Reproductive parameters in female yellow-blotched map turtles (Graptemys flavimaculata) from a historically contaminated site vs. a reference site

Graptemys flavimaculata, the yellow-blotched map turtle, is a long-lived, threatened, species, endemic to the Pascagoula River drainage in Mississippi. During the 1980s, one branch of the drainage (i.e. the Leaf River) was impacted by effluent from a wood pulp processing plant known to contain endocrine disrupters. A decade later, we examined seasonal reproductive parameters (i.e. monthly plasma estradiol-17β (E2), testosterone (T), vitellogenin (VTG) and follicular development) in adult female turtles from historically polluted and reference sites in the drainage to determine if legacy exposure to pollution impacts reproduction . We found no seasonal patterns in E2 or T and these patterns did not differ between sites. However, E2 differed significantly among ovarian stages for the reference, but not pollutant exposed females. A significantly greater percentage of reference site females were able to produce a second clutch than females from the historically polluted site (50% and 17%). Additionally, there was a significant positive correlation between E2 with VTG levels for reference, but not pollutant exposed females. Body and yolk tissue contaminant analysis indicated that exposure to pollutants is presently minimal and unlikely the cause of the reproductive differences observed between sites; instead, differences are potentially due to exposure history.