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

“在变暖、多重压力的世界中，改变软水、营养贫乏的湖泊的水蚤生态毒理学。”

• 批准号: 155275-2012
• 负责人: Yan, Norman
• 金额: $ 2.4万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=507010
• 关键词: Transforming; daphniid; ecotoxicology; soft; water

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.

湖泊的浮游动物或浮游动物群落本质上是有趣的，它也为人类提供了关键的生态服务，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使我们无法解释当前和预测浮游动物未来的变化。使用水生“白鼠”水蚤的生态毒理学方法应该有助于解释这些变化，但大多数水蚤毒理学都有一个监管重点，旨在确定在标准实验室而不是自然条件下致命的污染物水平。将管制毒理学的结果应用于该领域是有问题的，因为此类工作通常使用在我们的湖泊中没有发现的物种，在我们湖泊的非典型水域中饲养，持续时间错过了初级阶段，通常是最敏感的生命阶段。此外，动物喂养的藻类并不是主要的天然食物，其水平代表着过度受精，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，在反映其化学性质的介质中饲养，在反映初级的持续时间内，我和我的学生将解决这些知识空白，并以此改变盾湖水蚤生态毒理学的实践。我们将确定：1)产生我们湖泊典型繁殖力的喂养计划，2)区分野外典型产卵量影响所需的复制大小，3)天然食品质量对动物生产性能的影响，4)我们湖泊实际克隆和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种水蚤的共同损失。6)确定是否持续的金属毒性是造成萨德伯里湖泊恢复缓慢的原因。我们将改变水蚤生态毒理学的研究方法，这样做可以大大提高我们的能力，既可以解释自然界中发生的复杂变化，也可以预测在我们这个变暖的、人类主导的世界里可能很快会发生什么。生态学家、生态毒理学家以及湖泊和渔业管理者将从这项工作中获得长期的利益。