More Information
Related Jobs from ScienceCareers
|
|
Science 16 October 1998:
Vol. 282. no. 5388, p. 377
DOI: 10.1126/science.282.5388.377i
|
|
This Week in Science
Twenty-five years ago, Estes and Palmisano reported on the keystone role of sea otters in Western Alaska. Previously hunted nearly to extinction, their numbers were recovering and, by limiting the distribution of herbivorous sea urchins, their comeback had a positive effect on kelp forest development. Now Estes et al. (p. 473; see the cover and the news story by Kaiser) update the story: Otter populations have undergone precipitous declines in the 1990s, apparently as a result of predation by killer whales. This switch in the diet of the killer whales has likely been caused by the disappearance of their usual prey, sea lions and seals, which in turn appears to have been caused by human impacts that have led to a decline in fish stocks. Sea urchin populations are now expanding dramatically and the kelp forest is declining, illustrating the wide range of ecosystem disruption.
|
|
Science. ISSN 0036-8075 (print), 1095-9203 (online)
