Shedding light on the Great Lakes

Shedding light on the Great Lakes

Large prehistoric creatures are swimming in the Great Lakes. They are available for viewing at the Shedd Aquarium, and kids can reach out and pet them — which is more than you can say for the Loch Ness monster.

They're sturgeon. Lake Michigan cities could make a bundle selling their roe as caviar. And dinosaurs might well have eaten them, if they so desired.

A sturgeon fossil has even been found inside a dinosaur fossil, notes Dr. Phil Willink, a researcher at the Shedd Aquarium, though there's no way to prove the dino ate the fish.

Fossilized sturgeons come from the Upper Cretaceous period, so the fish are living fossils.

Shedd's newly revamped Great Lakes exhibit, "At Home on the Great Lakes," offers lessons on conservation, diversity of species and risks posed by invasive species.

These include Asian carp that have taken food away from natives, and salmon, which were introduced deliberately but are not thriving in their new environment, Willink said.

Jurassic sturgeon fossils look a lot like the modern boney fish, though scientists can spot distinctions, the researcher said.

Sixty other species share the sturgeon's spotlight, including bluegill, crayfish and some unexpected deep-water dwellers.

Why can't we all get along? Because native alewives, which were so plentiful in the 1960s that they washed ashore in Chicago in stinky piles, want the same plankton that invasive species do.

Quagga mussels, native to Ukraine, are outcompeting even the dreaded zebra mussels.

"The quaggas move in and filter plankton out of water, and alewives eat plankton, so their numbers are down. Salmon are also an invasive species; they eat alewives," Willink said.

"When there were no longer any alewives, the salmon disappeared."

Schools of fish in the Great Lakes tend to be alewives and minnows, while the bass and sturgeon hunt in solitary, he said.

"I remember swimming in Lake Michigan, dodging the schools of alewives as they died," Willink recalled of his childhood.

Three sturgeon are on tactile display, and once you've washed the sunscreen, perfume and other contaminants off your hands, you can have at them.

"They look really large when children are next to them," he said. "The kids all seem to really enjoy the experience."

Willink said sturgeon, which date back tens of millions of years, have special properties like tolerance for different climates, that have contributed to their longevity. Still, in parts of the world they are endangered.

Other species in the show include the alligator snapping turtle, banded darter, black crappie, blacknose dace, bluntnose minnow, bowfin, brook trout, dollar sunfish, gizzard shad, northern water snake, orange-spotted sunfish, pumpkinseed sunfish and the rosyface shiner.

All those imaginatively named sea creatures, a shipping empire and the vast supply of fresh water make the Great Lakes an important economic region.

"When visitors see the sea life, it starts a conversation about biodiversity, ecology, pollutants and other factors that affect the lakes," Willink said. "It can be hard getting people to appreciate what's out there — when people look at lakes and rivers, they often stop at the surface and waves."

The lakes are the world's largest freshwater ecosystem and support more than 200 globally rare plants and animals, according to Shedd.

If the Great Lakes region were a nation, its gross domestic product would be the fourth largest in the world, a fact sheet said.

Shedd is an official Observer of the Great Lakes Commission and past representative on the U.S. Commission on Ocean Policy representing the Great Lakes.

For more on Great Lakes conservation at Shedd, visit http://www.shedd-aquarium.org/greatlakes or join the conversation through Shedd's Great Lakes Twitter and Facebook pages.

If you go

What: Newly revamped Great Lakes exhibit: "At Home on the Great Lakes"

When: 9 a.m. to 6 p.m. every day through Sept. 3

Where: Shedd Aquarium, 1200 S. Lake Shore Drive, Chicago

Tickets: Adults $8 on site; children $6 (ages 3-11)

More information: 312-939-2438; http://www.sheddaquarium.org/

Topics (1):Travel

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