[Project DILEME] Fish larvae densities

In the Gironde estuary, the largest estuary in Western Europe, the ichthyoplankton was sampled twice in summer, winter and spring to understand the temporal dynamics of the occurrence of fish larvae in the estuary and their habitat use. In total, 32 499 larvae were identified, divided into 15 taxa. Summer was characterised by few taxa, including Engraulis encrasicolus, Dicentrarchus spp. or Pomatoschistus spp., in low abundance. Larval abundances were higher in winter and spring. Diadromous species were particularly present in winter and Pomatoschistus spp. dominated the Spring assemblage. Marine estuarine opportunist taxa were present in very low densities. The oligohaline area appeared to be the richest in taxa, compared to the meso- and polyhaline areas. Confluences appeared to be attractive and larvae engage in the estuarine tributaries, notably Chelon spp., Dicentrarchus spp. and Anguilla anguilla.