Pennsylvania Angler & Boater - March/April 2021 - 42

Protecting Wild Trout

photos-courtesy of Trout Unlimited

by Deborah Weisberg
In 2015, a team of conservationists replaced an old culvert
on Little Lyman Run-a high quality Class A wild trout
stream in Potter County-to enhance the movement of fish.
It was the kickoff of an ambitious program aimed at
making similar upgrades on thousands of streams across
Pennsylvania, where outmoded structures are degrading
habitat and isolating trout.
" Old culverts are a pretty prolific problem, " said Jacob
Tomlinson of Trout Unlimited (TU), one of several
partners in the statewide initiative that also includes the
Pennsylvania Fish and Boat Commission (PFBC), Penn
State University's Center for Dirt and Gravel Road Studies,
and the Western Pennsylvania Conservancy.
" We assessed about 8,000 structures so far and found
that only 20% allow for full passage of trout and other
species, " said Tomlinson, TU's Pennsylvania Coldwater
Habitat Restoration Program Manager.
Many of these culverts were built decades ago with
little regard for aquatic life. Today's flashy storm events-a
consequence of climate change-are overwhelming old
culverts, causing stream bed scouring at entrances and a
plunge pool effect at outlets.
" Trout cannot get to spawning areas or areas of thermal
refuge if flow is moving too fast or high or if it is too

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Pennsylvania Angler & Boater * March/April 2021	

shallow. Fish populations become isolated and lose genetic
viability when a waterway is broken, " said Tomlinson.
Replacing outdated culverts with stream crossings that
allow natural flow can have profound effects on a fishery.
Tracking of pit-tagged Brook Trout on Little Lyman Run
showed free movement plus a significant increase in the
number of redds (egg nests) after the new structures
were installed.
Similar successes are reported by the Western
Pennsylvania Conservancy. " We did a neat one in
Emporium in Salt Run, where a culvert was blocking fish
from their spawning habitat, " said Eric Chapman, the
Conservancy's Director of Aquatic Science. " As soon as
we removed it, fish were swimming a mile upstream. "
Fish-friendly culverts also allow for the dry passage of
amphibians, such as Wood Turtles. " When we talk about
connectivity, it is important to consider many species and
not just trout, " said Chapman.
In many cases, culverts on small streams can be
replaced with timber deck bridges for just $15,000 or
$20,000, although other kinds of structures can cost more.
Funding typically involves multiple private and public
sector partners and requires a long-term commitment
given the sheer number of structures-an estimated
100,000-in Pennsylvania. But, it is identified as a priority
in the PFBC's trout plan, according to Dave Nihart, Chief
of the Fisheries Management Division for the PFBC.
www.fishandboat.com
http://www.fishandboat.com
Pennsylvania Angler & Boater - March/April 2021

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