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Comparison of two freshwater turtle species as monitors of radionuclide and chemical contamination: DNA Damage and residue analysis
Author(s) -
MeyersSchöne Linda,
Shugart Lee R.,
Walton Barbara T.,
Beauchamp John J.
Publication year - 1993
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620120816
Subject(s) - chelydra , contamination , environmental chemistry , radionuclide , aquatic ecosystem , turtle (robot) , radioactive contamination , biomonitoring , biology , environmental dna , bioaccumulation , ecology , chemistry , biodiversity , physics , quantum mechanics
Two species of turtles that occupy different ecological niches were compared for their usefulness as monitors of freshwater ecosystems where both low‐level radioactive and nonradioactive contaminants are present. The pond slider ( Trachemys scripta ) and common snapping turtle ( Chelydra serpentina ) were analyzed for the presence of 90 Sr, 137 Cs, 60 Co, and Hg, radionuclides and chemicals known to be present at the contaminated site, and single‐strand breaks in liver DNA. The integrity of the DNA was examined by the alkaline unwinding assay, a technique that detects strand breaks as a biological marker of possible exposure to genotoxic agents. This measure of DNA damage was significantly increased in both species of turtles at the contaminated site compared with turtles of the same species at a reference site, and shows that contaminant‐exposed populations were under more severe genotoxic stress than those at the reference site. The level of strand breaks observed at the contaminated site was high and in the range reported for other aquatic species exposed to deleterious concentrations of genotoxic agents such as chemicals and ionizing radiation. Statistically significantly higher concentrations of radionuclides and Hg were detected in the turtles from the contaminated area. Mercury concentrations were significantly higher in the more carnivorous snapping turtle compared with the slider; however, both species were effective monitors of the contaminants.