A team of both Canadian and American scientists has released a comprehensive map identifying the greatest environmental stressors on the Great Lakes.

“The lakes face many different problems that would not necessarily be fatal on their own, but they can combine to create major declines in ecosystem condition,” said Jan Ciborowski, a biologist at the University of Windsor and one of the few Canadians who contributed to the environmental stress map, created by the Great Lakes Environmental and Assessment and Mapping Project (GLEAM). In other words, the Great Lakes are dying a “death by a thousand cuts,” according to another researcher involved in the project, who was also quoted in a recent report.

The detailed map identifies 34 of the biggest stressors on these lakes, which include coastal development, pollutants transported by rivers from agricultural and urban land, climate change, invasive species, and toxic chemicals.

According to the map, lakes Huron and Superior, where the coasts tend to be less populated and developed, experience relatively low stress. This was found in contrast to large regions of lakes Erie, Ontario, and Michigan, which have experienced moderate and even high levels of cumulative stress, particularly on their coastlines.

So how did the researchers distinguish low stress from high? To rank the stressors’ impact on ecosystem health, the team surveyed more than 150 researchers and natural resource managers from across the Great Lakes basin.

In short, their research is meant to function as a sort of “laundry list of items” that need to be addressed and points out exactly where. The team hopes that this information will help environmental managers and law makers form decisions that will better protect natural resources, critical to both sides of the border.

“A picture is worth a thousand words,” said Ciborowski in a report by the University of Windsor. “These maps show very clearly where some of the most serious problems are and this should help us identify the areas where we need to concentrate our efforts for both preservation and restoration.”

The findings were published earlier this week in the Proceedings of National Academy of Sciences. To view the map and zoom in on specific regions, visit GLEAM’s website.

For more updates on the protection and state of the Great Lakes, see Canada and U.S. update protection of Great Lakes and Government launches Great Lakes Protection Act.