Assessing and Managing the Impacts of Mixtures of Chemicals on UK Freshwater Biodiversity in a Changing World

我们正面临全球生物多样性危机，淡水生物多样性的下降速度比陆地或海洋生物多样性都要快。在英格兰，十分之一的淡水和湿地物种面临灭绝的威胁，三分之二的现存物种正在减少。监管数据表明，废水排放、交通、城市环境、农业和采矿造成的化学污染，都是导致不符合现有质量标准的原因之一。英国环境审计委员会最近将水质状况总结为：“英格兰的河流一团糟。污水、农业废弃物和塑料的‘化学混合物’正在污染英国许多河流的水。”然而，这些对化学品对英国地表水影响的评估不太可能反映真正的影响，因为它们：关注正在使用的一小部分化学品；采取单一化合物-单一终点方法；忽视化学品、水质参数和物种相互作用的综合影响；没有认识到生态群落的敏感性可能在空间和时间上有所不同。如果我们要阻止英国河流中生物多样性的丧失，同时继续实现化学品的社会效益，我们迫切需要更有效的方法来评估、预测和管理化学品现在和未来的影响。我们的目标是提供和展示一个新的评估框架，该框架考虑到一个流域的物理化学和生态特征的已知变异性，并以高空间分辨率确定化学品、生物有效性改良剂和营养素的混合物对物种组合的结构和功能的综合影响。该框架不仅将评估目前的化学影响，还将评估气候变化、城市化和人口增长等全球大趋势推动的变化所造成的未来影响。利用9个约克郡河流流域的350个站点，涵盖不同的土地利用和污染压力，我们将通过以下方式来开发、测试和演示我们的框架：1.确定排放到英国淡水中的化学物质的优先顺序，以识别那些在流域中驱动影响的化学物质；2.表征英国流域目前(2002-2022年)和未来(2061-2080年)的化学物质暴露和一般水质参数曲线；3.估计不同水质条件下化学物质对英国相关物种的影响；4.预测化学混合物、生物有效性改良剂和营养物质对生物多样性和生态系统功能的当前和未来综合影响；5.应用这些研究结果，确定在目前和未来气候和流域变化情况下减轻化学品对生物多样性的影响的干预措施。在该项目期间开发的理解和预测建模工具将为制定更好的计划，以适应和减轻与现在和未来水质下降有关的风险。通过与我们的合作伙伴密切合作，包括来自政策(JNCC)、监管(HSE)、主要行业(联合利华、UKWIR、Network Rail)和非政府组织(国家信托、河流信托)部门的主要代表，我们将为政策制定者提供知识和框架，以实现向化学风险评估的范式转变，保护脆弱地区的生物多样性和关键环境功能。监管机构和行业都将能够将未来的投资和努力集中在最有可能/实际发生伤害的情景上。化学品制造商将能够更好地生产对社会有益但不会对自然环境及其提供的生态系统服务产生负面影响的化学品。只有在这个项目中采取综合和全系统的方法，我们才能实现环境法的抱负，即“到2030年底扭转物种丰度下降的局面”。

We are facing a global biodiversity crisis and freshwater biodiversity is declining more rapidly than either terrestrial or marine biodiversity. One in ten freshwater and wetland species in England are threatened with extinction and two thirds of existing species are in decline. Regulatory data suggest that chemical pollution from wastewater discharges, transport, urban environments, agriculture and mining all contribute to failures against existing quality standards. The Environmental Audit Committee recently summarised the state of water quality as: "rivers in England are in a mess. A 'chemical cocktail' of sewage, agricultural waste, and plastic is polluting the waters of many of the country's rivers". However, these assessments of the impacts of chemicals on UK surface waters, are unlikely to reflect real impacts as they: focus on a small proportion of chemicals in use; take a single compound-single endpoint approach; ignore the combined effects of chemicals, water quality parameters and species interactions; and do not recognise that the sensitivity of ecological communities can vary in space and time. If we are to halt biodiversity loss in UK rivers while continuing to realise the societal benefits of chemicals, we urgently need more effective methods for assessing, predicting and managing the impacts of chemicals both now and in the future. We aim to deliver and demonstrate a new assessment framework that accounts for the known variability in the physico-chemical and ecological characteristics of a catchment and determines the combined impacts of mixtures of chemicals, bioavailability modifiers and nutrients on the structure and functioning of species assemblages at high spatial resolution. The framework will be developed not only to assess current chemical impacts but also future impacts resulting from changes driven by global megatrends such as climate change, urbanisation and population growth. Using 350 sites in nine Yorkshire river catchments covering different land-uses and pollution pressures, we will develop, test and demonstrate our framework by: 1. prioritising chemicals emitted to UK freshwaters to identify those chemicals in catchments that are driving impacts; 2. characterising current (2002-2022) and future (2061-2080) chemical exposure and general water quality parameter profiles in UK catchments; 3. estimating the effects of chemicals on UK-relevant species under different water quality conditions; 4. predicting the current and future combined effects of chemical mixtures, bioavailability modifiers and nutrients on biodiversity and ecosystem function; and 5. applying the findings to identify interventions to mitigate the impacts of chemicals on biodiversity now and under future climate and catchment change.The understanding and predictive modelling tools developed during this project will inform the development of better plans for adaptation and mitigation of risks associated with declining water quality now and in the future. By working closely with our partners, who include key representatives from the policy (JNCC), regulatory (HSE), major industry (Unilever, UKWIR, Network Rail) and NGO (National Trust, Rivers Trust) sectors, we will provide policy makers with the knowledge and frameworks to realise a paradigm shift towards chemical risk assessment that will protect biodiversity and key environmental functions in areas where they are vulnerable. Regulators and industry alike will be able to focus future investments and effort on scenarios where harm is most likely/actually occurring. Manufacturers of chemicals will be in a better position to produce chemicals that are beneficial to society but which do not negatively impact the natural environment and the ecosystem services that it provides. Only by taking an integrative and system-wide approach adopted in this project will we be able to deliver the Environment Act's aspiration to "reverse the decline in species abundance by the end of 2030".