Oceans and Estuaries - Exotic Species

Exotic species are plants, animals, and microbes that have been carried from one geographic region to another, either intentionally or unintentionally. Unintentional introduction includes transport in ballast water of ships, or as pests on imported fruits, vegetables, and animals or animal products. Prior to modern times, movement from one geographical region to another was infrequent and slow, allowing time for the ecology to absorb and counterbalance the newcomers.

Today, because of rapid transport, organisms can move across continents in a matter of hours or days. Once removed from their natural ecological system, where eons of evolution have established predator-prey relationships, competitive species, and other devices to maintain balance, exotic species may reproduce unchecked in their new locations because they have no natural competitors or predators.

Both estuarine and ocean habitats have suffered from exotic species introduction. In the Chesapeake Bay, MSX (Haplosporidium nelsoni) and Dermo (Perkinsus marinus), two oyster diseases that have ravaged oyster populations, came to the Bay with oysters introduced from other regions. The coral reefs in the Northern Mariana Islands are being decimated by the introduction of the crown-of-thorns starfish. The green crab introduced from the Baltic Sea to the shores of New England occurs in such high numbers that the crab is believed to be eating young scallops and other valuable seafood.

Passage of the Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 was a first step in attempting to prevent species migration. This legislation authorized the U.S. Fish and Wildlife Service and NOAA to adopt regulations to prevent the unintentional introduction of aquatic nuisance species. In 1999 the Invasive Species Council was created by presidential executive order to oversee efforts to control unwanted exotic species. The council is chaired jointly by the secretaries of Interior, Agriculture, and Commerce. Council members include the secretaries of State, Treasury, and Transportation, and the administrator of the EPA. To date, however, no method has been found to stop the potential flood of exotic species to the U.S. shores.

On April 13, 2005, Senators Carl Levin and Debbie Stabenow (both Democrats of Michigan) and Susan M. Collins (Republican of Maine) introduced into the U.S. Senate the National Aquatic Invasive Species Act of 2005 (NAISA). A similar bill was introduced into the House of Representatives at the same time. The proposed legislation would reauthorize and strengthen the National Invasive Species Act of 1996 so as to protect U.S. waters by preventing new introductions of aquatic invasive species.

If enacted, NAISA 2005 would accomplish its goals by:

• Regulating ballast discharge from commercial vessels
• Preventing invasive species introductions from other pathways
• Supporting state management plans
• Screening live aquatic organisms entering the United States for the first time in trade
• Authorizing rapid response funds
• Creating education and outreach programs
• Conducting research on invasion pathways, and prevention and control technologies
• Authorizing funds for state and regional grants
• Strengthening specific prevention efforts in the Great Lakes

As of July 2005 the Senate bill had been referred to the Committee on Environment and Public Works, and the companion bill in the House of Representatives had been referred to the Subcommittee on Fisheries and Oceans.