Great Lakes mapping project could help clean up Hamilton Harbour

A new project by the University of Windsor has identified stressors affecting the Great Lakes and mapped the data to identify areas with major environmental issues, and the news isn't good for Hamilton.

The colour-coded map showed the lowest-stress areas in dark blue, ranging to highest-stress areas in bright red. Almost all of Lake Ontario, including Hamilton Habour, was a bright red.

"The reason Lake Ontario looks red is that different stressors are affecting different areas," said Jan Ciborowski, a biology professor at Windsor and one of only two Canadian scientists who contributed to the map.

"Hamilton Harbour is subject to a large number of stressors, not only population but also loss of habitat, the historical discharge of chemicals, and invasive species like zebra mussels and round gobi fish."

The initiative, called the Great Lakes Environmental Assessment and Mapping Project, or GLEAM, is a joint effort between American and Canadian researchers. In order to create the map, scientists broke down the lakes into a grid of 5km by 5km squares. They then evaluated the impact of 34 stressors — things like fishing pressure, climate change, invasive species and toxic chemicals — in each square and accumulated these results to determine the level of environmental stress.

But they also looked at where we get our greatest benefit from the lake — places like shoreline power plants and fisheries — and found that these areas often overlapped with areas of high stress.

"It's the 'death by 1,000 cuts' idea: just restoring one thing may not be enough," Ciborowski said.

"You have to fix one thing at a time, but just getting of one stressor won't fix the whole area."

'Sustainability is a moving target'

The idea of multiple, changing stressors is a concept well understood in Hamilton, according to Chris McLaughlin, the executive director of the Bay Area Restoration Council. The local non-profit organization advocates for restoring and conserving the Hamilton Harbour ecosystem.

"Sustainability is a moving target," McLaughlin said. "It's almost like we're playing catch up. The more we invest, the more we learn and discover new issues that we need to address."

He pointed to pharmaceuticals as an emerging stressor on the watershed. When people flush a pill down the toilet, or even just injest and excrete medication, the chemicals wind up in the water system.

"There's no magic machine removing that from the water," McLaughlin said.

The impact of pharmaceuticals on the environment is not yet known and it's an example of why monitoring the evolving stressors on the Great Lakes is so important, McLaughlin said. He adds that the map project is particularly useful because it gives a baseline of where the lakes are now.

"It gives us a big picture context for understanding the widespread nature of Great Lakes concerns that still exist despite the progress we've made."

Planning for the future

In December, the federal and provincial governments dedicated more than $92 million to clean up Randle Reef, an area of the harbour about  60 hectares, or 120 football fields, in size that contains about 675,000 cubic metres of heavily contaminated sediment. It's the latest move in a restoration project that has spanned decades.

Great progress has already been made in the effort to restore Hamilton Harbour and remove it as an Area of Concern under the Canada–United States Great Lakes Water Quality Agreement, according to Gail Krantzberg, a McMaster University professor who specializes in Great Lakes restoration.

"Hamilton Harbour has come an enormously long way towards recovery. It's really a success story," Krantzberg said.

"It's always going to be a place where we're constantly fixing and protecting ... but if we have our eyes open to various stressors, then we can make strategies for how we develop in the future."