to the context of modern sampling and analytical technology? How can anthropogenic perturbations be distinguished from natural phenomena? How can unlike matrices from differing data bases with differing scales best be matched? Such questions are especially pertinent in today's research environment. The use of indicator organisms, while certainly not new, is the corner­ stone for much scientific research. In the past two decades, indicator organisms have played increasingly important roles in the development and implementation of public policy. In particular, indicator organisms are being used to describe local environments and natural or anthropogenic perturbations to them, although there are pitfalls and problems associated with those usages. A growing number of nonbiologists, including physical oceanographers, find indicator organisms helpful, and sometimes essential, to their re­ search.