A resurvey was conducted at French Lake in 2008 to evaluate the lake's physical, chemical, biological characteristics. A total of 14 different species of fish were sampled, plus hybrid sunfish. Some fishing occurred in the channel between French and Stahl's, but overall fishing pressure was light during this survey. French Lake has a history of taking partial winterkills. The lake was opened to liberalized fishing during the 2007-2008 winter because dissolved oxygen tests indicated that a partial winterkill was likely.
French's lakeshed (690 acres) was dominated by row crop agriculture. The lakeshed to lake ratio was 16:1. Most of the shoreline remained undeveloped, with forest and marshland being the dominant coverage's. Aquatic vegetation was fairly diverse (17 varieties) and plentiful. Coontail, cattail, yellow waterlily, and bladderwort were all ranked as abundant. Detritus was the dominant shoalwater substrate. Dissolved oxygen dropped below 2 mg/l at 12 foot during netting week. Water clarity was good, with a secchi disk reading of 9.3 feet in early July.
Gill nets sampled 4 walleye for a catch rate of 1.0/net, which was within the normal range for this type of lake. The 1998 catch rate was also 1.0/net. Walleye were 13.2 to 24.7 inches long averaging 19.4 inches. Walleye were 3 to 8 years old with 2 year-classes present. Fish were likely migrants from Stahl's Lake.
Gill nets sampled 18 northern pike for a catch rate of 4.5/net, which was within the normal range for this type of lake. The 1998 catch rate was 9.3/net. Northern pike were 21.5 to 35.4 inches long averaging 24.7 inches. Northern pike were 2 to 5 years old with 4 year-classes present. Winter spearers often congregate on French Lake because of the better water clarity.
Gill nets sampled 6 yellow perch for a catch rate of 1.5/net, which was within the normal range for this type of lake. The 1998 catch rate was 6.0/net. Yellow perch were 5.4 to 5.7 inches long averaging 5.7 inches. Yellow perch were 2 to 4 years old with 3 year-classes present.
Spring night-time electrofishing sampled 8 largemouth bass for a catch rate of 13.5/hr of electrofisher on-time. The catch rate in 2003 was 25.3/hr. Catch rates (n=5) from 1991 to 2008 ranged from 0.0 to 25.3/hr, averaging 12.3 inches. Largemouth bass were 13.5 to 17.5 inches long averaging 15.8 inches. Trap nets sampled largemouth bass up to 20.5 inches in length. Largemouth bass were 3 to 9 years old with 5 year-classes present.
Gill nets sampled 3 carp for a catch rate of 0.8/net, which was within the normal range for lakes of this type. The 1998 catch rate was also low at 0.5/net. Carp were 20.3 to 25.6 inches long averaging 23.3 inches. The trap net catch rate was 0.2/net.
Gill nets sampled 20 black bullhead for a catch rate of 5.0/net, which was below the normal range for this type of lake. The 1998 catch rate was 18.8/net. Black bullhead were 9.1 to 11.3 inches long averaging 10.6 inches. The trap net catch rate was 0.2/net, which was the lowest ever recorded at French Lake. Trap nets sampled 7 yellow bullhead for a catch rate of 0.8/net.
Trap nets sampled 2 black crappie for a catch rate of 0.2/net, which was below the normal range for this type of lake. The 2008 catch rate was the lowest ever recorded at French Lake. The 1998 catch rate was 3.4/net. Black crappie were 6.6 to 7.8 inches long averaging 7.2 inches. Gill nets sampled 35 black crappie for a catch rate of 8.8/net, with fish lengths ranging from 5.4 to 7.9 inches. Black crappie were 3 to 5 years old with 3 year-classes present. Growth was slow.
Trap nets sampled 572 bluegill for a catch rate of 63.6/net, which was above the normal range for this type of lake. The 1998 catch rate was 35.9/net. Bluegill were 3.3 to 6.7 inches long averaging 5.2 inches. Bluegill were 2 to 6 years old with 5 year-classes present.
Quarter inch trap nets sampled young-of-the-year: black bullhead (1), black crappie (7), bluegill (1), largemouth bass (20), northern pike (2), and yellow bullhead (3). A tadpole madtom (1) was also trap netted.