There are many ways by which non-native species may be introduced into Washington waters. Sometimes species migrate into new areas over time, or they may be carried into other areas by natural events, such as el nino's or flooding. However, many introductions are related to human activities. Some non-native species have been introduced for aquaculture, such as the Pacific oyster. When the Pacific oyster was introduced other species came along, or hitchhiked, with it. The Manilla clam, which proved to also be a beneficial aquacultural species, and the oyster drill, which is a predatory nuisance species. Not all "deliberate" introductions are on such a large scale, and sometimes introductions of a small number of species can cause very large problems.
Never release live pets, plants, bait, or seafood products:
- The release of aquarium or terrarium pets or plants - the agency has had to poison lakes in the past due to the presence of large populations of goldfish. Many lakes, rivers, and streams have such heavy infestations of Eurasian water milfoil that they are no longer usable for swimming, fishing, or boating.
- The release or escape of animals or plants used in research or education - science kits sent to elementary or middle schools sometimes contain live non-native animals and/or plants such as crayfish, Brazilian elodea or Eurasian water milfoil.
- The release or improper disposal of live seafood or the material it is packed in - it is possible that Spartina was introduced with shipments of live aquacultural products.
- The spread of aquatic plants or animals from one water body to another on a boat or boat trailer - IT IS ILLEGAL to have any aquatic plants on a boat or trailer on any road in Washington State. Always clean your boat before leaving a launch site.
- The release of unused bait - always dispose of all live bait at an appropriate upland site.
- Clean Your Boat Before You Float - Aquatic plants and animals are often inadvertently moved from waterbody to another by trailered boats. It is important to remove all visible plant or animal materials from your boat, motor, trailer of other equipment, and to drain all of the water from bilges and live wells away from the water body. Transporting aquatic plants on your equipment on any state or public road, including forest roads, is a misdemeanor. [RCW 77.15.290 (4) and (5).]
The websites below will provide you with more information on what you can do to stop the introduction and spread of invasive non-native species:
The discharge of ballast water from other ports, both foreign and domestic, is another source for the introduction of non- native invasive species. The Washington State Legislature has passed a law that requires water from other ports to be "exchanged" for open ocean water or treated before it can be discharged into state waters. The Department of Fish and Wildlife enacts and enforces the law. More information can be found on the ballast water website.