by RACINE, Wis. (AP) – Michigan Tech University biologists have been monitoring the Lake Superior island’s fragile wolf population every winter since 1958, but had to cut short this season’s planned seven-week survey after two weeks.
The ski plane they study the wolves on uses the frozen lake as a landing strip because there is nowhere to land on the island. But this strangely warm winter left the Great Lakes without much ice.
As climate change intensifies, scientists are trying to understand how ice-free winters could affect the world’s largest freshwater system. Most of the consequences remain theoretical since the lakes are typically too treacherous for data-gathering expeditions during the coldest months and biologists have long thought that little ecological activity occurs under the ice anyway. But they say the changes could have serious environmental, economic and cultural impacts, including harming certain species of fish, eroding beaches, pushing algae blooms and clogging shipping lanes.
“This year really drives home the point that we need to collect more data,” said Trista Vick-Majors, an assistant biology professor who studies aquatic ecosystems at Michigan Tech. “There’s no way you can predict how an ecosystem will respond to the large-scale changes we’re seeing.”
The planet had its hottest on record for an eighth straight month in January, according to the European climate agency. The upper Midwest is no exception, with Chicago enjoying temperatures of around 70 degrees (21 degrees Celsius) late last month and Wisconsin getting its first February tornadoes.
Ice cover on the lakes, which have a combined surface area about the size of the United Kingdom, has generally peaked in mid-February over the past 50 years, with as much as 91% of the lakes covered at times, according to the Great Lakes. Website ice tracker. By mid-February this year, only 3% of the lakes were covered, the lowest figure since at least 1973, when site records began.
Researchers don’t have much data on how years of ice-free winters might change the lakes, but they have plenty of theories.
Ice-free lakes may absorb sunlight more quickly and warm up earlier in the spring. Some biologists speculate that this could lead to an earlier and larger bloom of blue-green algae, which could be toxic to humans and put a damper on summer tourism.
Without ice, the upper levels of the lakes are likely to warm more quickly than usual, contributing to thermal stratification, in which layers of colder and warmer water form. The lower, colder, denser levels would be affected by less oxygen, which could kill plankton and other organisms, according to some scientists. Whitefish and lake trout typically hatch in the spring and eat plankton, so less plankton would likely reduce fish populations, which could lead to tighter fishing quotas and higher prices at stores groceries and restaurants.
Less ice could translate to longer fishing seasons, but winter storms could destroy nets and traps and destroy the eggs of whitefish that rely on the ice for protection, said Titus Seilheimer, a University of Wisconsin fisheries specialist. -Madison.
Charlie Henrikson runs a small commercial fishing operation off Wisconsin’s Door County peninsula. He said his boats were laying nets in February when they usually don’t start the season until late March. He said he is most concerned about the lack of ice which would lead to more evaporation, which would cause lake levels to drop and make it more difficult to get his boats into port.
“I’m 71 years old, so of course I like it warmer. I like being able to walk out on the dock here and not have icy conditions. Whatever you want to call it, the times are changing. And we are getting more extreme conditions. It will change our strategy and we will be able to find ways to use it. You always have to adapt.”
Less ice may also lead to a longer lake navigation season. But without the ice coating the lakes, powerful winter storms could erode shorelines more than usual, pushing more sediment into the harbors and making them shallower and shallower. difficult to navigate, said Eric Peace, vice president of the Lake Carriers Association, a trade group. Coupled with lower lake levels due to increased evaporation, ships may need to carry less cargo so they sit higher in the water, he said.
This year’s lack of ice allowed Michigan Tech’s Vick-Majors to launch a project to collect winter-specific data that scientists can compare to summer data. Researchers from around the Great Lakes are taking part in sampling this month.
On a recent day, Madeline Magee and Rae-Ann Eifert, lake monitors for the Wisconsin Department of Natural Resources, braved sub-freezing temperatures to collect buckets of lake water off the Racine breakwater as part of the Vick-Majors project.
The lake was completely open, an emerald expanse stretched to the sky, and the wind was howling. High swells hit the beach and Eifert showered while standing on the breakwater, leaving her ski pants covered in ice beads. Magee said the project is worth it.
“Continuing the data collection going forward will only add to what we know about the Great Lakes and how we could manage the lakes more effectively. … If we lose ice cover, we’re changing the underlying ecosystem of the Great Lakes in ways that we don’t really understand right now,” she said.
