On Thursday, February 5th, Rob Elliot was our guest speaker, and he chose to talk about lake sturgeon passage on the Menominee River. He is currently involved on a project that focuses on successfully getting lake sturgeon up past the first two hydroelectric dams on the Menominee River. This project has been in the works for roughly 15 years, and he is excited to see it finally being carried out.
The Menominee River is the first location where there will be substantial structures put in place specifically for sturgeon passage, possibly worldwide. Lake sturgeon used to be in the Great Lakes in great abundance, and even considered a nuisance fish at one time. Their numbers drastically declined when people realized that the adults and eggs were quite tasty. Their population dropped significantly within 20 years from overfishing and habitat degradation.
The Menominee has the highest abundance for spawning populations (~1,000 out of ~3,000 total lake sturgeon in Lake Michigan), yet the fish cannot make it up past the first dam to the most successful spawning habitat. The area they can access, the mouth of the river, consists of mostly adult populations because the larval fish are unable to make it back out to the bay if hatched further upstream. If lake sturgeon were able to make it past the first two dams in the river, they would have access to roughly 6 million m of juvenile habitat, crucial for the populations’ success. It seems as though when larvae hatch below the first dam, they get washed out into the bay too early and do not survive. Therefore, a fish elevator is currently being constructed on the first dam to collect the lake sturgeon who enter the river, and transport them upstream so they can be released past the two hydroelectric dams. Bypass gates are also being constructed to protect the fish from the turbines and guide them through with safety. The overall effects of this project may not be realized for a few years, but a successful outcome could prove crucial for the lake sturgeon population.