For an unknown reason, the Steller sea lion population in Alaska has declined by 80% over the past three decades. In 2001, the National Research Council began a study to assess the many hypotheses proposed to explain the sea lion decline including insufficient food due to fishing or the late 1970s climate/regime shift, a disease epidemic, pollution, illegal shooting, subsistence harvest, and predation by killer whales or sharks. The report's analysis indicates that the population decline cannot be explained only by a decreased availability of food; hence other factors, such as predation and illegal shooting, deserve further study. The report recommends a management strategy that could help determine the impact of fisheries on sea lion survival—establishing open and closed fishing areas around sea lion rookeries. This strategy would allow researchers to study sea lions in relatively controlled, contrasting environments. Experimental area closures will help fill some short-term data gaps, but long-term monitoring will be required to understand why sea lions are at a fraction of their former abundance.
National Research Council. 2003. Decline of the Steller Sea Lion in Alaskan Waters: Untangling Food Webs and Fishing Nets. Washington, DC: The National Academies Press.
Sign in to access your saved publications, downloads, and email
preferences.
Former MyNAP users: You'll need to reset your password on your first
login to MyAcademies. Click "Forgot password" below to receive a reset
link via email. Having trouble?
Visit our FAQ page
to contact support.
Members of the National Academy of Sciences, National Academy of
Engineering, or National Academy of Medicine should log in through their
respective Academy portals.
Register
Register
Download as a Guest
Download as a Guest
While logged on as a guest, you can download any of our free PDFs on
nationalacademies.org
. You will remain logged in until you close your browser.
Thank You
Thank You
Thank you for creating a MyAcademies account!
Enjoy free access to thousands of National Academies' publications, a
10% discount off every purchase, and build your personal library.
Forgot Password
Forgot Password
Enter the email address for your MyAcademies (formerly MyNAP) account to
receive password reset instructions.
Reset Requested
Reset Requested
We sent password reset instructions to
your email
. Follow the link in that email to create a new password. Didn't receive
it? Check your spam folder or
contact us
for assistance.
We sent a verification link to your email. Please check your inbox (and
spam folder) and follow the link to verify your email address. If you
did not receive the email, you can request a new verification link below