Communities of Corals and Reef Fishes

A new study of tropical corals and reef fishes in the 26 August 2005 issue of the journal Science provides insights into the structure of ecological communities and the effects of interactions between local and regional processes on biodiversity.

The global biodiversity crisis has made understanding the structure of ecological communities an urgent priority, particularly for high-diversity systems like coral reefs, according to the authors. There has, however, been much debate among ecologists about patterns of commonness and rarity in ecological systems, and the extent to which those patterns reflect how species divide resources.

Resolving this issue, say the authors, is critical to understanding how coral reefs will respond to ongoing environmental degradation. Sean Connolly and colleagues now show that relative abundances of different species, and their division of resources, both exhibit the same shape known for ecological systems on land, called a "lognormal distribution".

Unexpectedly, however, for both corals and fishes, this classical distribution of commonness and rarity became apparent only after the authors examined their data at the regional scale. Emergence of patterns of commonness and rarity in corals and fishes at such a large scale suggests that the scale and scope of coral reef conservation strategies are inadequate, highlighting the need for integration and networking of Marine Protected Areas regionally, across national boundaries, according to the authors.

Daniel B. Kane

25 August 2005