Aquatic Invasive Species

Where are the Aquatic Invasive Species?




All species: Early Detection & Distribution Mapping Systems
All species: U.S Geological Survey 
Multiple databases: Aquatic Invasive Species Network 
Invasive Mussel Monitoring: Aquatic Invasive Species Network 

Aquatic Invasive Species Profiles:


Image courtesy of the Invasive Species Society of British Columbia

Latin name:

Lithobates catesbeiana

Native to:

Eastern North America

Regional Distribution:

The American Bullfrog is not yet found within the Columbia Shuswap Regional District.  In British Columbia, it can be found in the lower mainland, southern Vancouver Island, South Okanagan, and recently in the South Kootenays.  It is widely distributed in the western United States where initial introductions took place.


American Bullfrogs are large robust frogs, green or brown in colour with large golden eyes. Adult females are larger than males and can reach 20 cm in length and 750 g in weight.  Both males and females have a large distinct tympanum (ear) behind the eye.  For more information visit the B.C. Frogwatch Program.

Impacts of invasion:

  • Voracious predator that eats anything that fits into its mouth, including endangered native amphibians and fish (including their eggs and larvae)
  • Can spread the chytrid fungus, which is responsible for declining amphibian populations
  • Readily outcompetes native frog populations. There is scientific evidence that when bullfrog colonies grow in wetlands it is followed by a rapid decline of native frogs
  • Tadpoles act as “ecosystem engineers”, meaning they are extremely competitive and take food and habitat away from native frogs


Mapping the spread and physically catching and removing American Bullfrogs from the ecosystem can reduce the movement of this invader into the Columbia Shuswap Regional District.

You can help! Don’t transport Bullfrogs from one pond to another.  Bullfrog tadpoles and adults can be enticing ‘pets’ for children and for gardeners looking to liven up their backyard ponds, but this simple form of movement seems to be one of the primary ways Bullfrogs spread across the province.

There are no known infestations of American Bullfrog within the Columbia Shuswap, so we need your help to report any sightings in this region. Please send in an online report and take photos to help with species ID.

Fun facts:
American Bullfrogs are voracious predators.  They will eat anything that fits into their mouth including insects and other small invertebrates, birds, small mammals, snakes, and other frogs (including smaller Bullfrogs). Watch this impressive National Geographic video of their hunting.

Helpful Links:
Video of American Bullfrog Calling

American Bullfrog in the Central Kootenays

Frogwatch BC – report provincial frog and bullfrog sightings!


Image courtesy of the Columbia Shuswap Regional District

Latin name:

Myriophyllum Spicatum L.

Native to:

Europe, Asia and North Africa

Regional Distribution:
Eurasian Water Milfoil was first introduced to the Columbia Shuswap Regional District in August 1981.  Since its introduction, Eurasian Water Milfoil has colonized throughout Shuswap Lake, Little Shuswap Lake, Mara Lake and the Shuswap River.  The largest infestation is located in the Salmon Arm Bay.


Eurasian Water Milfoil is a rooted aquatic plant colonizing lakes and rivers at depths from 0.5 m to 5 m.  The milfoil stem is slender and can grow up to 175 cm long, 4 to 5 leaves are arranged in whorls around the stem and are characterized by 12 to 21 leaflet pairs per leaf.  During the spring and summer months, rapid growth can create dense mats of surfacing milfoil adversely affecting recreational activities, flood control, drainage, water conservation facilities and fish spawning areas.


The Columbia Shuswap Regional District is actively controlling the Eurasian Water Milfoil with a state-of-the-art vessel used exclusively in the Shuswap for treating infested Milfoil sites. The treatment involves rototilling shorelines in autumn and early winter, when water temperatures are too cold for plant fragments to establish a new colony.

For lakes without Eurasian Water Milfoil, prevention is the best control. Clean, Drain and Dry your boat before launching into another water-body.

For more information visit the CSRD Milfoil Control Program. 

Fun facts:
Eurasian Water Milfoil spreads primarily by fragmentation in the summer months. Fragmenting pieces can spread rapidly through boating activities and natural water currents.  It only takes one small piece of Milfoil to start a new plant which can expand into a colony in a short period of time.


Image courtesy of the Invasive Species Council of BC

Latin name:

Zebra Mussels: Dreissena polymorpha

Quagga Mussels: Dreissena rostriformis bugensis

Native to:

Southern Russia and Ukraine

Regional Distribution:
No confirmed infestations in BC. However, there was a close call when a boat carrying viable zebra mussels entered Shuswap lake in 2012. Once found, the boat was removed and decontaminated. Currently the Ministry of Environment is monitoring water quality to check for any signs of larvae or mussel activity in the impacted area. CSISS conducts mussel detection surveys in coordination with the Ministry of Environment throughout the region.

Zebra and Quagga mussels are small fresh-water mussels. They have a D shaped shell with striped patterning.  They grow from the size of a finger nail up to about 4-5 cm long. They attach themselves to various substrates by using string-like ‘byssal threads”. For more info visit the Zebra/ Quagga Mussel Fact Sheet developed by the Province of BC.

The best control is prevention and early action.
Clean, Drain and Dry your boat before launching into another water-body.
Let’s keep BC Zebra mussel free; if you do find evidence of non-native mussels report them right away!

Fun facts:
These species could cause millions of dollars in damage if established in BC by clogging intake valves and waterways and damaging infrastructure. Zebra mussels damage local ecosystems and could impact recreational activities in the Shuswap and Columbia lakes.  The most effect step you can take to avoiding this damage is to Clean, Drain and Dry your boat before transporting it to another water body.


Zebra and Quagga Mussels

A major threat to BC’s freshwater lakes and rivers are zebra and quagga mussels.

For more information visit the BC Inter-Ministry Invasive Species Working Group. 

Screen Shot 2015-12-11 at 1.18.56 PMClick to watch Mussel Threat

To Report a Mussel:
In British Columbia any suspected, transport, possession, sale or release of Zebra Quagga Mussel should be reported immediately to:

Conservation Officer Services Hotline 1-877-952-7277 website.


Latin name:

Iris pseudacorus

Native to:

Europe, central Asia and northwest Africa

Regional Distribution:
Yellow flag iris can be found in the shallows along the perimeter of lakes in the Shuswap region. It has naturalized from people’s gardens and can form a dense mat of rhizomes, out-competing native vegetation and reducing the quality of wetland habitats. Please do NOT purchase or plant these deceptive invasives!

Large yellow flower with broad, sword-shaped leaves. It is most easily identified when in bloom.
Yellow flag is the only iris to inhabit wetland areas; if you see it report it immediately and remove from private property.

The best control is prevention (do not plant in your garden) and early action.
For recommended control methods please visit these resources:

Fun facts:
Recent efforts have been made by the White Lake Stewardship group to remove an infestation of yellow flag iris threatening the wetland there.  Check out new research on Yellow Flag Iris control in our area!