‘Asian carp’ is an umbrella term for four invasive species of carp native to Asia that include bighead, grass, bullhead and silver carp. Asian carp were brought to the States as a way for farm ponds, sewage lagoons and aquaculture facilities to control for algae, parasites and aquatic macrophytes (Baerwaldt et al, n.d.). They established themselves in the Mississippi river system after flood events and are rapidly making their way to the Great Lakes.
The Great Lakes fisheries can be valued up to $7 billion dollars annually and Silver carp threaten that market (Golowenski, 2019). Silver carp are filter feeders that can consume 5-20% of their body weight regularly, making them a formidable adversary against native species in the fight for food, and the cumulative feeding habits of Asian carp could reduce the turbidity that native fish depend on (Baerwaldt et al, n.d.). Adult Silver carp do not have predators in the Mississippi river system, and because this species reaches adulthood quite rapidly their window of vulnerability is quite low (ACRCC, n.d.).
Silver carp (Hypophthalmichthys molitrix ) are a particular interest of mine because of their tendency to jump out of the water when startled by boat motors. Weighing up to 20 pounds and with the ability to jump 9-10 feet out of the water, they are a hazard to the safety of recreational boaters.
Some ways carp are being managed by the Asian Carp Regional Coordinating Committee (ACRCC) is through electric barriers, contract fishing, and a new development of sound technology. A study by the University of Minnesota demonstrated that Asian carp have been deterred from barriers when low frequency noises were emitted, while native fish species are not known to be affected (Pennekamp, 2017). These methods alone would not prevent the introduction of Silver carp to the Great Lakes, but in conjunction may be enough. Personally, my favorite method of Silver carp control comes from the town of Bath, Illinois. Since 2005 the tiny town has been home to the annual Original Redneck Fishing Tournament. Equipped with dip nets and sometimes football padding, boaters take to the water in droves and try to snag the flying fish out of the air. Silver carp are a schooling species so the boaters will drive close together to ensure the fish start leaping. There are 4 heats and contestants have up to two hours to fill their boat with as many fish as they can grab. There is a prize of $1000 for the team that catches the most fish and past tournaments have been able to remove over 1500 Silver carp out of the river in the span of two day. Silver carp are edible and considered delicacies in some Asian communities but are not commonly consumed by Americans. If this was implemented in Ohio, a cookout contest could be used in conjunction with the tournament to introduce Silver carp into the midwestern diet. Obviously, this method of control would not work alone but it is a way to increase awareness, raise funds, and decrease the population.
References:
Asian Carp Regional Coordinating Committee. (2018). Asian Carp Action Plan for Fiscal Year 2018 (pp. 1276).
Baerwaldt, K., Credico, J., Kromrey, R., & Monroe, E. (n.d.). Asian Carp eDNA Monitoring. U.S. Fish and Wildlife Service
Golowenski, D. (2019, September 8). Outdoors: Asian carp threat remains for Great Lakes. Retrieved from https://www.dispatch.com/sports/20190907/outdoors–asian-carp-threat-remains-for-great-lakes
National Geographic, Redneck Fishing Tournament. (2010). Retrieved from https://www.youtube.com/watch?v=0bZ_9B_RlGY
Pennekamp, T. (2017, November 13). Broadcasting underwater noise may be a sound solution for repelling Asian carp on Mississippi River. Retrieved from https://www.guttenbergpress.com/articles/2017/11/13/broadcasting-underwater-noise-may-be-sound-solution-repelling-asian-carp