Lakes Grant
Large Scale Lake Planning
LPL-055 (5004-01)
1991
Complete
The Bear Lake surface area is 312 acres and its watershed encompasses 840 acres. The watershed land use is 26% wetlands (219 acres), 69% forests (580 acres), and 5% residential (41 acres). The original landscape of this area was pine forest. Today most of the watershed is still forest. Residential land use is found primarily by the lakes edge and is seasonal in nature. Summer dissolved oxygen (DO) and temperature profiles, complied from the information collected during the summer of 1991, indicate that the deeper water (greater than 20 feet) is nearly depleted of dissolved oxygen. The temperature remained basically the same from top to bottom indicating the lake frequently mixes (polymictic conditions). The average summer secchi disc for 1991 was 3.2 meters (10.4 inches). The Trophic State Index (Carlson's Index) indicates that Bear Lake is a mesotrophic lake, having a value of 41 for water transparency and 48 for total phosphorus. Something in Bear Lake is inhibiting the algae to grow because the water transparency is better than what would be expected in mesotrophic conditions found in Bear Lake. The zooplankton results from August 1984 and from August 1991 indicate that numbers have remained about the same. The zooplankton results from June 1985, 1986, and 1991 appear to have an increase in the numbers per liter. The potential impacts of biomanipulation from the removal of the stunted sunfish are inconclusive. However, water clarity has improved slightly in 1991 compared to 1984. The aquatic vascular plant study conducted in 1991 was compared to one done in 1977. Plant coverage in 1977 was 81% of the lake, and in 1991 it was 89% of the lake. In the 1991 study plants seemed to be rooted in deeper water. Stunted sunfish have been collected and removed from the lake since 1985 in hopes of removing some pressure on the food source so gamefish may have better recruitment. From 1985 - 1988 sunfish were removed and 1989 and 1991 were used as sampling years. The number of bluegills and pumkinseeds over 6 inches seem to be increasing compared to 1985 data. A phosphorus model was run for Bear Lake in 1991. Using the Canfield and Bachmann model a concentration of22 parts per billion (ppb) was predicted. The average total phosphorus concentration found in Bear Lake was 18 ppb.
Grant Awarded
Evaluation of impact of previous stunted panfish removal efforts involving collection of new fish survey information using 10 fyke nets for 5 days in June. All fish will be counted and weighed with approximately 10% being individually measured. Fishwill be handled according to DNR instructions. New information will be combined with previous DNR fish surveys and information on panfish and gamefish and when lake district first started removal project.
Monitor Fish Community
Lakes Planning Grant
Monitor Fish Community
Monitor Water Quality or Sediment
Nutrient Budget Development
Watershed Mapping or Assessment
Data analysis, report production