MARYLAND HEIGHTS, Mo. – After an intensive three-week purge, 85 percent of the Asian carp in Creve Coeur Lake are gone.
The experimental removal project was conducted by the Missouri Department of Conservation, the U.S. Geological Survey, the U.S. Fish and Wildlife Service and St. Louis County Parks last month.
Invasive Asian carp, primarily bighead carp and silver carp, entered Creve Coeur Park Lake by way of Missouri River flooding prior to 2009. They quickly began to compete with native species for food and space, reducing numbers of natives and severely curtailing sport fish like crappie. Asian carp also caused conflicts by leaping at and striking lake users, and have been the source of several nuisance fish kills, according to a press released from the Missouri Department of Conservation.
“We tried a new experimental method from Asia, called the Unified Method, to push all the Asian carp to one end of the lake where we able to harvest almost 50,000 of them,” reported MDC Fisheries Management Biologist Kevin Meneau. Meneau coordinated MDC’s involvement in the effort.
The Unified Method was adapted from techniques previously tried and proven in Asia.
Biologists say that the dramatically lower density of Asian carp will greatly reduce interactions with lake users like rowers and paddlers. At their current level, the Asian carp will no longer compete with native fish as severely as before, which should enable the crappie to come back on their own in the next couple years.
“One of the things that get Asian carp really fired up is the sound of outboard motors. We were able to isolate that sound and broadcast it underwater,” Meneau said. “We could project that sound and the Asian carp would leave that area, then we could quickly block off those areas they left with giant nets.”
Altogether, biologists took out around 47,000, or about 119 tons, of the unwanted invasive fish from the lake. Population estimates indicate that approximately 85% of the Asian carp population was eradicated.