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LakeQuality

Pearl Lake

F
Grade F — Algae-prone
Algae-prone · #6 of 6 lakes in the county · 1 ft clear · Hypereutrophic · 117 acres
Hypereutrophic

Pearl Lake in Jackson County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 1 ft visibility. Phosphorus: 153 µg/L. Chlorophyll-a (algae): 102.2 µg/L. Maximum depth: 6 ft. Surface area: 117 acres.

Clarity
1 ft
Typical in August
79°F
Max depth
6 ft
Area
117 acres
Type
Hypereutrophic
Trend
Improving
Public access
Yes

Grade F measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Pearl Lake

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FLoon Lake0.9 ft clear · Jackson CountyView →
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Pearl Lake is a 117-acre highly nutrient-loaded hypereutrophic lake in Jackson County, Minnesota with a maximum depth of 6 feet. Water quality is graded F based on 2 sampling years through 2023. Overall water quality is improving over recent sampling years. The lake supports 14 documented fish species including bigmouth buffalo, black bullhead, and black crappie. Public access is available with 1 public boat landing. Compared to the 5 other monitored lakes in Jackson County, Pearl Lake ranks #6 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2023-09-11. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Algae risk

Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom

Compare the safest swimming lakes near Mankato

Get alerts for Pearl Lake

Water Quality Grade: F (Algae-prone)

Very murky, less than 1 ft of visibility. Phosphorus level: 153 µg/L. Chlorophyll-a: 102.2 µg/L. Trophic State Index: 77.

MetricValueGrade
Water Clarity (Secchi Depth)1 ftNot graded
Phosphorus153 µg/LPoor
Chlorophyll-a (Algae)102.2 µg/LPoor
Trophic State Index (TSI)77Hypereutrophic

Very high nutrients, dense algae, poor clarity

Where to stay near Pearl Lake

Compare lakeside cabins, hotels, and vacation rentals near Pearl Lake in Jackson County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Pearl Lake are listed below.

Top-rated places to stay near Pearl Lake

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a whole trip? See where to stay at Minnesota’s top lakes →

Water Temperature

Pearl Lake typically sits around 79°F at the surface in August. Summer average is about 77°F. Usually warmest in Jul (about 79°F) and coldest in May (about 59°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
59°
Jun
73°
Jul
79°
Aug
79°
Sep
72°
Oct
Nov
Dec

Typical surface water temperature by month, from 31 field readings (20172023) via the EPA Water Quality Portal. See the full Pearl Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth6 ft
Surface Area117 acres
Shoreline Length1.9 mi
Littoral Zone100%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
16 sq mi
Elevation
1,404 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Pearl Lake (West)Public

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Pearl Lake

Invasive & Introduced Species

Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.

bighead carpsilver carp

DNR Fisheries Survey Summary

6 surveys on file from MN DNR Fisheries. Most recent: 2025-06-30 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Black Bullhead192.240.33 lb
Yellow Perch9.470.25 lb
Black Crappie8.690.35 lb
Walleye8.061.29 lb
Bigmouth Buffalo5.043.46 lb
Common Carp4.113.67 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

138 fish · 813 in · 2025-06-30
502508910111213

Yellow Perch

3 fish · 610 in · 2025-06-30
210678910

Black Crappie

166 fish · 412 in · 2025-06-30
48240trophy 10456789101112

Walleye

18 fish · 1025 in · 2025-06-30
420trophy 241012141618202224

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…

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Pearl Lake. 3 reports on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Based on 4 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.057 m/yr4
Phosphorus Declining+37.2 µg/L/yr4
Chlorophyll-a Improving-10.75 µg/L/yr4
See year-by-year chart →

EPA Impairment Status

Pearl Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

Nutrients (phosphorus, nitrogen)

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit MN32-0020-00 · Official waterbody report · Matched by proximity (1.7 km)

County Ranking

Ranked #6 of 6 lakes in Jackson County

Nearby Lakes With Higher Grades

Pearl Lake holds Grade F. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.

See full comparison →

Nearby Lakes in Jackson County

Frequently asked questions about Pearl Lake

What is the water quality grade for Pearl Lake?

Pearl Lake in Jackson County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 1 ft visibility. Phosphorus: 153 µg/L. Chlorophyll-a (algae): 102.2 µg/L. Maximum depth: 6 ft. Surface area: 117 acres.

Is Pearl Lake safe to swim in?

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom. Pearl Lake has a water quality grade of F (Algae-prone). Algae concentration (chlorophyll-a) is 102.2 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Pearl Lake?

Pearl Lake typically sits around 79°F at the surface in August, from 31 EPA Water Quality Portal field readings (2017–2023). That is a typical value for the month, not a live reading.

How deep is Pearl Lake?

Pearl Lake has a maximum depth of 6 feet. The lake covers 117 acres.

What fish are in Pearl Lake?

Fish species found in Pearl Lake include bigmouth buffalo, black bullhead, black crappie, bluegill, channel catfish, common carp, freshwater drum, largemouth bass, northern pike, shortnose gar, walleye, white sucker, yellow bullhead, yellow perch. Pearl Lake is located in Jackson County, Minnesota.

Are there boat ramps on Pearl Lake?

Pearl Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Pearl Lake (West). Public access is listed as yes.

Hypereutrophic Lakes in Minnesota

Where this data comes from

30 measurements from 1 monitoring station, 2022–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA30 samples · 2022–2023

Analytical methods

  • Field measurement/observation, generic method
  • Phosphorus by Colorimetry
  • 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.

Other records on this page

Impairment status from EPA ATTAINS 303(d) database

Lake size & watershed from HydroLAKES (HydroSHEDS)

Lake details from Minnesota DNR LakeFinder

Named boat-access points from the USGS National Boat Ramps inventory