Distribution and environmental characteristics of the spawning grounds of Scomberomorus niphonius in the coastal waters of Yellow Sea, China

Abstract

Japanese Spanish mackerel (Scomberomorus niphonius) is one of the main economic fish species in the Yellow Sea. To understand its spawning habitat and population dynamics in the early stage, we examined the distribution and environmental characteristics of spawning ground of Japanese Spanish mackerel using their egg survey data collecting in 2015 (late May) and 2017 (late May) in the coastal waters of Yellow Sea. The generalized additive model (GAM) with the Tweedie distribution was used to analyze the distribution and environmental characteristics of its spawning ground. The results showed that egg distribution was significantly related to the location (i.e., latitude and longitude), water depth, and sea surface temperature (SST), but not related to sea surface salinity (SSS). The optimal range of depth and SST were 15-30 m and 16-20 ℃, respectively. The mackerel spawning ground mainly distributed in the region Shidao fishing ground (area near 36°30' N,121°48' E) and Haizhou Bay (33°30'-36° N,119°30'-121°30' E). There were some clear inter-annual differences in the distribution of mackerel spawning ground, with the spawning ground tending to northward in the year with higher sea temperature. Therefore, it is necessary to manage and protect the above spawning ground (especially the Haizhou Bay), establishing the corresponding ecological protection and restoration strategy, to realize sustainable exploitation of mackerel fisheries resources in the Yellow Sea.