莱州湾水域鱼类生物完整性评价

Evaluation on Biological Integrity of Fish in Laizhou Bay

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。

The health and restoration of the Bohai Gulf ecosystem has attracted increasing interest among ecologists at home and abroad.Assessing the health status of the gulf ecosystem is necessary to set restoration goals and the fish index of biological integrity(F-IBI)is an important research method for evaluating ecosystem health.In this study,the health status of the Laizhou Bay ecosystem was evaluated using the F-IBI,based on fish resource surveys conducted in 2016-2017 using bottom trawls.The F-IBI for evaluating the Laizhou Bay aquatic ecosystem was constructed by comparing historical data(1982-1983)with the data from 2016-2017,as well as references from the literature.The evaluation system consisted of 12 metrics from four general attributes:species composition and abundance,reproductive guild,tolerance and trophic structure.The twelve metrics included:total number of fish species,proportion of cold water fish species,proportion of pelagic fish species,catch per haul per hour,Shannon-Wiener diversity index by weight,proportion of fish species with floating eggs,proportion of fish species with adhesive eggs,proportion of pollution sensitive fish species,proportion of fish species with a heterogeneous diet,proportion of fish species feeding on benthonic animals,proportion of fish species feeding on zooplankton and proportion of omnivorous fish species.The overall F-IBI score calculated for Laizhou Bay was 30,in the poor range,indicating that the aquatic ecosystem of Laizhou Bay needs to be better protected and restored.Non-point source pollution control and ecosystem-based fishery management are recommended to restore ecosystem health to Laizhou Bay waters.This result provides evidence for ecological restoration and the sustainable management of fishery resources in Laizhou Bay.