Allegra Cangelosi. 9 Jan 2003. Blocking Invasive Aquatic Species. Federal law must be updated to stop introductions of nonnative organisms, especially by ships. Issues in science and technology. National Academy of Sciences.

Examples of invasive aquatic species

• Voracious snakehead fish from China crawl out of a Maryland pond
• 100-pound Asian carp smash into recreational boats on the Mississippi River
• Armies of alien rats, numbering in the millions and weighing up to 20 pounds, raze wetland vegetation in Louisiana.
• Softball-sized snails called Rapa whelks silently devour any and all Chesapeake Bay shellfish in their paths
• A wasting syndrome afflicting the fry of native sport fish in Lake Ontario results from the adult fish eating nutritionally deficient nonnative forage fish.
• Recent die-offs among Great Lakes waterfowl due to botulism are being traced to the zebra mussel infestation that occurred more than 15 years ago.
• In Texas, an exotic snail carries parasites that are spreading and infecting native fish populations.
  In the Gulf of Mexico, a rapidly growing Australian spotted jellyfish population is threatening commercially important species such as shrimp, menhaden, anchovies, and crabs.
• The ruffe, a small perchlike fish native to southern Europe that has become the most abundant fish species in Duluth/Superior Harbor (Minnesota/Wisconsin) since 1986. The ruffe has spread to the Firesteel River in the Upper Peninsula of Michigan, the easternmost record in Lake Superior. The ruffe is expected to have major effects on important fish species, such as the yellow perch. The ruffe could cause fishery damages that may total $100 million once it becomes established in the warmer, shallow waters of Lake Erie.
• The Asian swamp eel threatens the Everglades National Park ecosystem. These eels are voracious predators of native fish and invertebrates.
• The zebra mussel from the former Soviet Union has clogged the water pipes of many electric companies and other industries, particularly in midwestern and mid-Atlantic states. It also threatens the existence of many endemic native bivalve molluscs in the Mississippi Basin. Infestations in the midwest and northeast cost power plants and industrial facilities nearly $70 million between 1989 and 1995.

How do they get here?

Scientists believe that most invasive aquatic organisms hitch rides to U.S. coastal waters by adhering to the hulls of commercial ships or by traveling in their ballast water (the water pumped into below-deck tanks to increase a ship’s stability). Today, ships move more than 80 percent of consumer goods, and the steady growth in global trade is increasing the opportunities for invasive species to reach new habitats.

References & Recommended reading

Carlton, J. T., Introduced Species in U.S. Coastal Waters: Environmental Impacts and Management Priorities. Arlington, Virginia: Pew Oceans Commission, 2001.

Committee on Ships’ Ballast Operations, National Research Council, Stemming the Tide: Controlling Introductions of Nonindigenous Species by Ships’ Ballast Water. Washington, DC: National Academy Press, 1996.

Schmitz, Don. 9 Jul 2001. Needed: A National Center for Biological Invasions. Issues in science and technology. National Academy of Sciences.

U.S. Coast Guard, Report to Congress on the Voluntary National Guidelines for Ballast Water Management, November 2001.

U.S. Environmental Protection Agency, Aquatic Nuisance Species in Ballast Water Discharges: Issues and Options, September 2001.