Relationship between fluvial discharge and sole (Solea solea L.) recruitment in the Bay of Biscay (France)

In this study we investigated whether the estuarine-opportunism of the Bay of Biscay sole affects its recruitment level. First, we estimated the abundance of juvenile sole on the basis of a survey of an estuarine nursery ground within the Bay of Biscay. A significant relationship between fluvial discharges in winter-spring and abundance of juveniles surviving into the second autumn of their existence indicated the sustaining effects of freshwater supply on the size of the nursery and its ability to support young sole. The second part of the work consists of a similar approach at the stock scale. The recruitment results from the respective contributions of different nurseries, and overall recruitment strength, tends to be smoothed relative to local variations. However, a correlation also exists between freshwater inputs in winter-spring and juvenile abundance in the scale of the French part of the Bay (ICES Division VIIIa/b). Sole recruitment in the Bay of Biscay appears to be driven by freshwater inputs. Hence, the variability of sole recruitment depends on fluvial discharge, but the lack of any trend

in river run-off regimes in the Bay of Biscay prevents any forecast on the evolution of sole stocks with regard to climate changes.

Article from Marine Science Symposia Vol. 219 - "Hydrobiological variability in the ICES Area, 1990-1999", symposium held in Edinburgh, 8-10 August 2001. To access  the remaining articles please click on the keyword "MSS Vol. 219".