In order to investigate the potential ecological risks of heavy metals at cage farming in surface sediments, 5 samples were collected from Zhanghu reservoir bay in Shuikou reservoir and the acid volatile sulfide (AVS) and simultaneously extracted metals (SEM) were studied. The results indicated that the AVS concentrations ranged from 0.57-2.13 μmol·g^-1, and the SEM concentrations ranged from 1.66-6.35 μmol·g^-1. Among heavy metals, Zn, Cr and Cu were the dominating metals, accounting for over 80% of SEM. By comparing the ratio of SEM to AVS, the values of annual average were ranged from 1.65-9.11. If Cr was not included in the calculation, the values were ranged from 1.42-7.75, and the value of (SEM-AVS) were mainly smaller than 5. These indicated that heavy metals were associated with the AVS phase in the sediments, while metals in surface sediments could not cause toxicity to benthic organism. Compared with the threshold of toxic effects, the most toxic metal was Pb in terms of individual heavy metals. According to the present study, the potential toxic effects of heavy metal release and hydrogen sulfide (H₂S) production from sulfides on cage aquaculture should be on the alert.

To restore the population of the endangered species Tachypleus tridentatus,artificial domestication and breeding research of T.tridentatus was carried out in Luoyuan County,Fujian Province in 2021—2022.Following the observation results of their natural spawning and nursery grounds,the simulated spawning environment was constructed,and the mating pairs were induced to spawn naturally in the artificial environment.The spawning habitat preferences and ecological requirements for T.tridentatus were determined through artificial incubation and seedling cultivation.This paper summarized the artificial domestication and propagation technology of horseshoe crab,and analyzed the significance of artificial domestication and natural propagation of T.tridentatus,providing theoretical basis for species conservation by the protection and restoration of T.tridentatus populations and artificial incubation in Fujian coastal area.