By Michael J. Caduto
On hot summer days we are drawn to cool shady shorelines to swim, fish or simply chill out while reading a good book or sharing a cookout with family and friends. Many people, in an attempt to get closer to the waters they love, remove the natural shoreline vegetation. But cutting and mowing down to the water’s edge is tantamount to killing the goose that laid the golden egg, for those environments are the very reason that the clean, clear waters exist in the first place.
The bankside riparian habitats of rivers, streams, lakes and ponds are critical boundaries between uplands and open water. Steep riparian habitats may be only 50 to 100 feet wide, but gently sloping shores along broad lakes and meandering rivers are lined with intermittently flooded meadows, swamps and bogs that can span thousands of feet. These ecological transition zones form essential habitat for plants and animals, providing food, cover and water, along with places for resting, breeding and raising young. In addition to harboring beaver, mink, muskrat, otter, heron, woodcock, yellow warbler, wood duck and others, riparian habitats support plants useful to people and wildlife alike, from red and silver maple to willow, alder, blueberry, cranberry, groundnut, cattail, Joe-Pye weed and arrowhead.
During spring melting and periods of heavy rain, the plants and soils of riparian wetlands store excess runoff, which then flows slowly into surrounding waters. This reduces flooding, allows silt to settle before entering waterways and decreases peak flood levels. It also reduces scouring from water and ice along riverbanks. From 50 to 100 percent of sediment settles out and is filtered as runoff passes through a healthy riparian zone. When water meanders through wetlands, it also percolates and recharges groundwater.
Riparian environments are buffers that protect bodies of water from shoreline disturbance. Soil particles, plant litter, roots and bacteria absorb 80 to 90 percent of nutrient runoff and pesticides before these enter surface waters and aquifers. Roots bind soil in place, preventing erosion. Overhanging branches cast shade essential for trout and other cool-water species. Autumn leaves provide food for aquatic insects. Fallen tree trunks and branches create habitats for insects, trout and other wildlife. Flowing water is churned up by these obstacles and enriched with oxygen.
Riparian environments perch precariously between humankind and aquatic ecosystems and are easily disturbed or destroyed. Forestry and construction projects that remove trees cause shorelines to slump. Plowing to the water’s edge or grazing animals along the banks creates erosion. Such impacts are compounded when runoff carries nutrients from manure and fertilizers plus toxins from pesticides. Mowing lawns down to the shoreline eliminates habitat and allows lawn chemicals to flow directly into the water.
These activities enable waves and currents to remove soil from lakeshores and riverbanks. Silt can bury the gravels of spawning grounds, envelop fish eggs and coat the gills of fish and aquatic insects, causing stress and suffocation. When shade from overhanging vegetation is removed, water heats up and holds less dissolved oxygen. This creates unfavorable conditions for trout and their favorite foods, such as stoneflies. Nutrients that enter waterways from eroded soil and fertilizer promote algal blooms, whose decay further depletes oxygen levels.
Destroying riparian buffers also takes an economic toll. Streams and rivers that flow through denuded shorelines remove tons of soil, washing away acres of valuable farmland. Floodwaters rise faster and crest higher—inundating properties downstream and undermining roads and bridge abutments.
What can be done? Wherever shoreline vegetation already exists, nature will do its job if we just let it be. The Connecticut River Conservancy and Vermont Agency of Natural Resources recommend maintaining buffers 50 feet wide to stabilize gradual slopes (100 feet for steep banks); 100 feet wide to protect fish habitat and filter nutrient runoff and pesticides; 150 feet wide to control erosion and sediments; 200 feet wide to mitigate flooding; and 300 to 600 feet wide for optimal wildlife habitat and corridors.
Fences can exclude livestock from riparian habitats. Forestry operations can minimize erosion by limiting stream crossings and using staked hay bales and silt fences. If a shoreline property has eroded and its habitat degraded, the banks can be stabilized and buffers restored with native plants.
In addition to their environmental and economic virtues, riparian habitats are prime areas for fishing, boating, swimming, bird watching and nature photography. They are crucial environments for educational programs and scientific study. And they are of inestimable value for reconnecting with nature and enhancing our aesthetic enjoyment of the outdoors.
Great blue herons depend on riparian environments for food and shelter. Photo credit: Michael J. Caduto
WHAT CAN YOU DO?
- Landowners can find technical expertise and financial assistance for protecting and improving critical riparian habitat. Assistance programs are available from Vermont’s Agency of Agriculture and Department of Environmental Conservation. The U.S. Department of Agriculture offers the Conservation Stewardship Program, Environmental Quality Incentive Program, Agricultural Management Assistance and the Forest Service’s National Best Management Practices (BMP) Program. The U.S. Fish and Wildlife Service runs the Partners for Fish and Wildlife Program.
- Contact your local guardians of riparian buffers to help protect and restore these precious environments, such as the Connecticut River Conservancy, Ottauquechee Natural Resources Conservation District and the Greater Upper Valley Chapter of Trout Unlimited.
This article was adapted with permission from Through a Naturalist’s Eyes: Exploring the Nature of New England by Michael J. Caduto (University Press of New England).