Ecological factors regulating chemical bioaccumulation and fish consumption advisories

鱼类消费限制对捕鱼活动造成经济限制，并引起公众对环境健康风险和水产资源可持续性的高度关注。甲基汞（MeHg）和多氯联苯（PCBs）是北美发布的大多数鱼类消费建议的原因，尽管这两种污染物在其生产（PCBs）中受到禁止或在商业用途和环境负荷方面受到重大限制。这些污染物在其物理特性、环境归宿和生物累积机制方面表现出差异，但有一个共同的特性，即经历食物网生物放大作用，并产生水生生态系统中观察到的任何环境污染物的最高营养放大因子。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的行为也存在差异，这表明每种化学品以不同的方式对共同的生态过程作出反应。甲基汞和多氯联苯分别被用作鱼类生物能示踪剂，但从未试图将其作为独立的生态示踪剂。在本提案中，我将生成和校准一个共同的生物累积模型，可应用于甲基汞和多氯联苯，以预测每个示踪剂如何对生态系统压力的集合作出反应。研究主题1的研究将侧重于揭示饮食和温度处理组合下鱼类化学毒物的差异，以预测每种示踪剂将如何对食物网结构和环境条件的变化作出反应。第二个研究主题将侧重于鱼类特定生长率的变化，以及蛋白质和脂质库的分隔大小的变化如何调节化学品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的成果，以开发和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。该模型将被用来预测鱼类消费量在五大湖的食物网假设的环境压力。拟议的研究将在本科和研究生阶段培训10名HQP，使他们接触实验方法，使用实验室和围隔实验，实地采样，先进的分析化学和环境建模技术，所有这些技能都是政府和行业的强烈需求。

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.