Zebra Mussels
- A New Problem in Oklahoma
A small mussel known to greatly impact the
environment has been found in the state, prompting concern by state and federal
officials. Zebra mussels have been found throughout the McClellan-Kerr
Navigation System from W.D. Mayo up to the Port of Catoosa, and several other
lakes in northeast Oklahoma, including Oologah, Kaw, Sooner, Keystone, below
Zink Dam on the Arkansas River in Tulsa, Lynn Lane, Skiatook, and Grand. It is
likely that other lakes in northeast Oklahoma already have zebra mussels but
have yet to be reported.
Researchers believe that zebra mussels were accidentally transported to North
America by trans-Atlantic ships. They were first found in the United States in
St. Clair, Michigan, in 1986, and are expected to spread throughout the majority
of the U. S. waterways within a decade.
What Are Zebra Mussels?
Most zebra mussels are thumbnail size. They have an elongated, D-shaped,
somewhat pointed, thin shell with a zebra-like pattern of stripes.
Adult zebra mussels can be as large as 1 1/2 to two inches and live up to five
years of age. They have threadlike filaments used to attach themselves to boat
hulls, reefs, navigational buoys and other submerged objects.
Zebra mussels reach sexual maturity when they are about one-half inch in length.
Females typically produce from 30,000 to 100,000 eggs per season, but can
produce a million eggs in a single season. Reproduction can occurs when water
temperatures are between 54 and 80 degrees Fahrenheit.
Due to their high reproductive rate and the limited number of natural predators,
zebra mussels can significantly populate a body of water in two or three years.
They can cluster together with hundreds of thousands per square meter.
Possible Impacts
The zebra mussel's reproductive and living habits have raised concerns that they
may affect the American aquatic environment. By altering the food chain and
water chemistry, as well as through sheer numbers of mussels, native aquatic
species may be adversely impacted.
Zebra mussels may also affect man made facilities either built in water or that
transport water. They clog water intake pipes and disrupting water withdrawal
operations. This causes problems with lakeshore municipalities and industries,
power plants, farms and irrigation systems. High water flow rates inside pipes
provide a constant source of food for the mussels. There, they cluster in mats
on top of each other, lining the inside of pipes. The larger facilities of the
Great Lakes are spending hundreds of thousands of dollars each year in efforts
to eradicate the Zebra mussel.
Zebra mussels feed by filtering water and removing microscopic plants and animals. These organisms form the basis for the food chain in aquatic ecosystems. The productivity of systems containing zebra mussels is dramatically lowered as a result of the vast amount of water that is filtered by zebra mussels. As a result, the pounds of fish that these systems can support is dramatically lowered and can lead to reductions in angling success.
Zebra mussels have become extremely abundant at
Oologah and Kaw lakes. Swimmers and waders have reported getting cuts from the
shells of zebra mussels. As a precaution, always wear tennis shoes when swimming
or wading in these waters.
Researchers face the challenge of finding a way to eliminate the zebra mussel
without harming native species. Experimental methods for controlling the mussels
have included chlorination, thermal flushing, mechanical filtration,
anti-fouling paints, electrical shock and acoustics. Although some treatments
have proven effective for spot control, eliminating zebra mussels once they are
established is not likely on a large scale basis.
Problems and Solutions for Boaters
Boat owners who frequent known zebra mussel waters (see above) should be
especially cautious. The mussels attach themselves to, and grow within, water
intakes of both inboard and outboard motors. Subsequent restriction of water
flow can cause motors to overheat.
They also attach themselves to boat hulls, which affects boat handling, reduces
fuel efficiency and slows boat speed. If a boat hull feels grainy or gritty, it
might be covered with young zebra mussels, which are about .02 millimeters
long.
As prevention, boats should not be left in the water for extended periods of
time. With regular use, engine heat will keep mussels from colonizing inside
most engine parts. Because microscopic zebra mussel larvae can be unknowingly
transported in bilges, engine cooling systems, minnow buckets, live wells and
anywhere water is trapped, the following pre- cautions should be taken to help
slow their spread.
• Drain the bilge water, live wells and bait buckets.
• Inspect the boat and trailer immediately upon leaving the water.
• Scrape off any zebra mussels found. Do not return them to the water.
• If possible, dry the boat and trailer for at least a week before entering
another waterway.
• Wash boat parts and accessories that contact the water using hot water (at
least 140 degrees F.), a 10 percent solution of household chlorine bleach and
water, or a hot saltwater solution. Do not wash your boat at the boat ramp where
these solutions could pollute the water. Always finish with a clean water
rinse.
These tips will help protect our environment from further spread of this mussel
and will help protect water users from expensive repairs and mussel clean-up
costs.
For the Future
To address Oklahoma's zebra mussel problem, a task force has been formed. The
task force includes representatives from the Wildlife Department, Oklahoma Water
Resources Board, Oklahoma State Department of Health, Oklahoma Conservation
Commission, Oklahoma Biological Survey, U. S. Bureau of Reclamation, U. S. Fish
and Wildlife Service, U.S. Geological Survey and the U.S. Army Corps of
Engineers.
Throughout the summer, Oklahoma water ways will be monitored by task force
agencies to find out how far the zebra mussel has spread. The task force is
asking people who find zebra mussels to collect some and contact any task force
agency.
For more information about zebra mussels or to report findings, call:
U.S. Army Corps of Engineers (918) 669-7411, or
Oklahoma Dept. of Wildlife (405) 521-3721.