Comparison of reproductive parameters in male yellow-blotched map turtles (Graptemys flavimaculata) from a historically contaminated site and a reference site.
From May to September of 1998, we collected monthly plasma samples from male yellow-blotched map turtles captured at two sites in the Pascagoula River drainage, Mississippi. One site (Vancleave) has a documented history of pollution from industrial sources (principally 2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD). Fish consumption advisories at the Vancleave site were lifted in 1996 and current impacts appear minimal. However, the yellow-blotched map turtle, a federally protected species, continues to decline in numbers. To determine if endocrine disruption could be a factor in the low reproductive rates observed in Vancleave turtles, we examined levels of plasma testosterone (T) and estradiol-17beta (E(2)) from males at this site and a second site (Leaksville), which has no known source of industrial pollution. Plasma was also tested for vitellogenin (VTG), which, in males, can be a biomarker of exposure to estrogenic contaminants. No males had detectable plasma VTG nor did mean monthly E(2) levels differ between sites. However, 10% of males from the historically polluted site were found to have high levels of E(2) (equivalent to levels found in females) and T was significantly lower for males captured at this site for 3 of 5 months. Our data suggest that the current impact of contaminants on reproduction in this population is limited. However, a portion of the population may have been affected developmentally, as represented by differences in reproductive parameters detected between sites.
Shelby
J A
JA
Department of Biological Sciences, Auburn University, 331 Funchess Hall, 36849, Auburn, AL, USA.
Mendonça
M T
MT
D000818:Animals; D004785:Environmental Pollutants / Q000009:adverse effects; D004958:Estradiol / Q000097:blood; D005260:Female; D007220:Industrial Waste / Q000009:adverse effects; D008297:Male; D000072317:Polychlorinated Dibenzodioxins / Q000009:adverse effects; D012098:Reproduction / Q000187:drug effects*; D012621:Seasons; D013739:Testosterone / Q000097:blood; D014426:Turtles / Q000502:physiology*; D014819:Vitellogenins / Q000097:blood
D004785:Environmental Pollutants; D007220:Industrial Waste; D000072317:Polychlorinated Dibenzodioxins; D014819:Vitellogenins; D013739:Testosterone; D004958:Estradiol