我们介绍了对大沼泽地(佛罗里达,美国)详细介绍了环境变量的差异如何改变食物网中的汞浓度。自1995年以来,已为美国环境保护局的大沼泽地区域环境监测和评估计划(“REMAP”)对整个淡水大沼泽地沼泽中大约1000个随机位置进行了采样。REMAP采样是天气和多媒体,包括丰富的猎物鱼(东部蚊子,Gambusiaholbrooki)作为汞生物积累的指标。放大了我们向大沼泽地国家公园报告的方法,我们在REMAP数据上使用广义Boosted模型来估计蚊子中的汞浓度有多少可以用水质成分或生态健康指标(协变量)来解释。由此产生的模型占环境对蚊子汞变化的影响的60%,一个强大的结果,受干扰的生态系统,如大沼泽地,鉴于其季节性,annual,和空间差异。在八个最有影响力的协变量中,两种是植物和水中的甲基汞,两个可以是营养状态的指标(碱性磷酸酶和叶绿素a),一个可以是雨水传输(电导率)的标志,和两个可能是汞甲基化的推动者(土壤和水中的硫酸盐)。虽然这些协变量的平均个体影响范围从4.0%到10.1%,它们合计占总相对影响的52.2%。低磷的水,但是硫和碳高于背景,通过修改现有的水管理系统,迁入大沼泽地受干扰较少的地区,可能会增加沼泽中汞的生物积累。
We present results of a multiyear study of the Everglades (Florida, USA) detailing how differences in environmental variables can alter mercury concentrations in the food web. About 1000 random locations throughout the freshwater Everglades marsh have been sampled for the United States Environmental Protection Agency\'s Everglades Regional Environmental Monitoring and Assessment Program (\"REMAP\") since 1995. REMAP sampling is synoptic and multimedia, including an abundant prey fish (eastern
mosquitofish, Gambusia holbrooki) as an indicator of mercury bioaccumulation. Amplifying an approach we reported to Everglades National Park, we used Generalized Boosted Models on the REMAP data to estimate how much of the mercury concentration in
mosquitofish could be explained by water quality constituents or indicators of ecological health (covariates). The resulting model accounts for 60% of the environmental influence on variation in
mosquitofish mercury, a robust outcome for a large, disturbed ecosystem such as the Everglades, given its seasonal, annual, and spatial differences. Of the eight most influential covariates, two were methyl mercury in periphyton and water, two can be indicators of trophic state (alkaline phosphatase and chlorophyll-a), one can be a marker of stormwater transport (conductivity), and two can be enablers of mercury methylation (sulfate in soil and water). While these covariates had an average individual influence ranging from 4.0% to 10.1%, together they accounted for 52.2% of the total relative influence. Water with low phosphorus, but with sulfur and carbon above background, moved into the less disturbed parts of the Everglades via modifications to the existing water management system, could increase mercury bioaccumulation in those parts of the marsh.