Effects of nutrient cycling on contaminant fate in aquatic food webs

营养循环对水生食物网污染物命运的影响

• 批准号: 312237-2012
• 负责人: Kidd, Karen
• 金额: $ 3.64万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=548684
• 关键词: Effects; nutrient; cycling; contaminant; fate

There is ongoing global concern about increasing anthropogenic releases of mercury (Hg) because it is deposited into aquatic systems, transformed by bacteria to methyl Hg (MeHg), and biomagnified (increases in concentration from prey to predator) through aquatic food chains to concentrations that may be toxic for fish-eating consumers or the fish themselves. Stable nitrogen isotopes (delta15N) are commonly used to understand the relative trophic position of aquatic organisms and the rate at which contaminants such as Hg are transferred through food webs. In diverse ecosystems, mercury concentrations in aquatic biota are significantly and positively related to their delta15N, but the rate (slope) of this transfer varies across systems for reasons that remain unexplained.

由于汞（Hg）沉积到水生系统中，经细菌转化为甲基汞（MeHg），并通过水生食物链被生物放大（从猎物到捕食者的浓度增加），从而达到可能对食用鱼类的消费者或鱼类本身有毒的浓度，因此全球一直对汞（Hg）的人为释放日益增加感到担忧。稳定氮同位素（δ ta15n）通常用于了解水生生物的相对营养地位以及汞等污染物通过食物网转移的速率。在不同的生态系统中，水生生物群中的汞浓度与其δ - 15n显著正相关，但这种转移的速率（斜率）在不同系统之间存在差异，原因尚不清楚。