The spiny water flea feeds on small animal life called zooplankton. When populations of this invader are high, zooplankton consumption can be significant. Compared to native zooplankton species, it eats up to three times as much food. Unfortunately, this prey is also the preferred food of native predatory zooplankton and native species of juvenile fish, resulting in direct competition. (prevention and control)
Grows to approximately 1 cm ( .4 in. ) long including the tail. The tail, often seven times the length of the body, has three tiny barbs and a unique loop at the end of its tail that looks like a fishhook. It has a single black eye and a large, pointed brood sac. They eat tiny, aquatic organisms called zooplankton that are an important food source for some fish (especially juvenile fish) and invertebrates. (prevention and control)
When it gets a foothold in a wetland, it forms a dense monoculture, replacing native plant species and the habitat where fish and wildlife feed, seek shelter, reproduce and rear young. (prevention and control)
Milfoil grows quickly in the spring and once the stems hit the water surface, they branch in all different directions to produce a dense mat of vegetation and blocks sunlight for plants below the surface. Because of its ability to out compete native plant species a monoculture is created, and aquatic plant diversity can decrease. These thick mats of vegetation can add more phosphorous and nitrogen to the water column and alter water quality by raising pH and temperature and decrease dissolved oxygen making poor habitat for fish, waterfowl and other species. (prevention and control)
It has the potential to displace native aquatic plant species, alter fish communities and accelerate the growth of other selective plant life in shallow lakes and bays. When dense mats of fanwort decay, dissolved oxygen levels can be depleted to a point where fish and other aquatic organisms can die. (prevention and control)
Is aggressive and appears to be able to spread and displace native shoreline vegetation such as bulrushes, willows and cattails because of its thick root system. The ecological and environmental impacts of flowering rush on native flora and fauna are still not entirely known. Muskrats have been observed using the roots and stems of flowering rush to build their houses but this activity may also lead to further spread from root fragments. (prevention and control)
It can have a negative impact on wetland ecosystems. It has become one of the dominant plants in many eastern Ontario wetlands since its introduction, and has reduced native plant biodiversity. Once established, frog-bit can form very dense, impenetrable mats of floating vegetation, that prevent sunlight from reaching the submersed aquatic plants below. The poor growth conditions created by frog-bit can affect the survival of indigenous plants. These thick mats can also impede the movement of large fish and diving ducks.
In the fall, European frog-bit breaks apart and decomposes, falling to the bottom of the lake. The decomposition of huge volumes of vegetation in the water can deplete dissolved oxygen levels. If there are insufficient amounts of oxygen, fish and other aquatic organisms can die. (prevention and control)
The tunnels created by the larvae in the cambial layer girdles the tree. Signs that a tree has been infested are apparent when the top of the tree begins to die back and there are much fewer leaves. The tree begins to produce root suckers or long shoots from the trunk of the tree. There are small D-shaped holes along the trunk where the adults emerged and often there will be cracks in the trunk from tree forming a callus where damage occurs.
(prevention and control)
ALHB attacks both healthy and stressed hardwood trees of all sizes and can kill a tree within one to two years after a heavy infestation. It is considered to be the most serious forest pest in its native range in China, particularly for poplar species. Among ALHB's favourite trees that it feeds on are poplar, maple, willow, birch, elm, ash and horsechestnut. The holes and subsequent feeding on the inner layers of the tree cause girdling and eventually kill the tree. Often sap will leak from these holes and there will be sawdust on branches and the ground from the larval feeding activity. (prevention and control)
Round gobies have become extremely abundant in the St. Clair River, Lake Erie and parts of Lake Ontario reaching densities of more than 100 per cubic metre of water. In some areas they have become an annoyance to anglers due to their habit of stealing bait. The round goby is an aggressive fish that can spawn several times each season. These characteristics, combined with its abundance and relatively large size, mean that the round goby will probably have an impact on native fish species. The smaller tubenose goby is not as abundant and widespread as the round goby and should not have as much of an impact.
(prevention and control)
Carp are members of the minnow family and can grow to very large sizes under the right conditions. There are currently five species of Asian carp in North America that are of concern and they include: common carp (Cyprinus carpio), grass carp (Ctenopharyngodon idella), bighead carp (Hypophthalmichthys nobilis), silver carp (Hypophthalmichthys molitrix), and black carp (Mylopharyngodon piceus). Common carp have been in North America since the late 1800s and are now so widely distributed that they are thought of as a native species in most areas.
Asian carp are considered injurious in many areas and in May 2004, the Ontario government placed a ban on buying and selling live bighead, black, silver and grass carp. This ban also extends to selling these fish for use in aquariums and to grass carp for use in backyard ponds. Any banned carp species that are sold in food markets must be killed before the customer takes them from the store. Similar bans have also been implemented in the United States in many individual states.
Asian carp are all huge having the potential to grow to 4' to 5' in length and living up to 21 years. All are currently in the Mississippi river basin with only an electrical barrier in the Chicago Sanitary and Ship canal preventing them from moving into the Great Lakes.
(prevention and control)
The impacts on native species are not completely known. It can hybridize with the native golden shiner, which could pose a risk to this important baitfish species. Over time, the unique genetics of the native golden shiner could be lost. Young rudd could also compete with native fish for food and habitat resources. Unlike most native fish, the adult rudd is omnivorous, which means it can change its diet from insects to plants. Rudd eat large amounts of aquatic vegetation around the shoreline, which could degrade spawning and nursery habitats for young fish. Northern pike, muskellunge, yellow perch, and alewife use shoreline vegetation for nesting and as nursery areas for their young. Rudd do not process the large amounts of vegetation it eats efficiently and this results in more nutrients being released into the water. This increased nutrient flow can result in increased algal blooms, lower levels of dissolved oxygen and reduced water clarity and quality. (prevention and control)