First estimates of vaquita abundance

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• 作者：Barlow ; J. ; Gerrodette ; T. ; Silber ; G.
• 刊名：Oceanographic Literature Review
• 出版年：1997
• 出版时间：July, 1997
• 年：1997
• 卷：44
• 期：7
• 页码：743
• 全文大小：102 K

文摘

The abundance of the only population of vaquitas, Gulf of California harbor porpoise (Phocoena sinus), is estimated from four surveys conducted in Mexico between 1986 and 1993, using a variety of methods. Vaquita abundance is estimated as 503 from 1986-1988 boat surveys, 885 from 1988-1989 aerial surveys, 572 from a 1991 aerial survey, and 224 from a 1993 ship survey. A weighted log-linear regression indicates a rate of population change (decline) of -17.7 % per year between 1986 and 1993. All of these estimates of vaquita abundance indicate that the species is at a critically low level.