The Maine Department of Inland Fisheries and Wildlife have been involved in an ongoing lake trout(togue) management study on Munsungan Lake in northern Maine. The fishery has been producing smaller sized togue that appear to be stockpiling. Maine fisheries biologists recently used radio telemetry to identify the trout spawning shoal in the lake which the department had been unable to identify for ~20 years. Once fish were documented to be concentrated in a certain area, a diver was deployed to verify the presence of spawning activity (see photo). There were several shoals within a short distance of each other, but only one large shoal was utilized by the togue in ~6 feet of water. This information will help fishery managers in the region to consider a methodology of removing spawning togue to suppress reproduction in the lake. The possible reason for increased production of smalled sized togue may have resulted from the removal of an old dam downstream that had once raised the lake water level to a point that restricted natural reproduction. Since the dam has gone into disrepair, lake levels may have dropped enough such that the shoal is within the ideal depth range for togue spawning now.
Additionally, they have also been actively involved in a brook trout study on the Rapid River in the Rangeley Lakes region. The river is a tributary to Lake Umbagog on the ME/NH border. Smallmouth bass had illegally been introduced into the lake. Because of the prized wild brook trout fishery in the Rapid River, the department annually monitors brook trout spawning activity in mid-October via SCUBA survey. Numbers and approximate sizes of spawning brook trout are documented at the only two known spawning sites (identified previously through radio telemetry) in the river to evaluate changes overtime following bass introductions. This study is conducted in partnership with Brookfield Renewable Power.
Photos courtesy of Dana DeGraaf, Maine Department of Inland Fisheries and Wildlife