Choose another lake


Lake Information

County: Massac

Acreage: 450

Average Depth: 200.13 feet

Shoreline Length: 3.5 miles

Recreational Amenities

Boat Fishing? Unrestricted

Boat Ramps? Yes

Boat Rental? Yes

Skiing? No

Swimming? No

Picnicking? Yes

Camping? No

Maps are not intended for navigation.

There are no zebra mussels in this lake.

Lake Status Summary  ( Full PDF Report )

Click here for a list of all reports.



Fish Status



Bluegill were more abundant in 2016 than in the previous year, but most of these fish were young-of-the-year size and quality in general decreased, as evidenced by the fact that 27% were larger than 6 inches and 18% exceeded 7 inches. Bluegill body condition was excellent.



Channel catfish are generally not a large component of the annual Mermet Lake electrofishing sample, and 2016 was no exception. In fact, only 2 were collected, which represented a decrease compared to the previous year. These fish were in excellent condition and ranged from 24 to 26.5 inches in length. Annual channel catfish stockings help support a fishery which is very popular with the angling public. Site regulation: 6 per day creel.


Very Good

Black crappie were collected at a minimal rate in 2016, which was less than the previous year. Black crappie ranged in size from 8 to 9 inches. White crappie were slightly more abundant than black crappie and were collected at a rate of 8 per hour. The size range of white crappie was 3 to 11 inches, and 50% larger than 8 inches, while 17% were larger than 10 inches in length. Body condition of white crappie was slightly substandard. Crappie weighing more than 2 pounds are regularly reported by Mermet Lake anglers. Site regulation: 25 per day creel.



Largemouth bass were collected at a somewhat substandard rate of 38 per hour in fall 2016, but 69% were larger than 12 inches, 48% were also longer than the old 14 inch minimum size limit, and 10% exceeded the newly implemented length limit of 16 inches (April 1, 2016). Bass condition remained excellent. Site regulation: 16” minimum length limit, 3 per day creel.



Much smaller numbers of redear were included in the 2016 sample compared to bluegill. Mermet redear ranged from 3 to 9.5 inches in length and were in excellent condition.

Location: Mermet Lake is a shallow, 452-acre, IDNR-owned impoundment located in Massac County approximately 10 miles north of Metropolis.

Description: Mermet was originally built as a water supply for flooding adjacent wetland compartments for waterfowl hunting, but sport fish flourished when stocked, and the lake has been managed for fishing for approximately 50 years. Curlyleaf pondweed, an exotic aquatic plant, invaded Mermet in 1999, and has caused occasional summer fish kills since then, but annual herbicide treatments have generally been successful at controlling the impacts of this plant in recent years, allowing the sport fish population to slowly recover.

Additional Lake Information: The outboard motor limit is 10 hp, but boats with larger outboards are allowed to operate at no-wake speed. Mermet Lake is closed to fishing during the duck season.

Site Regulations:
Largemouth bass: 16” minimum length limit, 3 per day creel (effective 4-1-16)
Black and white crappie: 25 per day creel
Channel catfish: 6 per day creel

Fish Attractors:

Contact Information:
Mermet Site Office
IDNR Fisheries Biologist, Luke Nelson

There were 10 tournaments held on this waterbody in 2018.

Species Total Fish Caught
Largemouth Bass 166

Top 5 Largemouth Bass caught on this waterbody in 2018 tournaments:

1     7.36 lbs
2     6.81 lbs
3     6.69 lbs
4     6.64 lbs
5     6.62 lbs

Top 5 Bag Weights of Largemouth Bass caught on this waterbody in 2018 tournaments:

1 136.00 lbs
2 117.56 lbs
3 58.40 lbs
4 47.50 lbs
5 35.24 lbs

Multiple day tournaments are listed with *end date and

Interested in participating in one of these public tournaments? Contact us with tournament ID for more information.

2019-2020 Approved or Pending Tournaments
Start Date ID Approval Ramp Location Bank/Boat
Max Boats Species Youth? Open to Public?
April-0415161ApprovedClub Ramp boat
15Largemouth Bass
April-1114999Approvedwest boat
15Largemouth Bass
May-1614834ApprovedClub Ramp boat
15Largemouth Bass
May-3015162ApprovedClub Ramp boat
15Largemouth Bass