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|Title:||A field and laboratory study using adenylate energy charge as an indicator of stress in 'Mytilus edulis' and 'Nephtys incisa' treated with dredged material|
|Authors:||Science Applications International Corporation.|
Tetra Tech, Inc.
Environmental Research Laboratory (Narragansett, R.I.)
United States. Environmental Protection Agency.
Field Verification Program (Aquatic Disposal)
Zaroogian, Gerald E.
Rogerson, Peter F.
Johns, D. Michael.
Nelson, William G.
Black Rock Harbor
Water quality bioassay
|Publisher:||Environmental Laboratory (U.S.)|
Engineer Research and Development Center (U.S.)
Abstract: A study was conducted to test the applicability of adenylate energy charge (AEC) and adenine nucleotide pool concentrations as measures of biological response in the blue mussel, Mytilus edulis, and the marine polychaete, Nephtys incisa, after exposure in the laboratory and field to contaminated dredged material from Black Rock Harbor (BRH), Bridgeport, Conn. A second objective was to include field verification of laboratory results, and a third objective was to investigate residue-effect relationships between tissue concentrations of BRH contaminants and AEC and adenine nucleotide pool concentrations. This project was part of the US Environmental Protection Agency/Corps of Engineers Field Verification Program. Biological responses were measured in a laboratory dosing system that provided constant exposure concentrations of suspended BRH sediment ranging from 0 to 10 mg/𝓁 for M. edulis and 0 to 200 mg/𝓁 for N. incisa. In the field, biological responses were measured in both species sampled along a transect of stations at the Central Long Island Sound disposal site. Strong exposure-residue relationships measured in laboratory experiments indicated that selected contaminants in BRH sediments were biologically available. Tissue residue concentrations, particularly of persistent compounds such as polychlorinated biphenyls, were found to be closely related to exposure concentration. This close relationship between exposure concentrations and tissue residues, as defined in laboratory experiments, was used to estimate field exposures based on tissue residues measured in field-collected M. edulis and N. incisa. The field exposures estimated from tissue residues were corroborated using estimates based on water and sediment chemistry. The biological responses evaluated in this report included the adenine nucleotide measures of adenosine triphosphate, adenosine diphosphate, adenosine monophosphate, adenylate pool, and AEC. These responses were measured in M. edulis and N. incisa exposed to BRH sediment in the laboratory and the field. The only significant laboratory response was a reduction in adenylate pool concentration measured in M. edulis at BRH exposure concentrations higher than any estimated exposures in the field. The only significant field responses were station-related changes in all adenylate nucleotide concentrations measured in N. incisa 16 weeks post-disposal and were indicative of nonstressed organisms. This represented an exposure lasting 10 weeks longer than the longest laboratory exposure, which was 6 weeks. The adenine nucleotide pool concentrations in organisms exposed to BRH sediments will respond in a concentration-related manner. However, these responses are relatively insensitive in M. edulis and are related to long exposure periods in N. incisa. The apparent differences between laboratory and field responses for M. edulis and N. incisa could be explained by differences in exposures between the two situations. For M. edulis, the exposures were much higher in the laboratory. For N. incisa, the exposures in the laboratory and the field were comparable, but the field response was significant at 16 weeks post-disposal. This length of exposure far exceeded the length of any laboratory experiments. Adenine nucleotides and AEC are important in energy transformation and in regulation of metabolic processes. Therefore, it is not surprising that responses in adenine nucleotide pools correlate with tissue concentrations of BRH contaminants in exposed organisms. Measurement of the adenine nucleotide concentrations may help to characterize the energy costs incurred by organisms under stressful conditions. NOTE: This file is large. Allow your browser several minutes to download the file.
|Appears in Collections:||Technical Report|