The latest report from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) highlights growing concern about the global proliferation of non-native species (NIS), exacerbated by rising temperatures. In 2023, the invasive blue crab Callinectes sapidus considerably extended its range in French Mediterranean lagoons (more than 20 lagoons and several estuaries with different invasion gradients). It has been established that this species is eurythermic (tolerating a wide range of temperatures from 0 to 40°C), making temperature non-limiting for its proliferation. On the other hand, variations in salinity are an essential parameter for its reproduction and for the maturation of eggs until they are laid in the marine environment.
This study presents the salinity tolerance of C. sapidus, using metabolic performance to define its tolerance to a wide range of salinity levels (13 levels ranging from 0 to 65 PSU). The results show that C. sapidus tolerates a wide range of salinities with a minimum critical threshold (CTmin) at 0 PSU, an optimum at 18.5 PSU, and a CTmax at 62.4 PSU. By applying a performance curve to the actual salinity data measured monthly in 20 invaded lagoons in 2023, it was possible to map, on a fine spatial scale, the distribution of favourable habitats for C. sapidus in 2023. In addition, a tool for prioritising lagoons according to their degree of habitability was developed, providing a decision-making framework for management measures in each lagoon. This shows that 50% of the lagoons are priority areas, 10% are intermediate and 40% require monitoring. This approach makes it possible to comply with European regulations by helping decision-makers to implement action plans and/or early detection programmes for the management of invasive species.
As a follow-up to this study, a training meeting was held on Wednesday 11 December 2024.
Bibliographical reference :
Marchessaux, G., Barré, N., Mauclert, V., Lombardini, K., Durieux, E. D. H., Veyssiere, D., Filippi, J.-J., Bracconi, J., Aiello, A., & Garrido, M. (2024). Salinity tolerance of the invasive blue crab Callinectes sapidus : From global to local, a new tool for implementing management strategy. Science of The Total Environment, 954, 176291. https://doi.org/10.1016/j.scitotenv.2024.176291
Contacts
Dr. Guillaume MARCHESSAUX
Researcher University of Palermo
Specializing in blue crab and NIS
[email protected]
Dr. Marie GARRIDO
Office de l’Environnement de la Corse
Coord. Observatoire Régional des Zones Humides de Corse
Project manager, Pôle-relais lagunes méditerranéennes, Corsica
Ecologist specializing in lagoon ecosystems
[email protected]
