Live garden plants like water hyacinth and water lettuce are being sold right across the country despite the fact they represent a clear and unregulated threat to Canada’s aquatic ecosystems, according to a UWindsor biology professor who will appear as an expert on invasive species before a government standing committee in Ottawa on Wednesday.

Hugh MacIsaac.

“These plants can clog tributaries of the Great Lakes during the summer and are likely reintroduced annually by people who purchase them in local stores,” said Hugh MacIsaac, director of the Canadian Aquatic Invasive Species Network.

Dr. MacIsaac was invited to speak at a May 16 meeting of the standing committee of the Department of Fisheries and Oceans to tell its members about some of the successes scientists have had in battling such invasive species as round gobies and zebra mussels, as well as some of the challenges they face from such new threats as Asian carp.

Besides the threat of laker ships transporting invaders in their ballast tanks throughout inland waterways and the lack of a federal hull fouling policy, MacIsaac said he’ll tell the committee that certain aquatic plants pose a serious threat to our lakes and rivers.

MacIsaac said he found one vendor in the Toronto area who sold nine species of aquatic plants that are all considered invasive in Canada. One of those species – water soldier – is the subject of an expensive, multi-year eradication effort by the Ontario government in the Trent-Severn Waterway, a mere 150 kilometers away.

“Clearly, the left hand does not know what the right hand is doing,” said MacIsaac, a professor at the University of Windsor’s Great Lakes Institute for Environmental Research.

Despite those threats, MacIsaac said the government has made a great deal of progress in battling invasive species.

“Compared to a short 10 years ago, Fisheries and Oceans Canada and Transport Canada have come a long way to identify and reduce threats of alien invasive species,” he said. “All of the DFO scientists in my network put in tremendous efforts to address alien species issues and are a great asset to the federal government and all Canadians.”

MacIsaac said he’ll also tell the committee about a new genetic detection technique called pyrosequencing, which the CAISN research network is using to analyse water samples for rare alien species by matching DNA sequences to on-line databases. He said the technique is far more sensitive than traditional sampling with nets and microscopes at detecting colonizing alien species as well as rare native species.

“We’ve completed screening of the port of Hamilton and have detected more than six times as many species of the two most common groups of organisms than all previous records in the literature based on traditional methods,” he said. Similar work in Vancouver, Churchill and Halifax also revealed much higher levels of diversity than previously recorded.