Black Carp in Illinois: An invasive threat to native ecosystems

Like many other states, Illinois has faced the challenge of dealing with invasive species, each of which has its own impact on natural ecosystems. One particular concern is the invasion of black carp (Mylopharyngodon piceus), a lesser-known invasive carp species. These bottom-dwelling fish, native to East Asia, pose a unique and severe risk to aquatic ecosystems, especially in the Mississippi River Basin, which includes significant portions of Illinois.

Background: The Black Carp

The black carp, a large, elongated fish, can grow to 5 feet and weigh upwards of 150 pounds. In its native range, which spans rivers in China and Russia, the black carp feeds primarily on mollusks. Its primary diet consists of snails, mussels, and other shelled organisms, which it crushes with powerful pharyngeal teeth. Diet studies have revealed that black carp will also eat multiple invertebrates, often part of the food chain for other native fish. These unique characteristics make the black carp a fascinating yet dangerous invader in non-native ecosystems.

Initially introduced to the United States in the 1970s and 1980s, black carp were brought in as part of efforts to control snail populations in aquaculture ponds, especially in the southern U.S. regions where snails were intermediate hosts for parasites that could harm fish farms. However, as with many non-native species introduced for human purposes, some black carp escaped captivity. Accidental releases from aquaculture facilities or fish farms, exacerbated by flooding events, have allowed black carp to establish wild breeding populations in U.S. rivers.

Black carp can be notoriously difficult for the average angler to identify vs, for instance, a grass carp. The publication “Keep Cool, Call” from USGS has excellent tips to help the average angler identify black carp.

The Spread of Black Carp in Illinois

Illinois, bordered by the Mississippi River to the west and threaded by the Illinois River and other tributaries, finds itself at the heart of the battle against black carp. The Mississippi River Basin, which includes the Illinois River, provides ideal habitat conditions for black carp, particularly its abundance of freshwater mollusks.

Since the first confirmed sighting of black carp in the wild in the U.S. in the early 2000s, their range has steadily expanded. By the 2010s, black carp were reported in Illinois waters. While their populations are not yet as widespread or as well-documented as those of silver or bighead carp, their presence is increasingly concerning due to the distinct threat they pose to native species, particularly freshwater mussels and snails.

Ecological Threats Posed by Black Carp

Black carp are voracious predators of mollusks, posing a severe risk to native mollusk populations. The Midwest, including Illinois, is home to a rich diversity of freshwater mussels, many of which are already endangered or threatened due to habitat destruction, pollution and the invasion of other non-native species like zebra mussels. The arrival of black carp adds another layer of pressure on these species.

Freshwater mussels play a crucial ecological role in rivers and streams. As filter feeders, they help maintain water quality by filtering out algae, plankton and other particles from the water. Their burrowing activity also helps to aerate riverbeds, contributing to overall river health. With black carp feeding on these mussels, there is a risk of significant declines in their populations, leading to cascading effects on water quality, sediment stability and biodiversity.

Black carp’s destruction of native mollusks and overfeeding on invertebrate populations could also affect other species that rely on them for food or as part of the ecosystem. Native fish, birds and other aquatic species may lose a critical food source, further disturbing aquatic ecosystems.

Impact on Illinois’ Fishing Industry

Illinois has a rich history of commercial and recreational fishing. Its waterways, particularly the Kaskaskia, Illinois and Mississippi rivers, are important fisheries contributing to the state’s economy and cultural heritage. However, the introduction of black carp, along with other invasive carp species, poses a definite threat to the ecological balance of these waters. This threat extends to the livelihoods of those who depend on fishing.

Additionally, black carp, like other invasive carp species, have the potential to outcompete native fish for resources. Although black carp primarily feed on mollusks, their presence in rivers could indirectly impact other fish populations by disrupting the food web and altering habitat conditions.

Efforts to Control and Prevent the Spread of Black Carp

State and federal agencies are working to address the threat of black carp in Illinois and other parts of the Mississippi River Basin. These efforts are part of a broader strategy to combat invasive carp species, prevent their spread into the Great Lakes, and reduce their populations in affected areas.

