Field Testing a Metal Bioaccumulation Model for Zebra Mussels

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• 作者：Hudson A. Roditi ; Nicholas S. Fisher ; and Sergio A. Sañ ; udo-Wilhelmy
• 刊名：Environmental Science & Technology
• 出版年：2000
• 出版时间：July 1, 2000
• 年：2000
• 卷：34
• 期：13
• 页码：2817 - 2825
• 全文大小：106K
• 年卷期：v.34,no.13(July 1, 2000)
• ISSN：1520-5851

文摘

A kinetic model of trace element bioaccumulation inzebra mussels, employing experimentally determined traceelement influx and efflux rates following food and waterexposures, was field-tested in the Hudson and Niagara Riversand Lakes Erie and Ontario. Ultraclean measurements ofwater column trace element concentrations in these watersand on suspended particles were used to predict metalconcentrations in zebra mussels that were measuredindependently by the NOAA Mussel Watch program. Fieldconcentrations of Ag, Cd, Cr, and Hg ranged from sub-picomolar (Ag) to low nanomolar (Cr) and displayed partitioncoefficients between particulate and aqueous phases of1-20 × 10⁵ L kg^-1. Despite variation in bioaccumulationfactors (BAF) between locations by up to 6× (for Ag),our model predicted mean body burdens of Ag, Cr, Hg, andSe that differed from measured tissue concentrations atthe same sites by only 30% on average. Cd predictions matchedmeasured values at the two lake sites but exceededmeasurements at the three river sites by 2.6-fold. Furthermore,the model predicted that, under all environmentalconditions likely to prevail in natural waters, Ag, Cd, andHg are predominantly accumulated from ingested particles,that Cr is accumulated mostly from the dissolved phase,and that the relative uptake pathway for Se varieswith environmental conditions. The highest BAF was forCd (15-64 × 10⁴) and the lowest BAFs were for Cr and Se(1.2-2.5 × 10⁴ and 0.5-2.8 × 10⁴, respectively), with Agand Hg being intermediate (2.0-12 × 10⁴ and 1.4-25 × 10⁴,respectively). The good agreement of the model withfield measurements suggests, for these elements, that (a)accumulation of these elements in zebra mussels is infact proportional to influx from food and water (that is, theorganism is not actively regulating internal concentrations),and (b) we can account for the processes governingmetal bioaccumulation in these animals. We concludethat for these elements the zebra mussel will be effectiveas a bioindicator of ambient metals in freshwater systems.