莱州湾水域鱼类生物完整性评价

采用莱州湾水域鱼类生物完整性指数评价生态系统健康状况,为该水域的生态修复和渔业资源的可持续管理提供科学依据。2016-2017年在莱州湾采用底拖网开展鱼类资源调查,共捕获鱼类52种。参照1982-1983年的历史资料确定评价标准,从鱼类种类组成与丰度、繁殖共位群和营养结构等角度,筛选适用于莱州湾水域鱼类生物完整性(Fish index of biological integrity,F-IBI)评价的指标体系,得到鱼类总种类数、冷温性鱼类比例、中上层鱼类种类数比例、平均单位网次渔获量、多样性指数、产浮性卵鱼类比例、产粘着性卵鱼类比例、低耐污鱼类种数比例、广食性鱼类比例、底栖动物食性鱼类比例、浮游动物食性鱼类比例和杂食性鱼类比例等12个参数指标。根据评价指标体系计算F-IBI,结果显示:莱州湾水域的F-IBI得分为30,其完整性等级为“差”,表明莱州湾水域生态健康状况差。建议采取面源污染控制和基于生态系统保护的渔业管理恢复莱州湾水域生态系统健康。

Evaluation on Biological Integrity of Fish in Laizhou Bay

To assess the biological integrity of the Laizhou Bay waters characterizing obvious land-sea interactions and serious human interferences, the fishery resources in Laizhou Bay were conducted by using the bottom trawls during the period of 2016-2017. By comparing the historical data in 1982-1983 with that data in 2016-2017 and referring to published literatures, the system of fish index of biological integrity (F-IBI) available for the Laizhou Bay aquatic ecosystem was constructed based on four metric attributes (species composition and abundance, reproductive guild, tolerance and trophic structure). A total of twelve metrics including total number of fish species, proportion of species of cold temperate fishes, proportion of species of pelagic fishes, catch per haul per hour, Shannon-Wiener diversity by weight, proportion of species of floating egg fishes, proportion of species of adhesive egg fishes, proportion of number of pollution sensitive fishes, proportion of species of feeding generalist fishes, proportion of catch of benthivorous fishes, proportion of species of zooplanktivorous fishes and proportion of species of omnivorous fishes were selected as the metrics for establishing the F-IBI system. Our results showed that the F-IBI score in Laizhou Bay was 30, and the biotic integrity grade was the "poor" level, indicating that bad status in aquatic ecosystem health status of the Laizhou Bay. It is suggested that non-point source pollution control and ecosystem-based fisheries management should be adopted to restore the ecosystem health in Laizhou Bay waters.