The anticipated environmental consequences of the proposal are positive. All of the invasive species proposed for regulation have caused significant negative ecological impacts when introduced in areas outside of their natural distribution. Applying the proposed prohibitions to these species would decrease the likelihood that these species will be introduced into or spread within Ontario, while also providing legislative tools to support their control and eradication if the species are found in Ontario.
The anticipated social consequences of the proposal are positive. As the majority of these species are not currently present in Ontario or are the subject of on-going eradication actions, the immediate social consequences are anticipated to be minimal. However, similar to the ecological impacts identified above, areas in which these species have been introduced have experienced reduced recreational and aesthetic values as a result of impacts such as habitat alteration and species loss. The application of regulatory prohibitions on the introduction or spread of these species in Ontario will reduce the likelihood that existing socio-economic values may be impacted in the future or will assist in reducing those impacts where they already occur.
The anticipated economic consequences of the proposal are neutral to positive.
• The four Carp species and Snakehead family are already subject to similar prohibitions under the Federal Aquatic Invasive Species Regulations. Therefore, the application of this proposal will not impact economic activities associated with those species.
• The remaining species proposed to be classified as prohibited are not known to have ever been in trade in Ontario, or have generally been regulated in neighbouring jurisdictions, and are therefore no longer common in trade, so there would be only a limited impact as a result of the application of import and transport prohibitions. Where there is an existing economic interest in a limited number of these species, alternative species have been identified which satisfy the interest while removing the ecological threat and other associated negative socio-economic consequences if these species were introduced in Ontario.
• The three species proposed to be classified as restricted are generally no longer sold commercially in Ontario due to their ecological impacts. Therefore, the impact to the horticulture trade is expected to be minimal. Alternatively, management and removal costs associated with these species are increasing on an annual basis as these species continue to spread in Ontario. The application of this proposal is expected to assist in efforts to prevent further spread of these species in Ontario, therefore reducing future economic impacts of these species.
The following web links provide additional (or supporting) information:
- Conference of Great Lakes and St. Lawrence Governors and Premiers “Least Wanted Aquatic Invasive Species List”
- Ontario Invasive Species Act, 2015
- Ontario Invasive Species Strategic Plan, 2012
- Ontario’s Invading Species Awareness Program
- Government of Canada Aquatic Invasive Species Regulations
Bighead Carp (Hypophthalmichthys nobilis)
Native to eastern Asia, Bighead Carp were introduced to the southern United States to improve water quality in aquaculture facilities and as a food-fish. They escaped to the Mississippi River basin during flooding events, and now threaten to invade the Great Lakes basin through hydrological connections between the two watersheds. Bighead Carp reproduce rapidly and consume vast quantities of zooplankton and phytoplankton (tiny microscopic animals and plants) – which is the basis of the aquatic food chain.
Bighead Carp could have major ecological and economic impacts on the Great Lakes basin by competing with native fishes for food, and disrupting the food web. These impacts could have significant effects on the Great Lakes commercial and recreational fishery. Although there have been incidental reports of Bighead Carp over the past decade in Lake Erie, extensive monitoring and surveillance by state and provincial agencies have not found any evidence of an established population.
Silver Carp (Hypophthalmichthys molitrix)
Native to the lowland rivers of eastern China and Russia Silver Carp species were introduced to southern United States’ aquaculture facilities in the 1970s to control algae. It escaped into the Mississippi, Missouri and Ohio Rivers during flooding events and is now spreading northwards towards the Great Lakes basin.
Silver Carp can grow rapidly consuming large quantities of food every day, and reaching sizes of up to 27kg and 0.9m in length. Silver Carp feed on phytoplankton and zooplankton (tiny microscopic plants and animals) which is the primary food supply of many of our native fishes. If Silver Carp were to become established in the Great Lakes they could have significant ecological impacts and harm the recreational and commercial fisheries. Silver Carp are sensitive to vibration in the water, and can leap out of the water, posing a health risk to boaters.
Grass Carp (Ctenopharyngodon idella)
Native to eastern Asia, Grass carp was introduced to the southern United States in the 1960s and 70s to control aquatic plants. It has also been used for this purpose in Alberta and Saskatchewan. Today, it has become established in the wild throughout the Mississippi river watershed, and has been reported in 45 U.S. states. Grass Carp are a problem because they feed heavily on aquatic plants and can degrade spawning and nursery habitats for other fish. Their feeding activity can also promote algal blooms, and impact water quality. There is no evidence to date of an established population in the Great Lakes basin, although Grass Carp have been captured at several locations in Ontario in recent years.
