Evidence of a decline in beluga, Delphinapterus leucas, abundance off West Greenland
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چکیده
Aerial surveys of belugas, or white whales, Delphinapterus leucas, were conducted off West Greenland in March 1993 and 1994. These surveys were designed to permit comparisons with similar surveys in 1981, 1982, and 1991. Differences in methods between the surveys in the early 1980s and those in the 1990s should mean that the 1990s surveys were, if anything, more efficient than the 1980s surveys. Weighted linear regressions of strip-census estimates of the relative abundance of belugas showed a significant decline from 1981 to 1994. While annual variability in ice conditions and other unknown factors may have had some local or small-scale effects on the movements and distribution of belugas off West Greenland, it is unlikely that these effects would account for the apparent decline in relative abundance. The most reasonable conclusion is that the stock size has declined considerably during the past 13 years, perhaps by as much as 62%. ? 1996 International Council for the Exploration of the Sea
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تاریخ انتشار 1996