Are chemical contaminants contributing to the recruitment failure of American eel (Anguilla rostrata)

化学污染物是否会导致美洲鳗（Anguilla rostrata）的招募失败

• 批准号: 350862-2007
• 负责人: Hodson, Peter
• 金额: $ 13.02万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Strategic Projects - Group
• 财政年份: 2009
• 资助国家: 加拿大
• 起止时间: 2009-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=431339
• 关键词: chemical; contaminants; contributing; recruitment; failure

The American eel (Anguilla rostrata) is on the verge of local extinction in L. Ontario, due to a precipitous decline in the arrival of juvenile eels from their spawning grounds in the Sargasso Sea. All L. Ontario eels are female, and they are the largest and most fecund females of the species. Hence, their loss will affect the status of the entire species because eels spawn as only one population. These impacts are already apparent in the closure of the L. Ontario fishery, a reduction by more than 50% of the fishery in Quebec, and declines in many eel fisheries throughout N. America. Chemicals accumulated by eels during their freshwater growth are one likely cause of premature mortality of eel embryos as they migrate from the Sargasso to fresh water. During their growth in fresh water, eels become top predators, accumulating compounds such as PCBs and polychlorinated dioxins to concentrations similar to those causing reproductive failure of lake trout in L. Ontario. Our objectives are to evaluate if eels accumulate sufficient chemical contaminants during their growth and maturation to cause embryo toxicity, and to estimate when contaminants might have affected eel recruitment. Our team of university and government scientists, including colleagues in the US and Europe, will collect fresh and archived samples of eels from reference and contaminated ecosystems. The eels will be analyzed for concentrations of chemicals known to be embryo-toxic, such as chlorinated and brominated organic compounds, selenium, and alkyl tin. The toxicity of extracted chemicals will be assessed with a battery of tests using fish embryos and fish cells in culture. The inclusion of archived samples and an extensive literature on chemical effects on other fish species will allow a retrospective assessment of the risks of chemicals to eel reproduction. Using these data, we will advise fisheries managers about the suitability of different habitats for re-stocking with juvenile eels, priorities for chemical controls, and potential hazards to human consumers. Because eels are highly valued and have a long time to maturity (7-30 years), it is essential that this research be done now, to help avoid a complete loss of eels from the Great Lakes.

由于来自马尾藻海产卵地的幼鳗数量急剧减少，安大略省的美洲鳗（Anguilla rostrata）正处于局部灭绝的边缘。所有安大略鳗鱼都是雌性，并且它们是该物种中体型最大、繁殖力最强的雌性。因此，它们的消失将影响整个物种的状况，因为鳗鱼仅作为一个种群产生。这些影响已经在安大略湖渔业的关闭、魁北克省渔业减少 50% 以上以及整个北美许多鳗鱼渔业减少方面显现出来。鳗鱼在淡水生长过程中积累的化学物质可能是鳗鱼胚胎从马尾藻迁移到淡水时过早死亡的原因之一。在淡水中生长期间，鳗鱼成为顶级捕食者，积累多氯联苯和多氯二恶英等化合物，其浓度与导致安大略省湖鳟鱼繁殖失败的浓度相似。我们的目标是评估鳗鱼在生长和成熟过程中是否积累了足够的化学污染物以引起胚胎毒性，并估计污染物何时可能影响鳗鱼的补充。我们的大学和政府科学家团队（包括美国和欧洲的同事）将从参考和受污染的生态系统中收集新鲜和存档的鳗鱼样本。将分析鳗鱼中已知对胚胎有毒的化学物质的浓度，例如氯化和溴化有机化合物、硒和烷基锡。提取的化学物质的毒性将通过一系列使用培养的鱼胚胎和鱼细胞的测试进行评估。纳入存档样本和关于化学物质对其他鱼类影响的大量文献将有助于对化学品对鳗鱼繁殖的风险进行回顾性评估。利用这些数据，我们将就不同栖息地是否适合放养幼鳗、化学控制的优先事项以及对人类消费者的潜在危害向渔业管理者提供建议。由于鳗鱼价值很高且成熟时间较长（7-30 年），因此现在就必须进行这项研究，以帮助避免五大湖鳗鱼完全消失。