Black Carp (Mylopharyngodon piceus)
Native to eastern Asia from southern Russia to northern China Black Carp were brought to the southern United States to assist with control of parasites in aquaculture facilities. It has been recorded in the Mississippi River and Red River watersheds in the United States. To date, it is not known to have spread as widely as the other invasive carp species.
Black Carp feed extensively on molluscs, and poses a significant threat to native snails and mussels in the Great Lakes basin many of which are considered species at risk.
Snakeheads - all species of the family Channidae including Northern Snakehead (Channa argus)
The Northern Snakehead is a predatory fish native to southern and eastern Asia that is now found in several American states including Virginia, Maryland, Pennsylvania and New York. It may have been introduced to the United States by people who bought live snakehead from fish markets or pet shops and later released them into lakes, rivers or ponds.
The Northern Snakehead is a voracious predator that lives in lakes, ponds, rivers and streams. The snakehead has been dubbed a “frankenfish” because of its reptile-like appearance, aggressive eating habits and mouthful of long, sharp teeth. It feeds on a wide range of foods including fish, frogs, small reptiles, small birds and mammals. Because the Northern Snakehead is highly adaptable it could thrive in the Great Lakes and Ontario waters and seriously threaten native fish and invertebrate populations.
While Northern Snakehead is the primary species of concern, all species of the Snakehead family Channidae are proposed to be prohibited under this regulation, as all species pose some level of risk to the natural environment of Ontario. This would also help to avoid the accidental import of Northern Snakehead juveniles as it is difficult to identify the various species of Channidae as juveniles.
Stone Moroko (Pseudorasbora parva)
Stone Moroko is a small minnow species (8cm), native to eastern Asia. It feeds on zooplankton (tiny aquatic animals that normally eat algae), and thus promotes algal blooms which can deplete oxygen in the water and affect native fishes. It also feeds on the juveniles of native fishes and can be a vector of infectious fish diseases. It is considered a serious invasive threat to both native and farmed fishes in Europe.
Stone Moroko has not been documented as either introduced or established anywhere in the United States or Canada. Its most likely means of introduction would be as an aquarium fish, or as a hitch-hiker with other fish species in trade.
Zander (Sander lucioperca)
Zander is a fish native to continental Europe to western Siberia. It is an aggressive fish which could out-compete native fish for food and habitat. Records of Zander in North America are limited to a single lake in North Dakota, where it was stocked in a single lake in 1989 and has since become established in that waterbody. Climate and risk assessment modelling within the Great Lakes suggest that it could become established if introduced.
Wels Catfish (Silurus glanis)
Wels Catfish is a large species of catfish native to areas of central, southern, and eastern Europe which has been introduced to western Europe. Voracious predatory habits make the Wels catfish a serious threat to populations of native species and may impact water quality where they are introduced. The primary pathway for the introduction of Wels Catfish in Ontario is illegal stocking.
Killer Shrimp (Dikerogammarus villosus)
Killer Shrimp is a small aquatic crustacean (3 cm) native to the Ponto-Caspian region. It is a voracious predator that feeds on other aquatic invertebrates and aggressively out-competes native species. It has recently invaded western Europe where it has disrupted ecosystems, reduced biodiversity and caused local species extinctions. Killer Shrimp has not been reported in North America, but is considered a serious threat to the health of the Great Lakes basin ecosystem. The primary pathway for the introduction of Killer Shrimp to the Great Lakes basin is via ballast water discharge from ocean-going vessels. In Canada, the federal government oversees ballast regulations which are designed to prevent the introduction of invasive species through this pathway.
Yabby (crayfish) (Cherax destructor)
The Yabby is a large crayfish native to southern Australia which grows to lengths of approximately 20cm. There are no reported introductions of Yabby in the United States or Canada. However, globally there is growing interest in crayfish for aquaculture and they are also gaining popularity as aquarium species. If introduced, Yabby possess a significant risk to native crayfish populations.
Golden Mussel (Limnoperna fortune)
Native to Asia, Golden Mussel has invaded several regions of the world including South America. Golden Mussel is similar in appearance and behaviour as the Zebra Mussel, and can cause significant economic impacts by clogging water intakes in industrial facilities. It can also reduce the diversity of native mussels and cause major ecological disruptions in aquatic ecosystems.
The Golden Mussel has not been detected in the Great Lakes basin. However, there is concern that the broad ecological tolerances of the Golden Mussel may enable it to invade colder climates.
Hydrilla (Hydrilla verticillata)
Hydrilla is widely considered to be the worst aquatic weed in the United States. Native to Asia, it has caused major economic and ecological impacts by forming dense stands that displace native species, impede water flow, restrict small boat navigation, and other recreation uses.
