Empirical habitat suitability model for immature albacore tuna in the North Pacific Ocean obtained using multisatellite remote sensing data

Abstract

This study developed an empirical habitat suitability model for identifying the optimal habitat of immature albacore tuna in the North Pacific Ocean (NPO) by using multisatellite remote sensing data and Taiwanese longline fisheries data between 2009 and 2016. An arithmetic mean model with five environmental variables is suggested to be appropriate for explaining the habitat variance of albacore in the NPO. A monthly albacore mean catch per unit effort (CPUE) of larger than 29.5 individuals/1,000 hooks occurred from November to March and was distributed over 25-40 degrees N. The optimal range of environmental variables in the sea surface temperature, sea surface height, mixed layer depth, sea surface chlorophyll-a concentration of the previous month, and eddy kinetic energy for the habitat of albacore are suggested to be approximately 17-21 degrees C, 0.24-0.84 m, 15-100 m, 0.07-0.29 mg m(-3), and 0.0001-0.0031 m(2) s(-2), respectively. We discovered a significant positive relationship between the suitable habitat area and nominal CPUE of immature albacore in the NPO (Pearson's correlation coefficient, r = 0.982). The mean position of the optimum habitat shifted southwardly from near 38 degrees N in November to near 28-31 degrees N during February to March. Overall, frontal structures play a major role in the stimulation of potential albacore habitats.