Invertebrates at the Land-Sea Interface in a Climate Change World: Heatwaves, Floods, Fire and Ice

With their location at the land-sea edge, coastal marine invertebrates withstand marked changes in water and air temperatures and abrupt salinity changes through tidal cycles. In a climate-changing world, these stressors are being magnified by the increased intensity and emergence of extreme climatic events (ECEs). Diverse habitat-dependent communities on rocky shores, mudflats, mangroves and saltmarsh are at the forefront of ECEs, which can co-occur and interact with other anthropogenic stressors. This review synthesises information on the vulnerabilities of coastal marine invertebrates living at the interface between marine and terrestrial environments to marine and atmospheric heatwaves, fire, flooding, hyposalinity and changes in intertidal ice cover. The impacts of ECEs on bivalves are investigated as these are ecologically and economically important keystone species. We synthesise impacts of extreme heat stress on these molluscs as a case study. Temperature and salinity extremes are particularly damaging to coastal invertebrate communities if they coincide with low tide cycles. As adaptation to environmental variability is an inherent feature of the evolution in the intertidal, it will be important to understand tolerance levels with respect to ECEs, as this varies between species and across tidal cycles. It is also important to understand the capacity to build climate resilience through acclimatisation, adaptation, plasticity and the presence of refuge habitats, as well as identify the potential for species' redundancy with respect to the provision of key ecosystem services.