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Bioécologie

Trophic Structure and Community Stability in an Overfished Ecosystem

13 Décembre 2010,

Publié par JMB

"In the latest issue of Science, scientists from Norway, South Africa and Namibia provide evidence to show how a small coastal fish (a goby) thrives in an environment that is hostile to most other organisms. The goby in question lives on the anoxic sea floor over the continental shelf off Namibia. Here it almost seems to “hold its breath” as it sits on the sulphidic sediments during the day, whilst at the same time eating the mud and associated infauna. Later, under cover of darkness, the goby swims up to the more oxygen rich surface waters in order to restore its oxygen debt and to digest its food.  Up in the water column, gobies appear to associate with jellyfish, which their predators avoid and yet at the same time, it now appears that the fish may also feed on their gelatinous shelter. Indeed, jellyfish seem to be a major food source for the gobies, together with the mud. Until now we have assumed that jellyfish and sulphidic mud are “dead-ends” for the wider food web, but off Namibia these are returned to higher levels in the food web (fish, birds, mammals and penguins) through the vehicle of the bearded goby."

More informations here 

Source: University of Bergen | Department of Biology

 

 

Trophic Structure and Community Stability in an Overfished Ecosystem

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