2026-04-14T04:39:44Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1711512025-12-05T09:39:56Zcom_2072_1057col_2072_478778col_2072_478917

00925njm 22002777a 4500 dc Cardona Pascual, Luis author Reñones, Olga author Gouragine, Adam author Saporiti, Fabiana author Aguilar, Àlex author Moranta, Joan author 2020-10-09T16:08:39Z 2025-08-27T05:10:09Z 2020-08-27 2020-10-09T16:08:39Z Resource partitioning in polymorphic fish species is expected to be altered by human exploitation, as individual specialization is density dependent in many vertebrates. We tested this hypothesis using the ballan wrasse Labrus bergylta as a model species. We compared the isotope niches of the plain and spotted morphs of the species in a marine protected area (MPA) and in adjoining areas open to fishing, both off Galicia (NW Spain). Underwater visual census confirmed a threefold increase in the biomass of the ballan wrasse off Cíes Islands compared to areas open to recreational fishing, thus demonstrating that populations outside MPAs are well below carrying capacity. The stable isotope ratio of C revealed differences in the resource use patterns of plain and spotted ballan wrasses both in areas open and closed to fishing, as plain wrasses were always depleted in 13C compared to sympatric spotted ones. The stable isotope ratio of N showed that plain ballan wrasses foraged consistently at a higher trophic level than spotted ones in areas of high population density closed to recreational fishing, whereas differences did not exist or were reversed in areas open to fishing. These results demonstrate that the pattern of trophic resource partitioning two morphs of the ballan wrasse is density-dependent and that plain and spotted ballan wrasses likely had different ecological niches in pristine ecosystems. Indústria pesquera Ecologia de les costes Influència de l'home en la natura Fisheries Coastal ecology Effect of human beings on nature Fishing alters the ecological significance of colour morphs in a temperate coastal fish