Brophy

A targeted survey of nearshore fish species in Brophy Lake was conducted on July 10, 2023, by Index of Biological Integrity (IBI) Program staff. Sampling sites 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 ten sampling stations, but one station was sampled from the boat due soft sediments and dense vegetation. Similarly, a 50-foot seine was used to sample nine stations and site conditions prevented the use of a seine at one station. Nearshore sampling captured twenty species of fish including seven species that are intolerant of disturbance (i.e., Banded Killifish, Blackchin Shiner, Blacknose Shiner, Iowa Darter, Least Darter, Pugnose Shiner, and Rock Bass) and one that is tolerant of disturbance (i.e., Green Sunfish). The nearshore data were combined with gill net and trap net data from a July 2022 survey to describe the fish community and provide a fish-based IBI (FIBI) score. 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. In Minnesota lakes, certain fish species cannot survive without clean water and a healthy habitat (e.g., Blackchin Shiner, Least Darter, and Rock Bass), while other species are tolerant of degraded conditions (e.g., Common Carp and Green Sunfish). 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. Results from this survey will be considered when the biological health of Brophy Lake is assessed during the Long Prairie River Watershed assessment process, which will be completed in coordination with MN Pollution Control Agency.

Lake Brophy is a 289-acre lake located five miles west of Alexandria. A DNR public access is located on the northwest shoreline. Lake Brophy County Park is located near the public access and features a swimming beach, fishing pier, mountain bike trails and an accessible playground. Water clarity was 13 feet during the survey. Clear water and abundant vegetation make Lake Brophy most suitable for bass and panfish. Bluegill relative abundance (10.1/trap net) is slightly lower when compared to similar lakes, or recent surveys. Even though most Bluegill were small, 28% of Bluegill sampled exceeded 7 inches, with the largest being just over 8 inches. Average length between trap nets and gill nets was 6 inches. Few Black Crappie have been sampled in past surveys, likely because of timing of the survey and therefore is not truly indicative of the population. Even though few crappies were sampled, Black Crappie abundance (2.8/gill net) was the highest since 1979. Most fish were young and therefore small, averaging almost 7 inches. The largest crappie sampled was just under 11 inches. Largemouth Bass numbers (38.2/hour of electrofishing) have significantly increased from the 2016 survey when very few bass were sampled. Bass ranged in length from 6 to 19 inches, with an average of 13 inches. Size structure has improved from previous surveys but many small bass are still present. The Northern Pike population (6.5/gill net) is similar to recent surveys in Lake Brophy but has been quite variable in the past. The size structure is poor, with 76% of pike under 22 inches. The largest pike sampled was almost 29 inches. Anglers are encouraged to harvest small Northern Pike. New Northern Pike regulations were implemented in 2018 to increase size structure. Lake Brophy is in the North-central Zone, where all pike from 22 to 26 inches must be released. Anglers can keep 10 pike, but not more than two can be longer than 26 inches. Northern Pike taken by spearing follow the same rules except one pike may be between 22 and 26 inches, or two larger than 26 inches. For more information see: https://www.dnr.state.mn.us/pike/index.html. Walleye are stocked as a ‘bonus' fishery and persist at a low abundance (0.5/gill net). Of the few Walleye sampled, they ranged in length from 18 to 23 inches. Too few Yellow Perch were sampled for any meaningful analysis. Other species sampled include Black Bullhead, Bowfin, Common Carp, Green Sunfish, Hybrid Sunfish, Pumpkinseed, Rock Bass and Yellow Bullhead.

This nearshore survey was conducted during summer 2017 to assess populations of non-game species and small game fish using backpack electrofishing and seining. Backpack electrofishing and/or seining were conducted at 10 stations, representing a variety of habitat types, along the shoreline of Brophy Lake. The survey was conducted during the five-year sampling window for intensive monitoring efforts within the Long Prairie River watershed, and will be contributing to a watershed assessment process in coordination with Minnesota Pollution Control Agency. Fifteen species were collected during this survey. Four species (Banded Killifish, Iowa Darter, Least Darter, and Rock Bass) were considered "intolerant" and only one species (Green Sunfish) was considered "tolerant" based on current tolerance classifications for Minnesota lakes. Nearshore catch data will be used along with gill and trap net catch data to develop an Index of Biotic Integrity (IBI) score, which is indicative of the health of Brophy Lake.

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

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

Brophy has a maximum depth of 44 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Brophy is from 2022.

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