One of the primary methods being explored is using physical barriers, such as electric barriers, to prevent the movement of black carp and other invasive species from the Mississippi River into the Great Lakes. The construction of the Brandon Road Lock and Dam, located on the Des Plaines River near Joliet, is a key component of this strategy. This lock system is a crucial choke point for preventing invasive carp from migrating further into the Great Lakes watershed.

In addition to barriers, state agencies are monitoring efforts to track black carp’s presence and population size in Illinois waters. This includes sampling efforts to detect carp eggs, larvae, and adults and genetic testing of water samples to identify the presence of black carp DNA (a method known as environmental DNA or eDNA).

Control efforts also involve encouraging commercial fishing of invasive carp species. While black carp are not yet as abundant as other invasive carp species, there is growing interest in incentivizing the harvest of invasive carp to reduce their populations. Some companies are exploring using Asian carp for products such as fishmeal, fertilizer and even food. However, some still feel black carp are less desirable for human consumption than other carp species. Those who have eaten black carp generally compare them in taste to grass carp.

Public Awareness and the Role of Citizens

Preventing the further spread of black carp and other invasive species in Illinois is not solely the responsibility of government agencies. Public participation is crucial. Anglers, boaters and other water users play a critical role in preventing the accidental transport of invasive species. By adhering to guidelines such as cleaning boats and equipment before moving between water bodies, properly disposing of bait, and reporting sightings of black carp to local authorities, citizens can actively contribute to the solution. Remember to remove, drain, dry every time. Be a Hero, Transport Zero!

Education campaigns to increase public awareness of invasive species’ dangers are also crucial. USGS has an interactive invasive species database filled with information that is easy for public use. One of the most successful public campaigns has been that of the black carp reward program.

The black carp reward/bounty program, first initiated by Illinois Department of Natural Resources in 2015, has continued to be one of the most successful tools in finding, reporting and data gathering. The program has successfully provided concrete data about the black carp that it continues today.

“This has been a relatively low-cost way to obtain data about black carp in Illinois,” said Brian Schoenung from Illinois Department of Natural Resources, Division of Fisheries. ” It’s much more cost-effective than sending enough fisheries staff and boats to try and find the black carp.”

The most current handout from USGS, “Keep, Cool, Call,” clearly explains how to identify a black carp, who to call, and how to preserve it until a biologist can gather the specimen.

One area that seems to be lacking on the public awareness front is reaching recreational anglers. Duane Chapman, recently retired from USGS, commented that he would like to see informational signs at boat ramps and fishing access areas where known populations of black carp exist.

“I think if we strategically placed this kind of signage with the regulations signs that are at these access areas, we would likely see an increase of folks reporting black carp sightings and catches,” Chapman noted.

Chapman agreed that most black carp submitted for the reward program were caught by commercial fishermen and fewer by recreational fishermen. Most of the recreational samples were from bowfishers, but he noted that some were caught by traditional hook-and-line anglers.

By understanding the risks posed by black carp and other non-native species, Illinois residents can become active participants in protecting their state’s natural resources.

Black carp in Illinois represent a significant ecological and economic threat to the state’s waterways. As these invasive fish spread, they endanger native mollusk and invertebrate populations, disrupt ecosystems, and threaten the state’s fishing industry. While efforts are underway to control their spread and mitigate their impact, the fight against black carp will require sustained commitment from government agencies, scientists and the public. Through this type of coordinated action, Illinois can continue to preserve the health of its rivers and protect its native species from the invasive threat that black carp pose.

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Gretchen Steele hails from Coulterville, Illinois. Steele is a freelance outdoor communicator. Her award-winning work appears as a regular columnist and contributing feature writer for Heartland Outdoors, Illinois Outdoor News and several Illinois newspapers. She enjoys spending her time afield as a volunteer for the Illinois Department of Natural Resources, Delta Waterfowl Foundation, Retrievers Unlimited and the Illinois Federation of Outdoor Resources. She is the President of Missouri Outdoor Communicators and a former board member of Association of Great Lakes Outdoor Writers.