An international team has discovered that it is the order of species extinction, rather than the number of species involved, that determines the ultimate impact on an ecosystem. In a study published in the journal Science, Diane SRIVASTAVA, professor of zoology at the University of British Columbia, and her colleagues study the declining populations of shrimp, clams, worms and other organisms in the sea floor and the long-term impacts on this ecosystem.
Deep in the oceans, lives an impressive collection of animals that play an essential role in the regulation and recycling of the planet's resources. The inhabitants of the seabed, necessary for the oxygenation of the 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 in Ireland, a modeling of the composition of the sea floor and its movements was carried out. It is thus proven that extinctions affect the mixing of sediments and the oxygen concentration, necessary for life.
The magnitude of the change seems to depend as much on the order of extinction of species as on the causes of their disappearance. This therefore suggests that conservation efforts should focus not only on apparently important species, but also on the biodiversity of ecosystems. Predicting the future of coastal environments, faced 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 - email@example.com
Sources: University of British Columbia Media Releases, 15 / 11 / 2004
Editor: Delphine Dupre VANCOUVER,