The health of America’s rivers has come a long way since Cleveland’s Cuyahoga River caught fire and the Connecticut River — though it never proved combustible — earned the dubious honor of being “the best landscaped sewer in the world.”
A look at most of our local rivers might suggest that the cleanup is complete. However, for those river inhabitants who need water that’s not only clean but cold, there is considerable room for improvement. At the top of that list is the trout – rainbows, browns, and the region’s only native, brook trout. Not only are trout a popular sportfish but also they’re also a good indicator of water quality.
“Trout have a set of habitat requirements that make them the proverbial canary in the coal mine,” said Mike Kline, a river ecologist who works as a planner for Vermont’s Water Quality Division. “They are the top predator and their absence in a river would be like the woods without the catamount or coyote.”
All trout require cold water, and of the three species in New England, the brook trout is most susceptible to high temperatures. More than a day or two at water temperatures above 77 degrees and brookies will go belly up. Rainbows and browns can handle slightly warmer temperatures, but the preferred temperature for all of them is within a few degrees of 60.
Most upland streams have populations of wild trout, usually brookies, because the water stays cool all summer long. These streams, fed by underground springs, generally run through forestland so the sun doesn’t have the opportunity to heat them up. Lowland rivers, however, running through farm fields or along road corridors, heat up quickly and suffer from low water levels and consequently have more trouble sustaining wild trout populations.
Shade makes a big difference. In one experiment, fisheries biologists recorded stream temperatures at the head and the tail of an open meadow and found that after a run of only 500 feet in the sun, the stream was 11 degrees warmer.
“Leaving a buffer strip is the single most important thing landowners can do to improve or maintain trout habitat,” said Rich Kirn, fisheries biologist for Vermont Department of Fish & Wildlife. “If you have a canopy over your brook, leave it there. If it’s gone, let it grow back. And I’m talking about even the tiny brooks that you can step across and that aren’t big enough to hold trout. The shade keeps the water cool, not just in the brook but in the river that it flows into. Once the water warms up, no amount of shade is going to cool it down. It takes cold water entering the stream to bring the temperature down.”
To visualize a buffer strip, stand on the streambank, turn your back to the stream, and walk five paces away from it, which will carry you 25 feet from the bank. The ground between you and the stream should be covered with brush and trees. There shouldn’t be any roads or trails, temporary or permanent, within that 25-foot strip. Take another five paces and you have the minimum width of protective strip – 50 feet – according to the “Acceptable Management Practices for Maintaining Water Quality on Logging Jobs in Vermont.”
If a lawn or a hayfield encroaches into the buffer strip, it’s time to let it go wild. If necessary, flag the edge of the buffer strip to remind overzealous mowers of the no-cut zone. Many of us have inherited from our European ancestors a love of the park; with its neatly trimmed grass and the occasional round-crowned shade tree, the park brings comfort to those who need to know that the wilderness has been tamed. It fails, however, to do anything for the stream or wildlife that depend on it. Undergrowth is good – it filters runoff and helps stabilize banks.
Livestock also help to tame the land, and they, too, can remove the vegetation so vital to rivers. If you have been pasturing livestock within this 50-foot strip, it’s going to take a sacrifice and some fencing to keep them out. The Natural Resources Conservation Service is in the business of helping landowners in this situation. They have funds available and can help to design an area where livestock can get water without having free access to the buffer strip.
Regeneration doesn’t take long. If you do nothing more than allow nature to take its course, early successional trees and shrubs – poplars, dogwoods, willows, or other quick starters – will be taller than the grass by the end of one growing season. Or you can transplant willows and dogwoods, and they’ll do a nice job of holding the bank while larger trees get established. It’s important to use native vegetation. Contact the Vermont Water Quality Division for its booklet: Native Vegetation for Lakeshores, Streamsides, and Wetland Buffers.