基于“OOAO原则”的罗源湾生态质量状况综合评价

Abstract

由于福建沿海经济的快速发展以及近岸海域开发利用的不断升级,位于福建省东北部的罗源湾面临着越来越大的人为环境压力,包括生境的破坏、港口活动、城镇生活废水、工农业废水排放、人工养殖等。综合评价罗源湾生态质量状况,为研究区受到的人为扰动和污染强度的分级评价提供依据,在对退化的生态系统进行有效修复和管理的相关决策中起着重要的作用。以欧盟水框架指令中近岸海域生态质量状况综合评价体系为参照,结合我国的近岸海域监测项目以及收集到的资料,对该指标体系进行了调整,同时建立了罗源湾专属的生态要素和物理化学要素参考基准值,基于"One-out all-out (OOAO)"原则(即所有要素中的最低等级作为综合评价的等级)对罗源湾的生态质量状况进行了综合评价,并通过与人为环境压力分布的一致性分析,对评价结果的合理性和客观性进行验证。建立的参考基准值中,部分指标的参考基准值与国内外的相关研究或标准有着一定的差异,说明目前我国采用统一的评价标准并不合适。综合评价结果中,罗源湾9个站位中1个站位等级为"良", 其余8个站位及海域平均状况等级都为"中",存在明显的污染和人为扰动,生态系统出现一定程度的退化。对评价结果的验证表明,除个别站位外,评价等级基本与人为环境压力一致,说明调整后的近岸海域生态质量状况综合评价指标体系、建立的罗源湾专属参考基准值以及基于"OOAO原则"的综合评价方法,能够较客观地评价研究区域的生态质量状况。;The fast development of coastal economy and increasing exploiting stress of coastal areas have greatly increased the pressures imposed on Luoyuan Bay, which located in the northeast of Fujian province. These pressures usually include habitat destruction, port activities, urban sewage, farmland fertilizer lossand and aquaculture. Assessing the Ecological quality status (EcoQS) comprehensively offers positive bases for assessing and ranking the severity of disturbance and pollution of coastal waters, and plays an important role in the course of related decision-making regarding effective remediation and management of the deteriorated ecosystem. How to refer to the relative mature assessment methods and standards to establish the integrated EcoQS evaluation methods suited to the characteristics of Chinese coastal water is an urgency of the comprehensive management of marine environment. In this study, based on the monitoring items of coastal water in China and the data collected, the EcoQS evaluation index system for coastal waters in the European Water Framework Directive (WFD) was adjusted and applied in Luoyuan Bay. The adjusted evaluation index system was also based on ecological elements (phytoplankton, zooplankton and benthos), chemical elements (priority controlled heavy metals and organic pollutions), physicochemical elements (dissolved oxygen, transparency and nutrients of water and sediment) and hydromorphological elements. According to historical data collected, the reference conditions of physicochemical and biological elements (Shannon-Wiener index of zooplankton, AMBI, richness index, Shannon-Wiener index of benthos) of Luoyuan Bay were established. The EcoQS was assessed based on ‘One-out all-out (OOAO) principle’, <em>i.e.</em>, the worst status of the element used in the assessment determines the final status of a water body, and was classified as ‘High, Good, Moderate, Poor and Bad’. The rationality and objectivity of assessment results was validated by anthropogenic disturbances information. According to the established reference conditions, several indexes among the current standards deviate from related researches and standards around the world, indicating that the current united standards used for marine ecology evaluation in China may not be appropriate. The assessment results showed that, among the 9 stations of Luoyuan Bay, 1 station was classified as ‘Good’ and the other 8 stations were ‘Moderate’, the average status of the whole bay was also ‘Moderate’. Luoyuan Bay was obviously polluted and disturbed by anthropogenic activities, and the ecosystem was deteriorated moderately, which meant restoration actions must be taken in light of WFD requirement. The validation of the assessment results indicated that the assessment results of all stations were basically consistent with the anthropogenic pressures information except for the station LY01 with higher anthropogenic pressures. It meant that the adjusted index system, established reference conditions and the evaluation method based on ‘OOAO principle’ were able to objectively assess the EcoQS of Luoyuan Bay.