Although images of exotic tropical streams and waterfalls are commonly used to denote the beautiful and unique features associated with island landscapes, such scenic habitats are threatened in a variety of ways, according to an introductory article in the section by Gordon C. Smith, Alan P. Covich, and Anne M. D. Brasher. The ecology and potential for sustainability of such ecosystems are not well understood, and many of them are affected by human alteration of their physical and biological characteristics. Tropical island watersheds are often influenced by major fluctuations in precipitation and tend to be more "event driven" than temperate stream ecosystems. There is growing recognition of the importance of conserving the biological resources of watersheds as well as the "ecosystem services" such watersheds provide, including a clean water supply, fishery resources, and recreation.

Two articles in the BioScience special section deal with Hawaii. An article by Brasher discusses impacts of human disturbances on life in Hawaiian streams, and an article by William F. Font considers the effects of the global spread of parasites on Hawaiian Stream fishes. In the fourth article in the section, James G. March and colleagues review the far-reaching ecological effects of dams on tropical island streams and explore ways to mitigate these effects.

In the fifth article in the section, Douglas A. Craig discusses the development of running water habitats on Polynesian islands and the effects of this process on black flies. David Bass then surveys invertebrate communities on small Caribbean islands. The communities are typically sparse, and they are suffering
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Contact: Donna Royston
droyston@aibs.org
202-628-1500 x261
American Institute of Biological Sciences
3-Nov-2003