Paleoenvironmental investigation of an emerging stressor to Canadian salmon rivers

对加拿大鲑鱼河流新兴压力源的古环境调查

• 批准号: RGPIN-2015-03784
• 负责人: Kurek, Joshua
• 金额: $ 1.75万
• 依托单位: Mount Allison University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=612569
• 关键词: Paleoenvironmental; investigation; emerging; stressor; Canadian

A long-term perspective is useful to distinguish natural ecosystem variability from human impacts, and to recognize the rates and magnitude of environmental change. Paleolimnology is the science that uses the physical, chemical, and biological information preserved in sediment records to track environmental changes over long periods of time, often decades to millennia. My research program combines a paleolimnological approach and modern ecological sampling to better understand how freshwater ecosystems respond to natural processes and human-caused stressors. This interdisciplinary approach can be a powerful tool to determine cause-and-effect, establish baseline ecosystem conditions, and set realistic recovery goals following the impacts from human activities. My proposed research program aims to understand the causes and effects of nuisance growths (blooms) of the bottom-dwelling alga, Didymosphenia geminata (Didymo), in remote, pristine salmon rivers in western (Vancouver Island, BC) and eastern (Gaspe region of QC and northern NB) regions of Canada. By studying the information preserved in sediment records within regions currently experiencing nuisance Didymo blooms we will be able to assess the long-term environmental drivers that cause blooms to form and proliferate across these ecosystems. This temporal perspective will allow us to determine whether climatic change, nutrients from global atmospheric pollution, or historic land-use practices are impacting freshwaters where Didymo blooms occur. These widespread stressors are believed to create conditions favorable to bloom formation and persistence, although detailed evaluations have not occurred to date. Our approach can recognize whether recent Didymo blooms are unprecedented over the last ~2000 years or whether blooms have occurred in the distant past. We will also conduct a modern ecological study of river habitats in two eastern Canadian rivers by sampling invertebrates, algae, and juvenile Atlantic salmon. This approach will help us to understand how Didymo blooms affect river habitat and ultimately impact the diet of juvenile salmon. At sites with and without Didymo blooms, we will investigate differences in food web structure and the quantity and quality of prey that juvenile salmon consume. A greater understanding of both the causes and effects of Didymo blooms will provide government and ecosystem managers with scientific knowledge to aid in the management of these iconic Canadian salmon rivers experiencing recent benthic algal blooms.

长期的观点对于区分自然生态系统变异性与人类影响的影响很有用，并认识到环境变化的速度和幅度。旧目的学是一种使用沉积物记录中保存的物理，化学和生物学信息的科学，可以在长时间（通常数十年到几千年）中跟踪环境变化。我的研究计划结合了一种古学的方法和现代的生态抽样，以更好地了解淡水生态系统如何应对自然过程和被人为引起的压力源。这种跨学科的方法可以是确定因果关系，建立基线生态系统条件并在人类活动影响下设定现实的恢复目标的强大工具。我提出的研究计划旨在了解西部偏远，原始的原始鲑鱼河（卑诗省，卑诗省）和东部（Gaspe of Eastern（Gaspe of Eastern of）加拿大QC和NB北部地区。通过研究当前遇到滋扰didymo blooms的区域内保存的信息，我们将能够评估导致花朵形成和扩散这些生态系统的长期环境驱动因素。这种时间的观点将使我们能够确定气候变化，全球大气污染或历史性土地利用实践是否会影响didymo Bloom发生的淡水。人们认为这些广泛的压力源会产生有利于开花和持久性的条件，尽管迄今为止尚未进行详细的评估。我们的方法可以认识到最近〜2000年中最近的Didymo Blooms是前所未有的，还是在遥远的过去发生了花朵。我们还将通过对无脊椎动物，藻类和少年大西洋鲑鱼进行采样，对两条加拿大东部河流的河流栖息地进行现代生态研究。这种方法将帮助我们了解Didymo Blooms如何影响河流栖息地，并最终影响少年鲑鱼的饮食。在有或没有Didymo Blooms的场所，我们将研究食品网络结构的差异以及少年鲑鱼消耗的猎物的数量和质量。对Dodymo Blooms的原因和影响的更多了解将为政府和生态系统经理提供科学知识，以帮助管理这些标志性的加拿大鲑鱼河流，并经历了最近的底栖藻类绽放。