Climate change, sea level rise, and potential impacts on rocky intertidal populations

Background/Question/Methods

Climate change is modifying communities, populations, and associated dynamics worldwide, recent work in marine systems has mainly focused on how changes in water temperature and chemistry are likely to impact marine species.  On rocky intertidal shores sea level rise has the potential to dramatically impact population viability, connectivity, and evolution, and yet little work has investigated how expected changes in sea level will impact intertidal communities.  Specifically sea level rise has the potential to rapidly modify the availability of intertidal area (viable habitat) due to the interaction of rising water levels and common geological features of rocky coasts, steep cliffs and flat terraces. 

Results/Conclusions

Two case studies are described in which sea level rise scenarios are combined with physical and ecological data to develop a model of how biomass and reproductive output of two populations of the California sea mussel will likely change during the next 100 years.  The results highlight the extreme sensitivity of these populations to such changes, suggesting potential for dramatic increases, decreases, or changes in the population stability based on the local geology and shore morphology.  Numerous intertidal species around the world share the structural features which make mussels sensitive to such changes, because of this a rapid assessment of how sea level rise will interact with rocky intertidal populations is argued for.