DeMontreville

A targeted survey was conducted on DeMontreville Lake July 24-25, 2019 by Fisheries Lake Index of Biological Integrity (FIBI) program staff. Sampling methods targeted nearshore, small-bodied fish and included seining and backpack electrofishing. Ten sampling stations were evenly spaced around the lake and each was sampled by backpack electrofishing and seining with a 50-foot or 15-foot seine, where possible. Backpack electrofishing was completed at all ten stations, but one station was sampled from the boat due to site conditions. A 50-foot seine was used to sample five stations, a 15-foot seine was used at four stations and soft substrates and dense emergent vegetation prevented the use of seines at one site. Nearshore sampling captured 10 native species of fish including one species intolerant of habitat disturbance (Iowa Darter) and one species tolerant of habitat disturbance (Green Sunfish). Data from this targeted nearshore survey is combined with data from a standard gill net survey completed June 2018 and a standard trap net survey completed June 2017 to calculate a Fish-based Index of Biological Integrity (FIBI) score that describes the overall health of the lake. The FIBI uses fish community data to measure a lake's health, and the types of fish species present can help identify stressors that may be negatively affecting the lake environment. In Minnesota lakes, certain fish species cannot survive without clean water and a healthy habitat (e.g. Iowa Darter and Banded Killifish), while other species are tolerant of degraded conditions (e.g. Green Sunfish and Common Carp). The FIBI score, composed of several fish community diversity and composition metrics, indicates the overall health of a lake by comparing it to what is expected for a healthy lake. For additional information on the FIBI, search for "lake index of biological integrity" on the mndnr.gov website. Data from this survey indicates DeMontreville Lake is in good health as indicated by a FIBI score above the impairment threshold for aquatic life use determined for similar shallow lakes. Data from this survey will contribute biological information about the health of the fish community to the Lower St. Croix River Watershed assessment process in coordination with MN Pollution Control Agency.

Lake Demontreville is a 146 acre, class 38 lake with 88% littoral area (15 feet and less) and is located in the City of Lake Elmo, Washington County. Much of the shoreline is developed as single family homes. A Jesuit Retreat Center is on the east shore. There is a public boat launch on the west shore and a limited area of shoreline available for the public to fish from. A navigable channel connects Lake Demontreville to Olson Lake, a smaller 87 acre waterbody with 100% littoral zone. Both of these lakes are meeting MPCA water quality standards for transparency, chlorophyll-a and total phosphorus. Demontreville is considered a deep lake for these standards and in 2018 had secchi depth of 12 feet. Lake Demontreville has Eurasian watermilfoil present in it and an aggressive treatment program is undertaken by the lake association. Largemouth Bass is the primary species managed in Demontreville, with Bluegill the secondary species. Bluegill continue to be present in above average abundance and small size in Demontreville Lake. The average Bluegill sampled in 2018 was 4.8 inches in length. Black Crappies were sampled in below average numbers than is typical for this lake. Black Crappie average length was 7.0 inches. Northern Pike continue to be found in high abundance averaging 21.7 inches. A small number of Largemouth Bass were sampled in the survey but are in above average abundance using gill nets. Largemouth Bass averaged over 15 inches. Other fish sampled in low abundance were Black, Yellow and Brown Bullheads, Yellow Perch and Pumpkinseed and Hybrid Sunfish.

A targeted survey of the nearshore fish community on Lake DeMontreville was conducted on June 16th, 2017 by Fisheries Lake IBI program staff. Sampling stations were evenly spaced around the lake and each was sampled by backpack electrofishing and seining with a 50-foot, where possible. Backpack electrofishing was completed at all ten stations with one site sampled from the boat. A 50-foot seine was used to sample eight stations, soft sediments with abundant emergent vegetation in deep water prevented the use of seines at two sampling sites. Nearshore sampling captured 9 native species of fish. Data from this targeted nearshore survey is combined with data from a standard gill and trap netting survey in June 2018 to calculate a Fish-based Index of Biologic Integrity (FIBI) score that describes the overall health of the lake. The FIBI uses fish community data to measure a lake's health, and the types of fish species present can help identify any stressors that may be negatively affecting the lake environment. The FIBI score, composed of several fish community diversity and composition metrics, indicates the overall health of a lake by comparing it to what is expected for a healthy lake. The FIBI score for Lake DeMontreville based on this survey is above the impairment threshold for aquatic life use determined for similar lakes. Data from this survey will contribute biological information about the health of the fish community to the lower St. Croix River Watershed assessment process in coordination with MN Pollution Control Agency. For additional information on the FIBI, search for "lake index of biological integrity" on the mndnr.gov website.

Based on Minnesota DNR survey data, anglers target Largemouth Bass, Hybrid Sunfish, Northern Pike, White Crappie, and Walleye in DeMontreville. See the full species list above for catch rates, size structure, and quality scores.

Minnesota DNR records list public access for DeMontreville. Check the DNR LakeFinder page for the launch type and directions before you go.

DeMontreville has a maximum depth of 24 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in DeMontreville is from 2018. Surveys this old should be treated with some caution — fish populations change over time.

Yes — DeMontreville has confirmed Eurasian watermilfoil and zebra mussel. Clean, drain, and dry your equipment to avoid spreading invasives to other waters.