Lake Sturgeon Overview
A relic from the dinosaur age, sturgeon are roughly 200-million years old. Unlike modern-day fish, sturgeon have five rows of bone-like plates instead of scales, no backbone, and primitive shark-like tails. The largest native fish of the Great Lakes system, lake sturgeon are threatened in 19 of the 20 states/provinces it is found.
In the early 1800s, sturgeons were slaughtered because their bony plates and size ruined commercial fishing gear. By the mid-1800s, however, sturgeons were a prized commercial catch for their eggs, used to make caviar. Over-fishing, along with dam construction, habitat loss, water pollution, and slow maturity rates, caused sturgeon populations to plummet.
Hundreds of thousands, possibly several million, sturgeons roamed Lake Michigan in the early 1800s. Researchers now estimate that only 2,000 to 5,000 adult sturgeons remain in the lake, with no record of sturgeons in the Milwaukee River since the 1890s.
Recognizing their cultural and historical significance, the Wisconsin DNR began stocking the Milwaukee River with hatchery-raised sturgeon in 2003. Like salmon, sturgeons return to the river where they were born to spawn. However, the hatchery sturgeons were likely too old to imprint on the river, and are unlikely to return.
To maximize the opportunity for sturgeons to imprint on the Milwaukee River, the Wisconsin DNR and Northern Environmental designed the streamside rearing facility. This 10’ by 20’ trailer pumps water from the Milwaukee River into rearing tanks, enabling sturgeon to be raised in Milwaukee River water from day one.
The goal of the program is to produce a breeding population of lake sturgeon in the Milwaukee River. To achieve this goal, 1,000 to 1,500 sturgeons will be raised and released every year for the next 25 years. In addition to the restoration efforts on the Milwaukee River, the Wisconsin DNR is working on three other Lake Michigan tributaries.