An international team has discovered that it is the order of extinction of the species, rather than the number of species concerned, that determines the final impact on an ecosystem. Diane SRIVASTAVA, professor of zoology at the University of British Columbia, and her colleagues study shrimp populations, shrimp, clams, worms, and other organisms on the sea floor in a study published in the journal Science and the long-term impacts on this ecosystem.
At the bottom of the oceans, lives an impressive set of animals which play an essential role in the regulation and the recycling of the planetary resources. The inhabitants of the seabed, necessary for the oxygenation of sediments, are particularly vulnerable because they are often unable to escape the disturbances of their environment. Thanks to a comprehensive study of 139 invertebrates living in Galway Bay, Ireland, a modeling of the composition of the seabed and its movements has been realized. This shows that extinctions affect the mixing of sediments and the concentration of oxygen required for life.
The importance of change seems to depend as much on the extinction order of the species as on the causes of their extinction. This suggests that conservation efforts should focus not only on apparently important species, but also on ecosystem biodiversity. Predicting the future of coastal environments, confronted with the decline of animal species linked to human activities, will depend on a better understanding of the role of each species within its ecosystem.
- Michelle Cook, UBC Public Affairs - firstname.lastname@example.org
Sources: University of British Columbia Media Releases, 15 / 11 / 2004
Editor: Delphine Dupre VANCOUVER,