Climate-induced threats are increasingly affecting marine populations worldwide. In the last few decades, several gorgonian species have been affected by mass mortality events in the north-west Mediterranean, putatively linked to local sea temperature increases during heatwaves.
This study analysed the population genetic structure and migration patterns of P. clavata populations across seven sites in the Ligurian Sea, some of which have been affected by mass mortality events.
The authors found significant genetic differentiation among P. clavata populations, reflecting habitat fragmentation at a regional scale, except for two populations found 20 km apart. While continuing gene flow between distant populations was also revealed. Additionally, it is suggested that gene flow among populations may have contributed to support their recovery from mass mortality events.
The study identified populations in the central part of the Ligurian Sea that can be strategic for the regional persistence of the species. It is underlined that these findings highlight that the preservation of key populations could maintain connectivity and gene flow in the metapopulation, and increase the resilience of the species.
The study suggests that the spatial arrangement of the Ligurian Sea network of MPAs is effective in maintaining connectivity among P. clavata populations in the study area. Moreover, the authors state that the distance between MPAs is in the range of the dispersal distance of the species. Therefore, so the authors claim, in case of future disturbances, the network of MPAs in the Ligurian Sea would support the recovery of the populations.
Padrón M, Constantini F, Bramanti L, Guizien K, Abbiati M (2018) Genetic connectivity supports recovery of gorgonian populations affected by climate change. Aquatic conservation: marine and freshwater ecosystems DOI: 10.1002/aqc.2912