Difference of spatio-temporal distribution of neon flying squid Ommastrephes bartramiii in the northwest Pacific Ocean under the El Niño and La Niña events

Abstract:

According to the fisheries data of Ommastrephes bartarmii combined with the sea surface temperature (SST) and sea surface height anomaly (SSHA) data obtained from 36°N to 48°N, 150°E to 170°E in northwest Pacific Ocean from September to November, 2006-2015, monthly habitat suitability index models (HSI) were established based on key marine environmental factors of different weighting scenarios, and monthly optimal model was selected and verified according to the model performance.Furthermore, the optimal HSI models predicted the habitat suitability, and the impacts of El Niño and La Niña on habitat suitability of O.bartramii are also compared, and the relationship between habitat quality and abundance, distribution are evaluated. The results showed that the weighting proportion of SI_SSTand SI_SSHA of the monthly optimal HSI models from September to November were as follows:0.9:0.1 in September, 0.7:0.3 in October, and 0.8:0.2 in November. Obviously, the contribution of SST was the highest, indicating that SST was the most important factor for spatial and temporal distribution of habitat. Moreover, comparing the impacts of El Niño years (2009 and 2015) and La Niña years (2007 and 2010) on habitat suitability,stocks abundance and latitudinal gravity center of fishing ground of O.bartramii, it is found that the La Niña events were more beneficial to the survival of O.bartramii than the El Niño events, and the suitable habitat area also increased the catch. Suitable SST moved north, resulting in a northward shift of fishing ground location as well.