. Fish., 1931, append.

~:1-108.)

BYCHKOV, V. A.

1967. 0 napadenii kosatok na morskikh kotikov y ostrova tyulen'ego (On killer

whale altacks on fur seals off Tyuleni Island). [In Russ.] ZooI. Zh. 46:149-

150. (Transl. 1968,4 p., available Natl. Mar. Mammal Lab., Natl. Mar. Fish.

Serv., NOAA, 7600 Sand Point Way NE., Seatlle, WA 98115.)

CHAPMAN, D. G.

1961. Population dynamics of the Alaska fur seal herd. Trans. 26th North Am.

Wildl. Conf. 1961:356-369.

1964. A critical study of Pribilof fur seal population estimates. U.S. Fish

Wildl. Serv., Fish. Bull. 63:657-669.

CHAPMAN, D. G., and A. M. JOHNSON.

1968. Estimation of fur seal pup populations by randomized sampling. Trans.

Am. Fish. Soc. 97:264-270.

CHELNOKOV, F. G.

1969. Ostatki skeleta morskoi korovy (Skeletal remains of the sea cow). [In

Russ.] Priroda (Mosc.)!:71-73. (Transl. by S. Pearson, 1971,2 p., available

Natl. Mar. Mammal Lab.. Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point Way

NE., Seattle, WA 981/5.)

OALL, W. H.

1870. Alaska and its resources. Samson Low, Son, and Marston, Lond.,

627 p.

OMYTRYSHYN, B., and E. A. P. CROWNHART-VAUGHAN.

1979. The end of Russian America. Captain Golovin's last report.

1862. Oregon Hist. Soc., Portland, 249 p.

EBERHARDT, L. L.

1981. Population dynamics of the Pribilof fur seals. 111 C. W. Fowler and T. O.

Smith (editors), Dynamics of large mammal populations, p. 197-220. John

Wiley & Sons, N.Y.

ELLIOTT, H. W.

1884. Report on the seal islands of Alaska. U.S. Dep. Inter., Censos Off.,

Tenth census, rep., 188 p. U.S. Gov. Print. Off., Washington, D.C.

GENTRY, R. L.

1981. Land-sea movements of northern fur seals relative to commercial harvest-
ing. /n J. A. Chapman and D. Pursley (editors), Worldwide furbearer conference proceedings, August 3-11, 1980, Frostburg, Maryland, USA. Vol. 2, p.

1328-1359. Worldwide Furbearer Conf., Inc., Frostburg, Md.

GRIBEN, M. R.

1979. A study of the intermixture ofsubadult male fur seals Callorhinlls IIrsinlls

(Linnaeus 1758) between the Pribilof Islands of St. George and St. Paul,

Alaska. M.S. Thesis, Univ. Washington, Seattle, 191 p.

JOHNSON, A. M.

1968. Annual mortality of territorial male fur seals and its management significance. J. Wildl. Manage. 32:94-99.

1975. The status of northern fur seal populations. Rapp. P.- V. Reun. Cons.

Int. Explor. Mer 169:263-266.

JORDA ,D. S. (editor).

1898. The fur seals and fur seal islands ofthe North Pacific Ocean. U.S. Treas.

Dep. Doc. 2017,4 parts. U.S. Gov. Print. Off., Washington, D.C.

KENYON, K. W

1962. History of the Steller sea lion at the Pribilof Islands., Alaska. 1. Mammal. 43:68-75.

KENYON, K. W, V. B. SCHEFFER, and D. G. CHAPMAN.

1954. A population study of the Alaska fur-seal herd. U.S. Fish Wildl. Serv.,

Spec. Sci. Rep. Wildl. 12,77 p.

KEYES, M. C.

1965. Pathology of the northern fur seal. J. Am. Vet. Med. Assoc. 147:1090-

1095.

1971. Pathology. /n Fur seal investigations, 1969, p. 7-11. U.S. Dep. Commer., NOAA, Natl. Mar. Fish. Serv., Spec. Sci. Rep. Fish. 628.

KHLEBNIKOV, K. T.

1979. Polozhenie ostrova Sv. Pavia (Conditions at St. Paul Island), p. 194-201;

Polozhenie ostrova Georgiya (Conditions at St. George Island), p. 201-217. /n

Russkaya Amerika v neopublikovannykh zapiskakh K. T. Khlebnikova (Russian American in the unpublished notes of K. T. Khlebnikov). [In

Russ.] Nauka, Leningrad. (Transl. by A. Y. Roppel, 1981,34 p., available

Natl. Mar. Mammal Lab.. Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point Way

NE., Seattle, WA 98115.)

