The Trout that Grow on Trees
As the trout fishing season winds down and the weather gets colder, it’s natural to turn our attention towards our other hobbies. The trout, however, swim on in our lakes, streams, and rivers, locked in an upstream battle against habitat loss and climate change. Warming waters, deforestation, and increasing pressure from non-native trout species such as rainbow trout and brown trout have caused a deep decline in Vermont’s native brook trout population. What’s more, these pressures make it much more difficult for you to find native trout on your hook during the fishing season. Fisheries biologists around the state have been working on projects for years to improve the outlook for trout and future fishing seasons to come. For the past several years, they have been cutting trees in upland forests and strategically placing them into streams and rivers to support Vermont’s trout fisheries. But how can cutting down trees on dry land help water dwellers like trout?
To answer that, we need to take a deep dive into the life and habitat of Vermont’s favorite fish. Trout start out as tiny eggs in a redd, or a clearing on the stream-bottom that the female crafts during the spawning season in the fall with her strong tail. As these eggs change over the course of the winter, fueled by the yolk of their egg sac, they develop eyes and become more sensitive to temperature changes and water quality shifts. In the spring, the eggs hatch and continue to feed off of their yolk sac. Trout in this stage are called sac-fry or alvelin. When the yolk sac is empty around February or March, the newly minted fry swim out of the redd to find plankton to eat. As the fry grow larger and spring turns to summer, they settle in shallow pools to hide from prey and feed on small insects and plankton. The fry develop dark vertical stripes on their sides called parr that act as camouflage. Trout in this stage are called fingerlings. They develop into adults throughout the summer and fall, trading their camouflage stripes for their more characteristic orange stomachs and dark green bodies.
Despite how differently trout look and behave in each phase of growth, there is one similarity: trout demand clear, clean, and cold waters in every step of their development. This means that they favor cold, fast-moving streams and rivers and the deep waters of lakes. Trout favor these conditions because colder waters hold more oxygen. As a respite from the harsh strength of quick-flowing streams, however, trout also use deep pools and slow-moving sections to save their energy, find food, and hide from predators. Fallen trees and branches can provide this kind of habitat because they can slow the water speed down while still allowing water to flow through and around them. Branches and trees in streams also attract insects and provide shelter from prey for hungry and vulnerable trout.
This is where fallen trees can help save our trout. Unfortunately, the amount of woody material in our streams and rivers has declined because of deforestation along stream banks. This creates faster-moving waters with lower visibility, which hurts trout development and growth. By returning woody material to our waterways, we create habitat complexity, structure, and stability that will support trout fisheries for years to come. So what can you do to help?
Leave it be! Save your chainsaw for another day and leave fallen trees, branches, and sticks in waterways that run through your property. The trout of Vermont and your fishing pole will thank you!
Plant a tree! Volunteer for a community tree planting along a river bank or start ayour own tree planting project along your own to stabilize our waterways and provide habitat complexity for trout! Contact the Franklin County Conservation District for opportunities: firstname.lastname@example.org
Save our Streams! Take a look at the websites of Vermont Fish and Wildlife, Trout Unlimited, and other organizations with articles full of information about trout in our waterways.