The 1996 Flatfish Symposium; a summary report

Abstract

A summary report of the 1996 Flatfish Symposium is presented. Three topics of the Symposium are discussed: taxonomy and systematics, recruitment processes, and management issues. It is strongly recommended that a taxonomic advisory committee should be formed that will facilitate the transfer of information between different scientific disciplines focused on increasing our knowledge about flatfishes. Recruitment variation in flatfish appears to be dominated by density-independent factors operating at a local scale on the eggs and larvae. Variability in hydrodynamic circulation is suggested to be an important factor. Density-dependent processes are likely to be restricted to the smaller size classes which are not affected by fishing. The debate on the species range hypothesis is continuing. The patterns in latitudinal variation observed in fish did not correspond with the expectations. However, the species range hypothesis could neither be accepted nor rejected, because other sources of variation such as water temperature, sampling strategy, age composition of catches, inshore–offshore gradients and shifts in species ranges are biasing and maybe overruling the patterns in recruitment. Evaluations of the management of different flatfish stocks stressed the importance of the interactions between management measures and flatfish population structures. This field should be strengthened in the future.