High plankton densities reduce mercury biomagnification
High plankton densities reduce mercury biomagnification
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DOI：
10.1021/es0403007
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发表时间：
2005-01-01
影响因子：
11.4
通讯作者：
Folt, CL
中科院分区：
文献类型：
--
作者：
Chen, CY;Folt, CL
这项研究测试的假设，即在浮游生物的密度在湖泊之间的差异，导致汞积累的生物群的显着变化。该研究包括（i）测量和比较浮游植物中总汞浓度的实地项目（0.4-45微米），两种大小级别的浮游动物（45-202和>202 μ m），和鱼类浮游植物和浮游动物密度从20个湖泊在美国东北部和（ii）对美国东北部另外38个EMAP湖泊的鱼类汞负荷和浮游生物密度进行统计分析。我们发现，浮游植物密度与汞浓度呈负相关，浮游植物和他们的主要消费者（小型浮游动物）。我们还发现，浮游动物密度和浮游动物中的汞浓度之间呈负相关关系，在草食性和捕食性鱼类。仅浮游动物密度就可以解释湖泊中捕食性鱼类汞含量变化的40%以上。我们讨论了几种机制来解释浮游生物密度的负相关关系，汞浓度在较低的营养级和生物放大的汞对鱼类。我们的研究结果表明，浮游生物密度的措施，这是相对容易和便宜的估计，可能是有效的预测汞生物放大潜力的湖泊。
This study tests the hypothesis that differences in the densities of plankton across lakes lead to significant variation in Hg accumulation by the biota. The study comprised (i) a field program to measure and compare total Hg concentrations in phytoplankton (0.4-45 mum), two size classes of zooplankton (45-202 and >202 mum), and fish to phytoplankton and zooplankton densities from 20 lakes in the northeastern United States and (ii) a statistical analysis of fish Hg burdens and plankton densities from 38 additional EMAP lakes in the northeastern United States. We found that phytoplankton density was negatively correlated with Hg concentrations within both the phytoplankton and their primary consumers (small zooplankton). We also found a negative correlation between zooplankton density and Hg concentrations in zooplankton and in both herbivorous and predatory fish. Zooplankton density alone explained more than 40% of the variation in predatory fish Hg levels across lakes. We discuss several mechanisms to explain the negative relationship of plankton density to Hg concentrations in lower trophic levels and to the biomagnification of Hg to fish. Our results suggest that measures of plankton density, which are relatively easy and inexpensive to estimate, may be effective predictors of Hg biomagnification potential across lakes.