Climate change will fragment Florida stone crab communities

Ocean acidification and ocean warming are the two components of climate change that impacts marine life the most. The commercially important Florida stone crab, Menippe mercenaria, is one of the species that is going to be affected by those changes. In this study we investigated the impacts of climate change on the distribution of the stone crab larvae on the West Florida Shelf. To understand the dispersion of the larvae, we coupled SLIM3D, a multi-scale ocean model, with a larval dispersal model. We then conducted a connectivity study and evaluated the impacts of climate change analyzing three different scenarios, one presenting the dispersion of the larvae for present conditions and the two others presenting the dispersion for moderate and extreme climate change. The results show a clear impact of climate change on larval dispersal and on the subsequent crab distribution. In the future, climate change could result in stone crabs moving north or to deeper waters. The second impact would be the increase in the number of larvae settling in the non-fishing zone, where the water depth exceeds 30 m. The distance traveled by larvae is going to decrease, resulting in an increase of self-recruitment and decrease of the size of sub-populations. The last impact we identified is the possibility of a shift of the spawning period earlier in the season. We also evaluated that the habitats in the non-fishing zone cannot serve as a significant source of larvae for the habitats in the fishing zone since there is very little exchange between the two zones. Overall, this work could help local authorities to better understand M. mercenaria and to take actions regarding the fishery management and its future considering the upcoming changes in the ocean conditions