Suitable habitat of the scad fish (Decanters spp.) in Northern South China Sea predicted by MaxEnt model

Abstract

As a pivotal economic pelagic fish species inhabiting in upper-middle layers, the scad fish (Decapterus spp.) was assumed a vital role in relieving the fishing pressure imposed upon demersal fish in Northern South China Sea (nSCS). To enhance production and sustain the prominence of the scad fish, this study combined species occurrence data of spanning the spring (March to May) and the autumn (September to November) seasons from 2018 to 2020, and contemporaneous environmental data for prognosticating habitat distribution patterns by the maximum entropy model (MaxEnt). The environmental factors considered were sea surface temperature (SST), sea surface salinity (SSS), sea surface height (SSH), and chlorophyll-a concentration (Chla). The findings highlighted that the application of MaxEnt for each month yielding exemplary results typified by AUC values exceeding 0.9. During the spring, the suitable habitats for the scad fish were observed from the east waters of Hainan to the eastern Guangdong waters, where the centers of gravity was within. Similarly, the suitable habitats in the autumn were delineated within the bounds of the eastern Hainan Island waters to and few waters in eastern Guangdong. The key factors influencing occurrence probabilities of the scad fish varied seasonally, SST and SSS were most important in the spring, SSH and Chla manifested the greatest contribution to in the autumn. By elucidating spatiotemporal habitat suitability, this study may furnish robust scientific foundations to optimize catches and identify primary fishing grounds for the ecologically and economically vital species, facilitating sustainable resource utilization.