Seasonal habitat patterns of jumbo flying squid Dosidicus gigas off Peruvian waters

Abstract

Abstract Habitat modeling approach is a useful tool to detect potential habitat of pelagic fish species for better fishery exploitation and management. In this study, an integrated habitat modeling approach was applied to examine seasonal habitat patterns of an ecologically and economically important squid species Dosidicus gigas in the Southeast Pacific Ocean off Peruvian waters. Fisheries data of D. gigas and three crucial remotely-sensed environmental variables including sea surface temperature (SST), net primary production (NPP) and sea surface height anomaly (SSHA) during 2006–2015 were used to develop and validate the habitat model. Results revealed that the model output robust predictions of seasonal habitat suitability for D. gigas stock. Potential habitat exhibited strong seasonal variability, characterized by an expansion of suitable habitat during spring-autumn period and an extreme reduction in winter. These seasonal habitat patterns of D. gigas were largely driven by spatial distribution of favorable environmental conditions. Spatial correlation analysis indicated that the habitat quality of D. gigas was negatively correlated with SST in the areas between 8°–15°S and 87°–79°W and with SSHA on the whole fishing ground. However, a negative relationship was found between HSI values and NPP in the east of 84°W, but with a significantly positive correlation in the west of 84°W. In addition, seasonal variations of CPUEs and latitude distribution of fishing efforts were highly coincided with the variability trends in the area of suitable habitats and their latitudinal distributions. Interannual variability was shown in the averaged HSI of D. gigas. Furthermore, comparing to the strong El Nino year in 2015, the La Nina event in 2011 yielded more enlarged favorable regions of each environmental factor in each season, leading to form extremely high-quality habitats.