Assessing Contaminant Sensitivity of Endangered and Threatened Species: Toxicant211 Classes

摘要

Under the Federal Insecticide, Fungicide and Rodenticide Act, the Toxic211u001eSubstances Control Act and the Clean Water Act, the U.S. Environmental Protection 211u001eAgency (EPA) is charged with determining if the manufacture, use, or disposal of 211u001ea chemical will present an unreasonable risk of harm to the environment. 211u001eTypically, management decisions are based on protecting populations of organisms. 211u001eHowever, the Endangered Species Act requires that, in some cases, managers must 211u001eestimate the take of individuals to determine if the loss of individuals might 211u001eadversely affect a population of an endangered or threatened (listed) species. 211u001eThe most direct assessment would be to determine the sensitivity of a listed 211u001especies to a particular contaminant or perturbation. However, this direct 211u001eapproach would be time consuming and expensive because it might require 211u001edevelopment of organism culturing and handling procedures, some species may not 211u001ebe amenable to culture, there might be multiple species to be considered, and 211u001ewould be contaminant specific. This research project had two objectives: (1) 211u001edetermine the relative sensitivity to contaminants of listed species using 211u001estandard acute toxicity tests; and (2) determine the degree of protection 211u001eafforded listed fish species through the use of standard species used in whole 211u001eeffluent toxicity tests.