Éditeur(s) : Elsevier
Résumé : As top predators of pelagic food webs, large fish naturally bioaccumulate mercury (Hg). Determining Hg burdens in commercialized fish is essential considering the concern about effects of contaminants on human health and the legal thresholds that are therefore set for local consumption and/or exportation. Total Hg levels were measured in the muscular tissue of 183 fish of five commercially important species from the tropical zone of the Western Indian Ocean. All individuals were measured and sexed in order to study the impregnation of Hg with size and sex within each species. Values of Hg found in this part of the Indian Ocean were comparable to Hg in muscular tissue of the same species studied in other areas. The highest Hg levels were noted in Swordfish (Xiphias gladius) caught in waters surrounding Reunion Island (3.97 +/- 2.67 mu g g(-1) dry weight). Following the Swordfish, in decreasing order of Hg content, were the Yellowfin Tuna (Thunnus albacares) and the Skipjack (Katsuwonus pelamis), then the Common Dolphinfish (Coryphaena hippurus) and the Wahoo (Acanthocybium solandri). In the North of the Mozambique Channel, Swordfish had higher Hg levels than Yellowfin Tunas, and Dolphinfish exhibited intermediate Hg levels. The size of a fish was a determining factor of its Hg burden, as was the species. Differences in size-normalized Hg levels were observed between the two study zones for Swordfish and Common Dolphinfish. Sex, in contrast, did not influence Hg levels suggesting that females and males have similar feeding habits. The muscular Hg levels presented here suggest that consumers of fish originating from the Western Indian Ocean should limit themselves to one Swordfish based meal per week, or one fish meal a day if they choose to eat tuna or Common Dolphinfish. (c) 2006 Elsevier B.V. All rights reserved.
The Science of The Total Environment (0048-9697) (Elsevier), 2006-08 , Vol. 366 , N. 2-3 , P. 688-700

Droits : 2006 Elsevier
http://archimer.ifremer.fr/doc/2006/publication-1862.pdf
DOI:10.1016/j.scitotenv.2006.02.006
http://archimer.ifremer.fr/doc/00000/1862/

Éditeur(s) : Communication, ICES Conference and Meeting (CM), 2010, Nantes
Résumé : Chlordecone is a very persistent insecticide used in banana plantations of the French West Indies between 1972 and 1993. Chlordecone residues were found in inland water, in agricultural and freshwater products, and in marine organisms. This pollution has become of great concern in 2007. Therefore, a governmental action Plan was launched to better assess the pollution and to improve the consumer’s protection. Within this plan, 1048 samples from 69 different species of marine fishes and crustaceans were collected all around both the Guadeloupe and the Martinique Islands and analyzed. The results confirm the presence of chlordecone in marine organisms, with highly variable concentrations (from the detection limit to 1000 μg.kg-1). In 17.9 % of the samples, concentrations exceeded 20 μg.kg-1, the maximum acceptable level in fish according to the French regulation (Anon, 2008). Two main features of this contamination were characterized. 1) Because of the sedimentation of contaminated suspended soil particles, the sheltered bays are more exposed to chlordecone than the open coast where terrigenous flux are dispersed. 2) Species biology, particularly their lifestyle and diet, appear to influence contamination levels. Thus, the more contaminated species live in relation with sediment or are at high trophic level. These results have directly supported political decisions in order to prevent too high exposure of consumers to chlordecone. Fishing activities in sheltered bays have been forbidden for potentially highly contaminated species like benthic crustaceans and top predators. Further studies are under way to assess the importance of the trophic transport of chlordecone within the foodweb, and to evaluate the historical deposition of this insecticide in sediment and its further bioavailability.

Droits : 2010 ICES/CIEM ; Ifremer
http://archimer.ifremer.fr/doc/00014/12511/9361.pdf
http://archimer.ifremer.fr/doc/00014/12511/

Éditeur(s) : Elsevier
Résumé : In the Caribbean, snappers (Lutjanidae) and groupers (Serranidae) are often heavily exploited by artisanal or industrial fisheries. This paper analyzes the catches of an artisanal fishery selectively targeting these species with a moderate fishing pressure in the Bay Islands (Honduras), and discusses the implications on the understanding of the early stages of development of reef fisheries. Although snappers and groupers are targeted with handlines and spearguns in the whole archipelago, the differences in species diversity and size structure of the catch reveals various exploitation patterns. In most areas, a depletion is observed for the most vulnerable snapper and grouper species, and most other species are mainly exploited in their juvenile phase; clear signs of an intensification process are apparent in one of the areas. The comparison of the relative production in the Bay Islands with other reef fisheries in the Caribbean suggests that higher values may be related to moderate fishing pressure and appropriate combinations of fishing effort and selectivity. This example shows how fisheries strictly targeting a high quality resource with selective fishing techniques can be quite productive even at high levels of effort, but also that they are progressively lead to broaden their species range (sooner or later at the expense of the most vulnerable, often large-sized, species) while increasingly using less selective gears.
Fisheries Research (0165-7836) (Elsevier), 2005-06 , Vol. 73 , N. 1-2 , P. 159-169

Droits : 2004 Elsevier B.V. All rights reserved
http://archimer.ifremer.fr/doc/2005/publication-512.pdf
DOI:10.1016/j.fishres.2004.12.008
http://archimer.ifremer.fr/doc/00000/512/