Thunder Bay

Invasive spiny water flea the focus of Quetico-based study

A tiny invasive species called the spiny water flea will be the focus of a three year study in Quetico Provincial Park.

LU researcher Michael Rennie has received a grant of $75,000 from Quetico Foundation for 3-year program

Spiny water flea - the long spiny tail is a defence against small fish. (Jake Walsh)

A tiny invasive species called the spiny water flea will be the focus of a three year study in Ontario's Quetico Provincial Park.

Michael Rennie, an associate professor in biology, canada research chair in freshwater ecology and fisheries, and research fellow at the Experimental Lakes Area, will be looking specifically at the impact on fisheries, and the results will be used to form management plans for Quetico Park.

Rennie has secured a $75,000 grant from the Quetico Foundation to study the impact of the spiny water flea on two of Quetico's key fish species.

He said the spiny water flea first entered the Great Lakes via ship ballast.

"They originally came from Europe," he said. "So like the zebra mussel they came over from the Baltic region through the ballast of ships. So we saw them initially in the Great Lakes in the early early 1980s and then they quickly moved to inland lakes from there."

Rennie said the organism has spread through Minnesota, into many parts of Ontario and they are starting to spread through the prairie provinces.

He said the spiny water flea has made significant inroads in northwestern Ontario watersheds and is now spreading through Quetico park.

Rennie said the spiny water flea competes with the tiny organisms small fish feed on.

"Juvenile walleye and yellow perch respond pretty strongly to the presence of the spiny water flea. So in terms of reducing their growth rates that can have big concerns."

Michael Rennie, an associate professor in biology at Lakehead University and canada research chair in freshwater ecology and fisheries, said invasive species like the spiny water flea, as well as climate change, threaten pristine water systems, and may require a change in management strategies given ongoing environmental changes. (submitted)

Rennie said the research in Quetico will be primarily focused on two species: walleye and lake herring. He said they will be using information from previous fish monitoring studies in the park to compare the average sizes of young fish before and after the arrival of the water fleas.

"We have good information thanks to the sampling that's in place with the broadscale monitoring program through the Ministry of Natural Resources and Forestry," Rennie said. "As well as the monitoring that Parks [Canada] has been doing for several years now. We have a fairly good handle on where where these things are. So every time a monitoring crew goes out ... part of the program is to take some zooplankton samples with the idea that we can use it to track the spread of invasive species."

Rennie said that there is a lot at stake, as recreational fisheries are a keystone of local economies.

He noted that fisheries are worth $1.3 billion per year in Ontario alone. Rennie said a component of the study will include monitoring any potential impacts of climate change.

"We've got information going back to the 1980s," he said." We have a really good opportunity to look for changes that are unrelated to spiny water. So for instance if we go to a lake where we've seen growth changes in the fish and spiny water flea has invaded you know very well climate change is happening too. We have to look at other lakes where they haven't invaded and see if we've seen similar changes as well."