Hillwalker Wendy E, Jepson Paul C, Anderson Kim A
Oregon State University, Department of Environmental and Molecular Toxicology, 1007 ALS, Corvallis, OR 97331, USA.
Sci Total Environ. 2006 Jul 31;366(1):367-79. doi: 10.1016/j.scitotenv.2005.12.024. Epub 2006 Feb 17.
Selenium (Se) concentrations in water column, sediment and insect compartments were measured over 3 years, in conjunction with selected physicochemical parameters, from lotic (flowing water) and lentic (standing water) sites within a single watershed in Utah, USA. There was evidence for steady-state concentrations of total [Se] in the insects, sediment and detritus, while there was no correlation between these concentrations and the concentration in surface water. Insect Se burden may therefore provide a more accurate measurement of food web accumulation risk than surface water Se concentration. The importance of organism-specific factors on Se transfer to higher trophic levels was revealed by the steady-state Se body burden within the same insect taxa occupying similar environmental compartments in both aquatic systems. Additionally, however, insect Se body burdens, even within similar taxa, were up to 7 times greater within the lentic compared with the lotic system, and site-specific biogeochemical processes are also likely to play a role in the pattern and level of Se accumulation between hydrogeochemically different aquatic systems occurring within the same watershed. Though a site-specific relationship was apparent between organic content and sediment and detritus Se concentrations, this factor did not account for insect Se accumulation differences between the lotic and lentic aquatic habitats. If carbon content is to be used as a site-specific predictor of Se accumulation potential, further investigations of it's influence on the food web accumulation rate of Se are required.
在美国犹他州一个流域内，对水柱、沉积物和昆虫体内的硒（Se）浓度进行了为期3年的测量，并结合选定的理化参数，测量地点包括急流（流水）和静水（死水）区域。有证据表明昆虫、沉积物和碎屑中总硒（Se）的浓度处于稳态，而这些浓度与地表水浓度之间没有相关性。因此，与地表水硒浓度相比，昆虫体内的硒负荷可能更准确地衡量食物网累积风险。在两个水生系统中占据相似环境区域的同一昆虫类群内，稳态硒体负荷揭示了特定生物因素对硒向更高营养级转移的重要性。然而，此外，即使在相似类群中，静水系统中昆虫的硒体负荷比急流系统中高出7倍，特定地点的生物地球化学过程也可能在同一流域内不同水文地球化学性质的水生系统之间硒积累的模式和水平中发挥作用。虽然有机含量与沉积物和碎屑中的硒浓度之间存在明显的特定地点关系，但该因素并不能解释急流和静水水生栖息地之间昆虫硒积累的差异。如果要将碳含量用作硒积累潜力的特定地点预测指标，则需要进一步研究其对食物网硒积累速率的影响。
