Ecological sensitivity and vulnerability of fishing fleet landings to climate change across regions.

The degree of exposure of fishing communities to environmental changes can be partially determined by the vulnerability of the target species and the landings composition. Hence, identifying the species that ecologically most contribute to the vulnerability of the landings are key steps to evaluate the risk posed by climate change. We analyse the temporal variability in intrinsic sensitivity and the ecological vulnerability of the Portuguese fisheries landings, considering the species proportions derived both from the weights and revenues. To account for the diversification of species of each fleet, we explored the species dependence of the fishery in combination with the vulnerability of them. The analyses were carried out separately for three fleet typologies and three regions. Opposite to what has been observed at a global scale, the ecological sensitivity of the fisheries landings between 1989 and 2015 did not display a decline across areas or fishing fleets. Considering each fleet independently, for trawling, where average vulnerability was lower than in the other fleets, the sensitivity of the landings increased since the 2000s. On the other hand, the high vulnerability found in multi-gear fleets was compensated by diversification of the species caught, while purse-seine fleets targeted low vulnerability species but presented a high fishery dependence on few species. The results highlight the importance of combining information on ecological vulnerability and diversification of fishing resources at a regional scale while providing a measure of the ecological exposure to climate change.

Climate change vulnerability assessment of the main marine commercial fish and invertebrates of Portugal.

This is the first attempt to apply an expert-based ecological vulnerability assessment of the effects of climate change on the main marine resources of Portugal. The vulnerability, exposure, sensitivity, adaptive capacity, and expected directional effects of 74 species of fish and invertebrates of commercial interest is estimated based on criteria related to their life-history and level of conservation or exploitation. This analysis is performed separately for three regions of Portugal and two scenarios of climate change (RCP 4.5 and RCP 8.5). To do that, the fourth assessment report IPCC framework for vulnerability assessments was coupled to the outputs of a physical-biogeochemical model allowing to weight the exposure of the species by the expected variability of the environmental variables in the future. The highest vulnerabilities were found for some migratory and elasmobranch species, although overall vulnerability scores were low probably due to the high adaptive capacity of species from temperate ecosystems. Among regions, the highest average vulnerability was estimated for the species in the Central region while higher vulnerabilities were identified under climate change scenario RCP 8.5 in the three regions, due to higher expected climatic variability. This work establishes the basis for the assessment of the vulnerability of the human activities relying on marine resources in the context of climate change.