Fish assemblage structure and spatio-temporal variation in Qingchuan bay, Ningde, Fujian

Based on fishery resources survey from Qingchuan bay, Ningde, Fujian province in April and October 2020, the fish assemblage structure and spatio-temporal variation were investigated, as well as the relationships between fish community and environmental factors. The results showed that a total of 55 species of fish, belonging to 49 genera and 29 families of 11 orders, consisting of 30 migratory species, were collected from Qingchuan bay. The diversity index showed obviously temporal and spatial differences that Trypauchen vagina and Harpadon nehereus was dominant in spring and autumn, respectively. The Shannon-Wiener diversity index and Pielou evenness index were higher in spring than in autumn, while the species abundance in autumn was significantly higher than that in spring. Non-metric multidimensional scaling and analysis of similarities showed significant seasonal variation of fish community. However, there were no significant spatial differences among fish community that only difference were detected in the composition of fish species at different habitats and migratory types. One-way analysis of variance showed that there was no difference in environmental variables between different stations. However, there were significant differences in water temperature, salinity, dissolved oxygen and chlorophyll a in spring and autumn at the same station. Finally, the result of redundancy analysis showed that chlorophyll a, salinity and dissolved oxygen had significant effects on fish communities in spring and autumn, respectively. This study firstly reports current status of fish resources in Qingchuan bay, and provides a basis for sustainable utilization and effective management of fishery resources of local marine ecosystem.