Invasive species, non-native species, nuisance species: Missouri has them all.
In an earlier post, I discussed a study that identified invasive species in Missouri’s forests. Three were most common: multiflora rose and two species of honeysuckle. But invasive species can live anywhere, and aquatic invasive species are of particular concern. In 2007, the Missouri Department of Conservation (MDC) prepared the state’s Aquatic Nuisance Species Management Plan. The plan identifies the aquatic nuisance species that represent the largest existing threats to Missouri’s water resources.
Aquatic invasive species represent an ecological threat and an economic threat. Ecologically, they kill other species that the ecosystem depends on. They form dense monocultures that obstruct waterways, completely cover all available habitat, and provide habitat for noxious pests to breed. For instance, the first photo at right shows purple loosetrife. It appears so beautiful, but it forms dense mats along waterways that provide no habitat for fish, birds, or animals. The mats crowd out all other species and serve as breeding grounds for disease carrying mosquitoes.
(Click on photos for larger view.)
The second photo at right shows zebra mussels colonizing a native mussel. The third photo at right shows them encrusting a piece of equipment. They kill native species, foul equipment, and completely plug water intake pipes, shutting down power plants and industrial operations. They are sharp and cause cuts, requiring the use of protective gear to swim or wade, destroying the recreational value of the lakes and rivers they invade.
Nationally, the annual damage and cost to control non-native species was estimated at $138 billion in 2000. Missouri has about 1.83% of the land area of the United States. Multiplying $138 billion by 1.83% yields an estimate that non-native species cause about $2.53 billion in damages in Missouri each year.
Even such a small thing as fishing grounds ruined by invasive species are not only ecological and recreational losses, they are economic losses. The U.S. Fish and Wildlife Service estimated that Missouri fishing-related activities accounted for $657 million in 2011 – $374 million of it for trip-related expenses, and $282 million of it for equipment, licenses, and other expenses.
Twelve aquatic nuisance species could already be found in Missouri waters, according to the report, and an additional 14 threatened to arrive in the near future. I will give the list in my next post.
Missouri Department of Conservation Aquatic Nuisance Species Management Plan. (2007). ANS Task Force Home Page » Documents » State and Regional Plans » Missouri Department of Conservation Aquatic Nuisance Species Management Plan. http://www.anstaskforce.gov/State%20Plans/MO_ANS_Management_Plan.pdf.
U.S. Department of the Interior, U.S. Fish and Wildlife Service, and U.S. Department of Commerce, U.S. Census Bureau. 2011 National Survey of Fishing, Hunting, and Wildlife-Associated Recreation. http://www.census.gov/prod/2013pubs/fhw11-mo.pdf.