PECOC

Pêche CÔtière de Crevettes en Normandie

2025 - 2027

The 36-month PECOC project, funded by the European Maritime, Fisheries and Aquaculture Fund, aims to deepen knowledge of the life cycle and population dynamics of three common shrimp species in the Bay of Seine: the bouquet shrimp (Palaemon serratus), the white shrimp (Palaemon longirostris) and the grey shrimp (Crangon crangon). These species play an essential role in the ecosystem, both as prey for higher trophic levels and in the processes of degradation and redistribution of organic matter. They are also economically important for professional fishermen. However, despite their emblematic presence on French coastlines and in estuaries, their life cycles remain poorly understood, particularly with regard to their early stages.

The PECOC project, which will run for 36 months and is funded by the European Maritime, Fisheries and Aquaculture Fund, aims to further our understanding of the life cycle and population dynamics of three common shrimp species in the Bay of Seine: the brown shrimp (Palaemon serratus), the white shrimp (Palaemon longirostris) and the common shrimp (Crangon crangon). These species play an essential role in the ecosystem, both as prey for higher trophic levels and in the processes of degradation and redistribution of organic matter. They are also of economic importance to professional fishermen. However, despite their emblematic presence on French coastlines and in estuaries, their life cycles remain poorly understood, particularly with regard to their early stages. Recent advances have been made in understanding the life cycle of the bouquet shrimp as part of a previous FEAMPA project (GEDUBOUQ; 2021-2023; thesis by Jean-Baptiste Baudet).
However, the results obtained need to be supplemented. For white shrimp and brown shrimp, studies are scarcer and generally outdated, leaving many uncertainties about their biology. Furthermore, scientific monitoring and observations by professional fishermen indicate a marked decline in shrimp populations over the last ten years, particularly for white shrimp and brown shrimp. This situation raises serious questions about the health of populations in the Bay of Seine.
In this context, the Normandy Coastal Monitoring Unit (CSLN) (https://www.csln.fr/) and UMR-I 02 SEBIO have obtained FEAMPA funding for the PECOC project (2025-2027), which aims to improve knowledge of the life cycle and population dynamics of these shrimp species.
In order to achieve this objective, demographic monitoring will be carried out over a two-year period based on bimonthly sampling of brown and white shrimp populations. These samples will be taken in the marine environment at several stations in the southern part of the Bay of Seine, as well as in the Seine estuary, from the estuary to Rouen. For juveniles and adults, adapted trawl fishing will enable a wide range of sizes to be sampled. Biometric measurements, such as the size and sex of individuals, will be taken, as well as observations on female reproduction, including reproductive status, fertility and embryonic stages where applicable. At the same time, plankton net fishing (Bongo) will be carried out to collect information on larvae, a life stage that is still poorly documented in the literature.
The data from these surveys will then be used to develop demographic models to better understand the life cycle, identify critical life stages and assess the status of shrimp populations in the Bay of Seine with a view to improving the management and conservation of these fishery resources. The analysis of these models will also draw on historical data acquired by the CSLN over more than 20 years.