The Detroit River produces a true dinosaur for researchers.
Perhaps the best-known river monster in North America is the lake sturgeon (acipenser fulvescens). These giant freshwater fish spend almost their entire lives on large river and lake bottoms feeding. This fish species has an incredible lifespan and adult lake sturgeon can grow to huge sizes that will make any angler look twice. Such was the case with a recent catch by the U.S. Fish and Wildlife Service and Alpena Fish and Wildlife Conservation Office from Michigan's Detroit River which is the dividing line between the United States and Canada.
The massive catch measured 6' 10" inches long and had a girth nearly four feet in diameter. When biologists weighed the fish, it put the needle at a whopping 240 pounds, making it one of the largest lake sturgeon ever recorded.
The biologists posted a jaw-dropping photo of the big fish next to one of their researchers. The huge rows of bony plates on its back making it look more like a dinosaur than a fish. It turns out the sturgeon likely has a storied life history too. They estimated her age to be over 100 years old!
"Based on its girth and size, it is assumed to be a female and that she has been roaming our waters over 100 years," the Alpena Fish and Wildlife Conservation Office posted on social media. "So, she likely hatched in the Detroit River around 1920 when Detroit became the 4th largest city in America."
A once in a lifetime catch for our Detroit River native species crew last week! This real life river monster was tipping...
In case you were wondering, the IGFA's official record for a lake sturgeon is 168 pounds, and was caught in Georgian Bay, Ontario back in 1982. Things have changed a lot for the lake sturgeon in the last 100 years since this fish was born. Large fisheries like the Great Lakes used to be home for large commercial fishing operations that took the fish, usually for their caviar. It did not take long for the lake sturgeon to become a threatened species and eventually an endangered species.
One of the reasons populations became so damaged was simply because the fish matures at incredibly slow rates. Some do not reach sexual maturity until over 20 years old. Male and female sturgeon spawn sparingly. With so few small fish hatching, lake sturgeon populations had a hard time keeping up with the rate of overfishing. In other river systems, this species was considered a "trash fish" and was removed simply for existing. As if that was not enough, pollution in places like the river where this latest giant was caught, has also taken a toll on many species of sturgeon by affecting the insect larva, crayfish, small mussels, leeches, and other creepy crawlies the sturgeon like to feed on using their barbels to search the river bottom.
These days, biologists are working hard to help the species make a comeback through a combination of rearing young fish in many state DNR hatchery facilities and concentrated efforts by natural resources officials to improve spawning habitat for these fish. Today the fish is commonly found in places like Hudson Bay, the Great Lakes, the Mississippi River, St. Lawrence River, and many lakes in Canada. After getting some data on the giant 240-pounder from the Detroit River, the researchers released her back into her home. We wish this old fish could talk. We are sure she would have some stories to tell!