Growth patterns and optimum habitat of Larimichthys crocea throughout ontogenesis based on a bioenergetics model

Abstract

Larimichthys crocea was one of the most common commercially harvested fish in the East China Sea before the 1980 s, while overfishing and habitat degradation have contributed to the collapse of this resource. Sansha Bay is an important spawning and nursery ground for L. crocea, where an enhancement and release program has been implemented to recover wild L. crocea stocks. It is also a well-known mariculture base in southeast China, especially for L. crocea. In this study, a growth model of L. crocea based on bioenergetics was developed to investigate crucial periods for survival, effects of variations in temperature and food density, and suitable habitat of L. crocea during its first year. The results show that the Min-Yuedong stock of L. crocea has two critical growth periods: summer (affected by food limitations) and winter (affected by cooler water temperatures). In early life, L. crocea showed greater sensitivity to variations in temperature than to variations in food density, whereas food density had a greater influence on the growth of L. crocea later in life. The model-estimated suitable habitat for L. crocea varied ontogenetically. Compared to outside the bay, L. crocea preferred the environment of the inner bay, where its habitat and migration routes were historically located. However, this area is highly impacted by anthropogenic activities. Based on limited data, we developed the growth model of L. crocea for the first time and described suitable habitat for L. crocea during the first year based on water temperature and prey conditions. This may have implications for the selection of L. crocea release sites and cessation of excessive mariculture in Sansha Bay.