By Steven Maier
Sturgeon are sometimes called the “gentle giants” of the Great Lakes. That label may not apply to the violent projection of their jawbone during feeding, captured here in slow motion.
The jawbones of these ancient fish are detached from their skulls, allowing them to vacuum up food by throwing their mouths open suddenly. The process, displayed here by a young sturgeon in a tank in the Great Lakes Fishery Commission’s office in Ann Arbor, Michigan, was captured by Cory Brant, a postdoctoral fellow at the University of Michigan.
Most of Brant’s research has focused on invasive species like sea lamprey, but the self-described “fish enthusiast” knows plenty about the Great Lakes’ own denizen of the deep, which can grow up to 8 feet long and weigh more than 800 pounds at the end of their 80-year lifespan.
“I’m blown away by them all the time,” he said. “I love that we have these gentle giants floating around the Great Lakes sucking up food with their vacuum mouths.”
This juvenile is using its barbels, or “sensory whiskers,” to locate food like snails and insect larvae, Brant said. It accidentally vacuumed up some tank rocks along the way.
Sturgeon were nearly wiped out in the upper Great Lakes in the mid-1900s after anglers discovered that the giant, armored fish that had plagued their fishing nets for decades were both delicious and a profitable source of caviar, Brant said. Within a few decades, overfishing, sea lamprey and habitat loss had taken their toll.
Anglers had waged war with the sturgeon for decades before then. Brant has been interviewing angling families and conservationists for years to reconstruct the oral history of invasive species in the Great Lakes for a documentary he’s producing. He’s heard stories of anglers piling sturgeon on the beaches and burning them, or even using the oily meat to fuel their stoves.
“It’s kind of amazing that they’re still around, and that they made it through it,” he said.
Conservation measures and rearing programs have contributed to a much brighter outlook for Great Lakes sturgeon. Populations are bouncing back, like those of Lake St. Clair and inland lakes in Wisconsin.