Distribution of the order Pleuronectiformes in relation to the sediment type in the North Irish Sea

Despite their economic importance, there are no recent studies of the distribution of flatfish in the Irish Sea, and the knowledge of this is important for an effective management of the resource. In the present study, data on flatfishes were collected during demersal fish surveys carried out by the Department of Agriculture and Rural Development for Northern Ireland (DARD) in the North Irish Sea between March 1995 and October 1998. Distribution and abundance patterns were ascertained using the total number caught per species. Differences in the condition factor and hepatosomatic index were associated with season and sediment type, and were used as indicators of habitat quality. Higher index values indicated higher habitat quality, and it was expected that these areas would also be associated with elevated abundances. Once the habitat requirements for each species are known, predictions on the abundance and distribution of flatfishes can be given for changes in habitats caused by natural or anthropogenic events.