Mapping the Azores Marine Park Vulnerability to Temperature Changes

Aim

Identifying highly vulnerable regions to climate change is increasingly incorporated in marine management planning given the expected redistribution of species with latitude, longitude, and depth following temperature changes. Here, we developed a spatially explicit vulnerability framework incorporating sensitivity, exposure, and adaptive capacity of species living in one of the largest networks of Marine Protected Areas (MPAs) within the EU.

Location

Azores Marine Park, North Atlantic.

Methods

We quantified benthic, benthopelagic, and pelagic species sensitivity to temperature changes based on adult thermal affinity and georeferenced their distribution with quality-controlled records from various data compilators. To assess their exposure, we extracted historical (1995–2020) temperatures across latitudes, longitudes, and depths and calculated mean interannual change (i.e., increase or decrease) and variability. We estimated the adaptive capacity of species with traits related to relocation ability during adult and early life stages (i.e., “Motility” and “Developmental Mechanism”) using the FUN Azores trait database. To map the results, we pooled the species into 3D-regions of 0.25° × 0.25° resolution and 50 and 500 m depth bands at shallow and deep areas, respectively. We assigned a sensitivity, exposure, and adaptive capacity score to each region based on species scores and combined them into a final vulnerability class (i.e., “Highly Vulnerable” (HV), “Advisable Monitoring” (AM), “Expected Relocation” (ER), and “Least Concern” (LC)).

Results

HV and AM regions exist only in the benthic environment across various MPAs and depths. Increased mobility of species explains the absence of the most vulnerable categories in the benthopelagic and pelagic environments.

Main Conclusions

We advise strong conservation measures in HV areas and to maintain connectivity with climate refugia and monitoring of environmental variables and populations in areas classified as AM and ER, respectively. Our results suggest that the Azores deep-sea benthos is the most vulnerable environment to both warming and temperature variations.