AUTHOR=Tang Guanglong , He Zehua , Liu Yong , Xiao Yayuan , Bi Sheng , Sun Ye , Liang Jiman , Wu Peng , Wang Teng , Ye Jinyu , Li Chunhou 

TITLE=Acanthopagrus latus migration patterns and habitat use in Wanshan Islands, Pearl River Estuary, determined using otolith microchemical analysis

JOURNAL=Frontiers in Marine Science

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2023.1104528

DOI=10.3389/fmars.2023.1104528

ISSN=2296-7745

ABSTRACT=The waters surrounding the Wanshan Islands are important traditional fishing grounds in China. Acanthopagrus latus (Houttuyn, 1782) is an economically important species in this area; however, the distribution of its spawning grounds and habitat use patterns remain unknown. Therefore, the otolith microchemical method was used in this study to investigate the Wanshan Islands. We collected 100 otolith samples from three geographic areas: Qi'ao Island Mangrove Water Habitat (MW), Yamen Estuary Oyster Farm Water Habitat (OW), and Dong'ao-Guishan Island Reef Water Habitat (RW). Sr and Ca concentrations were measured using LA-ICP MS along the shortest axis of the vertical otolith annual or lunar rings, spanning the entire life cycle of an individual, with the core and edge areas corresponding to environmental characteristics at birth and capture, respectively. Analysis of covariance (ANCOVA) revealed significant differences between all sampled points (p < 0.05) for edges. For the core, there were no significant differences between sampling points (p>0.05). Cluster analysis and non-metric multidimensional scaling (nMDS) indicated that at the juvenile stage, RW and MW individuals in the two main clusters belonged to the same cluster. There was no significant difference between the cores of the RW samples and the edges of the MW and OW samples (p>0.05). Therefore, the spawning area in the Wanshan Islands is thought to have originated from low to medium-salinity waters with mangroves and oyster farm habitats in the Pearl River Estuary. A. latus from RW was found to have three distinct habitat-use patterns: 1) Marine Resident (7.2% of sampled fish) fish that remain in marine habitats for life; 2) Marine Migrant (16.4% of sampled fish)- juveniles inhabit low to moderate salinity habitats and migrate to marine habitats as they grow; 3) Estuarine Visitor (76.4% of sampled fish) repeated migration between low to moderate salinity and marine habitats. The partial migration theory was confirmed. This suggests widespread migration between estuarine and marine habitats throughout the ontogeny. The plasticity of this habitat use and the protection of spawning grounds should be considered in future fisheries management because A. Latus in this area has been the victim of the overexploitation of resources.