PEORIA, Ill. — Despite habitat losses and an Asian carp invasion, the Illinois River is experiencing a resurgence in bass fishing.
After the Illinois River hosted three Bassmaster SuperStars events (1993-95), its bass fishery steadily declined.
“It went down dramatically,” said Rob Hilsabeck, Illinois Department of Natural Resources district fisheries biologist. “A lot of it is habitat related. We have a lot of habitat and sedimentation issues and no submerged rooted aquatic plants left in the Illinois River because of the common carp and grass carp.”
The fisheries biologist noted the river’s bass fishery also suffered when “the Asian carp swarm” arrived in the mid-1990s. “The Asian carp is the colonizer of all colonizers,” Hilsabeck said of the invasive species.
Yet despite these hindrances, the river’s bass population has revived thanks to two years of high water levels.
“Historically, what we have seen on the Illinois River with the loss of backwater habitat when we have had high-water springs — basically flood conditions — that have lasted into early to mid-June, then we get a year class of bass produced because they have habitat they can spawn in and that habitat is great for rearing young bass,” Hilsabeck said. “We have had two years in a row of that now.”
“Those high-water springs have dramatically improved some of the sportfish but has also resulted in another year-class of Asian carp so we have to take the good with the bad,” the biologist said.
The floodwaters the last couple years have also produced better year classes of gizzard shad, the main forage of Illinois River bass. The increased forage in the river has resulted in a booming population of 15- to 16-inch bass.
“The bass are just little footballs,” Hilsabeth said. “They are growing extremely fast and have extremely good body conditions.”
An abundance of small Asian carp following a large spawning event in 2014 has also provided some extra forage for sportfish. A recent diet study of 1,500 predatory fish on the Illinois River conducted by Western Illinois University revealed Asian carp were found in the stomachs of largemouth bass and other gamefish. However, Hilsabeth said he doubts the bass population resurgence was influenced by bass feeding heavily on Asian carp.
“The problem with the Asian carp is that they grow so fast they get above a size range where they can be a forage base for sportfish,” he said.
Bass fishing on the river is at a high peak now, but Hilsabeck is unsure about future prospects.
“We are along for the ride on a lot of things we see on the river,” he said. “We see the glimmers of what the bass fishing once was, and now the challenge is that we can’t manage it.”
The highs and lows of the Illinois River will ultimately decide the fate of its bass fishing.
