English Channel (Eastern) - Ecology

The megafauna of the eastern English Channel is rich, in terms of both quantities and diversity (pelagic, flatfish, gadoids, skates, catsharks, crustaceans and cephalopods) and is supported by a high benthic abundance acting as a food source for many fish species. This area is important for fisheries, not only because many commercial fish species are abundant here, but also because of the presence of spawning and nursery areas, and migratory routes linked to specific environmental characteristics. The fish larvae originating from the eastern English Channel reach the coastal zones of the Channel but also the Southern Bight of the North Sea. Some of the species are resident in the Channel, others are seasonal owing to their migration or reproductive behaviour, but most have a broader distribution and are found in adjacent seas.

During the last two decades, the structure and composition of the demersal assemblages have not changed significantly. The composition of sub-communities, identified according to particular species assemblages and characterized by abiotic conditions (depth, salinity, temperature, seabed stress, sediment type), has not changed during this period, neither has their spatial distribution, reflecting the relative stability of the habitats in the Eastern English Channel. Even though the fish populations are highly exploited, there is currently no sign of degradation of these species. Since 1988, changes in the community biomass are mainly due to a decrease in horse mackerel biomass (due to the development of the fishery) and an increase in red mullet and sea bass, probably due to changes in environmental conditions.