Evolution de peuplements benthiques des fonds sédimentaires de la région de Roscoff, perturbés par les hydrocarbures de l' Amoco Cadiz
Cabioch, L.; Dauvin, J.-C.; Retière, C.; Rivain, V.; Archambault, D. (1982). Evolution de peuplements benthiques des fonds sédimentaires de la région de Roscoff, perturbés par les hydrocarbures de l' Amoco Cadiz. Neth. J. Sea Res. 16: 491-501
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, more
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| Authors | | Top |
- Cabioch, L.
- Dauvin, J.-C., more
- Retière, C.
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- Rivain, V.
- Archambault, D.
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| Abstract |
The main biological effects on the sublittoral benthic communities after the Amoco Cadiz oil spill may be summarized as follows: at the beginning, the oil severely affects the fine and very fine sand communities. Little disturbance is found in the sandy-mud community, in spite of an important contamination. Mortality is selective, affecting only a limited number of species. The extent of total disturbance varies from place to place in one community, and even more from community to community along the sediment gradient. Presumably there are two causes for these variations in disturbance; the mortality in sensitive species may vary from one place to another, e.g. because of differences in immediate pollution, and the relative abundance of sensitive species varies from one place to another. After the initial disturbance, no further periods of maximum mortality in adults occurred, but the recruitment in some species continued to be affected during one or more years after the oil spill. This effect was relatively more important in sediments with high residual concentrations of oil. In most cases, affected or eliminated species start recolonization during the second year after the oil spill. The insular distribution of part of the affected or eliminated species lacking a pelagic larval life delays their reintroduction. Most species not affected by the initial stress continued to exhibit normal annual density cycles. Some species, however, mostly Capitellidae and Cirratulidae, showed population increases that lasted one or more density cycles and began at different times, probably indicating the first steps of a succession. This occurs either after an important disturbance of other species (the studied communities of fine and very fine sands) or after a slight disturbance (sandy-mud community). |
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