Ecosystem interactions and anthropogenic impacts on king scallop populations in the English Channel – COMANCHE

The king scallop Pecten maximus is currently the most important species in landings (as well in tons as in value) for the French inshore fleet of the English Channel. The main exploited layers, within the Bay of the Seine and the Bay of Saint-Brieuc, are scientifically assessed since several years; many specific studies on this species have been carried out, but to date no global project taking into account the whole set of research topics - from the comprehension of the biological phenomenon to the economic aspects related to the fisheries - has been undertaken.

The COMANCHE project (Ecosystem interactions and anthropogenic impacts on king scallop populations in the English Channel) falls under this logic. It aims to improve our knowledge on scallop at the level of the whole English Channel, through an ecosystem approach to fisheries, by calling upon a large range of scientific disciplines (physics, chemistry, genetics, ecology, geostatistics, modeling, economics….).

The project proposes to better characterize the spatial distribution of the king scallop at the English Channel scale, and better understand the mechanisms of connectivity between the main layers implying larval dispersal. The temporal fluctuation of recruitment will also be studied in relation to environmental variables. The relationships of the king scallop with its ecosystem will be addressed by studies on the dynamics of its food, and especially the conditions of the appearance of toxic algal blooms which affect scallop populations. This project also aims to model individual growth and population dynamics according to food and abiotic environment fluctuations. Moreover, the complex interactions between king scallop and one of its competitors, the slipper-limpet, will be investigated so the impact of this invasive species can be determined. Finally, the fishing activity of scallop will be studied with the aims of quantifying its impact on the ecosystem and analysing the economic performance of the channels supported by the different layers of the English Channel.

The project COMANCHE is of double interest, scientist on the one hand since it will allow the acquisition of new knowledge in the field of the ecosystem approach to fisheries (publication of results in international journals is planned, as well as broad diffusion to the scientific community), and directly operational on the other hand by proposing new management strategy evaluation tools to stakeholders within the scope of sustainable management of scallop stocks in the Channel.