16 July 2004
Vol 305, Issue 5682

About The Cover

Cover image expansion

COVER The pteropod Clio pyramidata, a common planktonic mollusk with a calcium carbonate shell. The oceanic uptake of CO2 released to the atmosphere from human activities is changing seawater chemistry (see page 367). These changes make calcium carbonate shells dissolve at shallower depths and ultimately may impair the ability of pteropods, corals, and other marine organisms to calcify (see page 362). [Photo: R. W. Gilmer and G. R. Harbison]