–Northwest Discovery Water Trail-5c-Natural World-Invasive Species

Invasive Species

Invasive species are organisms introduced into habitats in which they are not native. They are a major cause of biological diversity loss throughout the world and are considered biological pollutants. Without predators, parasites, and competitors that have kept their numbers in check, invasive species introduced into new habitats often overrun their new homes and crowd out native species. Once established, invasives can rarely be eliminated and the cost of control measures can be very high.

Humans cause most invasive species introductions. Invasives are carried in or on animals, vehicles, ships, commercial goods, produce and even clothing. Along the Clearwater, Snake and Columbia Rivers, there have been several introduced invasive species in the past few years, with the threat of further infestation by new species in the near future.

One invasive of particular concern is the zebra mussel. The zebra mussel is a nasty invasive species that spreads to new places by attaching to any hard surface in the water, this includes boat hulls, trailers, and fittings, and even aquatic plants. Colonies of these tiny shellfish have already infested numerous waterways in the east and midwest, causing hundreds of millions of dollars in damage through clogged pipes, ruined boat motors, and degraded fish and wildlife habitat.

Before moving your boat between bodies of water:

  • Inspect your boat, trailer, and boating equipment (anchors, centerboards, rollers, axles) and remove any plants and animals that are visible before leaving the immediate vicinity of any water body.
  • Drain water from the motor, livewell, bilge and transom wells on dry land before leaving the dock area.
  • Dispose of bait in proper disposal facilities. Never release live bait into a water body or release aquatic animals from one water body into another.
  • Wash and dry your boat, tackle, downriggers, trailer and other boating equipment to kill harmful species that were not visible at the boat launch. This can be done on your way home or once you have returned home. Be aware that some aquatic invasive species can survive more than two weeks out of the water.
  • Learn what these organisms look like. If you suspect a new infestation of an invasive plant or animal, immediately report it to your natural resource agency.

For more information on invasive species: