Wood is good for brook trout
Recognizing good brook trout habitat is nothing mysterious or new. In a 1921 issue of Field and Stream, C.S. Shafer wrote “[The brook trout is] a creature of cold brooks and little singing tributary streams. He loves the gentle ripples, deep, dark haunts beneath the roots of overhanging trees, the catacombs of drift piles, the erosion chambers of the banks and the shade of overhanging bushes.” Why is it that brook trout are so attracted to deep water and overhead cover? For the most part, the answer is simply that this is where they feel safe.
As many anglers can attest, brook trout are delicious baked, fried, or grilled, and I think that their many feathered and furred predators would add that they are also good raw, wet, and wriggling. Deep water and overhead cover, in the form of surface turbulence, overhanging banks, or large pieces of woody material provide brook trout with relatively safe places to watch for passing meals while reducing the chance of becoming a meal themselves.
The northeast has thousands 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 that brook trout rely on, 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. Actually, the loggers and river men had nothing against brook trout, but the large boulders and downed trees that provided good habitat were not conducive to floating large rafts of logs from the region’s highlands to the saw mills downstream, so they removed many of these obstructions, even dynamiting boulders that were too big to move.
The log driving days have long since passed, but some streams have been slow to heal. The big boulders will not be growing back any time soon, and streamside forests are still recovering from repeated rounds of clearcutting, a practice which outlived the log drives. We now know that we should not be harvesting trees from the stream bank, partly because we want these trees to get big and fall into our streams, 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 U.S. Fish and Wildlife Service, Weyerhaeuser Company, the Vermont Land Trust (VLT), and the Vermont Housing and Conservation Board (VHCB). The U.S. Fish and Wildlife Service has provided assistance as a willing and helpful landowner and also by providing funds through the Sport Fish Restoration program. Funding from this program supports healthy fisheries, connecting people with nature, and important conservation projects, like this one.
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 improvements.
Progress has been good. To date, the partners have improved brook trout habitat in over 17 stream miles by using chainsaws to strategically drop nearby trees into the streams. The intent is nearly always to have the trees remain in the same place once dropped, even during floods. If the trees are too short to reach the entire width of the stream, the partners use a machine called a grip hoist to lock these 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 impact to the stream bed and banks.
The brook trout are responding. Six years of sampling data has revealed that brook trout abundance has increased an average of 150% at treated sites, and the number of brook trout over six inches in length has nearly quadrupled.
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 would benefit brook trout in these streams. We also worked very hard to ensure that dropped trees would stay in place, and that if they did move, they would not be likely to damage downstream property. A willing landowner, like Weyerhaeuser, is also a must for this type of project. Ultimately, what we anglers should really want are mature streamside forests that will naturally add wood on their own, and once the wood is in the water, we need to leave it there.
