Besser John M, Ingersoll Christopher G, Brumbaugh William G, Kemble Nile E, May Thomas W, Wang Ning, MacDonald Donald D, Roberts Andrew D
United States Geological Survey, Columbia, Missouri.
Environ Toxicol Chem. 2015 Mar;34(3):626-39. doi: 10.1002/etc.2849. Epub 2015 Feb 10.
Sediment toxicity tests compared chronic effects on survival, growth, and biomass of juvenile freshwater mussels (28-d exposures with Lampsilis siliquoidea) to the responses of standard test organisms-amphipods (28-d exposures with Hyalella azteca) and midges (10-d exposures with Chironomus dilutus)-in sediments from 2 lead-zinc mining areas: the Tri-State Mining District and Southeast Missouri Mining District. Mussel tests were conducted in sediments sieved to <0.25 mm to facilitate recovery of juvenile mussels (2-4 mo old). Sediments were contaminated primarily with lead, zinc, and cadmium, with greater zinc and cadmium concentrations in Tri-State sediments and greater lead concentrations in southeast Missouri sediments. The frequency of highly toxic responses (reduced 10% or more relative to reference sites) in Tri-State sediments was greatest for amphipod survival (25% of samples), midge biomass (20%), and mussel survival (14%). In southeast Missouri sediments, the frequency of highly toxic samples was greatest for mussel biomass (25%) and amphipod biomass (13%). Thresholds for metal toxicity to mussels, expressed as hazard quotients based on probable effect concentrations, were lower for southeast Missouri sediments than for Tri-State sediments. Southeast Missouri sites with toxic sediments had 2 or fewer live mussel taxa in a concurrent mussel population survey, compared with 7 to 26 taxa at reference sites. These results demonstrate that sediment toxicity tests with juvenile mussels can be conducted reliably by modifying existing standard methods; that the sensitivity of mussels to metals can be similar to or greater than standard test organisms; and that responses of mussels in laboratory toxicity tests are consistent with effects on wild mussel populations.
沉积物毒性测试比较了幼年淡水贻贝（用细纹蚌进行28天暴露试验）的生存、生长和生物量的慢性影响，以及标准测试生物—— 双足类动物（用阿氏摇蚊进行28天暴露试验）和蠓（用稀释摇蚊进行10天暴露试验）在来自两个铅锌矿区沉积物中的反应：三州矿区和密苏里州东南部矿区。贻贝试验在筛分到小于0.25毫米的沉积物中进行，以便于幼年贻贝（2至4月龄）的回收。沉积物主要受到铅、锌和镉的污染，三州矿区沉积物中的锌和镉浓度更高，密苏里州东南部沉积物中的铅浓度更高。在三州矿区沉积物中，高毒性反应（相对于参考地点降低10%或更多）的频率，双足类动物生存（25%的样本）、蠓生物量（20%）和贻贝生存（14%）时最高。在密苏里州东南部沉积物中，高毒性样本的频率，贻贝生物量（25%）和双足类动物生物量（13%）时最高。基于可能效应浓度以危害商表示的贻贝金属毒性阈值，密苏里州东南部沉积物低于三州矿区沉积物。在同时进行的贻贝种群调查中，有毒沉积物的密苏里州东南部地点活贻贝分类单元为2个或更少，而参考地点为7至26个分类单元。这些结果表明，通过修改现有标准方法，可以可靠地对幼年贻贝进行沉积物毒性测试；贻贝对金属的敏感性可能与标准测试生物相似或更高；并且贻贝在实验室毒性测试中的反应与对野生贻贝种群的影响一致。
