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Missouri Department of Conservation

ANS Frequently Asked Questions in Missouri

What are aquatic nuisance species (ANS)? Aquatic nuisance species are non-native organisms which threaten the diversity of native plants and animals or the ecological stability of infected waters. They may also impact human health, and lead to negative impacts on agriculture, aquaculture, and the recreational use of Missouri waters.

Why are aquatic nuisance species a problem? Introducing plants and animals to new habitats is risky. Free from natural predators and competitors, some non-native species reproduce rapidly in their new homes, out-compete native species (leading to their decline or extinction) and become a costly nuisance. In general, invasive species are considered “biological pollutants” that have led to a severe loss of biodiversity and habitat alteration throughout the world.

How many aquatic nuisance species have entered Missouri ?   Thirty-four (34) non-native aquatic species of plants and animals have established populations in Missouri and 14 have been classed as aquatic nuisance species.

Are all non-native species considered a nuisance? No. Some non-native species are ecologically harmless.

How do non-native species get into Missouri waters?   Many exotic species have been transported from European ports in the ballast tanks of ocean-going freighters and are later released into the Great Lakes . These species eventually spread throughout the Great Lakes , down the Illinois River , and into the Mississippi River . From the Mississippi River they can gain access to many Missouri streams. Other introductions result from aquarium releases, escapes from aquaculture facilities, or left-over bait dumped into a lake or stream. Some species, such as zebra mussels, can be transported from one stream or lake to another on boats and trailers, in live-wells and boat motors, and in bait buckets

Why are invasive plants a problem? Invasive plants such as purple loosestrife and Eurasian watermilfoil are aggressive plants that establish themselves quickly in wetlands and inland lakes and out-compete and replace native vegetation. They provide little food or habitat for wildlife, crowd-out plants that are valuable to wildlife, form a dense growth that can block access to the water, or hinder activities such as boating and fishing.

What are scientists doing to control aquatic nuisance species? Many organizations across the country, such as fish and wildlife agencies, Sea Grant, U.S.G.S, and others, support research and provide information about aquatic nuisance species. Research is being conducted to develop control measures for certain aquatic nuisance species.

What can I do to help? Learn to recognize aquatic nuisance species. By becoming familiar with native and non-native species citizens can help scientists monitor invasive species populations and slow their spread. You can also learn how to inspect your boat, motor, trailer, and other fishing and boating equipment, to detect the presence of non-native species. Please dispose of unused bait into the trash after first placing species that can crawl out (such as crayfish and worms) into a sealed container. Also, don't transport bait collected from one lake or stream to another. Following these general guidelines will help you avoid transporting non-native species to new locations. Once you become knowledgeable about aquatic nuisance species, you can inform your fishing and boating friends about aquatic nuisance species so that they can also become part of the solution.

How and when can I prevent the spread of aquatic nuisance species into the waters where I recreate? By following the simple procedures described below each time you leave the water, you can help stop aquatic hitchhikers.

  • Remove any visible mud, plants, fish or animals before transporting equipment.
  • Eliminate water from equipment before transporting.
  • Clean and dry anything that came in contact with water (Boats, trailers, equipment, clothing, dogs, etc.).
  • Never release plants, fish, or other animals into a body of water unless they came out of that body of water.

Why should I use this procedure to prevent nuisance species? Because aquatic nuisance species :

  • reduce game fish populations,
  • ruin boat engines and jam steering equipment,
  • render lakes and rivers unusable by boaters and swimmers,
  • dramatically increase the operating costs of drinking water plants, power plants, dam maintenance, and industrial processes,
  • reduce or eliminate native species and degrade ecosystems, and
  • diminish human health, reduce property values, and negatively impact the economies of communities which depend on the water.

If I only fish in a certain lake, do I need to follow these general procedures? The one procedure you'll want to be sure to follow is to not introduce anything into that lake. Therefore, don't bring your aquarium from home and dump the contents into the water. Don't accept a fish from another lake (even if it is a big one) to release in your lake. If you borrow someone's equipment, clean it before using in your lake.

You'll also want to inform others about cleaning their equipment before they come to your lake. You might consider working with local authorities to put up signs to that effect around the lake or at public access points on waterways.

If you decide to explore other waters, clean all your equipment before you go, and again, when you return.

If my boat has been in infested waters, do I need to do anything more than general procedures? The longer a boat sits in infested waters, the greater the chance a hitchhiker can attach to your boat, motor, bumpers, live wells, anchors, etc. If you feel a rough surface on the bottom of the boat, propeller, or other items, be sure to clean your boat and equipment using the procedure for boaters under the “Prevention Section” above or click here: http://www.protectyourwaters.net/prevention/user_boaters.php

Do I have to know which aquatic nuisance species are in which lake or river? Not if you follow the recommended procedure every time you leave a body of water. Even if a lake is considered pristine, you never know when an ANS has been introduced, but not yet discovered. So, if you get in the habit of following ANS safety procedures, you'll help protect more waters.

