The Nature Conservancy and the RI Department of Environmental Management (DEM) recently constructed a small wood and fiberglass structure at a fork in Gilbert Stuart Brook, closing off a costly detour for migrating river herring.
The structure, known as a picket weir, consists of five removeable grates, resting on wooden abutments and set in the water at a thirty-degree angle. Durable and easy to maintain, it will be stored offsite each year from June to February and then reinstalled in March, just prior to the start of the herring run.
The goal of the project is to prevent river herring from swimming into a historic mill race canal that dates to the mid-1700s. Whenever water flows over Gilbert Stuart dam in the spring – because of heavy rain or the operation of the waterwheel – it creates false attraction to the mill race, which leads to a dead end at the base of the Gilbert Stuart dam. As the water levels recede, the fish become stranded and perish, if not rescued by DEM staff and volunteers.
The picket weir replaces DEM’s longstanding practice of using temporary plastic fencing to deter herring from the mill race. While inexpensive, the fencing trapped debris flowing downstream and was prone to failing during high flows.
Read more about the project here – TNC Closes a “Wrong Turn” for River Herring at Gilbert Stuart Museum