Aggregations of bluefish Pomatomus saltatrix (L.) at Mediterranean coastal fish farms: seasonal presence, daily patterns and influence of farming activity

Abstract Fernandez-Jover, D., Sanchez-Jerez, P., Bayle-Sempere, J. T., Valle, C., and Dempster, T. 2008. Seasonal patterns and diets of wild fish assemblages associated with Mediterranean coastal fish farms. – ICES Journal of Marine Science, 65: 1153–1160. Fish are attracted to floating structures, including coastal cage fish farms, sometimes in dense aggregations. To understand better the influence of aquaculture on wild fish stocks, we carried out seasonal visual censuses around three southwestern Mediterranean farms over 2 years to assess the temporal patterns of the aggregated fish assemblage. In addition, we analysed the diet of the five most abundant species. Aggregations around all farms were large throughout the year, although species composition and abundance differed among farms and seasons. Fish farms are attractive habitats for certain species of wild fish in specific seasons. Adult fish of reproductive size dominated the assemblages, and stomach content analysis revealed that 66–89% of fish of the five most abundant taxa had consumed food pellets lost from the cages. We estimated that wild fish consume up to 10% of the pellets used at farms, indicating that food is a key attractant. Regional monitoring of farm-associated wild fish assemblages could aid management of the interaction of aquaculture and wild fish resources, because changes in feeding behaviour may have consequences for fish populations and local fisheries.

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Coastal Fish Farms as Fish Aggregation Devices (FADs)

Artificial Reefs in Fisheries Management - Marine Biology ◽

10.1201/b10910-13 ◽

2011 ◽

pp. 187-208 ◽

Cited By ~ 18

Author(s):

Pablo Sanchez-Jerez ◽

Damian Fernandez-Jover ◽

Ingebrigt Uglem ◽

Pablo Arechavala-Lopez ◽

Tim Dempster ◽

...

Keyword(s):

Fish Farms ◽

Coastal Fish ◽

Fish Aggregation

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Exportation of excess feed from Mediterranean fish farms to local fisheries through different targeted fish species

ICES Journal of Marine Science ◽

10.1093/icesjms/fsu179 ◽

2014 ◽

Vol 72 (3) ◽

pp. 930-938 ◽

Cited By ~ 11

Author(s):

David Izquierdo-Gómez ◽

Daniel González-Silvera ◽

Pablo Arechavala-López ◽

José Ángel López-Jiménez ◽

Just Tomás Bayle-Sempere ◽

...

Keyword(s):

Wild Fish ◽

Small Scale ◽

Fish Feed ◽

Total Lipids ◽

Fish Farms ◽

Pomatomus Saltatrix ◽

Coastal Fisheries ◽

Cage Aquaculture ◽

Sea Cage ◽

Mediterranean Fish

Abstract Coastal fisheries and sea cage aquaculture coexist along the coastal zone, and it has been suggested that wild fish feed on excess feed around farms. If this occurs, the condition of wild fish can increase and their lipid profile can become modified. However, the influence of fishfarming on coastal fisheries has not been described in detail. Four targeted species of different trophic gilds, Sardinella aurita, Caranx rhonchus, Mullus barbatus, and Pomatomus saltatrix were studied and the lipid profiles of individuals captured by coastal fisheries and around fish farms were compared. Results show that fish captured at farms showed increased levels of total lipids and/or the terrestrial fatty acids contained in feed pellets. Individuals with increased terrestrial fatty acid proportions were detected in the catch of small-scale artisanal fisheries but not among trawled fish. Consequently, this study demonstrates the influence of fishfarming on coastal fisheries through the exportation of excess feed in the shape of wild fish biomass.

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