In Warm Water: Fish & the Changing Great Lakes

The Great Lakes are changing. Warming air and water, shorter winters with less snow and ice and more extreme weather are impacting the lakes and the fish that live there. This could make it harder for native cold water fish to survive, and give invasive species an edge. In addition, harmful algal blooms are creating dead zones that are bad news for fish, and impact boaters and everyone else that enjoys being on or near the water. These changes impact both sport fishermen and the commercial fishing industry, which together contribute an estimated $5 billion to the Great Lakes economy.

The Environment Report is examining this issue in a special five part series, In Warm Water: Fish & the Changing Great Lakes. You can listen to the reports on Michigan Radio (91.7 FM in Southeast Michigan, 104.1 FM in West Michigan, 91.1 FM in Flint) Monday, Sept. 30 – Friday, Oct. 4 at 8:50 a.m. and 5:45 p.m. Updated reports will also be posted each day on this page. Support for this series is provided by the Great Lakes Fishery Trust.

Michigan Radio is making a free audio CD of this series and the accompanying photo slide show available for educational use. To request a copy, please click here.

The stat comes from Jeff Reutter, Director of Ohio State University's Stone Laboratory. He says the converse is true for Lake Superior. It holds 50% of the water, but just 2% of the fish.

It's a rough estimate, he says, but it gives you a good understanding of how each of the five Great Lakes have unique characteristics, which present unique challenges in managing these lakes.

As part of our series on how climate change is affecting the Great Lakes, Reutter spoke to us about how Lake Erie is especially vulnerable to temperature variations. It is the southernmost, and the shallowest of the five Great Lakes.

He also spoke about how, unlike the other four Great Lakes, Lake Erie is surrounded by agriculture and a more urbanized landscape.

You can listen to him speak about his "50 and 2 Rule" here:

Lake Erie has seen a resurgence in blooms of cyanobacteria (sometimes referred to as blue-green algae) over the last ten years. It was once a big problem in the 60s and 70s, and it has returned as a problem again.

Mark Brush / Michigan Radio

Big, ugly blooms of cyanobacteria (sometimes referred to as blue-green algae) are reappearing in the western basin (and sometimes the central basin) of Lake Erie.

The blooms happen when excess nutrients – mostly phosphorus – run off into the lake from farms and sewage treatment plants.

Some of these kinds of cyanobacteria produce toxins that are among the most powerful natural poisons on Earth.

Over the past decade, these cyanobacteria blooms have been common in Lake Erie. And scientists predict climate change could make the problem worse.

Too warm for your fried perch dinner?

Oct 3, 2013
Jennifer Szweda Jordan

Yellow perch are a staple of firehouse and church fish fries, and the delicate fish on that dish might once have lived in the Great Lakes. But warmer lake waters in a changing climate threaten the yellow perch population as well as other popular cool water fish, like walleye.

A mystery at the bottom of the Great Lakes food web

Oct 2, 2013
David Sommerstein

Phytoplankton – the algae that are food for plankton which in turn feed fish – are behaving strangely. They’re surrounded by a nutrient they need to grow. But for some reason, they’re not using it.

The puzzle has big implications for how scientists think about the Great Lakes’ future in a warming world.

Great Lakes fish on a diet

Oct 1, 2013
Chuck Quirmbach

Scientists say one way climate change is harming the Great Lakes is by warming the water too quickly in the spring.

That warm-up can decrease food for tiny creatures in the lakes--the creatures that game fish like trout and salmon eat.

The Great Lakes are changing. Warming air and water, shorter winters with less snow and ice and more extreme weather are impacting the lakes and the fish that live there. In addition, harmful algal blooms are creating dead zones that are bad news for fish, and impact recreational users as well.

A chilly Lake Superior warms up

Sep 30, 2013
Photo by Doug Fairchild, courtesy of the Minnesota Sea Grant Institute.

We kick off our week-long series In Warm Water: Fish and the Changing Great Lakes with a look at Lake Superior.

It has long been the coldest and most pristine Great Lake. Its frigid waters have helped defend it from some invasive species that have plagued the other Great Lakes.  But Lake Superior’s future could look radically different. Warming water and decreasing ice are threatening the habitat of some of the lake’s most iconic fish.