Wood is Good for Backcountry Brook Trout
Vermont Freshwater Fishing
An ambitious habitat restoration project has created excellent backcountry brook trout fishing in northern Vermont
By Jud Kratzer, Fisheries Biologist, Vermont Fish & Wildlife
Any angler who has pursued brook trout in Vermont’s sparkling, icy streams knows good brook trout habitat. Deep water and overhead cover, whether in the form of surface turbulence, overhanging banks, or large pieces of woody material, provide these fish with relatively safe places to watch for passing meals while reducing the chance of becoming a meal themselves.
Vermont has been blessed with hundreds of miles of cold, clean streams that support self-sustaining populations of wild brook trout. Many of these streams offer deep water and overhead cover, while others have room for improvement.
Past land and water use practices have severely degraded brook trout habitat in some streams; for example, brook trout habitat was intentionally destroyed for log-driving purposes. The loggers and river workers had nothing against brook trout, but the large boulders and downed trees that provided good habitat were not conducive to floating rafts of logs from the highlands of Vermont to the sawmills downstream, so they removed many of these obstructions and dynamited boulders that were too big to move. The log-driving days have long since passed, but some streams have been slow to heal. We now know we should not be harvesting trees from stream banks, partly because we want these trees to grow large and fall into the water, where they can provide habitat for brook trout and other aquatic species.
Several streams in northeastern Vermont were especially affected by past logging practices and now have long reaches that are unnaturally wide, shallow, and lacking in cover. The good news is that these streams don’t have to remain like this forever. With a unified goal of reversing some of this legacy damage, the Vermont Fish and Wildlife Department and Trout Unlimited began a partnership in 2009 and have since been joined by the US Fish and Wildlife Service, Weyerhaeuser Company, the Vermont Land Trust (VLT), and the Vermont Housing and Conservation Board (VHCB). The US Fish and Wildlife Service has provided assistance as a willing and helpful landowner and with funds from the Federal Aid in Sportfish Restoration Act. Weyerhaeuser is a private timber company that owns a large portion of forested lands in northeastern Vermont, and VLT and VHCB co-manage the conservation easements on these lands. The early years of this partnership were spent identifying and prioritizing opportunities to improve brook trout habitat, and since 2012, the partners have been actively implementing habitat improvement.
Progress has been good – to date, the partners have improved brook trout habitat in over 13 stream miles by using chainsaws to strategically fell trees into the streams. The intention is to nearly always ensure the trees remain in place, even during floods. If the trees are short relative to the width of the stream (i.e. less than 1.5x stream width), the partners use a machine called a grip hoist to lock felled trees into secure positions. While it would be much faster to perform this work with an excavator or other heavy equipment, the use of muscle power and small machines minimizes the impact to the streambed and banks.
The brook trout are responding. Six years of electrofishing data revealed that brook trout biomass (total weight of the population) has increased an average of 150 percent at treated sites, and the number of brook trout over six inches in length has nearly quadrupled. Brook trout abundance has also increased slightly at untreated sites, which suggests that the woody cover is not just concentrating fish but may be contributing to increased numbers and size of brook trout beyond the areas where habitat has been improved.
Yes, these results are exciting, but before you ask your local fisheries biologist to start adding wood to your favorite stream, consider that this type of habitat improvement work is not appropriate everywhere. Before adding a stick to any of these streams, the Vermont Fish and Wildlife Department and Trout Unlimited spent years determining whether woody habitat was limiting brook trout abundance in these streams. A willing landowner, like Weyerhaeuser, is also a must for this type of project. Ultimately, what we anglers should want are mature streamside forests that naturally add wood on their own.
A longer version of this story was originally printed in the April 20, 2018 issue of On the Water Magazine.
C.S. Shafer wrote, “[The brook trout is] a creature of cold brooks and little singing tributary streams.”