Hoffmaster State Park, Norton Shores. Image credit: Todd Marsee, Michigan Sea Grant

ANN ARBOR—Freshwater researchers from the Great Lakes region and around the world gathered at Cobo Center in downtown Detroit May 15-19 for the 60th annual conference of the International Association for Great Lakes Research.

More than 1,000 participants, including many University of Michigan researchers, spent the week networking with colleagues and delivering more than 820 oral and poster presentations highlighting scientific findings in the areas of freshwater health and management.

IAGLR session topics included aquatic invasive and nuisance species, Great Lakes Areas of Concern, and fisheries and fishery management. The theme of this year’s meeting was “From cities to farms: shaping Great Lakes ecosystems.” Local hosts for the event were Michigan Sea Grant (a federally funded collaboration between U-M and Michigan State University) and Wayne State University.

Here are summaries of a few U-M-led projects discussed at the meeting:

Lake Erie’s harmful algal blooms and dead zone

Reducing phosphorus entering the Detroit River; real-time, autonomous stormwater control

Efforts to control Lake Erie’s algae problem have largely focused on reducing the levels of the nutrient phosphorus entering western Lake Erie from the heavily agricultural Maumee River watershed. But the Detroit River carries about 80 percent of the water that enters Lake Erie and 21 percent of the algae-promoting phosphorus from both urban and agricultural sources in the U.S. and Canada. While the Detroit River is not a significant driver of harmful algal blooms, it is an important contributor to Lake Erie’s dead zone.

In 2015, U-M researchers at the Graham Sustainability Institute were awarded a $3 million grant from the Erb Family Foundation to determine the relative contributions of various phosphorus sources, both urban and agricultural, in the Detroit River watershed. Preliminary data from the study indicate that the largest U.S. urban sources of phosphorus entering the Detroit River are municipal wastewater treatment plants.

Great Lakes ice cover

Forecasting the Apostle Islands ice caves

U-M climate researchers and their partners, including the National Park Service, are developing a tool to predict the upcoming ice cave season at Apostle Islands National Lakeshore, off the Wisconsin shore of Lake Superior.

Harmful algal blooms

Role of nitrogen in shaping the toxicity of Lake Erie algal blooms

While much of the work to curtail Lake Erie’s harmful algal blooms has focused on the availability of phosphorus, a U-M-led team has for several years been investigating the role of another nutrient found in crop fertilizers, nitrogen, in shaping the toxicity of those blooms.

Kevin Meyer, a postdoctoral researcher at the Cooperative Institute for Limnology and Ecosystems Research, will provide an update on the team’s findings.

Restoring native fish populations

Very young lake sturgeon and artificial spawning reefs in the Detroit and St. Clair rivers

Rock spawning reefs have been built at several locations in the Detroit and St. Clair rivers over the past 13 years to attract lake sturgeon and other native fish species. Sturgeon are spawning at these sites, but where do the baby fish go after they hatch and leave the shelter of the rock reefs? A study of the St. Clair River led by U-M scientists shows that despite river-current speeds of more than 3 feet per second, some recently hatched lake sturgeon manage to remain in the St. Clair’s North Channel, a surprising finding with implications for the siting of future spawning reefs.