The Asian Carp Threat in Ohio
Asian carp are a group of invasive species, which have spread in the US through both accidental and purposeful release. There are three species of Asian carps currently present in Ohio’s lakes and rivers: Bighead Carp, Silver Carp, and Grass Carp. Bighead and Silver carp where accidentally released from aquaculture facilities in Arkansas during the 1970s (Freeze and Henderson, 1982) and have spread throughout the Mississippi River Basin, including the Ohio River. Grass Carp on the other hand were stocked to ponds and lakes to control aquatic vegetation growth.
Grass Carp have been previously found in Lake Michigan, Erie, and Ontario. In Ohio, currently only sterilized Grass Carp may be stocked but the process that is utilized is not always 100% effective. New surveys conducted this year by the Ohio Department of Natural Resource have found that Grass Carp are successfully spawning in the Sandusky River, near Lake Erie (Seewer, 2017). This is some of the first evidence that this species can naturally reproduce in the Great Lakes. The expansion of Grass Carp populations has been a concern of fisheries managers throughout the past few decades, because they can consume large quantities of aquatic vegetation. A decline of aquatic vegetation around shorelines and in wetlands surrounding Lake Erie may reduce habitat, impacting native fish species that utilize these areas for food or to spawn. While this species is a pressing worry to Lake Erie and increased efforts for control are currently being developed (Seewer, 2017), the estimated impacts of Bighead and Silver carp are far more concerning (Zhang et al., 2016).
Bighead and Silver carp are both filter feeders, primarily consuming zooplankton (Burke et al., 1986). They are primarily located in and around the Ohio River, but there have been reports that these species have been found in small numbers within Lake Erie. The main concern associated with these species is their ability to grow to large sizes (18-23 kg) in a relatively short amount of time (4-5 years) (Henderson, 1978). Zooplankton are especially important for juvenile fish as well as fish that are important prey species for commercial and sport fish. A model of potential impacts by Zhang et al. (2016) found that these species may be able to alter current food webs, which could affect a 7-billion-dollar annual sport fishery in the Great Lakes (Southwick Associates, 2007).
There are still many unknowns associated with Asian carp’s potential for proliferation within Lake Erie, but significant efforts are underway to develop plans for controlling the spread of these species. More information regarding current regional and national management and control of Asian carp can be found at http://asiancarp.us/documents/2017ActionPlan.pdf and http://asiancarp.us/documents/Carps_Management_Plan.pdf.
Burke, J.S., Bayne, D.R., and Rea, H. (1986). Impact of silver and bighead carps on plankton communities of channel catfish ponds. Aquaculture 55, 59–68.
Freeze, M., and Henderson, S. (1982). Distribution and Status of the Bighead Carp and Silver Carp in Arkansas. North Am. J. Fish. Manag. 2, 197–200.
Henderson, S. (1978). An evaluation of the filter feeding fishes, silver and bighead carp, for water quality improvement. In Smitherman R.O., W.L. Shelton, and J.H. Grover, (Eds.). Culture of exotic fishes symposium proceedings. Fish Culture Section, American Fisheries Society, Auburn, Alabama, 121–136.
Seewer, J. (Sept. 24, 2017). Invasive grass carp pose risk to Lake Erie. The Columbus Dispatch, B5.
Southwick Associates. (2007). Sportfishing in America: an economic engine and conservation powerhouse. American Sportfishing Association, Multistate Conservation Grant Program.
Zhang, H., Rutherford, E.S., Mason, D.M., Breck, J.T., Wittmann, M.E., Cooke, R.M., Lodge, D.M., Rothlisberger, J.D., Zhu, X., and Johnson, T.B. (2016). Forecasting the Impacts of Silver and Bighead Carp on the Lake Erie Food Web. Trans. Am. Fish. Soc. 145, 136–162.