Resident Fisheries implements beaver dam analogs
BDA structure locations and analogs.
Submitted by ZACHARY WADSWORTH
Shoshone-Bannock Fish & Wildlife Resident Fisheries
FORT HALL — In 2019 the Resident Fisheries Program with cooperation of Watershed Solutions Inc. selected West Fork Bannock Creek as a project site to implement beaver dam analogs (BDA).
Beaver Dam Analogs (BDA) are woody structures that imitate natural beaver dams. They are built in complexes made of two to five individual structures. Stream reaches were assessed and BDA complexes were designed and built to maximize pond habitat that beavers utilize for refuge, and a safe access for forage in areas that provide cover (Bouwes, 2020).
BDA’s were prepared also to enhance habitat for trout in stream and promote healthy growth. These complexes focused more on better connectivity between the stream and surrounding bank area via flooding. It will help minimize the steep banks and create a gradual flood plain. It would also connect historic side channels that have dried up because of the absence of a beaver population. The side channels provide a rearing or “safe zone” for juvenile fish to escape from larger predators. The dams were installed by Tribal Fish & Wildlife employees with a total of 31 BDA’s constructed in West Fork Bannock Creek throughout diverse locations (Bouwes, 2020). BDA’s were constructed with untreated and natural materials to maintain its natural characteristics.
Fish and Wildlife staff build BDA structures.
An increase of the trout population was found not only in the project area for the beaver dam analogs, but overall. The project area consisted of larger fish in pool and many juveniles were observed in stream along the banks under growth.
In 2019 trout sampled in West Fork was 23 trout per 100 meters. 2020 showed an increase to 28 trout per 100 meters. Before implementation of the BDA’s there were 19 trout per 100 meters. Two beavers were released into West Fork in the Fall of 2019 within the project area. One of the goals of the project is to reestablish a beaver population in West Fork Bannock Creek. Reestablishment would create more diversity in habitat as well as increased fish production. It would also increase wetlands habitat for other wildlife to utilize.
The Resident Fisheries Program employees include Hunter Osborne, Resident Fisheries Program Manager/Deputy Director and Zach Wadsworth, Wetlands and Nursery Manager. They would like to thank the Fort Hall Business Council, Chad Colter Fish and Wildlife Director, Boyd Bouwes Watershed Solutions Inc, and tribal staff involved with the project.
Source: Bouwes, B. 2019. 2019 West Fork Bannock Creek Watershed Restoration Design Report. Watershed Solutions Inc. Shoshone Bannock Tribes.
Beaver being released in Bannock Creek.