Hydrilla can be used as an aquarium plant, and is sometimes also found as a “hitch-hiker” in aquatic plants used in water gardens. It has been found throughout the southern United States and has most recently begun to invade the northern Great Lakes states including New York, and Indiana. Significant efforts are currently underway to eradicate populations in these jurisdictions. Hydrilla has never been recorded in the wild in Ontario or Canada. It has occasionally been reported to be sold in the aquarium industry in the province.
Brazilian Elodea (Egeria densa)
As its name suggests, Brazilian Elodea is an aquatic plant, native to South America. It was introduced to North America in the late 19th century, and is commonly used in aquariums. Its vigorous growth enables it to out-compete native aquatic plants, and form dense impenetrable stands over large areas. These dense stands interfere with water flow and recreational uses.
It has not been reported in the wild in Ontario waters; however, it has been reported in the Great Lakes states of Ohio, Pennsylvania, New York, Indiana and Illinois.
Water Soldier (Stratiotes aloides)
Water Soldier is an aquatic plant, native to Europe and southwest Asia but is established in Ontario within the Trent Severn Waterway, where it was first discovered in 2008. Ontario is the only known jurisdiction in North America where this species has been found in the wild.
Water Soldier is used in Ontario as an ornamental plant for water gardens. In the wild, it can form dense floating mats that out compete native plants and hinder recreational boating, angling and swimming; its sharp serrated leaf edges can also cut swimmers.
European Water Chestnut (Trapa natans)
Water chestnut is an aquatic invasive plant, native to Eurasia and Africa but is established in specific locations in Ontario. It forms extremely dense floating mats of vegetation which can shade out native vegetation, decrease plant biodiversity, and reduce oxygen levels which can lead to fish kills. The thick mats of vegetation also make recreational activities extremely difficult. The fruits’ “nuts” have sharp spines which can accumulate on shore and cause injury when stepped on.
Water chestnut has been used in North America as an ornamental water garden plant. From original points of introduction it can be spread by recreational boaters, and dispersed by water currents. It is an extremely problematic plant, and jurisdictions in the north-eastern United States including Quebec and New York have spent millions of dollars in control programs. In Ontario, European water chestnut is present in the Ottawa River, Rideau River Canal and Lake Ontario near Wolfe Island, where eradication efforts are underway.
Parrotfeather (Myriophyllum aquaticum)
Parrotfeather is an aquatic submergent plant native to South America. It can form dense stands that can completely colonize small ponds and restrict water flow in drainage ditches and irrigation canals. It can also outcompete and replace native species that may be more valuable to fish and wildlife.
Parrotfeather is commonly sold for water gardens and aquariums, as an “oxygenating” species. It can also be spread by recreational boats via plant fragments. It has been reported in the wild in numerous U.S. states, as well as in the Fraser Valley in British Columbia.
Phragmites (Phragmites australis subsp. australis)
Invasive Phragmites (European Common Reed) is an established invasive plant causing damage to Ontario’s biodiversity, wetlands and beaches throughout southern and central Ontario. Invasive Phragmites is a perennial grass that has been damaging ecosystems in Ontario for decades. It is not clear how it was transported to North America from its native home in Eurasia.
Invasive Phragmites is an aggressive plant that spreads quickly and out-competes native species for water and nutrients. It releases toxins from its roots into the soil to hinder the growth of and kill surrounding plants. While it prefers areas of standing water, its roots can grow to extreme lengths, allowing it to survive in relatively dry areas.
Dog Strangling (Vincetoxicum rossicum, V. nigrum)
The name “Dog-strangling Vine” refers to two invasive plants native to Eurasia– black swallowwort and pale swallowwort. These look-alike members of the milkweed family were introduced to the northeastern United States in the mid-1800s for use in gardens. In recent years these perennial vines have spread rapidly throughout central and southern Ontario.
Dog-strangling Vine forms dense stands that overwhelm and crowd out native plants and young trees, preventing forest regeneration. Leaves and roots may be toxic to livestock. Deer and other browsing animals also avoid dog-strangling vine, which can increase grazing pressure on more palatable native plants. The vine also threatens the monarch butterfly, a species at risk in Ontario. Monarch’s lay their eggs on the plant, but the larvae are unable to complete their life cycle and do not survive.
Japanese Knotweed (Fallopia japonica)
Japanese Knotweed is an aggressive semi-woody perennial plant that is native to eastern Asia. In the 1800’s it was introduced to North America as an ornamental species and also planted for erosion control. It has since spread throughout the United States and Canada, and is established in Ontario. It is especially persistent due to its vigorous root system, which can spread nearly 10 metres from the parent stem and grow through concrete and asphalt. This invader is very persistent and once it becomes established, is incredibly difficult to control.