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National Estuary Program (NEP)

How the National Estuary Programs Address Aquatic Nuisance Species

As the ease of transporting organisms around the globe has increased, so have the rates of intentional and accidental introduction of aquatic nuisance species (ANS). These ANS introductions often have unexpected ecosystem, economic and social impacts.

For example, ANS harm native fish and wildlife in many ways. They can take over native species' habitats, out-compete and prey upon those species and disturb entire food webs. As well, a few ways in which they affect human activities include:

  • Disrupting agriculture, shipping, water delivery, recreational and commercial fishing
  • Undermining levees, docks and environmental restoration activities
  • Impeding navigation and enjoyment of local and regional waterways

NEP Approach/Success Stories

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San Francisco Estuary Partnership (SFEP)

The San Francisco Bay is one of the most "invaded" estuaries in the world. The San Francisco Estuary Partnership (SFEP) works to minimize the impacts of ANS by supporting efforts in the areas of planning, mitigation, prevention and detection.

For example, SFEP helped develop the California Aquatic Invasive Species Management Plan, which provides a framework for responding to aquatic invasive species and protecting native plants and animals in California. The Partnership worked with the State Coastal Conservancy, the California Department of Fish and Game and other state and federal agencies involved with invasive species to complete the plan, which California's Governor signed in 2008.

The SFEP also supports the 100th Meridian Initiative, a collaboration among government, private industry and public stakeholders to prevent the westward spread of zebra mussels. The collaboration provides education and outreach on preventative measures, such as voluntary boat checks. The partnership includes the six states that straddle the 100th Meridian (100º longitude), the Canadian province of Manitoba and most of the western states.

Additionally, SFEP completed the Aquatic Invasive Species Early Detection Program, which assists watershed volunteer groups in identifying new invasions of aquatic species.

The SFEP also supported efforts to control the spread of the Chinese mitten crab. Although introduced elsewhere in the United States, Chinese mitten crabs became an established U.S. population after being introduced into San Francisco Bay. Once established, the crabs excavate and burrow into river banks, eroding those banks and damaging levees. The crab's sharp claws also cut through commercial fishing nets and reduce or damage catch.

Further, while not found in the California crabs to date, mitten crabs can host lung fluke, a parasite that causes tuberculosis-like symptoms in humans. At some California Aqueduct and State Water Project fish salvage facilities, mitten crabs clogged screens, holding tanks and transport trucks used to salvage fish from the pumping stations. To mitigate the crabs' impact, the state built "Crabzilla,” an 18-foot high traveling fish screen.

In 1998, the state transported approximately one million mitten crabs trapped by the screen to another facility that ground them up for fertilizer. By 2005, the mitten crab population in the San Francisco Bay watershed had declined considerably.

For more information, see: California Aquatic Invasive Species Management Plan Exit.

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Peconic Estuary Partnership (PEP)

The Peconic Estuary Partnership (located in New York) facilitates a monitoring and removal program to control the invasive aquatic plant Ludwigia peploides from the Peconic River system. First detected in the system in 2007, Ludwigia is a threat to the river because it:

  • acts as unsuitable fish habitat;
  • out-competes and blocks sunlight to native plants; and
  • impedes recreational uses of the river.

Soon after the Ludwigia discovery, numerous stakeholders united to eradicate the plant from the Peconic River. From 2008-2012, 13 volunteer “Ludwigia Eradication” events were held, where 438 volunteers spent 2,360 hours hand pulling 130 cubic yards of the plant. To ensure this invasive plant does not re-establish in the river, the community holds annual monitoring and periodic maintenance pulls.

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Puget Sound Partnership

To help prevent the introduction of new invasive species in the Puget Sound region, EPA invested $250,000 for implementation of key recommendations in the Invasive Species Council’s “Invaders at the Gate” Strategic Plan. As an example, one project assessed the 15 highest priority invasive species in the Puget Sound basin to determine their extent and distribution, as well as to identify current management practices and any management gaps.

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