Ecological health assessment and improvement strategies of the Dongzhaigang Mangrove Wetlands

By investigating water quality, sediments, vegetation, fauna, environmental conditions, and anthropogenic disturbances in both natural and artificial mangrove wetlands at Tashi, Yanfen River, Sanjiang Bay, and Zhuxi River in the Dongzhaigang region, we applied a fuzzy comprehensive evaluation method to establish two assessment systems: an ecological health assessment system (six criteria and nineteen indicators) and an ecotourism resource evaluation system (four criteria and nineteen indicators). Each system was classified into five grades according to relative performance. The results show that the overall ecological health of the Dongzhaigang mangrove wetlands is moderate, with natural wetlands in better condition than artificial ones. Among the four sites, ecological health ranked from highest to lowest as follows: Tashi, Sanjiang Bay, Yanfen River, Zhuxi River. The wetlands possess unique and diverse ecotourism resources; however, due to anthropogenic disturbances, their overall tourism resource quality was assessed as moderate. The ranking of tourism resources was: Tashi and Yanfen River were the same, followed by Sanjiang Bay and Zhuxi River. To enhance resource protection, we recommend designating the lagoonal mangrove wetlands as core conservation zones and general control zones, further subdivided into no-aquaculture and no-fishing areas, restricted-aquaculture and fishing areas. Peripheral wetland parks should be zoned into ecological conservation, rational utilization, and ecological restoration areas, while non-park wetlands should be planned as ecological aquaculture zones, aquaculture-to-forest conversion zones, and aquaculture-to-wetland conversion zones. Furthermore, eleven ecological engineering measures are proposed, including aquaculture cessation, pond conversion to mangroves or wetlands, and the creation of bird habitats, to restore ecosystem functions and improve tourism resource quality.