Some say a bad day of fishing beats a good day working. It's a little more complicated for U.S. Fish and Wildlife Service's Krissy Sardina and her Bureau of Indian Affairs WaterCorps AmeriCorps members Chuck Taylor and Bradley Gooch. For this invasive carp early detection crew, not catching their target fish is a very good day at work.
The trio have been monitoring the Red River downstream of Denison Dam to learn more about the movements of adult invasive carp and conducting early detection sampling for carp larvae. They're currently tracking about 88 adult carp, including silver or "jumping" carp, and have yet to document larval invasive carp in this river system.
"That would be a worse-case scenario — getting a larval fish," said Sardina. "Once you start seeing larval fish in a river system, especially carp, their populations tend to explode. It's one thing to have a slow migration of adults. It's another to have millions of fry that are growing into adulthood and getting established in that location."
Something Wickedly Invasive This Way Comes
Oklahoma is still in the early pages of the ecological horror story that is invasive carp. Though multiple carp species have been introduced in the United States since the 1800s, three species have been making headlines in recent decades with their outsized impact to river systems and native fish communities. Bighead and silver carp, collectively known as bigheaded carp, were originally brought to the United States in the 1970s to control algae growth in aquaculture facilities and sewage ponds. (Silver carp are especially known for jumping from the water when startled and have become a bizarre risk to anglers and boaters.) Black carp were unintentionally brought over in grass carp shipments around that time and later intentionally imported to control snails and grubs in aquaculture farms. Over the next 20 years, flood events led to escapement from facilities and the fish quickly settled in the lower Mississippi River. They've since become known for their ability to invade and have moved into several major tributaries in the Mississippi and Great Lakes basins where they consume river-loads of plankton and other foods and, in some states, have outcompeted native fish communities.
"The Red River is like a turnpike," said Chuck Taylor. "A turnpike doesn't have very many turnoffs. These fish just jump on the turnpike, come upriver, and exit whenever they can."
For the carp, these turnpikes are best traveled when high flows fill the banks and connect the sometimes braided and shallow rivers. They'll swim against the powerful current to potentially spawn and expand their range and use slower moving tributaries as exit ramps. The adult fish can either move back downriver as flood waters recede, or find new homes in the slower, deeper sections of the tributaries.
Bighead carp have been documented in Oklahoma's Neosho and Grand rivers above and below Grand Lake, as well as Lake Hudson, the Red River below Lake Texoma, and the Kiamichi River below Hugo Lake. Silver carp have been found in Oklahoma's Arkansas and Red rivers. And Oklahoma's first confirmed black carp, an adult fish caught in a private pond, was recently reported in McCurtain County.