Ecosystem Health Depends on Biodiversity

Invasive species pose a threat to Georgian Bay

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Jeremy Ramshaw and Tina Deenik go fishing.

U of G students Jeremy Ramshaw and Tina Deenik

For one U of G research group, “gone fishin’” means work, not play.

Guelph biologists have teamed up with partners including a multinational fishing-tackle company in a proposed study to help monitor and protect the increasingly threatened ecological health of Georgian Bay.

Following a pilot study last year, they hope to expand their project to help maintain water quality, preserve native plants and animals, and better understand ecosystems, not just in northern Lake Huron but around all of the Great Lakes.

Referring to Georgian Bay, integrative biology professor Kevin McCann says, “In the Great Lakes, this is one of our classic iconic ecosystems. The Canadian Shield and the Great Lakes are things we should probably protect.”

At Guelph, he’s working with Prof. Neil Rooney, School of Environmental Sciences; Chris Weland, forensic analyst with U of G’s Biodiversity Institute of Ontario; and project manager Jamie Simpson.

They say Georgian Bay faces a number of ecological threats.

Invasive species may supplant native plants and animals or at least disrupt long-established food webs. Those invaders include such animals as gobies and zebra mussels, and plants such as Eurasian water-milfoil.

Some observers believe the bay now supports fewer kinds of organisms than it used to. Less diverse ecosystems may be less healthy and more vulnerable to ecological impacts, says McCann, an ecologist.

Water quality changes in some spots around the bay also worry cottagers, including Weland. He has observed more algal blooms in recent years near his family cottage on Sturgeon Bay.

Effects of falling water levels in the Great Lakes alarm scientists, industry and commercial groups, and the general public.

Referring to several municipal proposals to top up dwindling groundwater supplies by tapping into the lakes, Simpson says, “The Great Lakes are under such tremendous pressure from development and water-taking. The pressures are enormous, and it’s going to change the structure of food webs.”

This project is intended to help scientists sketch out current food webs and catalogue organisms living in the bay. Adds Simpson: “If we don’t know what we have now, we won’t know how changes will affect the sustainability of ecosystems and the sustainability of society.”

The Guelph team is working with Georgian Bay Forever, a charitable research and teaching organization based in Caledon, Ont., and with Pure Fishing Canada.

Based in Brantford, Ont., the latter company will supply high-tech angling equipment for the project. Those supplies will allow the biologists to pinpoint particular species and land only as many fish as they need for their studies. That’s an improvement over less discriminating gill nets and other equipment that can scoop up too many specimens and unwanted organisms.

Referring to the company, Rooney says, “Their whole business depends on a sustainable recreational fishery. They are showing great vision sponsoring research that aims to document and protect the diversity and stability of this ecosystem.”

The partners have applied to Environment Canada for three years’ worth of project funding.

Their proposal mixes traditional angling practices with emerging analytical techniques.

They will use DNA barcoding methods to identify species of organisms – including their stomach contents – in the bay. Developed at Guelph, barcoding allows scientists to identify creatures based on a short telltale stretch of their genetic material.

The group will also subject tissue samples to stable isotope analysis. Tracking carbon and nitrogen especially tells scientists what species are eating and their place in the food web.

In the future, they hope to look at fish hormones as markers of short-term stressors.

Few ecosystem studies so far have brought together these varied analyses, says Rooney: “I think this is pretty novel.”

“This is integrative impact assessment that crosses disciplines and scales,” adds McCann.

The group hopes to be able to infer environmental impacts from changes in what organisms are eating and where they appear in the bay. For instance, finding an invasive goby species in another creature’s gut clearly indicates a change.

In a more subtle change, a predator’s shift into open water might signal inshore fouling.

For last year’s pilot study, researchers used barcoding and isotope analysis in three sites around the bay. That work was funded by a GBF grant.

David Sweetnam, GBF executive director, says his group is especially concerned about changes in biodiversity and the effects of climate change and invasive species. He hopes the study will provide baseline data to assess what’s happening in the bay.

Municipal bylaws and policies are key tools in regulating development in the area, says Sweetnam. “It’s important to properly and scientifically inform those policies that municipalities want to put in place.”