It is helpful to learn about ANS which are common to your area. However, you don't have to know which ANS are in any given lake or stream – as long as you always follow the procedure.

How do I find out more about aquatic nuisance species (ANS) which have already invaded Missouri and those which are future threats? Click on the Missouri Nuisance Species – Where are they section of this site. Contact any Missouri Department of Conservation office in your area, or visit the Department's web site at http://www.conservation.state.mo.us/nathis/exotic/ . You might also visit Sea Grant at http://www.sgnis.org/ on the internet to learn about the specific nuisance species that have already invaded and those which are potentially capable of invasion.

Who do I contact if I find an animal or plant which may be an ANS?  Email MDC Biologist Mike Kruse at Mike.Kruse@mdc.mo.gov

Where did zebra mussels come from? Zebra mussels are native to the Caspian, Black and Aral Sea regions of Eastern Europe and Western Asia . Zebra mussels were likely introduced into the Great Lakes by ships dumping ballast water from Russian or European ports.

How do I know if it's a zebra mussel? Adult zebra mussels are small, yellowish or brownish, typically ¼ to 1 ½ inches long, with a triangular or “D” shape with light and dark colored stripes. They attach by means of byssal threads - hairy thread-like secretions on the underside of their shells. This is the only mussel or clam in Missouri that attaches to the surface of an object. Zebra mussels detach themselves prior to moving, and, usually, before dying.

When were zebra mussels discovered in Missouri ? Zebra mussels were first discovered in Michigan in 1988 and first documented in Missouri in 1991 in the Mississippi River .

Where have they been found in Missouri since 1991? Since 1991, we have been very fortunate that only a few sightings outside the Mississippi River have occurred. In 1999 a single adult zebra mussel was found attached to a native mussel in the Meramec River not far from where it joins the Mississippi River near St. Louis . In 2001 seven dead shells were found on an intake screen at a power plant on the Missouri River near Kansas City . It is likely that the zebra mussel can now be found throughout all of our Missouri and Mississippi river waters.

Are they likely to establish and spread in Missouri ? We hope not, but the fact remains that they are well established in the Mississippi and Missouri rivers. In turn, almost all of our inland streams and rivers are ultimately connected to them. Barges and unknown numbers of recreational boaters coming into Missouri waters from zebra mussel infested waters of the Missouri and Mississippi rivers (or other out-of-state waters) are a threat to spread this ANS throughout Missouri . Alert marina operators have prevented several infested boats from entering Lake of the Ozarks . Know how zebra mussels can spread and how to inspect for them.

Why are zebra mussels such a problem? Zebra mussels can attach to any hard surface and can potentially form dense colonies rather quickly. Every year zebra mussels cost power companies, municipal water supply companies, and other industries millions of dollars to routinely clear intake pipes and screens. This cost is passed on to consumers. Zebra mussels can affect boaters by clogging cooling systems in motors which causes them to overheat, and by encrusting boat and barge hulls which impacts boat performance and damages the “finish.” These unwanted creatures can also dramatically impact our native aquatic animals, such as mussels and crayfish, by directly attaching in numbers sufficient to impair breathing, feeding and movement by the victims. Additionally, zebra mussels can trigger a decline in sport fisheries by filtering too much organic material from the water which affects the whole food chain. Many public beaches on lakes with zebra mussels become smelly, undesirable places with sharp shells littering the sand after periodic die-offs of zebra mussels.

What can be done to get rid of zebra mussels? At present, getting rid of zebra mussels seems to be a near impossible task. They persist at some low level in all of the waters they've ever invaded, even after die-offs. There are no safe large scale chemical controls, and, though there are some natural predators, none are effective enough to eliminate zebra mussels from a water body.

What can be done to prevent zebra mussels from invading additional lakes and streams? Currently, the only way that zebra mussels can be prevented from expanding their range is for every angler and boater to take appropriate preventive measures. For this to work, we must do a better job educating the public about their threats. Everyone needs to be aware that they're already found in the Missouri and Mississippi rivers and are threatening our other precious in-state waters. For control methods please click here http://www.conservation.state.mo.us/nathis/exotic/zebra/

How do zebra mussels spread? Zebra mussels can spread either by the transfer of either the larvae (called veligers) or adults. The adults can “hitchhike” by attaching to boat hulls or vegetation stuck on boat trailers. Zebra mussel veligers, a free-swimming microscopic stage, can be transferred in bait bucket water, a boat's bilge water or motor cooling system water. Anything that can carry adults or larvae, even wet clothing, is a potential hazard.

What do I do if I find a zebra mussel? Make note of the date and exact location, put the specimens in a container with rubbing alcohol and contact your nearest Missouri Department of Conservation office (or representative), or call 573-882-9880.

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