||Dynamics and production of two natural mussel beds from the Algerian coast. Effects of thermic and anthropic factors.
||Abadaboudjema Ym, Dauvin Jean-Claude
||International Colloquium on Long-Term Changes in Marine Ecosystems, ARCACHON, FRANCE, FEB 01-03, 1995
||Oceanolica Acta (0399-1784) (Gauthier-Villars), 1997 , Vol. 20 , N. 1 , P. 229-241
|WOS© Times Cited
||Mytilus galloprovincialis, Perna perna, long term, production, Algerian coast
|Résumé en anglais
||A long-term survey of two mussel populations from two natural mussel beds, Bordj El Kiffan and Boudouaou, was carried out from the end of 1984 to the beginning of 1991. Samples had been also collected from 1978-1979 then from 1992-1993, but only from the first of these. Maximal densities were higher than 10,000 ind. m(-2), due to the spring and summer heavy spatfall. At Bordj El Kiffan, densities of M. galloprovincialis were 50 times more important than those of P. perna. At Boudouaou, the abundance of P. perna was 1.7 times higher than that of M. galloprovincialis. From 1986 to 1988, the mean annual biomass in dry weight of tissue including ash was higher for P. perna at Boudouaou (0.886 kg. m(-2)) than at Bordj El Kiffan (0.486 kg. m(-2)). For M. galloprovincialis, it was greater at Bordj El Kiffan (0.791 kg. m(-2)) than at Boudouaou (0.224 kg. m(-2)). The average production on M. galloprovincialis from Bordj El Kiffan and P. perna from Boudouaou was about 2.4 kg. m(-2). yr(-1). The most important production were essentially provided by individuals older than one year. In both stations, the average P/B ratio was higher than 2. The turnover rate (E/B) was about 3 in both species at Bordj El Kiffan and 2.65 in P. perna at Boudouaou, but only 0.68 in M. galloprovincialis, whose population was in the course of development. The decrease in the populations was essentially a consequence of human activities: waste water discharged at Bordj El Kiffan mussel bed; burial of the Boudouaou mussel bed after construction of a sea wall in the area; and intensified mussel fishery on both mussel beds.