KLEIN, D. H., and E. D. GOLDBERG.

1970. Mercury in the marine environment. Environ. Sci. Technol. 4:765-768.

LANDER, R. H.

1975. Method of determining natural mortality in the northern fur seal (Collorhinus IIninus) from known pups and kill by age and sex. J. Fish. Res.

Board Can. 32:2447-2452.

1979. Role of land and ocean mortality in yield of male Alaskan fur seal,

Callorhinlls uninus. Fish. Bull., U.S. 77:311-314.

1981. A life table and biomass estimate for Alaska fur seals. Fish. Res.

I( 1981/1982):55-70

LANDER, R. H. (editor).

1980a. Summary of northern fur seal data and collection procedures. Vol. I.

Land data of the United States and Soviet Union (excluding tag and recovery

records). U.S. Dep. Commer., NOAA Tech. Memo. MFS F/NWC-3, 315 p.

(Available U.S. Dep. Commer., Nall. Tech. Inf. Serv., Springfield, Va., as PB

81-106502.)

1980b. Summary of northern fur seal data and collection procedures. Vol. 2.

Eastern Pacific pelagic data ofthe United States and Canada (excluding fur seals

sighted). U.S. Dcp. Commer., NOAA Tech. Memo. NMFS F/NWC-4, 541 p.

(Available U.S Dep. Commer. , Nall. Tech. Inf. Serv., Springfield, Va., as PB

81-124513.)

LANDER, R. H., and H. KAJIMURA (editors).

1980. Summary of northern fur seal data and collection procedures Vol. 3:

Western Pacific pelagic data of the Soviet Union and Japan, 1958-78 (excluding

fur seals sighted). U.S. Dep. Commer., NOAA Tech. Memo. NMFS

F/NWC-5, 304 p. (Available U.S. Dep. Commer. , Natl. Tech. Inf. Serv.,

Springfield, Va. as PB 81-165904.)

LYOlllS, E. T.

1%3. Biology of the hookworm, Uncinaria lucasi Stiles, 1901, in the northern

fur seal, Callorhinus uninlls Linn. on the Pribilof Islands, Alaska. Ph.D.

Thesis, Colorado State Univ., Fort Collins, 98 p.

MARINE MAMMAL BIOLOGICAL LABORATORY.

1969. Fur seal investigations, 1966. U.S. Fish Wildl. Serv., Spec. Sci. Rep.

Fish. 584, 123 p.

1970a. Fur seal investigations, 1967. U.S. Fish Wildl. Serv., Spec. Sci. Rep.

Fish 597, 104 p.

1970b. Fur seal investigations, 1968. U.S. Dep. Commer., Spec. Sci. Rep.

Fish. 617,125 P

MERRELL, T. R., Jr.

1980. Accumulation of plastic litter on beaches of Amchitka Island, Alaska. Mar. Environ. Res. 3:171-184.

25

NORTH PACIFIC FUR SEAL COMMISSION.

1967. Proceedings of the tenth annual meeting. North Pacific Fur Seal Commission, Washington, D.C., 48 p.

1970. Proceedings of the eleventh annual meeting. North Pacific Fur Seal

Commission, Washington, D.C., 33 p.

1971. Proceedings of the fourteenth annual meeting. North Pacific Fur Seal

Conunission, Washington, D.C., 33 p.

1973. Proceedings of the sixteenth annual meeting. North Pacific Fur Seal

Commission, Washington, D.C., 36 p.

1974. Proceedings of the seventeenth annual meeting. North Pacific Fur Seal

Commission, Washington, D.C., 47 p.

1976. Proceedings of the nineteenth annual meeting. North Pacific Fur Seal

Commission, Washington, D.C., 38 p.

1977. Proceedings of the twentieth annual meeting. North Pacific Fur Seal

Commission, WaShington, D.C., 42 p.

1978. Proceedings of the twenty-first annual meeting. North Pacific Fur Seal

Commission, Washington, D.C., 43 p.

1979. Proceedings of the twenty-second annual meeting. North Pacific Fur

Seal Commission, Washington, D.C., 39 p.

