Invasive Species
Invasive species have negative ecological, economic, social and public health impacts. They have been widely identified as a serious threat to global and local biodiversity. Once established, they often out-compete native species for limited resources such as food and habitat, alter and damage existing habitat, displace native species and in some cases prey directly upon native species. Their impacts are found in our waterways, along our roadsides, in our wilderness areas and in both rural and urban communities. The Michigan Department of Natural Resources recognizes these threats and is working hard to prevent new invasions, limit the spread of existing invasions and limit their associated impacts.
|
| |
|
Invasive Species of the Month
Rusty Crayfish (Orconectes rusticus)
The Rusty crayfish is one of over 350 crayfish species in the world and despite being a native species in the Ohio River Basin, has become an invader in Michigan waters. Introduced through anglers who commonly use the rusty crayfish as bait, this species has out-competed native crayfish species and has caused significant declines in aquatic plants and invertebrates. The decline of plants and plant beds in northern lakes can have far-reaching effects as these environments provide important habitat for aquatic invertebrates and young game fish, such as perch and walleye. The rusty crayfish is a successful invader due to its opportunistic eating habits; it can eat much more than native species because it has a higher metabolic rate and a wide-ranging diet, as well as its ability to establish a population with just a single female. Female crayfish may carry viable eggs with them into new environments, and populate a new water body in the absence of a male crayfish. Rusty crayfish may be found in lakes, streams or rivers, though unlike many native species, require permanent water bodies to persist. They prefer areas with logs or rocks which provide cover. Rusty crayfish are identified by distinctive dark spots on the carapace and black bands on the claws. Managing for rusty crayfish requires both removal of adults from the population through manual means and also managing for higher fish populations in the effected water body. Recent research has shown a negative response in crayfish to higher populations of bass and sunfish. Chemical controls are infeasible, as chemicals available do not successfully target a single species of crayfish. The best method of control is to prevent further spread by becoming educated about the species, removing individuals from the wild when properly identified and choosing bait alternatives. For more helpful information visit the Minnesota Sea Grant site by clicking here.
|
| |
| |
Invasive Species News
Michigan's Aquatic Invasive Species Plan Approved On June 17, 2013 the federal Aquatic Nuisance Species Task Force approved Michigan's Aquatic Invasive Species Management Plan. The plan was developed collaboratively between the Departments of Environmental Quality, Natural Resources, Agriculture & Rural Development and Transportation, in an effort to develop a comprehensive strategy for preventing the spread of aquatic invasive species.
The Michigan AIS Management Plan outlines a direction for preventing future invasions, detecting new threats, treating current infestations and managing negative impacts posed by AIS on the Great Lakes. The Plan underwent a review by the Michigan AIS Advisory Council before ultimately being approved. Currently, a cooperative effort is underway to administer and implement the AIS Management Plan on a diverse array of projects including Asian Carp monitoring and management, early detection, rapid response efforts and education & outreach. To read the entire AIS Management Plan visit michigan.gov/aquaticinvasives.
No signs of White Nose Syndrome in Michigan bats
Thirty-three known wintering sites of bats residing in Michigan were surveyed for this deadly fungus and no indications of its presence were found. White nose syndrome (WNS) appeared in 2006 in eastern New York and has spread rapidly, infecting bats in 22 states and 5 provinces. With an estimated 98 percent mortality rate in infected sites, the US Fish and Wildlife Service have estimated that WNS has killed 6.7 million bats. Of the nine species in Michigan, the five cave-dwelling species including the federally endangered Indiana bats are highly susceptible to this disease. The fungus, Geomyces destructans, that causes WNS grows in cold conditions similar to those of the caves and mines where bats hibernate. It can be moved from place to place by humans and the bats themselves. No known human health risk is associated with WNS and the disease does not affect other wildlife. All of Michigan's bat species are highly beneficial insectivores and consume large amounts of insects that cause crop losses, damage forests and affect human health. Recent research estimates benefits of bats to the agricultural industry at $508 million annually. For more information on WNS, to view the Michigan WNS Response Plan or to report unusual bat observations, visit the Michigan Emerging Diseases website at michigan.gov/emergingdiseases.
|
| |
|
| |
|
Hot Topics
|
Sign up for email from the DNR