An invasive aquatic plant called hydrilla was detected in Ontario water for the first time in September, and according to a University of Guelph biologist, it most likely took an unusual path.  

Dr. Josef Ackerman, professor in the Department of Integrative Biology, studies physical ecology and aquatic sciences. He says scientific sources indicate the original introduction of hydrilla in North America likely occurred in the late 1950s when it was imported through the southern United States for the aquarium trade and used in personal aquariums or water gardens. 

“Many people accidentally or intentionally empty their aquaria into ditches, rivers or lakes,” he says. “If there are hydrilla plants, fragments or sediment containing their tubers in the water, then the plant can establish itself in a new location.” 

Hydrilla is a species of concern because it can grow up to 2.5 centimetres per day and quickly choke out native species because of its competitive nature. 

Many aquatic invasive species spread most rapidly through human transport on boats and other watercraft, or from bait buckets moving between lakes. Hydrilla is an aquatic plant that has evolved to live in water and can also spread naturally downstream in a watershed. 

Once in the ecosystem, it is difficult and expensive to get rid of species like hydrilla, so Ackerman recommends a preventative approach.  

“People should never empty their aquariums in nature and, better yet, avoid using hydrilla in the first place,” he says.  

Ackerman also encourages people to inspect and clean their watercraft to remove any plants and sediments they may have collected in the water. 

Ackerman is available for interviews. 

Contact: 

Dr. Josef Ackerman 
ackerman@uoguelph.ca