A Novel Testing Paradigm to Identify and Manage Multiple Stressor Impacts on Wildlife

生物多样性正在以惊人的速度下降。多重压力因素正在推动其中许多下降，淡水(FW)生态系统受到的影响尤为严重。短暂性浮游植物(如沼泽、池塘)具有特殊的生物多样性，并高度暴露于不同的环境应激源，但在学术界和监管机构中通常被忽视。至少3.5亿年来，两栖动物一直是这些栖息地的主要动物组成，高度进化到这些生态系统。两栖动物和湿地是全球最受威胁的植物群/生态系统之一，湿地健康是气候危机的关键，因为受人类影响的系统排放的甲烷水平很高。在这里，我们将使用野外和实验室方法，研究环境应激源组合对两栖动物(普通青蛙、临时林蛙)的负面影响，并寻求开发一种生物监测方法来评估这些重要生态系统的健康状况。由于两栖动物是最受威胁的脊椎动物门，该项目与保护优先事项高度相关。将测量野生和笼养蝌蚪的一般健康状况、疾病状况、应激标记和全球基因表达。利用毒理基因组学和生理学改变来评估对蝌蚪的影响，既可以将分子启动事件锚定到下游的生理终点和由此产生的逆境，也可以将这些反应映射到应激源组合。这种映射提供了一种非常新颖的方法，允许识别驱动负面影响的特定应激源及其组合，并广泛适用于整个生物区系。在野生类群和压力源的存在/严重程度之间进行的流域规模的生态流行病学研究往往将污染列为导致FWS负面影响的最重要变量之一。然而，关于污染对环境相关水平和混合物组合的影响的研究很少，特别是在多重应激源的背景下。在这里，污染物混合物配方将直接基于短暂的FWS中测量的水平，并与其他无处不在的应激源(盐度、热浪和/或入侵小龙虾-Pacifasticus leniusculus cue)相结合，所有这些都是与环境相关的水平和组合。这些实验室暴露将是非常新颖的，对于了解多种应激源对栖息在至关重要的短暂FWS中的标志性两栖生物群的真实影响至关重要。它将测试如何最好地利用单一应激源暴露的数据，以使用理论模型预测影响。为此，我们将把新的理论范式应用于数据优势(很少有应激源对观察到的效应做出不成比例的贡献)和负担(总应激源负荷决定效应)-这两个概念具有广泛应用于多应激源科学的巨大潜力。与单端点方法不同，这里我们建议使用生态模型来调查对整个生物体及其种群的影响，以便显著提高这些数据在保护方面的效用。最后，通过移植产卵和对笼养和原生蝌蚪进行采样，将评估幼稚/本地适应的蝌蚪作为评估FW湿地健康状况的生物监测工具的效用。这项工作将解决文献中的一个重要差距，即证明多重应激源的重要性的实地集水区证据与目前有限的基于实验室的证据/理解之间的差距；以及开发一种可实际应用于保护的新的测试范式。研究团队结合了FW生态毒理学、多应激源/混合效应生物学、FW生态学、生态建模、生物信息学和该项目所需的化学方面的卓越经验。此外，项目合作伙伴和支持组织包括一系列利益相关者，他们专注于FW生态系统的健康和减少污染的影响。

Biodiversity is declining at an alarming rate. Multiple stressors are driving many of these declines with freshwater (FW) ecosystems particularly impacted. Ephemeral FWs (e.g. marshes, ponds) are exceptionally biodiverse and highly exposed to varied environmental stressors but are generally overlooked within academia and regulation. Amphibians have been a major faunal component of these habitats for at least 350 million years, being highly evolved to these ecosystems. Amphibians and wetlands are some of the most highly threatened Phyla/ecosystems globally, with wetland health key to the climate crisis, due to the high methane levels emitted from human impacted systems. Using both field and laboratory approaches, here we will investigate the environmental stressor combinations driving negative impacts in amphibians (common frog, Rana temporaria) and seek to develop a biomonitoring approach to assess the health of these vital ecosystems. As amphibians are the most highly threatened vertebrate Phyla, this project is highly relevant to conservation priorities. General health, disease status, stress markers and global gene expression in wild and caged tadpoles will be measured. The use of toxicogenomics and alterations to physiology to assess impacts on tadpoles allows both the anchoring of molecular initiating events to downstream physiological endpoints and resulting adversity, as well as mapping these responses to stressor combinations. This mapping presents a highly novel approach, allowing the identification of specific stressors and their combinations that are driving negative impacts, and is widely applicable across biota. Catchment-scale eco-epidemiological studies between wild taxa and the presence/severity of stressors often rank pollution as amongst the most important variables driving negative effects in FWs. However, studies on effects of pollution at environmentally relevant levels and mixture combinations are scarce, particularly in the context of multiple stressors. Here pollutant mixture formulations will be based directly on measured levels in ephemeral FWs and combined with other ubiquitous stressors (salinity, heat wave and/or invasive crayfish - Pacifasticus leniusculus cue), all at environmentally relevant levels and combinations. These laboratory exposures will be highly novel and of vital importance to understand the true impacts of multiple stressors on iconic amphibian biota that inhabit vital ephemeral FWs. It will be tested how best to utilise data from single stressor exposures, to predict effects using theoretical models. For this, we will apply novel theoretical paradigms to the data - dominance (few stressors contribute disproportionately to observed effects) and burden (total stressor load determines effects) - which have huge potential for wide applicability for multi-stressor science. In contrast to the single-endpoint approach, here we propose to use ecological modelling to investigate effects on whole organisms and their populations in order to drastically improve the utility of these data for conservation. Finally, by transplanting spawn and sampling both caged and native tadpoles, the utility of naïve/locally adapted tadpoles as a biomonitoring tool to assess the health of FW wetlands will be assessed. This work will address an important gap in the literature between field-based catchment-level evidence demonstrating the importance of multiple stressors and the current limited laboratory-based evidence/understanding; as well as developing a new testing paradigm with practical application for conservation. The research team combines excellence in FW ecotoxicology, multiple stressors/mixture effect biology, FW ecology, ecological modelling, bioinformatics and chemistry needed for this project. In addition, the project partners and supporting organisations comprise a range of stakeholders that are focused on the health of FW ecosystems and reducing the impacts of pollution.