SPATIOTEMPORAL DISTRIBUTION PATTERN OF COLLICHTHYS LUCIDUS IN THE CENTRAL – NORTHERN COASTAL WATERS OF ZHEJIANG BASED ON ENVIRONMENTAL DNA (EDNA)

To elucidate the spatiotemporal distribution pattern of spinyhead croaker (Collichthys lucidus) and its relationship with environmental factors, this study combined environmental DNA (eDNA) techniques with traditional fishery resource surveys to systematically investigate C. lucidus in the central-northern coastal waters of Zhejiang during summer and autumn. The results showed that: (1) C. lucidus exhibited a wider distribution range in autumn, but its eDNA concentrations were lower than those in summer; (2) vertically, eDNA concentrations were higher in bottom waters than those in the middle and surface layers; (3) key environmental factors (water depth, temperature, salinity, dissolved oxygen, chlorophyll a, and chemical oxygen demand) had significant effects on its distribution; and (4) the spatial pattern of C. lucidus eDNA concentration was broadly consistent with the biomass distribution derived from conventional fishery resource surveys. Overall, this study demonstrates that eDNA technology can effectively characterize the spatiotemporal distribution of C. lucidus and its responses to environmental drivers, providing a novel technical approach and scientific basis for dynamic resource monitoring, habitat conservation, and sustainable utilization of this species.