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AFSC Historical Corner:  Northern Fur Seal Research & Management, 1960s on

Early Pioneers
Research and Mgmt.
Species Research
  - Salmon
  - Other Fish
  - Fur Seals 1,2,3,4
  - Whales / Whaling
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Fisheries Management
Environmental and Ecosystem Monitoring
northern fur seals
Northern fur seals in the waves.  AFSC photo.


On 1 January, the State of Alaska assumed responsibility for its own fisheries, though the Federal Government continued to manage the fur seal industry.

On 7 August, sealing was terminated by the Government on St. Paul Island, partly on the advice of Fouke Fur Company employees who judged that the proportion of "stagy" skins had reached a critical level. In later discussion it was agreed that a few standard sealskins in critical molt should be processed and sent to the Pribilofs for the future guidance of the men responsible for closing the sealing season.

The skulls of 24 bull seals were collected on St. Paul Island in 1960 and were sent to Soviet fur seal biologist Sergei Vasilievich Dorofeev (in 1961). About 1963, bull skulls from Soviet seal rookeries were received in exchange. Dorofeev had proposed to make a systematic comparison of Asian and North American seals

In 1960 the first recognized post-parturn animal that had delivered twins on land was killed on Reef Rookery. She was a 4-yr-old taken in a sealing drive; her pups were not identified. Another female killed was carrying a full term fetus in her abdominal cavity; the placenta was entwined among the intestines. This the only record of ectopic pregnancy.

In the summer of 1960, [W. M.] Chapman visited the Pribilofs in order to familiarize himself with research operations, such as tagging, upon which his statistical analyses for nearly a decade had been based. Upon his return, he was in a position to discuss past and future statistical work with a new appointee to the Laboratory. Chapman also developed "a simple model...on the premise that reduced survival [to age 3] is due to pressure on the food supply around the islands which affects the survival of the seal pups in their first year.

1960:  Larry R. Nygren successfully fed a captive pup. [He wrote:] "One pup learned to suck warm fur seal's milk from a human baby bottle. The hole in the tip of the nipple had been enlarged to accomodate the thick milk. To my knowledge this was the first successful bottle-feeding involving a captive fur seal pup." Nygren wrote that the pup had been taken by caesarean section in late June or early July and was still alive in September.

W. J. L. Sladen (Johns Hopkins University) began in 1960 a study of upper respiratory infections of Pribilof Islanders. He had been a biologist and medical officer in 1947 and later. His interest soon extended to fur seals; he collected blood samples and biopsies in 1960 and 1961. He isolated Clostridium perfringens from seals in 1961; this probably causes enteritis in pups.

The first of many attempts to anesthetize or tranquilize fur seals for research purposes was made in 1960. The Palmer "Cap Chur Gun," firing a drug-loaded syringe, had been released for sale in 1958 in Georgia. It soon became a popular research tool for wildlife managers. Against fur seals in 1960 it was not a success. Between 1961 and 1964, however, [Richard S.?] Peterson and [Mark Chenault] Keyes carried on further experiments in immobilizing seals and were satisfied with the results.

Also at the Pribilofs in 1960 were three Soviet observers representing the first U.S.S.R.-United States exchange of visitors as provided for by the Convention of 1957.

A breakthrough in the long and discouraging study of hookworm [summer 1961].

[E. T.] Lyons and [O. W.] Olsen found that the fur seal pup gets its initial infection through mother's milk. Larvae wintering over in the rookery soil are not essential in the life cycle of the egg passed in the feces of an infected pup develops to a third stage strongyliform larva, within its egg case, in rookery soil. In late summer it hatches into a free-living third stage larva. Some larvae penetrate the naked flippers of adult female seals and migrate to the belly blubber and mammary tissue. Others winter over in the soil. In certain years free-living third stage larvae are hard to find in soil in summer or spring. During the first few days of lactation, larvae enter the mother's milk and pass into the intestine of the nursling. In about 2 weeks, or in the latter half of July, the larvae mature in the lower intestine and enter their most destructive phase. This is the only intestinal phase of the worm; it lasts 4 or 5 months, or until autumn. Almost no worms can be found in the intestine in September.

