By the Numbers: Invasive Species

In recognition of National Invasive Species Awareness Week (Feb. 22-28), we present a look at some invasive species facts.

10

The top 10 reported invasive species in Wisconsin are: European swamp thistle, Reed canarygrass, Glossy buckthorn, Common buckthorn, Bull thistle, Garlic mustard, Bush honeysuckle, Japanese knotweed, Lesser burdock, Common mullein.

49

Percentage of threatened or endangered species that have declined due to invasive species.

75

The number of organisms added to the list of prohibited and restricted species in the state by the Wisconsin Natural Resource Board in December 2014.

180

The number of non-native species that have established in the Great Lakes basin in the past two centuries.

2,000

The number of seeds a Phragmites seed head can produce each year.

13112

The number of the Feb. 3, 1999, Executive Order that directed federal agencies to address invasive species issues and established the National Invasive Species Council.

50,000

The estimated number of non-native species in the United States. Of that, approximately 4,300 are considered invasive species.

34.7 billion

Estimated annual cost in dollars of invasive plants to the U.S. economy.

Source: Door County Invasive Species Team newsletter; Invasive Plants Association of Wisconsin, Midwest Invasive Species Network; U.S. Fish and Wildlife Service