Invasive species affect native wildlife

The past couple of weeks the Oklahoma Department of Wildlife Conservation has posted warnings about two invasive species found in Oklahoma waters. Zebra mussels in Fort Supply and Hydrilla in the Kerr Navigation system.

Invasive zebra mussels have been detected for the first time in Fort Supply Lake in Woodward County, according to biologists. The mussels were discovered during recent sampling efforts. The presence of zebra mussel veligers, or offspring, confirms that the lake is now host to the invasive aquatic species.

The zebra mussel normally grows to about the size of a thumbnail and is named for the striped pattern on its shell. The mussels are typically found attached to surfaces, objects or other mussels. Zebra mussels affect ecosystems they invade by threatening native mussels, fish and wildlife by consuming available food, and costing taxpayers millions of dollars by clogging water intakes and pipes, and damaging boat engines.

Invasive zebra mussels spread to “clean” waters normally by hitching a ride on boats and other gear that people take from lake to lake. In only two or three years from first arriving, zebra mussels can significantly populate a waterbody.

Fisheries Biologist Elaine Gainer, aquatic nuisance species coordinator for the wildlife department, said once these invasive mussels are present, there is no feasible way to eliminate them. The best strategy is to prevent them from spreading to other water bodies, she said.

ODWC’s Aquatic Nuisance Species (ANS) program has confirmed invasive zebra mussels in more than 25 water bodies throughout Oklahoma, including Kaw, Sooner, Hefner, Keystone, Robert S. Kerr, Grand, Skiatook, Eufaula, Oologah, Claremore, Greenleaf, Tom Steed and Texoma lakes, as well as in the lower Canadian, Cimarron, Arkansas, Verdigris, Washita and North Canadian rivers.

Invasive hydrilla, an aquatic weed, has been confirmed for the first time in Robert S. Kerr Reservoir in far eastern Oklahoma, according to the Oklahoma Department of Wildlife Conservation. This aquatic nuisance species (ANS) was confirmed by ODWC fisheries biologists after being reported by a citizen.

“Once hydrilla has made its way into a body of water, it will very likely persist as it is incredibly hardy and will further spread the more it is fragmented, said Gainer.

Hydrilla, native to parts of Asia, Africa, and Australia, was first introduced to the U.S. in the 1950s as a live plant used in the aquarium trade. Hydrilla was first found in Oklahoma in 2006. Now, hydrilla has been found in nearly 40 states.It is a submerged, rooted perennial with long stems (up to 30 feet) that branch at the surface and form dense mats. Small white flowers grow above the waterline on stalks. The stems are covered in small, pointed, often serrated (“saw-toothed edge”) leaves, which are bright green and measure 5/8 of an inch long.

Hydrilla is named after Hydra, the nine‐headed serpent of Greek mythology, because it can grow an entirely new plant from a tiny stem fragment.

ODWC’s Aquatic Nuisance Species program has confirmed invasive hydrilla in Lake Murray, Lake of the Arbuckles, Sooner Lake, Lake Nanih Waiya, Ardmore City Lake, Scott King Lake, and the Lower Mountain Fork River.

In just a few years from first arriving in a waterbody, ANS can significantly infest the ecosystem. Preventative actions taken by boaters and other people using infested waters is vital to slow or stop the spread of invasive nonnative species like hydrilla. Using the “Clean, Drain, Dry” procedure is highly encouraged.

To fight ANS, please remember to drain bilge water, live wells, bait buckets, and boat motors; inspect boats and trailers when leaving the water; scrape off any mussels or aquatic vegetation found when on dry land; then wash and dry off the boat, trailer and accessories. Also, boats allowed to dry for at least a week after contacting infested water are considered safe to take to a different waterbody. For more information on “Clean, Drain, Dry,” go to StopAquaticHitchhikers.org or wildlifedepartment.com/fishing/regs/aquatic-nuisance-species-ans.

Gainer said invasive species of any kind — plant or animal — should never be returned to the water, and any sightings suspecting ANS should be reported to ODWC by submitting a form online at wildlifedepartment.com/wildlife/report-wildlife or by calling 918-200-4815. Anyone reporting a suspected invasive species should take photos to help experts with species identification.

To learn more about various invasive species affecting Oklahoma, go to wildlifedepartment.com/wildlife/field-guide/invasive.