Observed impacts of climate change on fish and fisheries in small islands include declines in reef-associated species due to coral bleaching or cyclone damage , oceanic-scale shifts in the distribution of large pelagic fish and hence their fisheries , changes to the size structure or breeding behaviour of species  ). Many studies of future fishery productivity in a changing climate suggest that yields will fall as a result of ocean productivity reductions, local species extinction and/or migration . Asch et al.  provided future projections for biodiversity and the maximum catch potential of fisheries in Pacific Island countries and territories. These authors concluded that nine of 17 Pacific Island entities  could experience ≥50% declines in maximum catch potential by 2100 relative to 1980-2000 under both an RCP2.6 and RCP8.5 scenario . In Wallis and Futuna, maximum catch potential was projected to increase slightly  by 2050, later declining by the year 2100. Similar projections have now been provided for all countries worldwide, including Pacific, Caribbean, Atlantic, Mediterranean and Indian Ocean small islands . The small islands that show the largest anticipated decrease in the maximum catch potential of fisheries by the end of the century  include the Federated States of Micronesia, Kiribati, Nauru, Palau, Tokelau, Tuvalu, São Tomé and Príncipe, whereas some other small islands such as Bermuda, Easter Island , and Pitcairn Islands , might actually witness increases in fish catch potential  . Monnereau et al. showed that for the fisheries sector, small island states are generally more vulnerable to climate change impacts compared to continental least-developed countries or coastal states because of their increased reliance on fisheries, the exposure of coastal communities to potential climatic threats and their limited adaptive capacity.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report