Possible influence of reared gilthead sea bream (Sparus aurata, L.) on wild stocks in the area of the Messolonghi lagoon (Ionian Sea, Greece) |
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| Authors: | Evagelos Dimitriou George Katselis Dimitrios K Moutopoulos Constantin Akovitiotis & Constantin Koutsikopoulos |
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| Institution: | Prefecture of Etoloakarnania, Messolonghi, Greece; Department of Aquaculture and Fisheries Technology, Technological Educational Institute of Messolonghi, Messolonghi, Greece; Department of Biology, University of Patras, Patra, Greece; Prefecture of Preveza, Preveza, Greece |
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| Abstract: | More than 25% of Greek fish farms and 20% of Greek hatcheries of gilthead sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) are located along the Western Hellenic coast. The part of sea bream production is about 60% of the total production of these species. During the last decade, a spectacular increase in both the number of farms and their production, accompanied by a substantial price decrease and modification of their structure and functioning, has been recorded. These changes resulted in the maintenance in cages of large individuals (more than 500 g) of gilthead sea bream which are potential spawners. The study, based on both the maturity stage and the decrease in individual mean weights during the reproductive period of the species, confirmed reproduction in cages. In parallel, during the last 5 years a remarkable increase (about 80%) in sea bream landings from the fish trap fisheries of the Messolonghi‐Etoliko lagoon, which is a typical nursery for the species, was recorded. The increase was accompanied by a decrease both in price and mean size of the 0‐group individuals. The possible influence of the rearing activities in the area, the density‐dependent mechanisms and the negative impacts of this unintentional enhancement of the traditional lagoon fisheries of the area are discussed. |
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| Keywords: | aquaculture gilthead sea bream ecological impact carrying capacity density dependence Messolonghi-Etoliko lagoon |
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