Species and Origin: The common carp is a large omnivorous fish. They have large scales, a long dorsal fin base, and two pairs of long barbels (whiskers) in its upper jaw. Native to Europe and Asia, it was intentionally introduced into Midwest waters as a game fish in the 1880s. (Be aware of a native look-a-like: the native fish bigmouth buffalo looks like a carp without barbells)
Common carp are one of the most damaging aquatic invasive species due to its wide distribution and severe impacts in shallow lakes and wetlands
Their feeding disrupts shallowly rooted plants muddying the water
Location: Grows from the shore to depths of up to 15 feet.
Description: Leaves are somewhat stiff and crinkled, approximately 1/2-inch wide and 2 to 3 inches long; leaves are arranged alternately around the stem, and become more dense toward the end of branches; produces winter buds can be confused withclaspingleaf pondweed.
Hints to identify: Has small "teeth" visible along edge of leaf; begins growing in early spring before most other pondweeds; dies back during midsummer; the flower stalks, when present, stick up above the water surface in June; appears reddish-brown in the water, but is actually green when pulled out of the water and examined closely. Easily confused with claspingleaf pondweed, which has leaves with no "teeth" around their edges.
Importance of plant: Provides some cover for fish; several waterfowl species feed on the seeds; diving ducks often eat the winter buds.
Eurasian watermilfoil was accidently introduced to North America from Europe. Spread westward into inland lakes primarily by boats and also by waterbirds, it reached Midwestern states between the 1950s and 1980s.
In nutrient-rich lakes it can form thick underwater stands of tangled stems and vast mats of vegetation at the water's surface. In shallow areas the plant can interfere with water recreation such as boating, fishing, and swimming. The plant's floating canopy can also crowd out important native water plants.
A key factor in the plant's success is its ability to reproduce through stem fragmentation and runners. A single segment of stem and leaves can take root and form a new colony. Fragments clinging to boats and trailers can spread the plant from lake to lake. The mechanical clearing of aquatic plants for beaches, docks, and landings creates thousands of new stem fragments. Removing native vegetation creates perfect habitat for invading Eurasian watermilfoil.
Origin: Chinese mystery snail (CMS) is native to Asia. It was brought to California in 1892 as a food source, and found in Massachusetts in 1915 — likely an aquarium release. The historic range of the banded mystery snail (BMS) is the southeastern U.S., primarily in the Mississippi River system up to Illinois. It is a popular aquarium snail that’s been released in Minnesota.
Impacts: Both snails can form dense aggregations. In Asia, the CMS can transmit human intestinal flukes, however, cases have not been documented in the United States. It also is a carrier of trematode parasites found in native mussels. BMS can cause mortality of largemouth bass embryos when they invade nests.
Status: CMS are present in over 80 waters and BMS occurs in about 50 waters in Minnesota.
Where to look: They are mainly found in lakes and in slow moving rivers. They are called “mystery” snails because in spring, they give birth to young, fully developed snails that suddenly and mysteriously appear. After reproducing in their fourth year, they die and their shells wash up on shore.
Regulatory classification (agency): Chinese, Japanese, and other mystery snails (species in the genus Bellamya / Cipangopaludina) are regulated invasive species (DNR). The banded is an unlisted nonnative species. All are illegal to introduce into state waters.
Means of spread: Most likely introduced via dumping of aquariums and by transfer from one water body to another.
Keys to identification: Chinese mystery snail has small shallow depressions above the shell opening and rows of fine, short stiff hairs parallel to the whorl of the shell (may wear off with age and abrasion).
Banded mystery snail has red bands that are parallel to the whorl of the shell.
How people can help:
Never move aquatic species from one water body to another.
Purple loosestrife is a wetland plant from Europe and Asia. It was introduced into the east coast of North America in the 1800s. First spreading along roads, canals, and drainage ditches, then later distributed as an ornamental, this exotic plant is in 40 states and all Canadian border provinces.
Purple loosestrife invades marshes and lakeshores, replacing cattails and other wetland plants. The plant can form dense, impenetrable stands which are unsuitable as cover, food, or nesting sites for a wide range of native wetland animals including ducks, geese, rails, bitterns, muskrats, frogs, toads, and turtles. Many rare and endangered wetland plants and animals are also at risk.
Currently there are about 2,000 purple loosestrife infestations recorded in 77 of Minnesota's 87 counties. Of those sites, the majority (70%) are lakes, rivers, or wetlands. Inventory totals indicate that Minnesota presently has over 58,000 acres infested with purple loosestrife.
Likely means of spread: Seeds escape from gardens and nurseries into wetlands, lakes, and rivers. Once in aquatic systems, seeds are easily spread by moving water and wetland animals.
Appearance: Perennial aquatic herbaceous plant. It grows 1-4' high on an erect stem along shores in shallow water. In deeper water it grows submerged without producing flowers. Flowering rush is very difficult to identify when not in flower. It closely resembles many native shoreland plants, such as the common bulrush.
Leaves: Leaves are sword-shaped, triangular in cross section.
Flowers: Pink flowers are arranged in umbels (umbrella-shaped).
Seeds: Populations in the eastern U.S. produce seeds. Only one Minnesota population (Forest Lake) produces viable seeds.
Roots: Reproduces by vegetative spread from its rootstock in form of bulb-lets. Both seeds and bulb-lets are dispersed by water current.