1980. Proceedings of the twenty-third annual meeting. North Pacific Fur Seal

Commission, Washington, D.C., 39 p.

OSGOOD, W H., E. A. PREBLE, and G. H. PARKER.

19/5. The fur seals and other life of the Pribilof Islands, Alaska, in 1914. U.S.

Bur. Fish., Bull. 34, 172 p.

PETERSON, R. S.

1965. Behavior of the northern fur seal. Ph.D. Thesis, Johns Hopkins Univ..

Baltimore, Md., 214 p.

1968. Social behavior in pinnipeds with particular reference to the northern fur

seal. /n R. J. Harrison, R. C. Hubbard, R. S. Peterson, C. E. Rice, and R. 1.

Schusterman (editors), The behavior and physiology of pinnipeds, p.

3-53. Appleton-Century-Crofts, N. Y.

ROPPEL, A. Y., and S. P. DAVEY.

1965. Evolution of fur seal management on the Pribilof Islands. J. Wildl.

Manage. 29:448-463.

ROPPEL, A. Y., A. M. JOHNSON, R. E. ANAS, and D. G. CHAPMAN.

1965. Furseal investigations, Pribiloflslands, Alaska, 1964. U.S. Fish Wildl.

Serv., Spec. Sci. Rep. Fish. 502,46 p.

1966. Furseal investigations, Pribiloflslands, Alaska, 1965. U.S. Fish Wildl.

Serv., Spec. Sci. Rep. Fish. 536,45 p.

ROPPEL, A. Y., A. M. JOHNSON, R. D. BAUER, D. G. CHAPMAN, and F.

WILKE.

1963. Fur seal investigations, Pribiloflslands, Alaska, 1962. U.S. Fish Wildl.

Serv., Spec. Sci. Rep. Fish. 454, 101 P

ROPPEL, A. Y., A. M. JOHNSON, and D. G CHAPMAN.

1965. Furseal investigations, Pribiloflslands, Alaska, 1963. U.S. Fish Wildl.

Serv., Spec. Sci. Rep. Fish. 497,60 p.

SCHEFFER, V. B.

1950a. Growth layers on the teeth of pinnipedia as an indication of age. Science (Wash., D.C.) 1/2:309-311.

1950b. Experiments in the marking of seals and sea-lions. U.S. Fish Wildl.

Serv., Spec. Sci. Rep. Wildl. 4, 33 p.

1950c. Winter injury to young fur seals on the northwest coast. Cal if. Fish

Game 36:378-379.

1962. Pelage and surface topography of the northern fur seal. U.S. Fish WildI.

Serv., North Am. Fauna 64, 206 p.

1972. The weight of the Steller sea cow. J. Mammal 53:912-914.

1973. The last days of the sea cow. Smithsonian 3(10):64-67.

SCHEFFER, V. B., C. H. FISCUS, and E I. TODD.

In press. History of scientific study and management of the Alaskan fur seal,

Ca/lorhinlls IIninlls, 1786-1964. U.S. Dep. Commer., NOAA Tech. Rep.

NMPS SSRF.

SCHEFFER, V. B., and A. M. JOHNSO

1963. Molt in the northern fur seal. U.S. Fish Wildl. Serv., Spec. Sci. Rep.

Fish. 450, 34 p.

SIMPSON, E.

1968. Report on sealing in the Pribi!of Islands, 1967. World Fed. Protect.

Animals, Zurich, Switzerland, 8 p. (Availablo Natl. Mar. Mammal Lab., Natl.

Mar. Fish. Serv., NOAA, 7600 SanJ Point Way E.. Seattle, WA 98115.)

SPENCER, M. P, Y. OYAMA, A. C. VAN GOETHEM, N. SIMMONS, and

M. C. KEYES.

1971. Physiologic responses of the northern fur seal to hypoxia and submersion. [Abstr.] J. Am. Vet. Med. Assoc. 158:1874.

U.S. CONGRESS, SENATE.

1970. Treaties and other international agreements on oceanographic resources,

fisheries, and wildlife to which the United States is party. U.S. Gov. Print.

Off., Washington. D.C.. 672 p.
YORK, A. E., and J. R. HARTLEY.

1981. Pup production following harvest of female northern fur seals. Can. J.

Fish. Aqua!. Sci. 38:84-90.

26