The stomachs of four seal pups were examined at St. Paul Island in October 1961. The contents included sandfish, walleye pollock, smelt, and amphipods. The sample was small but important; it contributed to our still meager knowledge of the weaning food of the seal.

An important 3-year study of the behavior of fur seals on land was started in 1961 by Richard S. Peterson. He was attracted to the problem because fur seals are among the very few mammals in the world whose behavior can be easily observed and documented without disturbance, and [there is] need for knowledge of comparative mammal behavior. He developed new and useful techniques for immobilizing and marking seals, and for defining and categorizing behavior traits. He marked 1,300 seals, concluding that the best method was to shear a pattern in the pelage and follow with a peroxide foam bleach.

In 1961, yearling seals were tagged for the first time, to get evidence on mortality rates from birth to age 1 year and from age 1 to 3. The number tagged was disappointingly low; yearlings were hard to find.

On 8 October 1963 a protocol amending the Interim Convention on Conservation of North Pacific Fur Seals was signed in Washington, D.C., by representatives of the four parties. It entered into force 10 April 1964. It extended the Convention for another 6 years, or until 14 October 1969. It relaxed certain research requirements such as the number of seals to be collected at sea by each party in each year. It changed slightly the apportionment of sealskins to Canada and Japan. At the request of Japan, it called for study of the effectiveness of each method of sealing from the viewpoint of management and rational utilization of fur seal resources for conservation purposes (and) quality of sealskins by sex, age, and time and method of sealing.

Summer of 1962 on St. Paul Island
William G. Reeder and James W. Nybakken (University of Wisconsin) spent 2 wks...making a preliminary study of fur seal vocal patterns, particularly those contributing to mother-young recognition.
The first motion pictures for specific use in television were taken on St. Paul Warren Garst (Don Meier Productions), starring Marlin Perkins, director of the St. Louis Zoological Park.

At the close of the 1963 season, a halt was called to "herd reduction," an operation which had been designed to reduce the herd to the level of maximum sustainable productivity. During the 8-year period 1956-63, the herd reduction program on the Pribilof Islands had removed 270,054 female seals. One visible effect was the decline in numbers of females on hauling grounds. Where 16,498 females of ages 3 and 4 year were killed in 1958, only 646 were killed during a comparable period in 1963. In the last year, methods of harvesting and curing had been so improved that over 97% of the female skins taken were cured; fewer than 3% were condemned and destroyed on the islands.

Curing was performed for the first time in history by Government employees. Former employees of the Fouke Fur Company were hired by the Government to train new men in blubbering, brining, and the other operations of curing.

An important pup shearing program, designed to provide an early estimate of the population, was initiated in 1963. Galvanized stakes were set in concrete early in the summer to mark off sample transects; 21,929 pups were sheared in late July and early August. To obtain an estimate of the population, the marked-to-unmarked ratio in samples of 25 pups was ascertained a week or two after marking. From the results, it was estimated that 229,900 pups were alive at time of shearing on St. Paul Island.

The first general "glossary of terms used in fur seal research and management" was published in 1963. It defined 114 terms. Some of the terms and several new ones, were later defined by [A. Y.] Roppel, et al [in 1965]. Ten veterinary terms were defined by [M. C.] Keyes [in 1964].

One or more Fish and Wildlife Service biologists had been studying the fur seal herd almost continuously since 1940. In December 1963 the Service began to publish their research findings in two series of annual progress reports, one dealing with Pribilof studies and one with pelagic studies. The publications were retroactive to the field season of 1962.

Event Items:

  • Seals to radio their voyages to scientists, 1975

    Scientists at the National Marine Fisheries Service's Northwest Fisheries Center in Seattle, Wash., will equip fur seals with sound this summer [1975] to gain more information on their feeding, movements, and behavior.

    Harnesses with radio transmitters will be attached to 50 young male fur seals when they return to St. George Island in July. St. George and St. Paul are two of the Pribilof Islands in the Bering Sea used for breeding grounds by approximately 80 percent (1.3 million) of the world's northern fur seals.

