Projects

Project Summary

The Indiana Geological Survey, in cooperation with the U. S. Fish and Wildlife Service, is investigating the effects of oil- and gas-well effluents on the declines of aquatic biodiversity in the Patoka River watershed. Oil and brine effluents are known to be acutely toxic to crayfish, fish, and mussels. This study will focus on ground-truthing and toxicological analysis that may be essential for protecting the rare Indiana crayfish, which is found only in the Patoka River system. Information gained from this project will identify point sources that cause biological declines, result in direct corrective actions, and provide essential guidance in developing an aquatic ecosystem management plan for protecting all aquatic resources in the Patoka River watershed and the Patoka National Wildlife Refuge (NWR). The IGS Geochemistry Section will provide water quality data for the toxicology studies and for affected sites and point sources where biological declines are documented. This research is funded through the Environmental Contaminants Program of the U. S. Fish and Wildlife Service as an On-Refuge Investigations Sub-Activity. The project began in October 2000 and will continue for three years.

Ecology

The Patoka River is a tributary of the Wabash River that flows through southwestern Indiana. The river once included high biological integrity that provided excellent physical habitat, supporting diverse mussel, crayfish, and fish communities (Hottell, 1978; Simon et al., 1995). However, a 1994 survey of 66 locations concluded that about a third of the streams in the Patoka River watershed were devoid of aquatic life (Simon et al., 1995). The freshwater crayfish community of the Patoka River consists of four extant species (T. Simon, unpubl. data) and includes the main populations of the Indiana crayfish (Orconectes indianensis), once proposed as a candidate for the federal endangered species list. In addition, three mussel species are considered federally endangered, although, the likelihood of their present occurrence in the river is speculative due to the lack of definitive distribution studies.

Environmental Impact

The Patoka River watershed has been affected by acid mine leachate, strip mining, and oil and gas exploration (Corbett, 1969; Allen et al., 1978). Staff from the Patoka River NWR have observed and documented numerous oil spills and breaches of protective levees that have caused fish kills, contamination of the sediments, and chronic impacts to wildlife through the bioaccumulation of heavy metals, loss of sensitive species, and reduction in habitat quality. The principal pathway for oil and brine to enter the Patoka River is the result of poor land management practices including negligence of the retaining levees, spills and poor transport and handling practices, discharge of effluents, and contamination of ground water from byproducts that result from drilling. A recent leak from an oil well on mine land property nearly resulted in the loss of an entire tributary that flows through the Patoka River NWR.

Objectives

Year one fieldwork includes definitive assessments of species distribution at 122 sites in the Patoka River watershed and evaluation of contamination from oil- and gas-well effluent. In addition, year one will include toxicological investigations of sediment and oil field brine using surrogate crayfish (Procambarus clarki) species. Samples that show acutely toxic effects will be further tested during year two. Year two includes toxicological investigations of surrogate crayfish species to evaluate contaminant specific lethal effects (for example, heavy metals or other contaminant byproducts) and a dilution series of water quality and sediment from areas that were contaminated by oil and brine spills and unauthorized discharges. Year three includes completion of outstanding toxicological investigations, including the specific contaminant testing and chemical analyses associated with the toxicological samples, and the preparation and presentation of a final report.

Benefits

Information gained from this project is essential in defining specific causes for the general decline in freshwater aquatic organisms and to any future development of an aquatic ecosystem management plan for the protection of aquatic resources in the Patoka River watershed. Crayfish are restricted movement organisms having a limited home range and are considered good indicators of the health of aquatic ecosystems. They are dependent on good water quality, specific physical habitat conditions, and an environment that will support reproduction. Thus, the information gathered from this contaminant investigation will be valuable for general knowledge of the sensitivity of crayfish communities and could be used to develop biotic indexes for scoring and ranking the overall ecological health of aquatic ecosystems.

References

Allen, J.H., Thomas, T.C., Kelly, R.R., 1978, A survey to determine the extent and environmental effect of derelict lands resulting from the surface extraction of coal. P.L. 62, Acts of 1976, Indianapolis, Indiana: Indiana Dept. Natural Resources, 46 pp.

Corbett, D.M., 1969, Acid mine-drainage problems of the Patoka River watershed, southwestern Indiana, Bloomington, Indiana: Water Res. Research Center, Indiana University, No. 4, 173 pp.

Hottell, H.E., 1978, Fisheries survey of the Patoka River watershed above, in and below Patoka Lake, Indianapolis, Indiana: Indiana Department of Natural Resources, Division of Fish and Wildlife, Fisheries Section, 77 pp.

Simon, T.P., Sobiech, S.A., Cervone, T.H., Morales, N.E., 1995, Historical and present distribution of fishes in the Patoka River basin: Pike, Gibson, and Dubois Counties, Indiana, Proceedings of the Indiana Academy of Science 104: 193-206.

Map of Patoka River watershed showing locations of surface coal mines and oil wells. Click the map to download a full-size version (1,371 KB. Requires Adobe® Acrobat® Reader®. Select the button below if you don't have the reader.)