Influence of biotic and abiotic factors on mesozooplankton and fish larvae community structures in a fisheries resource protected area: A case study of Gangjin Bay, Korea

Mesozooplankton and fish larvae are critical components of aquatic food webs, and their community structure is essential for effective fisheries management. However, since 1999, no data on these communities have been recorded in Gangjin Bay, Korea, a designated Fisheries Resources Protected Area and a crucial spawning and nursery ground for various fish species. This study investigated the community structure of mesozooplankton and fish larvae in Gangjin Bay from March to November 2022 through monthly sampling. In spring, Noctiluca scintillans dominated, while copepods and cirripedian larvae prevailed in summer and autumn, respectively. The biotic and abiotic factors influencing the community structure of Paracalanus orientalis and Acartia ohtsukai included water temperature and concentrations of chlorophyll a in the micro- and pico-fractions. The biotic and abiotic factors influencing the community structure of anchovy and goby larvae included the abundance of P. orientalis and A. ohtsukai, while those affecting Sebastes inermis larvae were influenced by the abundance of Calanus sinicus and mesozooplankton biomass, particularly in the 1.0-mm size class. This study provides baseline data to describe the community structure of mesozooplankton and fish larvae in Gangjin Bay, thereby contributing to the development of policies for fisheries resource protection and management.