A Comparison of Metal Accumulation in Arctic and Temperate Marine Organisms

点击翻译按钮获取中文摘要

Abstract OPP-9986069FisherThe Principal Investigator will compare the bioaccumulation of metals and nuclear-waste associated radionuclides by Arctic and temperate populations of three organisms. High concentrations of heavy metals and radionuclides are often observed in terrestrial and aquatic organisms that are key to the livelihood of native human populations. Thus, there may be large sources for these elements in the Arctic and/or efficient accumulation of metals and from the environment by Arctic food chains. The large scale controlled discharge of radioactive materials in the Irish Sea, the North Atlantic, and the Russian Arctic has generated concern about impacts on sensitive commercial and subsistence fisheries. A fundamental assumption behind risk assessments of the danger posed by anthropogenic radionuclides and heavy metals in the Arctic is that bioaccumulation and trophic transfer studies conducted on temperate organisms under temperate conditions are applicable to the Arctic. This study will address this assumption directly and systematically.Standard radiotracer methods of assessing metal accumulation will be used to compare uptake of metals into three species: clams, Macoma balthica; mussels; Mytilis edulis; and brown alga, Fucus vesiculosus. These species are either eaten by humans or organisms important to native diets, or are used extensively in biomonitoring programs. Six radioisotopes will be used: 137Cs, 241Am, 109Cd, 203Hg, 65Zn, and 110mAg. They represent either components of radioactive waste material (131Cs, 241Am, 110mAg and 65Zn) or metals which are found at high levels in the soft tissues of organisms in the Arctic and elsewhere (Ag, Zn, Cd, Hg). These metals also span a wide range in particle reactivity, association with proteins and biological function. The temperature dependence of radionuclide uptake and loss in whole organisms will be directly compared between Arctic and temperate populations of each species.The results of this study will have three applications: 1) the uptake and loss of metals and radionuclides from Arctic organisms will improve assessments of the danger posed to native populations by anthropogenic metals and radionuclides: 2) the results will advance the interpretation of geographic variability in target organism tissues; and 3) the results will help establish a baseline that will improve our understanding of the mechanisms behind the effects of temperature and adaptation on the accumulation of metals in marine organisms.