State Wildlife Grants support projects that benefit wildlife and their habitats. The goal is to keep species healthy and off the threatened and endangered species list. The department’s effort to restore native landlocked Atlantic salmon populations to Lake Champlain is one project benefiting from the State Wildlife Grant program.
Landlocked salmon were once abundant in Lake Champlain, but habitat degradation and over-fishing destroyed the native population by 1850. Removing migration barriers such as dams and cleaning up Vermont’s rivers has helped the restoration effort. The department has also been stocking Lake Champlain and its tributaries with landlocked salmon.
The Huntington River, a tributary to the Winooski, has been stocked with one-inch salmon fry for several years, but evaluating the success of these stockings has been limited. With funding from the State Wildlife Grant program, fisheries managers now have the opportunity to study salmon movement using a specialized fish trap known as a rotary-screw or auger trap.
The salmon trap consists of two 24-foot floating pontoons between which a revolving mesh-covered cone is suspended. Fish migrating downstream pass through the cone and are collected in a live box at the end. Trapping occurs in May when the juvenile salmon, known as smolts, are migrating downstream towards Lake Champlain.
The trap has provided excellent results, especially when the river flows are steady. In 2008, the trap captured 360 salmon smolts, which translated to an estimated total of more than 2,200 smolts migrating from the river to the lake.
However, Vermont springs are a challenge when rains and snow melt can cause large fluctuations in water flows. In 2011, a chain of thunder storms raced down the Huntington River watershed causing a flash flood that tore the trap from its anchor and sent it down the raging Winooski River.
When the flows receded enough for safe passage, US Fish & Wildlife Service biologist Nick Staats and a summer intern launched kayaks at the mouth of the Huntington and proceeded down the Winooski in search of what remained of the trap.
“Much to our delight, we found the trap 15 miles down the river at a hydroelectric station in Essex,” said Staats. “The facilities staff had rescued it before it floated over the dam.”
The trap was retrieved and safely installed back into the Huntington River. Despite the challenges, the trap has provided valuable information for helping fisheries managers evaluate the best stocking strategy for restoring landlocked salmon to Lake Champlain.
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