The National Invasive Species Act (NISA) is a United States federal law intended to prevent invasive species from entering inland waters through ballast water carried by ships. NISA reauthorized and amended a previous measure, the Non-indigenous Aquatic Nuisance Prevention and Control Act of 1991 (NANPCA).
Organisms targeted by NISA are categorized as aquatic nuisance species, including in particular zebra mussels and Eurasian ruffe. To extend upon NANPCA, NISA authorizes regulation of ballast water, a key factor in the spread of aquatic invasive species; funding for prevention and control research; regional involvement with the Aquatic Nuisance Species Task Force; and education and technical assistance programs to promote compliance with the new regulations. NISA also includes specific actions for certain geographical locations, such as the Great Lakes, Chesapeake Bay, the Gulf of Mexico, and San Francisco Bay.
Environmental issue NISA directly addresses problems associated with nonindigenous species, with special attention on aquatic nuisance species in the Great Lakes. In the proper conditions, nonindigenous species can out-compete indigenous species by dominating resources or spreading diseases or parasites. These disruptions can lead to a loss of biodiversity and as a result, ecosystems and economies are greatly affected. Below are a few descriptions of nonindigenous species that are mentioned in NISA.
Zebra mussels
In 1988 zebra mussels (Dreissena polymorpha) were found in Lake Erie, and soon after they spread to all the Great Lakes.University of Minnesota (a). "Zebra Mussels Threaten Inland Waters: An Overview." (March 6, 2009) http://www.seagrant.umn.edu/ais/zebramussels_threaten Accessed on March 1, 2011 Since then, zebra mussels can still be found in each of the Great Lakes, as well as throughout the major navigable rivers in the eastern part of the United States (including the Hudson, St. Lawrence, and Niagara Rivers). Recent reports have revealed that this species has dispersed as far as California.US Forest Service. "Whiskeytown, Shasta and Trinity Lakes National Recreation Area Boater Alert." (May 2010). Accessed March 1, 2011.
A native of southern Russia, the zebra mussel most likely made its way to North America through the release of ballast water from cargo ships traveling from the Black Sea to the Great Lakes.USGS. "Zebra mussel (Dreissena polymorpha) Fact Sheet." (July 8, 2010). https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=5 Accessed on March 1, 2011. After its introduction there, it was carried through the lakes and connected waterways via recreational and commercial traffic. A large part of the zebra mussel's ability to disperse has to do with its travel flexibility. In the larval stage, zebra mussels can float along passively. In the adult stage, zebra mussels can attach themselves to boats very well. Overland dispersal can be achieved, too, because these mussels can survive dry conditions for several days. This was most likely the way that they were introduced to California: agricultural inspection stations have reported finding mussels on the hulls or motor compartments of at least 19 trailered boats arriving into the state. In addition to being able to travel long distances during both immature and mature stages of life, zebra mussels can produce up to several hundred thousand eggs in a single season.
Zebra mussels are most disruptive in two ways. The first is that they can colonize and clog water supply pipes, thereby restricting water flow for systems used for cooling, fire-fighting, hydroelectricity, etc. Colonies can also be very dense: it was reported that at one power plant in Michigan, 700,000/m2 of zebra mussels were found in the pipes, the diameters of which were reduced by two-thirds. The United States Fish and Wildlife Service once estimated that zebra mussel infestations could cost $500 million per year due to increased costs for utility companies and industrial plants, as well as loss of income revenue for fishing and fishing-related businesses. The economic repercussions of this type of species invasion can be devastating.
The second issue with zebra mussel invasions is that they can deplete food sources in aquatic ecosystems. Zebra mussels are filter feeders, meaning that they consume microorganisms, and they do so at very fast rates. Microorganisms form the bottom of the food chain, and eliminating that food source can be dangerous to the survival of native species. The spread of the nonindigenous zebra mussels have greatly decreased the numbers of native mussels in Lake St. Clair and Lake Erie, which may be at risk for extinction.
Eurasian ruffe
The Eurasian Ruffe (Gymnocephalus cernuss) is another aquatic nuisance species that has spread to the Great Lakes, Wisconsin, and Michigan, after first being discovered in the St. Louis River Estuary of the Duluth-Superior Harbor in 1986.University of Minnesota (b). "Eurasian Ruffe (Gymnocephalus cernuss)." Dec. 2, 2010. http://www.seagrant.umn.edu/ais/ruffe Accessed on March 1, 2011. Originally from southern Europe, the ruffe is believed to have arrived in North America through the release of ballast water from foreign seas.
The Eurasian ruffe is an extremely aggressive species. It can produce 200,000 eggs in the first batch and 6,000 eggs in later batches, and it is able to thrive in a number of different habitats where waters range from fresh to brackish, in ranges of depth from 0.25m to 85m.Invasive Species Specialist Group. "Gymnocephalus cernuss (fish)." Global Invasive Species Database. http://www.issg.org/database/species/ecology.asp?si=544&fr=1&sts=sss Accessed on March 1, 2011. A fierce competitor for food sources, it feeds on plankton, bottom-dwelling insect larvae, and sometimes fish eggs. One advantage that the ruffe has over native species is better eyesight in dark conditions, allowing it to consume more food and at a quicker rate.Fuller, Pam and Greg Jacobs. March 26, 2010. Gymnocephalus cernuus. USGS Nonindigenous Aquatic Species Database, Gainesville, FL. https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=7 Accessed on March 1, 2011. The ruffe is now considered a dominant species in Lake Superior and the St. Louis River Estuary, and native species are becoming compromised. Early efforts to control the ruffe populations attempted to introduce predator species; however the predators preferred native fish. Current management strategies are centered more on regulating ballast water discharge, as well as focused programs for identifying, monitoring, and netting the ruffe.
