Devilfish Lake

How big is Devilfish Lake?

How deep is Devilfish Lake?

What kind of fish can you catch in Devilfish Lake?

Are there boat launches on Devilfish Lake?

Are there places to eat and drink near Devilfish Lake?

What aquatic invasive species are found in Devilfish Lake?

The 2020 survey of Devilfish Lake was scheduled in the 2018 lake management plan (LMP) revision to determine if the Walleye population goal could be met in the absence of stocking. The long-term goal for Walleye in Devilfish Lake, established in the 1990 LMP, is to maintain a population with a minimum gill net catch of 4.0 fish/net. That goal was met in most surveys done through 2008.

Walleye were present in fair numbers in Devilfish Lake in 2020, with a few larger fish available. However, the 2020 Walleye gill net catch was the lowest ever recorded in this lake, and fell below the normal range for a lake of this type. The 2020 survey gill net catch was the third in a row that failed to meet the long-range goal for the Walleye population, with each catch lower than the previous. The mean weight of Walleye sampled in gill nets in 2020 was the highest observed for this lake, mainly due to a lack of small Walleye in the catch rather than high numbers of large fish.

It is clear from results of the 2016 and 2020 surveys that Walleye natural reproduction has been inadequate, and that a resumption of stocking is needed to meet the goal for this population. Aging results in 2020 indicated only relatively weak natural year classes had been produced since stocking ceased in 2010. Although growth for the youngest Walleye taken in this survey appeared to have been adequate (based on a very small sample size), growth for older fish had been slow. The oldest fish sampled was a 19-year-old fish that was just 15.8 inches long when captured. The largest fish taken (27.6 inches) was 16 years old.

Smallmouth Bass, introduced illegally and first documented in Devilfish Lake in 2008, have become well-established since that time. They appeared to have been abundant in 2020, with fair numbers of fish over 12 inches present. Smallmouth Bass collected in all gears in 2020 ranged in length from 6.8 to 14.0 inches. Smallmouth Bass are considered an undesirable species for Devilfish Lake due to the additional competition they impose on Walleye for limited forage. In some lakes where they have been introduced we have seen the nearly complete elimination of small fish species in the nearshore fish community. In addition, deep drops in the production of young-of-year Walleye and Yellow Perch, with reduced Walleye recruitment, have been seen in some cases.

The White Sucker gill net catch in 2020 fell within the normal range for a lake of this type, and was similar to past catches in Devilfish Lake. A majority of the White Sucker sampled were too large to serve as forage for Walleye. White Sucker can compete with Walleye for some types of invertebrate forage, resulting in slower Walleye growth where White Sucker abundance is high.

Yellow Perch, another species that was introduced illegally into Devilfish Lake, have been sampled periodically since 1989. None were found in 2016 or 2020. Rainbow Smelt and Lake Trout were also present at one time in Devilfish Lake, but neither species has been observed since the 1980s.

In 2016 crews from the 1854 Treaty Authority surveyed a number of Cook County lakes for the presence of Spiny Waterflea. They documented the presence of Spiny Waterflea in Devilfish Lake. The lake is now designated an infested water.

Are there any state parks near Devilfish Lake?