Pinna nobilis is an endemic bivalve of the Mediterranean Sea and a vulnerable species registered as endangered and protected under the European Council Directive 92/43/EEC and the Barcelona Convention. This bivalve has been worryingly impacted by a mass mortality that started in the Western Mediterranean Sea in autumn 2016.

This study evaluated the connectivity of P. nobilis post-larvae and adults in seagrass habitats around the Balearic Islands and identified its source and sink populations. The assessment was undertaken from a multidisciplinary approach including population genetics and hydrodynamic modelling.

The results show high genetic diversity and significant genetic differentiation between post-larvae samples, but not between adult populations. While the genetic connectivity pattern was found to be consistent with marine currents and dispersal models.

From a conservation and management perspective, the connectivity patterns described in this study are crucial, so the authors state, to design effective marine reserves protecting P. nobilis, but even more so to plan restocking programmes in the Balearic Islands, affected by the mass mortality event, where close to 100% of the populations became extinct locally due to the mass mortality.

https://onlinelibrary.wiley.com/doi/full/10.1002/aqc.2976

González-Wangüemert M et al. (2018) Gene pool and connectivity patterns of Pinna nobilis in the Balearic Islands (Spain, Western Mediterranean Sea): Implications for its conservation through restocking. Aquatic Conservation: Marine and Freshwater Ecosystems. DOI: 10.1002/aqc.2976