Two species of exotic carp continue to thrive in the Lower Missouri River. Silver carp and bighead carp came to this country gratis of the People’s Republic of China. The two species arrived in the U.S. in the 1970s, at the beginning of an improved relationship between two former Cold War adversaries. Initially confined to ponds in the southern United States, the aggressive fish eventually found its way into the Missouri and Mississippi rivers. A combination of floodwaters, busted dams, lax state and federal environmental regulations, and negligence on the part of fish farm operators enabled the Asian carp to escape into the open waters of the nation’s two largest mid-continental rivers. Once there, their populations exploded and expanded outward. Today, the silver and bighead carp are found along the Missouri River near Yankton, South Dakota, approximately 800 river miles from the Missouri’s mouth near St. Louis.
The carp have been so successful in the Missouri because they have found a rich and accessible food supply. The carp consume huge amounts of zooplankton. It’s not unheard of for a bighead carp to reach a six-foot length and a weight of 110 pounds feeding on Missouri River zooplankton. Native Missouri River species which rely on that same food source are feeling intense pressure from the invaders. Spoonbill, bigmouth buffalo, and even catfish are suffering declines in population in the face of the Asian carp onslaught. Those species no longer have the food to sustain their previous populations.
Although the two species of Asian carp suffered die-offs last year in the Lower Missouri, this year has been a banner year for the ugly, bugged-eyed creatures. The population is reaching such a density in the Missouri, that legions of the fish are moving into the Missouri River’s tributaries. This year, observers noted large numbers of Asian carp along the Kaw River near the two Kansas Cities. The question asked by everyone involved with the Missouri River fishery is whether the silver and bighead carp can be stopped? And if so, how? If they cannot be stopped, what will become of the native fish species in the Missouri?