Spatial analysis of the trophic interactions between two juvenile fish species and their preys along a coastal-estuarine gradient
|Author(s)||Kopp Dorothee1, Le Bris Herve2, Grimaud Lucille1, Nerot Caroline3, Brind'Amour Anik1|
|Affiliation(s)||1 : IFREMER, Unite Ecol & Modeles Halieut, F-44311 Nantes 03, France.
2 : Univ Europeenne Bretagne, UMR 985, Agrocampus Ouest, F-35042 Rennes, France.
3 : Inst Univ Europeen Mer, LEMAR, UMR CNRS UBO IRD 6539, F-29280 Plouzane, France.
|Source||Journal Of Sea Research (1385-1101) (Elsevier Science Bv), 2013-08 , Vol. 81 , P. 40-48|
|WOS© Times Cited||23|
|Keyword(s)||Stable isotopes, Gut content, Food web, Nursery ground, Solea solea, Trisopterus luscus|
|Abstract||Coastal and estuarine systems provide nursery grounds for many marine fish species. Their productivity has been correlated with terrigeneous inputs entering the coastal-estuarine benthic food web, thereby favouring the establishment of fish juveniles. Studies in these ecosystems often describe the nursery as a single large habitat without verifying nor considering the presence of contiguous habitats. Our study aimed at identifying different habitats based on macrozoobenthic communities and morpho-sedimentary characteristics and assessing the trophic interactions between fish juveniles and their benthic preys within these habitats. It included 43 sampling sites covering 5 habitats in which we described taxonomically and quantitatively the invertebrates and fish communities with stable isotopes and gut contents. It suggested that the benthic common sole Solea solea displayed feeding plasticity at the population level, separating the juveniles (G0) from the older fish (G1) into different "feeding sub-populations". Size-based feeding plasticity was also observable in the spatial occupancy of that species in the studied bay. The demersal pouting, Trisopterus luscus, equally used the different habitats but displayed low feeding plasticity across and inside each habitat. Stable isotopes proved to be powerful tools to study the spatial distribution of trophic interactions in complex ecosystems like the bay of Vilaine and to define optimal habitats for fish that use the coastal-estuarine ecosystem as nursery grounds.|