On February 4, the Forbes Trail Chapter of Trout Unlimited announced it will begin an extensive two-year study of wild trout in Linn Run near Rector, Westmoreland County.
The stream currently supports populations of wild trout in certain sections of the main stream and tributaries. But habitat destruction, climate change and gill lice are threatening their survival.
Trout Unlimited (TU) has received a grant through the Foundation for PA Watersheds to conduct studies to find out what is needed to improve the health of the stream and the coldwater fishery.
TU will be partnering with a number of state and local government agencies and nonprofit organizations to conduct the research.
The result of the studies will be the development of a “Coldwater Conservation Plan” for the entire Linn Run watershed. It will identify impairments, threats to the fish health and what might be done to improve conditions.
Linn Run and the Laurel Highlands had more acid rain research conducted on it in the 80s and 90s than most areas east of the Mississippi. Those studies were conducted by Penn State University along with the DCNR Bureau of Forestry, Fish and Boat Commission, and others.
The pH (measurement of acidity) of the rain and snow over decades was very low, especially during spring runoff, which damaged the fishery. The acidic rain also leached out much of the limestone in upper stretches of the ridges, and with it, its buffering capacity.
After implementing sulfur dioxide and nitrogen oxide controls on both stationary and mobile sources over the past two decades, the direct impact from acid rain is no longer as severe.
And even with diminished buffering capacity, many of the streams are healthy enough to support wild trout fisheries once more.
Forbes Trail has been working on a remediation project on Rock Run, a tributary to Linn Run for the past decade. Using special crushed limestone distributed in its upper reaches, the pH and alkalinity of the stream have improved to the point of sustaining a healthy population of wild brook trout.
That’s the good news. Less encouraging is the damage being done due to climate change, insects damaging the forest canopy, and gill lice.
“Gill lice (Salmincola) are parasitic copepods that attach to and damage the gills of trout. They have been known from Pennsylvania rainbow trout populations since at least the 1980's, but it was not until 2016 that they were discovered on native brook trout,” said Andrea Kautz, Research Entomologist with Carnegie Museum of Natural History at Powdermill Nature Reserve. “It is not yet known what the direct mortality impact these parasites have on our brook trout, but studies here and in other states have shown population decreases in streams with gill lice infestations. This can lead to the replacement of wild brook trout populations with introduced rainbow and brown trout.
“Because of this, it is critical to document all infested streams in the state and work with PFBC to mitigate the spread, as well as conduct further studies to better understand the effects gill lice have on their hosts,” added Kautz.
Among the first studies will be electro-shocking of fish to, among other things, determine the presence of gill lice. The fish will be released unharmed. Other studies include collecting and identifying macroinvertebrates (trout bugs) in the streams that trout eat to survive.
Volunteers will also walk every foot of Linn Run and its tributaries to assess the condition of trout habitat, impairments to fish movement in the streams, and other factors that contribute to stream degradation.
Groups will collect water samples to analyze throughout the watershed to determine which areas might benefit from forms of remediation.
They will also be looking for ways to improve access for fishers and other park visitors.
“Linn Run State Park sees over 200,000 visitors per year” said Corey Snyder, Park Manager. “They include hikers, birders, anglers, classes from local schools and families enjoying picnics at our pavilions. Over the past year during the pandemic, the number of park users skyrocketed. The Park has served as a COVID-19 escape for many local residents and a destination vacation for those wanting to enjoy our cabins in a quiet mountain setting. We have lots to offer!”
Volunteers Needed
The assessments will be conducted in late spring and early fall. There are limited seats available for the public if they would like to volunteer to be trained and participate in these assessments. Most of the work will be done during daylight hours during the week.
To register as a volunteer, please contact Larry Myers at 724-454-9345 or send email to: myersld@comcast.net.
For more information activities, upcoming events and how you can get involved, visit the Forbes Trail Chapter of Trout Unlimited website.
[Posted: February 4, 2021] PA Environment Digest
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