In the Thau Lagoon, the populations of noble pen shells have been monitored since May 2020. Analyses conducted on tissue samples taken from moribund noble pen shells at the end of 2020 revealed the presence of the parasite Haplosporidium pinnae, likely responsible for a significant mortality episode in the Eaux Blanches area, located in the southeastern part of the lagoon. Today, the monitoring indicates a positive population dynamic, with a good recruitment rate, even in sites affected by the parasite.
