Blanding’s turtles and groundwater - now published

July 2026 - Now published in Chelonian Conservation and Biology: Groundwater upwelling and Blanding’s turtle (Emydoidea blandingii) habitat in constructed and reference wetlands.

ABSTRACT

In a warming climate, organisms may use thermal refuges. One type of refuge in the Temperate Zone is afforded by groundwater upwelling, which cools the microclimate in summer and warms it in winter. To investigate the role that groundwater exchange plays in turtle habitat use, relative to more commonly measured habitat variables, we draw on 9 yrs of detailed habitat and turtle trapping data from Blanding’s turtle (Emydoidea blandingii) core habitats in 6 wetland pools in proximity. Three pools are in preexisting, seminatural, “reference” wetlands, and 3 are in “constructed” wetlands built to offset habitat loss for the threatened Blanding’s turtle, at the site of a school facilities expansion. The site is on gravelly glacial outwash in the town of La Grange, Dutchess County, New York. Quantification of vegetation, benthic organic matter layer thickness, water depth, and groundwater exchange (measured with volumetric seepage meters) was completed in each wetland pool and compared to turtle trap catches in each pool. Rank correlations (q) indicated that maximum groundwater seepage rate was correlated with turtle catch-per-unit-effort as was organic matter thickness in the reference wetlands. We also conducted an organic sediment-removal experiment to investigate the relationship between groundwater exchange dynamics and organic matter thickness. Groundwater exchange rates were either higher or lower following organic matter removal. The organic layer modulates groundwater exchange, increasing spatial homogeneity. We provide preliminary evidence that upward groundwater exchange is related to habitat use by Blanding’s turtle. We suggest that volumetric measurements of groundwater exchange should be more commonly considered in research and conservation of freshwater turtles and other aquatic fauna.'

Peterson, B.E., C.A. Drexler, M. Pregnall Mueller, E. Kiviat, and P.Z. Klos. 2026. Groundwater upwelling and Blanding’s turtle (Emydoidea blandingii) habitat in constructed and reference wetlands. Chelonian Conservation and Biology 25(1):31-40.