ArrayOctober 11, 2019 at 9:05 am
By Fisheries Biologist Kevin Dunham
Rainbow smelt are the preferred forage fish of landlocked salmon. That’s not to imply that other fishes don’t prey on smelt, they certainly do. However, supporting every healthy, robust salmon population is a thriving smelt population. One of the keys to a thriving smelt population in a lake is adequate spawning habitat in the tributaries. Though smelt will use suitable habitat along the shoreline of a lake, without clean, free-flowing shallow riffle spawning habitat, smelt populations may become imperiled.
Deering (Longfellow) Lake in Weston is one such water. This 474-acre lake historically has very good salmon growth thanks to a steady population of smelt. In more recent years, however, routine fishery monitoring work conducted by MDIFW shows a decrease in salmon growth and condition. Smelt production for the lake has suffered due in part to habitat degradation of Deering Brook, the major smelt spawning area for the lake. Through various non-point source issues along and around Rte. 1, a large amount of sediment and debris has entered the brook and, over time, the accumulations have deteriorated smelt spawning habitat. Sediment build-up at the mouth of Deering Brook to the point is affecting the velocity of the brook and backing up water flow.
In 2017, the Maine Department of Transportation (MDOT) repaired the culvert on Rte. 1 at Deering Brook. This increased the water flow and helped flush some of the sediment. However, there remained a large amount of debris in the brook which prevented smelt from reaching spawning habitat. In the spirit of cooperation and reaching a common goal, volunteers from Chiputneticook Lakes International Conservancy (CLIC), a non-profit group heavily involved in conservation issues surrounding the East Grand Lake watershed, joined fisheries biologists from MDOT and MDIFW to clear and remove debris from the brook. This resulted in better access to the brook for smelt, but the accumulated sediments at the mouth of the brook were still seen as an impediment during smelt spawning. We reached out to the Maine Department of Environmental Protection (MDEP) for their assistance and after many on-site meetings with all stakeholders, MDIFW obtained a permit for a rainbow smelt habitat enhancement project at the brook.
The project involves removing a modest amount of accumulated sediment from the mouth of the brook. The MDOT arranged for one of their contractors to complete the project this October. This sediment removal will re-establish the channel of Deering Brook where it flows into the lake, which should result in increased water velocity to facilitate the flushing of future sediment loads and improving brook access for spawning rainbow smelt.
This project would never have been able to move forward without the immense help and support of MDOT’s fisheries biologists, environmental scientists, and engineers. Their willingness to provide resources and technical expertise is greatly appreciated by MDIFW. The cooperation of multiple state agencies, CLIC, and the property owner, fostered a collaborative process from the beginning, which will surely lead to better conditions for smelt, and in turn healthier salmon at Deering Lake.