"Transforming daphniid ecotoxicology for soft-water, nutrient-poor lakes in a warming, multi-stressor world."

湖泊中的浮游动物或浮游动物群落本质上是有趣的，它还为人类提供关键的生态服务，将食物传递给鱼类，并在此过程中保持水的清澈。然而，最近气候、水化学、食物基础和捕食者的变化正在混淆我们解释当前和预测浮游动物未来变化的能力。利用水生“白鼠”--水蚤--的生态毒理学方法应该有助于解释这些变化，但大多数水生动物毒理学都有一个调节重点，旨在识别在标准实验室而不是自然条件下致命的污染物水平。将调控毒理学的结果应用于这一领域是有问题的，因为这类工作通常使用在我们的湖泊中找不到的物种，这些物种在非典型湖泊的水域中繁殖，持续时间错过原始性，这通常是最敏感的生命阶段。此外，动物被喂养的藻类不是主要的自然食物，其水平通常是过度肥沃的，而不是我们正常的、营养贫乏的水域。使用从我们的湖泊中分离出来的水蚤，在反映它们的化学成分的介质中饲养，在反映初级的持续时间内，我和我的学生将解决这些知识差距，并通过这样做来改变盾牌湖的水蚤生态毒理学的实践。我们将确定：1)产生典型湖泊繁殖力的投喂计划，2)在野外典型幼崽大小下区分影响所需的重复大小，3)自然食物质量对动物性能的影响，4)实际克隆和湖泊物种之间应激源效应的差异，然后5)我们将使用我们的新方法来确定钙和磷的下降是否可以解释我们湖泊中5种爬行动物的共同损失，以及6)确定持续的金属毒性是否导致萨德伯里湖恢复缓慢。我们将改变水蚤类生态毒理学的方法，并通过这样做极大地提高我们解释我们在自然界中发生的复杂变化的能力，并预测在我们这个由人类主导的变暖世界中可能很快发生的事情。生态学家、生态毒物学家以及湖泊和渔业管理者将从这项工作中认识到长期的好处。

The animal plankton or zooplankton community of lakes is intrinsically interesting, and it also provides key ecological services to mankind passing food to fish, and maintaining water clarity in the process. However, recent changes in climate, water chemistry, food base and predators are confounding our ability to explain current and predict future changes in zooplankton. Ecotoxicological methods using the aquatic "white rat", Daphnia, should help explain the changes, but the majority of daphniid toxicology has a regulatory focus, designed to identify levels of contaminants that are lethal under standard lab, not natural conditions. Applying the results of regulatory toxicology to the field is problematic, because such work commonly uses species not found in our lakes, reared in waters not typical of our lakes, for durations that miss primaparity, often the most sensitive life stage. Further, animals are fed with algae that are not the dominant natural food, at levels typifying over-fertilized, not our normal, nutrient-poor waters. Using Daphnia isolated from our lakes, reared in media that reflects their chemistry, over durations reflecting primparity, I and my students will address these knowledge gaps, and in so doing transform the practises of daphniid ecotoxicology for Shield lakes. We will identify: 1) feeding schedules that produce fecundities typical of our lakes, 2) replicate sizes needed to distinguish effects at field-typical clutch sizes, 3) the influence of natural food quality on animal performance, and 4) differences of stressor effects among actual clones and species from our lakes, then 5) we will use our new methods to determine if calcium and phosphorus decline can explain the common loss of 5 daphnid species from our lakes, and 6) to determine whether ongoing metal toxicity is responsible for the slow recovery of Sudbury lakes. We will transform the methods of daphniid ecotoxicology, and in so doing dramatically increase our ability both to explain the complex changes that our occurring in nature, and to predict what may soon happen in our warming, human-dominated world. Ecologists, ecotoxicologists and lake and fisheries managers will realize long-lasting benefits from this work.