Title
Fisheries Restoration Potential of the Clark Fork River Superfund Site: Habitat Use and Movement in Relation to Environmental Factors
Abstract
Fish populations in the Upper Clark Fork River were completely decimated in the early 1900s due to the deposition of hazardous mining waste. Improvements in wastewater treatment and mine waste remediation have allowed fish population to return to the river, although in numbers less than 10% of expected carrying capacity. In April 2009, 100 trout were surgically implanted with radio transmitters throughout the Upper Clark Fork River, from Warms Springs to Turah. Transmitters were spatially distributed evenly throughout the study area and species were selected based on relative abundance found in the river: 72 brown trout Salmo trutta, 15 westslope cutthroat Oncorhynchus clarki lewisi, 6 rainbow trout O. mykiss, 6 suspected cutthroat/rainbow hybrids, and 1 bull trout Salvelinus confluentus. An additional 100 trout will be surgically implanted with radio transmitters in the spring of 2010. Radio tagged fish are relocated at least once a week during spring, summer, and fall (more during periods of spawning) and at least twice per month during the winter. Fish will be tracked year round until winter 2011. Using the relocation data, we will identify areas of critical habitat, such as spawning areas, refuge habitat, and over-wintering habitat. Movement patterns will also be analyzed to assess how fish are reacting to the environmental factors unique to the Upper Clark Fork River Basin (pulsed metal events, increased temperature, and others). By identifying the critical habitat of the system, efforts can be made to guide remediation in order to be most effective for fisheries restoration.
Start Date
5-3-2010 12:00 PM
End Date
5-3-2010 2:00 PM
Document Type
Poster
Fisheries Restoration Potential of the Clark Fork River Superfund Site: Habitat Use and Movement in Relation to Environmental Factors
Fish populations in the Upper Clark Fork River were completely decimated in the early 1900s due to the deposition of hazardous mining waste. Improvements in wastewater treatment and mine waste remediation have allowed fish population to return to the river, although in numbers less than 10% of expected carrying capacity. In April 2009, 100 trout were surgically implanted with radio transmitters throughout the Upper Clark Fork River, from Warms Springs to Turah. Transmitters were spatially distributed evenly throughout the study area and species were selected based on relative abundance found in the river: 72 brown trout Salmo trutta, 15 westslope cutthroat Oncorhynchus clarki lewisi, 6 rainbow trout O. mykiss, 6 suspected cutthroat/rainbow hybrids, and 1 bull trout Salvelinus confluentus. An additional 100 trout will be surgically implanted with radio transmitters in the spring of 2010. Radio tagged fish are relocated at least once a week during spring, summer, and fall (more during periods of spawning) and at least twice per month during the winter. Fish will be tracked year round until winter 2011. Using the relocation data, we will identify areas of critical habitat, such as spawning areas, refuge habitat, and over-wintering habitat. Movement patterns will also be analyzed to assess how fish are reacting to the environmental factors unique to the Upper Clark Fork River Basin (pulsed metal events, increased temperature, and others). By identifying the critical habitat of the system, efforts can be made to guide remediation in order to be most effective for fisheries restoration.