The effect of regional sea surface temperature rise on fisheries along the Portuguese Iberian Atlantic coast

The environmental effects of climate change are expected to impact fisheries, and related economies, and represent a significant challenge for the development of government policy. The impact of ocean warming on fisheries yields is of particular concern. The effect of sea surface temperature (SST) on fisheries in three distinct biogeographic areas (north-western, NW; south-western, SW; and south, S) and different fleet sectors (trawl, seine, and multi-gear) of the Portuguese coast was examined. The mean temperature of the catch (MTC) was applied to the official landings statistics to assess the effect of global warming on the exploited marine communities. MTC increased from 16.9, 16.7, and 17.4 degrees C in 1989 to 17.9, 18.1, and 18.3 degrees C in 2009, whereas the linear rate of MTC increase was 0.54, 0.49, and 0.70 degrees C per decade in the NW, SW, and S regions, respectively. The increase of warmer species in fisheries landings is regional-specific. The percentage increases in landings of warmer water species increased significantly from north to south: 5.1, 6.7, and 18% per decade in the NW, SW, and S, respectively. The results confirmed that ocean warming has affected the composition of fisheries landings (of warmer and colder species) in the three regions of the Portuguese coast. The results highlight the importance and urgency of considering the temperature-induced shift in species distribution in fisheries management.