Spatial patterns and GIS habitat modelling of Solea solea, Pleuronectes flesus and Limanda limanda fish larvae in the eastern English Channel during the spring

Abstract

The spring distribution of larval fish stages of flatfishes in the Dover Strait (eastern English Channel) was studied in 1995 and 1999. Fish larvae were identified and sorted according to developmental stages in order to study their ontogenic distribution. The French coastal waters are characterised by an unstable tide-dependent front, which influences larval dispersion. In spring, the French coastal waters have a high phytoplanktonic production. They have higher temperatures, lower salinities and differences in current intensity compared with the central English Channel waters. Generalised Additive Models (GAM) combined with Geographic Information Systems (GIS) were used to model the potential habitats of life stages considering data from three major surveys in this area. The models were developed by coupling presence-absence models with non-null abundance models. The potential habitat of larval stages was then mapped using a geostatistical method (kriging). This revealed different species strategies in which young stages were abundant in central waters and older ones were distributed mainly along the French and Belgian coasts. It is concluded that the central English waters are important for young stages after hatching and that coastal waters are essential nurseries for future juveniles. The models of three flatfish species having similar life cycle strategies are presented here: Limanda limanda, Platichthys flesus and Solea solea.