Photo: Ben McCauley
Acerca of
Invasive species
Five aquatic invasive alien species (EAEE) are found in the Brome Lake watershed, namely the rusty crayfish (Orconectes rusticus) as a wildlife representative, the Eurasian watermilfoil (Myriophyllum spicatum), the common reed (Phragmites australis ), the curly pondweed (Potamogeton crispus) and the frogbit (Hydrocharis morsus-ranae) as representatives of the flora. Introduced in a new region, outside their natural environment, the EAEE have no natural predator which allows them to grow rapidly. Once established, they can take the place of native species.
Rusty Crayfish
Faxonius rusticus
How to identify it?
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Blue-gray or brownish-green shell
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Red spots on the sides of the shell
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Black bands at the tips of the claws
Origin
Ohio River watershed, United States
Impact
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It is larger and more aggressive than native crayfish.
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It is highly voracious, monopolizing resources such as food.
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It has a greater reproductive capacity than other crayfish species.
Action
The rusty crayfish is already well established in Brome Lake. A 2018 survey estimated the crayfish population at over 1.8 million individuals, possibly reaching up to 10 million. As such, population control is no longer feasible. However, it remains important to contain the species and prevent its spread to other bodies of water by thoroughly cleaning boats and water equipment.
Did you know the rusty crayfish is edible? You can catch it using a dip net or a trap. Conservation Lac Brome offers a trap loan program from April to August each year!
Flora
Eurasian watermilfoil
Eurasian watermilfoil is an invasive alien plant species. This rooted plant has a stem surrounded by leaflets that look a bit like conifer thorns. It spreads rapidly by cuttings when a fragment is cut. Watermilfoil, which can reach 6 m in height, forms dense canopies on the surface, which interferes with recreational activities and the development of native aquatic plants.
