Heat waves will likely cause increasing mass mortality events of benthic species, mostly invertebrate organisms, such as corals, sponges, bivalves, ascidians and bryozoans, increasing the risks of abrupt collapse of endemic species . Deep-water corals live near their upper thermal tolerance and further warming could thus reduce their biotic potential and long-term survival , although there are some exceptions  and also knowledge gaps . Warming has been shown to severely reduce the metabolism of some Mediterranean coral species . In summary, the observed shift in marine ecosystems since 1980 is projected to continue and intensify, resulting in very high risks for marine ecosystems between 1.5℃-2℃ global warming levels  .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report