Clean, Drain, Dry: Stopping Aquatic Invasive Species in the National Parks

National parks hold thousands of lakes, rivers and other waters to explore by boat, float or fishing line. But boaters and anglers can unknowingly carry aquatic hitchhikers — plants, animals and other organisms that hide in and on boats and gear — from one water to the next. There's a simple way to stop them: clean, drain, dry.

Boating at Mississippi National River and Recreation Area (NPS photo).

What aquatic invasive species are

Aquatic invasive species are plants or animals that are not native to an ecosystem and whose introduction causes, or is likely to cause, harm to the economy, the environment or human health. They can quickly and severely harm native species by:

• introducing diseases;
• outcompeting native species;
• altering food chains;
• changing the physical character of aquatic habitats.

They affect people too: they spoil outdoor recreation, damage equipment, threaten health and safety, and hurt local and regional economies. They are a growing risk to the parks. The United States now has more than 250 non-native aquatic species from other continents, and more than 450 from elsewhere in North America that have been moved outside their native ranges.

How they spread

An aquatic hitchhiker is any plant, animal or organism carried along by recreation. Invasive species travel on boats, seaplanes and equipment and through fishing, boating and diving, hiding in mud, dirt, sand and water where they're hard to see. Thousands have been introduced into park waters this way.

Some are introduced on purpose — by dumping aquariums, stocking lakes or tossing out unused bait fish. Most, though, spread by accident, clinging to boats, motors and gear, or riding in the water of ballast tanks, motors, bilges, live wells and other compartments until that water is released somewhere new.

Invasive species can cling to boat surfaces and anchors (NPS photo).

What you can do

Follow these steps every time you move from one body of water to another.

Clean

Cleaning removes visible plants, mud and larger organisms.

• Before you arrive, clean all plants, animals, sand, mud and debris from your boat, trailer, anchor, boots and equipment — and clean everything again as soon as you leave.
• Clean your gear before leaving the place you fished; all equipment and footwear can carry invasive species, whatever it's made of.
• Where available, professional cleaning with high-pressure hot water (120 to 140°F) is recommended for boats. Check owner's manuals first. Bleach and other chemicals are not recommended, because of risks to the environment and human health.

Cleaning boats and equipment helps stop the spread of invasive species (NPS / Jacob W. Frank).

Drain

Draining removes the water where tiny, nearly invisible organisms hide.

• Drain all water from the boat — motor, bilge, live well and other compartments — before you arrive.
• Leave the bilge plug out while trailering; some states require it by law.

Dry

Many organisms survive in small amounts of standing water.

• Let everything dry for at least five days, or wipe it down with a towel before using it again.

Check that no standing water or debris remains, then let the boat dry (NPS / Jacob W. Frank).

Dispose

• Throw unwanted bait, worms and fish parts in the trash.
• Live bait is often prohibited in park waters, so check the rules before fishing.
• Never dump water, live fish or other organisms from one body of water into another.

Sources

• National Park Service: "I Didn't Know That!: Clean, Drain, Dry."