The content you've requested is available without charge only to active Sigma Xi members and
If you are an active member or an individual subscriber, please log in now in order to access this article.
If you are not a member or individual subscriber, you can:
Recent evidence suggests that one predicted consequence of global warming—reduced oxygen levels in parts of the world’s oceans—is now happening. If the trend continues, the number of hypoxic areas, or dead zones, in the oceans may increase. In fact, although little is known about them, there are already permanent hypoxic zones along a number of continental margins; these are found in areas of upwelling where masses of phytoplankton decay as they sink, consuming oxygen in the water column and thereby starving the middle depths, where circulation is more sluggish. Levin and other ecologists find life here, but it is different: dense mats of large sulfur-oxidizing bacteria and worms mining loose soils rich in decayed organic material, surrounded by fringe areas full of shrimp, vertically migrating zooplankton and fish adapted to low-oxygen conditions. Paleontologists have reconstructed the environmental history of some of these regions, but we have only a sketchy understanding the adaptations that allow a few present-day marine animals to cope with permanent oxygen starvation.
Connect With Us:
An early peek at each new issue, with descriptions of feature articles, columns, and more. Every other issue contains links to everything in the latest issue's table of contents.
News of book reviews published in
and around the web, as well as other noteworthy happenings in the world of science books.
To sign up for automatic emails of the
American Scientist Update
issues, create an
, then sign up in the
My AmSci area
JSTOR, the online academic archive, contains complete back issues of American Scientist from 1913 (known then as the Sigma Xi Quarterly) through 2005.
The table of contents for each issue is freely available to all users; those with institutional access can read each complete issue.
View the full collection here.
Receive notification when new content is posted from the entire website, or choose from the customized feeds available.