100-year-old sturgeon measuring almost 7 feet caught in Detroit River

DETROIT -  A Michigan lake sturgeon that conservation officers caught last week is one of the largest ever recorded.

Crews said the fish was six-foot-10-inches, had a girth of nearly four feet, and weighed 240 pounds. "Caught in the Detroit River, this fish is one of the largest lake sturgeon ever recorded in the U.S." (Alpena Fish and Wildlife Conservation Office via Facebook)

That's according to the United States Fish and Wild Life Service, who estimated the monster marine animal to be at least 100 years old.

To put that in perspective, the cold-water fish was likely hatched during the famed roaring 20s more than a century ago.

Crews from the Alpena Fish and Wildlife Conservation Office posted on Facebook Friday to showcase their discovery to the public.

Crews said the fish was six-foot-10-inches, had a girth of nearly four feet, and weighed 240 pounds. "Caught in the Detroit River, this fish is one of the largest lake sturgeon ever recorded in the U.S."

A note on the post said the fish was processed before being returned to the river.

Lake sturgeon are a unique species in Michigan and a keystone fish that inhabits the Great Lakes. Commercial fishing of the sturgeon decimated the population, leading to their near-collapse decades ago.

It can take decades for the species to reach their full size. The lifespan of a typical male is about 55 years while females are known to live for 100 years.

Commercial fishing of sturgeon in Michigan is strictly prohibited while the sportfishing season for them is heavily regulated. In the Detroit River, any sturgeon caught between July and March when it's permitted must be immediately released.

RELATED: Michigan's sturgeon season lasted just 78 minutes

Sturgeon fishing season is also permitted in Lake St. Clair and the St. Clair River, Otsego Lake, boundary waters between Michigan and Wisconsin, the St. Mary's River, and Portage and Torch Lakes.

There is also a popular fishing event on Black Lake where fishermen have the opportunity to harvest only a few a year. The event is typically over after a few hours.

If you'd like to learn more about sturgeon, the fish has their own advocacy group that protects it from poaching.