Mitten crabs
Mitten crabs (Eriochir sinensis) from China were first sighted in San Francisco Bay in 1992, and are suspected of being purposely introduced to initiate a fishery.United States Environmental Protection Agency (EPA). "Non-native Crab Species." 2011. Accessed on March 1, 2011. Like other invasive species, the mitten crab is an ecological competitor that threatens the availability of food for native species. It also feeds on salmon eggs, which is a great problem for dwindling salmon populations in California. Although the current geographic range of the mitten crab is limited to Northern California, it is expected to move toward Oregon and Washington.National Sea Grant Library. "A Guide to Least-Wanted Aquatic Organisms of the Pacific Northwest." http://nsgl.gso.uri.edu/washu/washuh00001.pdf Accessed on March 1, 2011. In 2009, mitten crabs were reported to be found in Chesapeake Bay, Delaware Bay, the Hudson River, New York, and New Jersey.Smithsonian Environmental Research Center. "Chinese Mitten Crab Update: U.S. Atlantic Coast Bays & Rivers." April 2009. http://www.serc.si.edu/labs/marine_invasions/news/CHINESE_MITTEN_CRAB_UPDATE_APR21_09.pdf Accessed on March 1, 2011.
The Chinese mitten crab also poses many threats to humans. First, they can damage the nets of commercial fisheries and clog water pipes. Second, mitten crabs tend to burrow, which can adversely affect the integrity of banks and levees. Lastly, they are a vector for the disease Asian lung fluke.
Causes Physical Invasive Species In general, invasive species can potentially do great damage to local environments and native species. Ecosystems across the United States, such as the San Francisco Bay, Chesapeake Bay, the Great Lakes, Hawaii, and Florida inland waters, are now host to a wide number of non-indigenous species, 15 percent of which cause serious harm.ANS Task Force. "Aquatic Nuisance Species Impacts." http://www.anstaskforce.gov/impacts.php Accessed on March 1, 2011. In the case of aquatic habitats, nonindigenous species can reduce nutrient availability and water quality, or make land prone to erosion, like the mitten crab that burrows into levees. Adverse impacts to other species include predation, heightened competition for food, and disease.The National Invasive Species Council. "Frequently Asked Questions (FAQ)." http://www.invasivespecies.gov/main_nav/mn_faq.html Accessed on March 1, 2011. The Aquatic Nuisance Species Task Force states that nonindigenous species have impacted 42 percent of endangered species and are an important reason in the decline of species, as well as an obstacle to environmental restoration.
Ballast water A key component of NISA is to introduce regulations for the discharge of ballast water, which is a significant source for transporting nonindigenous species. Ballast water is water brought into holding tanks by a ship to add stabilizing weight before the ship loads cargo. When the ship is going to load and unload the cargo, it releases the ballast water at the port of entry in order to offset weight and navigate shallow port waters. It was estimated that nearly 99 percent of U.S. overseas trade is transported over water, and more than 80 million tons of ballast water, and the thousands of foreign species in it, are released into U.S. waters every year. Not all the species in ballast water can survive life in the holding tanks or are a threat to local environments, but since the species composition in ballast water is variable, unpredictable, and innumerable, the potential for introducing harmful species remains high.
Social Aquarium and Ornamental Trades NISA specifically identifies ballast water as a source of aquatic nuisance species, but another substantial source is from the aquarium and ornamental industry, which is worth $25 billion per year.Padilla, Dianna K. and Susan L. Williams. "Beyond Ballast Water: Aquarium and Ornamental Trades as Sources of Invasive Species in Aquatic Ecosystems." April 2004. Frontiers in Ecology and the Environment 2:3 (pp. 131-138). Aquarium species are considered to be stronger than ballast water species, because they are typically traded as healthy adults capable of reproduction. Owners of exotic species may release them for a variety of reasons, including boredom, species aggression, or having to move. The United States trade of aquarium species involves over 2000 species and about 150 million exotic freshwater and marine fishes from all over the world.Global Invasive Species Programme. "IAS Toolkit Case Study: Release of Exotic Fish by Aquarium Hobbyists – the USA Experience." 2008. http://www.gisp.org/casestudies/showcasestudy.asp?id=128&MyMenuItem=casestudies&worldmap=&country= Accessed on March 1, 2011. Regulation of this industry is not very stringent; the ease of the Internet has allowed trade to grow and federal and international policies lack teeth. Governments also do not want to hinder trade, and aquatic hobbies are sometimes promoted as environmentally-friendly, which can be attractive to certain groups.
Fishermen