    Fur seals are harvested each year on St. Paul Island by NOAA under the provisions of the Interim Convention on the Conservation of North Pacific Fur Seals. Commercial harvesting on St. George Island was stopped in 1973 to permit scientists to study a protected population of northern fur seals.

    Practically nothing is known about the normal cyclic activity of the young males because they have traditionally made up most of the annual harvest, which normally took place in June or early July. Lack of this knowledge reduces the acuracy of population estimates for young males. A count of these animals on land cannot give the total population because there are always animals feeding at sea and many are as late as October in arriving on the island. The census is further complicated because of differences in behavior due to age and because the ratio of the number of animals on and offshore probably changes because of weather and human disturbances.

    The use of telemetry equipment is essential in studying the behavior of young males because, unlike adult males and females with pups, they do not confine themselves to a particular land area, but move readily from one land area to another, and it is difficult to keep an accurate record of their movements.

    The transmitters have a range of about one-half mile and will be monitored for a little over three months. Each has a different frequency and pulse repetition to permit the scientists to identify the individual seals.

    The seals to be equipped with the radios will be between two and five years old and weigh 50 to 115 pounds. (Full grown males weigh 400 to 600 pounds.) The harnesses will be recovered from the seals. However, in the event any harness is not recovered, a saltwater corrosion mechanism will release it, and prevent any adverse long term effect on the animal's movement.   (From NOAA Week newsletter, 13 June 1975, 6(24), p. 1, 3).

View the fur seal photos in the AFSC Multimedia Gallery.

Additional reading  (also see "The Pribilof Islands" facility page)

  • Scheffer, V. B., C. H. Fiscus, and E. I. Todd. 1984. History of Scientific Study and Management of the Alaska Fur Seal, Callorhinus ursinus, 1786-1964. U.S. Dep. Commer., NOAA Tech. Rep. NMFS SSRF-780, 70 p.  (.pdf, 48.1 MB)
  • Roppel, A. Y. 1984. Management of Northern Fur Seals on the Pribilof Islands, Alaska, 1786-1981. U.S. Dep. Commer., NOAA Tech. Rep. NMFS-4, 26 p.  (.pdf, 1.11 MB)
  • Stanley-Brown, J. 1894. Past and Future of the Fur Seal, p. 361-370. In Bulletin of the United States Fish Commission, Vol. XIII, for 1893. Wash. G.P.O.  (.pdf, 943 KB).
  • Osgood, W. H., E. A. Preble, and G. H. Parker. 1915. The Fur Seals and Other Life of the Pribilof Islands, Alaska, in 1914 (doc. 820). Wash. G.P.O. 172 p. + maps.  (.pdf, 17.3 MB).
  • U.S. Treasury Department. 1896. Reports of Agents, Officers, and Persons, Acting Under Authority of the Secretary of the Treasury, in Relation to the Condition of Seal Life on the Rookeries of the Pribilof Islands, and to Pelagic Sealing in Bering Sea and the North Pacific Ocean, in the Years 1893-1895, Pt. 1 (doc. 137). Wash. G.P.O. 379 p.  (.pdf, 64.3 MB).
  • Stejneger, L. 1926. Fur Seal Industry of the Commander Islands, 1897 to 1922, p. 289-332. In Bulletin of the United States Bureau of Fisheries, Vol. XLI, 1925. Wash. G.P.O.  (.pdf, 4.18 MB.)
  • * Scott, T. L., K. M. Yano, J. Baker, M. H. Rickey, M. Eames, and C. W. Fowler. 2006. The Northern Fur Seal (Callorhinus ursinus): a Bibliography. AFSC Processed Rep. 2006-05, 246 p.  (.pdf, 1.42 MB).

  • Northern Fur Seal (Callorhinus ursinus). National Marine Mammal Laboratory (Alaska Fisheries Science Center) website.
  • Northern Fur Seal Photo Archive. National Marine Mammal Laboratory (Alaska Fisheries Science Center) website.
  • North Pacific Fur Seal Treaty of 1911  ("NOAA Celebrates 200 Years of Science, Service, and Stewardship" website).

<<< 1940 to 1959

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