GéDuBOUQ

Analyse préalable à une gestion durable des pêcheries de bouquet en Normandie

2020 - 2022

The project aims to conduct a targeted study of the European prawn (Palaemon serratus) using an ecosystem approach to fisheries in a context of global change.

Fished along the entire rocky coastline of Normandy, the European prawn (Palaemon serratus) is becoming a symbol of Normandy. A few dozen professional fishermen traditionally engage in this activity on a seasonal basis (between August and February) along the entire coastline of the English Channel, Calvados and Seine Maritime. The low volumes landed should not obscure the fact that this activity generates significant profits. However, over the past twenty years, there has been a significant decline in fishing yields for this species (CRP survey, 2002). More recently, professional fishermen operating in the Chausey Islands have observed a decrease in the size of the organisms and the quantities caught. On the other hand, amateur shore fishing for bouquets represents an important economic and cultural issue for Normandy. Based on these findings, a preliminary study was conducted on this species and fishing practices. This study was carried out in 2019 based on the bibliography and a survey of 164 practitioners from all along the Channel and Calvados coasts. It led to two findings:

• A significant lack of data on the biology and ecology of this species in Normandy makes it impossible to establish an accurate diagnosis of the status of the population(s) and stock(s).
• There is a strong perception of a downward trend in catches (size and quantity) along the entire coastline.

Therefore, as part of a consortium (CRPN, SMEL, Universities of Normandy (Caen, Le Havre), LABEO,+ subcontractors), a study focusing on this species is being proposed through the implementation of an ecosystem approach to fisheries in a context of global change (changes in water temperature, ocean acidification, anthropisation of the coastline, modification of favourable habitats, etc.).
 

Objectives of the study:

• Evaluate the causes and consequences of the decline in shrimp populations in Normandy.
• Understand, in relation to environmental factors, the life cycle of the bouquet in Normandy (reproduction period, larval phase and recruitment of juveniles, migration and distribution on the foreshore according to seasons and habitats, growth and distribution of age classes, including the size of mature females, etc.) and characterise the trophic regime.
• Better identify mantis shrimp fisheries in Normandy
• Participate in raising awareness about this species among all stakeholders

The project is structured into 3 Workpackages

• Biology and ecology of the brown shrimp (Palaemon serratus) (growth, reproduction, involvement in the food web, associated fauna and flora, etc.)
• Cumulative effects of human activities on this species (temperature, contaminants, catches)
  Socio-economic study of shrimp fisheries and eco-awareness among stakeholders (respect for size limits, opening/closing dates, fishing techniques, etc.).

This work will be carried out in collaboration with all fishermen to obtain information on all fishing sites and exchange empirical knowledge. The study will be conducted in depth at four sites over a period of three years to better understand the biology and ecology of the species:

• Manche: Chausey Islands and west coast of Cotentin (Agon-Coutainville/Pirou sector)
• Calvados: Grandcamp-Maisy sector
• Seine-Maritime: Fécamp-Antifer sector

Expected results:

• Improve knowledge of the biology and ecology of the species and understand the role of the bouquet in the lower levels of the food web through isotope analysis
• Study the spatio-temporal evolution of the species across Normandy, in the context of global warming and the cumulative effects of human activities (including chemical contamination)
• Assess the importance of this species for coastal fishing (type(s) of fleet(s) concerned, fishing locations and seasonality, volumes landed).