Fisheries Restoration Potential of the Clark Fork Superfund Site: Habitat Use, Movement, and Health of Trout in Relation to Environmental FactorsEPA Grant Number: FP917101
Title: Fisheries Restoration Potential of the Clark Fork Superfund Site: Habitat Use, Movement, and Health of Trout in Relation to Environmental Factors
Investigators: Mayfield, Mariah Pine
Institution: Montana State University - Bozeman
EPA Project Officer: Lee, Sonja
Project Period: September 1, 2010 through August 31, 2013
Project Amount: $74,000
RFA: STAR Graduate Fellowships (2010) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Fellowship - Ecosystem Services: Aquatic Systems Ecology
Fish populations in the Upper Clark Fork River Superfund Site were decimated over large portions of the river in the 1900s due to the deposition of hazardous mining waste. Improvements in wastewater treatment and mine waste remediation have resulted in a rebound of trout populations, although in numbers well below expected carrying capacity. The objective of this study is to identify critical habitat areas, such as spawning sites, refuge areas, and over-wintering habitat, in order to set priorities for trout restoration. Movement patterns will also be analyzed to assess how fish are reacting to the environmental factors unique to the Upper Clark Fork River Basin (combination of heavy metal pulses during storm events and warm summer temperatures).
Mining waste deposition in the Upper Clark Fork River, Montana, decimated fish populations in the early 1900s. Due to remediation, fish have returned, although in numbers less than expected. Radio tagged trout will be monitored to identify critical habitat areas, such as spawning and refuge habitats. Movement patterns will also be analyzed to assess how fish are reacting to the environmental factors unique to the Upper Clark Fork River Basin (heavy metal pulses and poor water quality).
Two hundred trout have been surgically implanted with radio transmitters throughout the Upper Clark Fork River, from Warm Springs to the confluence with the Blackfoot River, a distance of 120 river miles. Transmitters were spatially distributed evenly throughout the study area and species were selected based on relative abundance found in the river. The primary species tagged was brown trout Salmo trutta, although westslope cutthroat trout Oncorhynchus clarki lewisi, rainbow trout O. mykiss, suspected cutthroat/rainbow trout hybrids, and bull trout Salvelinus confluentus were also tagged in reaches where they were present. Radio tagged fish are re-located at least once a week during spring, summer, and fall (more during periods of spawning) and at least twice per month during the winter. Water quality data, such as temperature, dissolved oxygen, conductivity, and turbidity, are also collected throughout the study area in order to determine what environmental factors are contributing to fish movement and habitat use.
Habitat use by radio tagged trout will be analyzed, and critical habitat areas will be determined as restoration priorities. Using the movement and water quality data, the effects of poor water quality on trout behavior will give us a better idea of how mining waste deposition affects trout movement and overall health. Based on previous laboratory studies, it is expected that trout avoidance of increased heavy metal contamination will be observed throughout the study period.
Potential to Further Environmental/Human Health Protection:
This study offers the opportunity to help guide remediation efforts in the Upper Clark Fork River, in order to restore trout populations to expected carrying capacity levels. Results from this study may also be able to help restoration plans in other mine impacted basins. In addition to increasing trout populations, this project will help bring economic development to rural Montana communities, in the form of tourism and fishing industries.