Calvin Keeys
For hundreds of years, people have been moving to the United States and bringing parts of their culture with them. One effect of this is that wildlife is brought over accidentally or purposely and becomes invasive. Invasive species are non-native organisms that cause damage to a new environment by competing against native species for resources and habitat. Even though it is natural for organisms to enter another environment, this is happening more often now than it has in the past due to human actions such as trade, travel, and climate change.
Freshwater ecosystems have a greater biodiversity per surface area than marine and terrestrial ecosystems (Havel et al. 2015). Unfortunately, these environments, especially lakes and streams, have been some of the most affected by invasive species and species loss. Most aquatic species cannot move from one body of water to another and have instead been moved by people for reasons such as accidental releases, aquarium releases, and fishermen dumping bait. As people continue to change the environment and weather, many non-native aquatic species are expected to increase their populations because they can survive in different environmental conditions while many native species cannot. Invasive species are also better at handling increased land use from people such as habitat destruction and pollution. Invasive species in aquatic ecosystems and the control of them have cost the United States approximately $7.7 billion USD.
Invasive fish can wipe out native species and cause irreversible damage to their environments, and some of the most notable examples are specific carp species.
Common carp (Missouri Department of Conservation)
The common carp (Cyprinus carpio) was introduced into the Midwest in the late 1800s primarily as a food fish for growing migrant populations. The popularity of the fish and its ability to live in different water conditions led to the US Commission of Fish and Wildlife stocking carp throughout the country to make up for the declining native fish species that were overfished at the time. Common carp eventually spread to other waters outside of the commission’s control and is now established in rivers and lakes in every state except Alaska. It is an active feeder, disturbing sediments and uprooting plants as it forages. High carp populations can cause a deterioration of water quality and habitat for native fish species under certain conditions, such as smaller water bodies with silty bottoms.
Asian carp species (Tennessee Wildlife Federation)
Asian carp refers to several species of carp: silver (Hypophthalmichthys molitrix), bighead (Hypophthalmichthys nobilis), black (Mylopharyngodon piceus) and grass (Ctenopharyngodon idella) that were introduced in the 1970s to aquaculture ponds and wastewater treatment places in the Southeast to clear weeds and parasites. Asian carp have escaped into the Mississippi River basin by jumping over barriers, intentional release, and through flood events. Asian carp can dominate native fisheries in both abundance and biomass, consuming 5-20 percent of their body weight daily. Their high level of feeding on plankton can outcompete native fish and eliminate the main food source for larval and native planktivorous fish.
They are continuing to make their way up the Mississippi River and its tributaries, the Missouri River and the Illinois River since they are all connected. The Illinois River is connected to the Great Lakes by the Chicago Sanitary and Ship Canal, a manmade connection. The Great Lakes provide a wide range of habitat types that Asian carp can use for spawning, recruitment and maturation. When not feeding on plankton, Asian carp will eat detritus and root in the bottom of protected embayments and wetlands, which could threaten aquatic vegetation that provides spawning habitat for native fish and breeding areas for native waterfowl. Experts are worried that if these fish get into the Great Lakes, they may negatively affect the area’s $7 billion/year fishing industry.
There are a few ways that you can prevent the spread of invasive fish. Learn to identify juveniles and adults. If you catch one while fishing, do not release it and instead contact your nearest fish and game agency or the US Fish and Wildlife Service (703-358-2148) as soon as possible. Only use wild-caught bait fish in waters where they came from. With your help, we can stop this problem from getting worse.
References
“Asian Carp Control | U.S. Department of the Interior.” Doi.gov, Aug. 2018, www.doi.gov/ocl/asian-carp-control-0.
“Asian Carp – New York Invasive Species Information.” Nyis.info, 2024, nyis.info/invasive_species/asian-carp/.
Brown, Kubie. “The American Dream: How Invasive Species Have Created New Fisheries | MeatEater Fishing.” Themeateater.com, MeatEater, 18 Jan. 2023, www.themeateater.com/fish/general/the-american-dream-how-invasive-species-have-created-new-fisheries.
“Common Carp – Mississippi National River & Recreation Area (U.S. National Park Service).” Nps.gov, 2017, www.nps.gov/miss/learn/nature/ascarp_common.htm.
Couch, Claire, et al. “Evaluating the Institutional and Ecological Effects of Invasive Species Prevention Policy: A Case Study from the U.S. Fish and Wildlife Service.” Management of Biological Invasions, vol. 14, no. 2, 2023, pp. 269–88, https://doi.org/10.3391/mbi.2023.14.2.06.
Havel, John E., et al. “Aquatic Invasive Species: Challenges for the Future.” Hydrobiologia, vol. 750, no. 1, 2015, pp. 147–70, https://doi.org/10.1007/s10750-014-2166-0.
“History of Common Carp in North America – Mississippi National River & Recreation Area (U.S. National Park Service).” Nps.gov, 2023, www.nps.gov/miss/learn/nature/carphist.htm.
“Invasive Carp Overview – Mississippi National River & Recreation Area (U.S. National Park Service).” Nps.gov, 2023, www.nps.gov/miss/learn/nature/ascarpover.htm.
Klein, Zachary B., et al. “Suppression of Invasive Fish in the West: Synthesis and Suggestions for Improvement.” North American Journal of Fisheries Management, vol. 43, no. 2, 2023, pp. 369–83, https://doi.org/10.1002/nafm.10827.
Varble, Sarah, and Silvia Secchi. “Human Consumption as an Invasive Species Management Strategy. A Preliminary Assessment of the Marketing Potential of Invasive Asian Carp in the US.” Appetite, vol. 65, 2013, pp. 58–67, https://doi.org/10.1016/j.appet.2013.01.022.
