MANAGING THE EXPLOITATION OF PACIFIC WALRUSES: A TRAGEDY OF DELAYED RESPONSE AND POOR COMMUNICATION¹

Abstract

The Pacific walrus population has been depleted and subsequently allowed to recover three times in the past 150 yr. As we see it, the population has been made to fluctuate like an r‐selected species, rather than being maintained at a high, stable level, as befits a K‐selected species. The latest depletion began in the 1930s but was not recognized until 25 yr later, by which time the population had been reduced by at least half. Without benefit of communication, the U.S.S.R. and the State of Alaska put similar protective measures into place by 1960, and in the next two decades the walrus population recovered again, at least doubling in size. By 1980, it already was showing density‐dependent signs of having approached or reached the carrying capacity of its environment. As productivity and calf survival declined sharply in the late 1970s and early 1980s the catches more than doubled. We believe that the combined effects of natural curtailment and human intervention may be bringing the population down again rather rapidly. With the present, crude monitoring methods, delayed management responses, and poor international communications, however, the downward trend may not be acknowledged for at least another decade, by which time the unilateral Soviet and American corrective measures are likely to be too much, too late. Walrus management needs to be based less on response to immediate crisis and more on long term prediction than it has been in the past. Because the U.S.A. and U.S.S.R. are trying to manage the same walrus population, without sufficient communication or consensus and sometimes to opposite ends, an international joint management program needs to be implemented.

Pacific walruses, indigenous hunters, and climate change: Bridging scientific and indigenous knowledge

“…Hunters may simply say that "there are more bulls on the Siberian side than we have here" or that there is always "a concentration of adult bull walruses off Savoonga (ayughaayak) in springtime," when females with calves are passing by Gambell. Whereas walrus biologists interpret walrus groups in terms of population dynamics (e.g.. Fay et al, 1989), to hunters the groups they see are outcomes of specific winds, currents, and ice conditions that occur in specific combinations each season or each year. Additionally, a typical hunter's account is always year-and site-specific, with little relevance to variability of the whole population.…”

“…The Pacific walrus population was soon reduced from possibly as many as 300,000 animals, estimated to be the carrying capacity, to about 50,000 (Fay, 1957(Fay, , 1982Fay et al, 1989). Whalingship logbooks and statistical models indicate that about 200,000 walruses were killed from 1867 to 1883, with 35,700 killed in 1876 alone (Bockstoce, 1986;Bockstoce and Botkin, 1982;Fay et al, 1989). A byproduct of that slaughter was the acquisition of substantial knowledge of walrus life cycle and behavior (cf.…”

Movements of Walruses Radio-tagged in Bristol Bay, Alaska

“…1). By about 1960, protective measures had been established in Russia and Alaska, and by the 1980s, the population had apparently increased to its pre-exploitation levels (Fay et al, 1989). Concurrently, walruses reoccupied Amak Island and Port Moller in the southern part of Bristol Bay, and walrus numbers at the Walrus Islands (mostly Round Island) grew from about 3000 animals in the late 1950s to about 12 000 in the early 1980s (Frost et al, 1982;Fay et al, 1984).…”

“…Fay (1957) and Fay et al (1989) provide a detailed history of the exploitation and ensuing distribution of walruses during three periods of commercial harvests from the mid1800s to the 1980s. In the Bristol Bay region, during the mid-1950s decline from the last period of commercial harvests, no walruses were observed along the Alaska Peninsula, and only about a thousand animals were recorded at the Walrus Islands (Fig.…”

Molecular Method for Determining Sex of Walruses

“…Nearly the entire Pacific walrus subspecies occupies Arctic and sub-Arctic waters of the Bering and Chukchi seas and breeds in the Bering Sea. From the mid-19th to the mid-20th centuries, Pacific walrus numbers fluctuated wildly as a result of commercial harvest (Fay et al 1989), reaching the lowest population size in the 1950s of between 50,000 and 100,000 individuals (Fay 1982;Fay et al 1997). After that time, rigid restrictions placed on harvesting walruses in both Alaska and Russia have undoubtedly aided in their recovery (Fay 1982;Scribner et al 1997).…”