Introduced Species Invading U.S. Waters at Rising Pace

By Cat Lazaroff

WASHINGTON, DC, October 23, 2001 (ENS) - The rate of non-native species invading U.S. coastal waters has risen exponentially over the past 200 years and shows no sign of leveling off, warns a new report from the Pew Oceans Commission. Introduced species crowd out native species, alter habitats, disrupt ecosystems and impose economic burdens on coastal communities.


Zebra mussels are now widespread in the Great Lakes and inland rivers (Photo courtesy University of Wisconsin Sea Grant Institute)
When the historic battleship USS Missouri was moved from Puget Sound to Hawaii, it carried mussels that recolonized a nearby submarine. Marina floats towed from New Jersey to Massachusetts brought with them a population of Asian crabs.

Atlantic salmon are reproducing in the Pacific Northwest after escaping from fish farms. A toxic Mediterranean green seaweed has colonized a lagoon near San Diego, California, probably after someone dumped out a home aquarium.

In a report entitled "Introduced Species in U.S. Coastal Waters" presented to the Pew Oceans Commission Monday, James Carlton, PhD, of Williams College and Mystic Seaport, describes a "game of ecological roulette" playing out along the U.S. coast. Hundreds of species arrive each day by way of ship ballast waters, fishing activities and other means, Carlton said.

"We really don't have a good grasp on the number of invasions going on," Carlton said Monday at a press conference releasing the report.


Exotic lamprey eels, shown attached to a native lake trout, may have traveled to the Great Lakes in boat ballast waters (Photo courtesy U.S. Environmental Protection Agency)
The report highlights the loss of coastal habitat and biodiversity and the millions of dollars spent each year to research and control introduced species. Carlton recommends a compulsory ballast water management program, an early warning and rapid response system, and greatly expanded research and public education programs.

"Once an introduced crab, fish or seaweed takes hold in a coastal area, it can cause tremendous environmental disruption and result in millions of dollars in damage," said Leon Panetta, chair of the Pew Oceans Commission.

Panetta is leading an independent group of leaders on a national review of the policies needed to restore and protect the living resources of the oceans.

"For coastal areas already threatened by polluted runoff, poorly planned coastal development, or declining fisheries, the effects of introduced species are especially damaging," Panetta added.


Caulerpa taxifolia, a toxic invasive algae, has colonized a lagoon near San Diego, California (Photo courtesy Alexandre Meinesz, University of Nice-Sophia Antipolis)
Carlton's report begins with a look at why introductions continue to occur along U.S. coasts and how they affect the nation's ability to restore and protect coastal habitats. He then discusses the primary sources of introductions, including ballast water and fouling organisms (those that attach to ships and other structures), maritime activities such as exploration and commerce, fishing activities, and the aquarium industry.

Carlton concludes with a review of efforts to prevent, reduce and control introductions and offers several recommendations for action. The report calls for a federal "strike force" to combat invasive marine species, and a $50 million commitment to eliminate established populations of non-native pests.

"The management of introductions should be tackled from the point of origin to the point of arrival," concludes Carlton. "We must prevent and reduce invasions, coordinate response to newly discovered introductions, expand research and improve public awareness of the problem."

The General Accounting Office (GAO), the investigative arm of Congress, reported in July that invasive species cause billions of dollars in damage to crops, rangelands and waterways each year. The GAO report called invasive pests "one of the most serious environmental threats of the 21st century."

The U.S. Department of Agriculture spent more than half a billion dollars in 2000 on invasive species research and control efforts, the GAO found.


Taking ballast water samples on a ship (Photo courtesy SERC)
The Pew Oceans Commission has contracted with a number of distinguished scientific and technical experts to prepare reports on key marine resource issues. Authors review the latest information and offer recommendations on how best to address the ecological, economic, political or social problems they identify.

Carlton's report is the third in a series that includes reports on marine pollution and aquaculture. Additional reports on coastal development, fishing and marine protected areas are underway.

"Introduced Species in U.S. Coastal Waters: Environmental Impacts and Management Priorities" is available at: