The Atlantic walrus (Odobenus rosmarus rosmarus) in West Greenland

Abstract

In the early part of the 20th century Atlantic walruses (Odobenus rosmarus rosmarus) occurred abundantly between approximately 66°N and 70°45'N in Central West Greenland from September until mid June. Between September and December several hundred walruses hauled out on small islands and promontories between the entrance to Nassuttooq (Nordre Strømfjord, approx. 67°30'N) and approximately 67°45'N, south of the settlement of Attu. From 1911, the hunt for walruses at terrestrial haul out sites was intensified, and by the late 1930s the walruses had abandoned the terrestrial haul outs in this area.

Between 1911 and the early 1940s, the catches of walruses in western Greenland (excluding the Avanersuaq/Thule area) increased rapidly, reaching a maximum of more than 600 animals reported for 1938 and 1940. Mainly reproductive females were caught and the proportion of unretrieved kills was high. Between the early 1940s and the mid 1960s catches decreased rapidly, apparently reflecting a decrease in the stock of walruses wintering off Central West Greenland. Between 1965 and 1987, the recorded annual catch in western Greenland south of 76°N averaged 56 walruses (SD = 19.7; range 19- 101 animals). It is estimated that during this period the total number of walruses removed by hunting was about 100 per year.

Comparisons of the results of systematic aerial surveys conducted in early spring of 1981, 1982, 1984, 1990 and 1991 over the walrus wintering grounds at Central West Greenland revealed no trend in abundance. The line transect methods used in the 1990 and 1991 surveys gave higher and more robust estimates of abundance than the strip censuses used in the previous surveys, and resulted in estimates of abundance of about 500 walruses (not corrected for submerged animals).

The stock structure of the total walrus population in the Baffin Bay and Davis Strait regions is obscure. However, this study has shown that the numbers of walruses in Central West Greenland are much lower than historical levels, and that walruses in this area are vulnerable.