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Journal Article

STELLER SEA LION STATUS AND TREND IN SOUTHEAST ALASKA: 1979–1997

D. G. Calkins; D. C. Mallister; K. W. Pitcher; G. W. Pendleton
Marine Mammal Science · Vol. 15, Issue 2 · pp. 462-477 · 1999

Abstract

A bstract Steller sea lion ( Eumetopias jubatus ) numbers in the United States declined by about 75% over the past 20+ yr. They are classified, under the U. S. Endangered Species Act, as “threatened” in the eastern portion of their range and as “endangered” in the western portion. We analyzed trends in numbers of pup and non‐pup Steller sea lions counted in Southeast Alaska between 1979 and 1997. Sea lion numbers, based on counts of pups on rookeries, increased by an average of 5.9% per year between 1979 and 1997. However, numbers of pups increased at a much slower rate (+ 1.7% per year) between 1989 and 1997. For counts of non‐pup Steller sea lions we used models that controlled for the effects of date, time, and tide at the time of the survey to analyze trends. This technique reduced bias and increased precision of the resulting trend estimates. Numbers of sea lions were stable (+0.5%) between 1989 and 1996, based on counts of non‐pups. We estimated the Southeast Alaska breeding population of Steller sea lions at about 19,000 animals of all ages in 1997, a level that is probably near the highest in recorded history.

Bibliographic Information

JournalMarine Mammal Science
PublisherWiley
Publication Date1999-04-01
Publication Year1999
Volume15
Issue2
Pages462-477
Document TypeJournal Article
Print ISSN0824-0469
eISSN1748-7692
DOI10.1111/j.1748-7692.1999.tb00813.x
SubjectMarine Biology

Access Information

NARA Access Coverage1997-01-01~Current
Journal Homepagehttps://onlinelibrary.wiley.com/loi/17487692
Publisher PageOpen Publisher Page
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