Ecological factors regulating chemical bioaccumulation and fish consumption advisories

鱼类消费建议对捕捞活动施加了经济限制，并引起公众对环境健康风险和水生资源可持续性的高度关注。甲基汞 (MeHg) 和多氯联苯 (PCB) 是北美发布的大部分鱼类消费建议的罪魁祸首，尽管这两种污染物已受到生产禁令 (PCB) 或商业用途和环境负荷的重大限制。这些污染物在物理特性、环境归宿和生物累积机制方面表现出差异，但具有经历食物网生物放大的共同特性，并产生水生生态系统中任何环境污染物观察到的最高营养放大因子（TMF）。然而，即使在生态系统的规模上，甲基汞和多氯联苯在同一环境中也表现出不同的行为，这表明每种化学物质以不同的方式对常见的生态过程做出反应。甲基汞和多氯联苯均已被用作鱼类生物能示踪剂，但从未尝试将其共同解释为独立的生态示踪剂。在本提案中，我将生成并校准一个通用的生物累积模型，该模型可应用于甲基汞和多氯联苯，以预测每个示踪剂对生态系统压力源的反应。研究主题 1 的研究将重点揭示鱼类在饮食和温度处理组合下化学毒代动力学的差异，以预测每种示踪剂对食物网结构和环境条件的变化的反应。第二个研究主题将重点关注鱼类特定生长率的变化，以及蛋白质和脂质库的区室大小的变化如何调节化学浓度并产生生物累积残留物的个体差异。第三个主题将整合主题 1 和 2 的结果，开发并验证适用于甲基汞和多氯联苯的随机、非稳态食物网生物累积模型。该模型将用于预测在假设的环境压力因素下五大湖食物网中的鱼类消费建议。拟议的研究将培训 10 名本科生和研究生水平的 HQP，让他们接触使用实验室和介观实验、现场采样、先进分析化学和环境建模技术的实验方法，以及政府和工业界急需的所有技能。

Fish consumption advisories place economic constraints on fishing activities and generate a high degree of public concern about environmental health risks and sustainability of aquatic resources. Methyl-mercury (MeHg) and polychlorinated biphenyls (PCBs) are responsible for most of the fish consumption advice issued in North America even though both contaminants have been subject to bans in their production (PCBs) or major restrictions in commercial uses and loadings to the environment. These pollutants exhibit differences in their physical properties, environmental fate and mechanisms of bioaccumulation yet have a common property of undergoing food web biomagnification and generate among the highest trophic magnification factors (TMFs) observed for any environmental contaminants in aquatic ecosystems. Yet, even at the scale of ecosystems, MeHg and PCBs show differences in their behavior when present in the same environment suggesting that each chemical responds to common sets of ecological processes in different ways. MeHg and PCBs have each been used as fish bioenergetic tracers but have never been attempted to be co-interpreted as independent ecological tracers. In this proposal I will generate and calibrate a common bioaccumulation model that can be applied to MeHg and PCBs to predict how each tracer responds to sets of ecosystem stressors. Studies in Research Theme 1 will focus on uncovering differences in chemical toxicokinetics in fish under combinations of diet and temperature treatments to predict how each tracer will respond to alterations in food web structure and environmental conditions. The second research theme will focus on changes in specific growth rates of fish and how changes in compartment size of protein and lipid pools regulate chemical concentrations and generate individual variation in bioaccumulated residues. The third theme will integrate results of theme 1 and 2 to develop and validate a stochastic, non-steady state food web bioaccumulation model applicable to MeHg and PCBs. The model will be used to forecast fish consumption advisories in the Great Lakes food webs under hypothetical sets of environmental stressors. The proposed research will train 10 HQP at the undergraduate and graduate levels exposing them to experimental approaches using laboratory and mesocosm experiments, field sampling, advanced analytical chemistry and environmental modelling techniques, all skills that are in strong demand in government and industry.