Pearl Lake
Jackson County, MinnesotaHypereutrophic
On the LakeGrade rubric Pearl Lake fails the cutoffs — a TSI of 77 and persistent algal pressure put it in the bottom tier. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.
A TSI above 70 puts Pearl Lake in hypereutrophic territory: visible blooms are common, and clarity rarely climbs even in early summer. Pearl Lake is a shallow lake at 6 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. The lake's 117 acres and 1.9 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Within the 7 graded lakes of Jackson County, Pearl Lake sits at rank 7, near the bottom of the county list.
An invasive species record — bighead carp — has been logged at Pearl Lake; Minnesota PCA maintains the official infested-waters list. Walleye are documented at Pearl Lake, one of 14 fish species on record for the lake. A documented public access point at Pearl Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2023-09-11. Grade methodology: LakeGrade methodology.
Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 1 ft of visibility. Phosphorus level: 152 µg/L. Trophic State Index: 77.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1 ft | F |
| Phosphorus | 152 µg/L | F |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 77 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 6 ft |
| Surface Area | 117 acres |
| Shoreline Length | 1.9 mi |
| Littoral Zone | 100% |
| Public Access | Yes |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Pearl Lake (14-day solunar calendar)
→ Is it safe to eat fish from Pearl Lake? (mercury & PFAS guide)
→ Pearl Lake fishing regulations (limits, seasons, special rules)
Invasive Species
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.057 m/yr | 4 |
| Phosphorus | ↑ Improving | -79 µg/L/yr | 2 |
| Chlorophyll-a | ↓ Declining | +3.51 µg/L/yr | 5 |
Location
County Ranking
Ranked #7 of 7 lakes in Jackson County
Nearby Lakes in Jackson County
More Minnesota Lake Rankings
State Parks Near Pearl Lake
Other Grade F Lakes in Minnesota
DNR Fisheries Survey Summary
6 surveys on file from MN DNR Fisheries. Most recent: 2025-06-30 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Black Bullhead | 192.24 | 0.33 lb |
| Yellow Perch | 9.47 | 0.25 lb |
| Black Crappie | 8.69 | 0.35 lb |
| Walleye | 8.06 | 1.29 lb |
| Bigmouth Buffalo | 5.04 | 3.46 lb |
| Common Carp | 4.11 | 3.67 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Black Bullhead
Yellow Perch
Black Crappie
Walleye
From the 2025-06-30 survey
Pearl Lake is a 117-acre, class 43 lake located in Jackson County approximately 9 miles southwest of the City of Jackson, near the Iowa-Minnesota border. Pearl Lake is shallow with an average depth of 4.0 ft. and a maximum depth of 6.0 ft. Pearl Lake is managed primarily for Black Crappie and secondarily for Northern…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Pearl Lake. 3 reports on file.
- —Fisheries Lake Survey — PearlFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — PearlFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — PearlPublic Water Access Sites · MN DNR LakeFinder
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Lake details from Minnesota DNR LakeFinder
Most recent sample: 2023-09-11
Monitoring stations: 1