Grantee Research Project Results
2003 Progress Report: Modeling the Individual and Interactive Risks to an Amphibian Population Resulting from Breeding Site Contamination and Terrestrial Habitat Loss
EPA Grant Number: R829087Title: Modeling the Individual and Interactive Risks to an Amphibian Population Resulting from Breeding Site Contamination and Terrestrial Habitat Loss
Investigators: Rowe, C. L. , Hopkins, William A.
Institution: University of Maryland Center for Environmental Science , University of Georgia
EPA Project Officer: Packard, Benjamin H
Project Period: January 1, 2002 through December 31, 2003 (Extended to December 17, 2004)
Project Period Covered by this Report: January 1, 2003 through December 31, 2004
Project Amount: $280,059
RFA: Wildlife Risk Assessment (2001) RFA Text | Recipients Lists
Research Category: Biology/Life Sciences , Ecological Indicators/Assessment/Restoration , Aquatic Ecosystems
Objective:
The overall objective of this research project is to examine the individual and interactive risks associated with aquatic habitat contamination and per capita reduction in terrestrial habitat for a population of eastern narrow mouth toads (Gastrophryne carolinensis) in South Carolina. This objective is being met by incorporating existing data on postmetamorphic traits and data currently being gathered on embryonic and larval traits into stage-based matrix population models. At a reference site, and at a site contaminated by coal combustion residues, we are conducting: (1) site-specific surveys of female fecundity; and (2) experimental exposures of embryos and larvae to conditions representative of those in the field sites. When all survey and experimental data are available, they will be incorporated into stage-based matrix population models to compare and contrast effects of contaminants in the aquatic embryonic/larval environment with per capita habitat reductions in the terrestrial, juvenile/adult environment.
Progress Summary:
All field surveys and experiments with embryos have been completed. One experiment to examine larval survival remains to be completed in Year 3 of the project. Although fecundity did not differ between populations (contaminated = 598 ± 41, reference 670 ± 49 eggs per female [P = 0.71]), females collected from the contaminated site transferred significant concentrations of Se to their eggs (P < 0.001). Hatching success was reduced for eggs from the contaminated site (contaminated = 82 ± 7 %, reference 93 ± 3 % [P = 0.03]). Moreover, 96-hour-old larvae derived from females from the contaminated site displayed a slightly greater frequency of axial malformations and edema than reference larvae (P = 0.018), concomitantly reducing swimming ability (P = 0.007). When hatching success and frequency of abnormalities were combined into a metric of total viable offspring per female, animals from the contaminated site displayed considerable reductions in offspring viability (P = 0.006).
The data collected thus far provide values for fecundity and hatching success for both populations. The experiment on larval survival (metamorphic success) to be completed in 2004 will provide the final data set required to construct the population models. The results of the studies on 96-hour-old larvae suggest that the experiment examining metamorphic success will provide key data that may strongly influence model outputs. The pending experiment with larvae will determine whether chronic exposure throughout larval development influences recruitment of juveniles from the contaminated site.
Future Activities:
We will complete the final experiment on metamorphic success and parameterization of the population models during Year 3 of the project (calendar year 2004). The project will be completed by the end of the project period.
Journal Articles:
No journal articles submitted with this report: View all 2 publications for this projectSupplemental Keywords:
narrow mouth toad, Gastrophryne carolinensis, South Carolina, SC, terrestrial habitat, metamorphic success, coal combustion, fecundity, embryonic development, larvae, juveniles., RFA, Scientific Discipline, Waste, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Aquatic Ecosystems & Estuarine Research, Ecosystem/Assessment/Indicators, exploratory research environmental biology, wildlife, State, Ecological Effects - Environmental Exposure & Risk, Monitoring/Modeling, Aquatic Ecosystem, Habitat, Southeast, Ecology and Ecosystems, Ecological Risk Assessment, Incineration/Combustion, coal combustion wastes, ecological exposure, anthropogenic stress, anthropogenic stresses, predicting risk, stressors, demographic data, contaminants, contaminated habitats, dose-response, endocrine disrupting chemical, amphibians, animal responses, endocrine disruptors, multiple stressors, modeling, amphibian, habitat loss, terrestrial, breeding site contamination, terrestrial habitat loss, anthropogenic, breeding site contamination, Savannah River Site, anthropogenic stressors, contaminant impact, South Carolina (SC), ecosystem stress, contaminant stressors , ecological response, amphibian populationRelevant Websites:
None.Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.