27 Lake Sturgeon Rescued From Low-Water Channel Below Ontonagon Michigan Dam
The lake sturgeon rescue raises questions about how seasonal water diversions affect a threatened species being restored to Lake Superior tributaries.
ONTONAGON, Mich. — Wildlife officials rescued 27 lake sturgeon from shrinking pools below a western Upper Peninsula hydroelectric dam after hikers found the fish stranded in a section of the Ontonagon River that receives little or no water at times of the year.
The Michigan Department of Natural Resources conducted three rescue missions with the Keweenaw Bay Indian Community and Upper Peninsula Power Co., which operates Victoria Dam. The fish were carried nearly a mile over rugged terrain and released where the West Branch Ontonagon River returns to full flow.
The operation prevented what state biologists said could have been a damaging loss for a lake sturgeon population that Michigan has spent decades rebuilding.
The largest rescued fish measured 55 inches. Since Michigan began stocking the Ontonagon River in 1998, DNR biologists believe none of the fish has been more than 28 years old. Lake sturgeon have been listed as a threatened species in Michigan since 1994.
Hikers’ Report Led Crews to Stranded Fish
The rescue began with an Aug. 23 report from hikers crossing the river on the North Country Trail downstream from Victoria Dam. They saw three sturgeon confined to isolated pools and contacted the DNR’s Report All Poaching hotline.
DNR fisheries technicians Kyle Urban and Jack Cole responded and found two fish in one pool. They carried the sturgeon downstream in hiking bags that kept their gills immersed in fresh water.
The technicians returned with help from the Keweenaw Bay Indian Community and the power company. That team discovered more sturgeon in a sediment-clouded pool and relocated 10 fish. Others could not immediately be reached with the equipment available.
UPPCO then released water into the channel within the limits of its permit while the agencies organized another operation. During the third mission, crews captured and relocated 15 more sturgeon. Officials said a subsequent search confirmed that no fish remained in the dewatered channel.
Federal License Allows Seasonal Diversion
Victoria Dam is part of the federally licensed Bond Falls Hydroelectric Project. Water entering Victoria Reservoir is routed through a 6,050-foot pipeline to two turbines before being returned to the river downstream.
That arrangement bypasses about 1.6 miles of the West Branch Ontonagon River. The project has two generating units with a combined capacity of 12 megawatts.
The project’s Federal Energy Regulatory Commission license requires UPPCO to release at least 150 cubic feet per second of water into the bypassed channel from April 15 through June 15. That spring requirement is intended to protect spawning fish.
The license does not impose the same minimum bypass-channel flow during the remainder of the year. Consequently, the riverbed between the dam and the powerhouse discharge can be dry or partly dry during late summer.
The DNR announcement did not allege that UPPCO violated its license. Instead, it identified an environmental risk arising under the project’s permitted seasonal operations.
“Projects like hydroelectric dams have environmental impacts,” DNR Lake Superior Basin Coordinator Dave Caroffino said.
Each Adult-Sized Sturgeon Represents Decades of Recovery
Lake sturgeon grow slowly and reproduce late in life. Michigan DNR information indicates females generally mature between ages 14 and 33 and usually spawn only once every three to seven years. Individual fish commonly live for more than 50 years, and some have exceeded 100.
Those characteristics make the loss of several dozen fish more consequential than the number might suggest. Replacing mature or nearly mature sturgeon can take decades.
The Ontonagon River restoration program uses streamside rearing, in which young sturgeon are raised in river water before being released. Biologists believe exposure to that water helps the fish imprint on the watershed and return to it when they reach spawning age. The Ontonagon facility is one of four streamside sturgeon-rearing operations staffed by the Michigan DNR.
Agencies Reviewing How to Prevent Another Stranding
The DNR is reviewing historical river flow and water temperature data to better understand how the fish entered the bypassed channel and became trapped.
The department is also considering expanded surveys with UPPCO and the Keweenaw Bay Indian Community. Those surveys could help crews detect and relocate sturgeon or other aquatic species before isolated pools become dangerous.
The incident also demonstrates the importance of public reports. People who see threatened fish in immediate danger can contact the DNR’s Report All Poaching hotline at 800-292-7800. Other unusual fish or wildlife observations can be submitted through the state’s Eyes in the Field reporting system.
The hikers’ original report concerned only three sturgeon. The resulting search saved nine times that number.
Lake Sturgeon Rescue FAQs
Why were the lake sturgeon stranded?
Water is diverted around approximately 1.6 miles of the West Branch Ontonagon River to generate electricity at Victoria Dam. The bypassed channel may receive little or no water during parts of the year.
How many lake sturgeon were rescued?
Three rescue operations conducted by state, tribal and utility personnel relocated 27 lake sturgeon to a section of the river with full flow.
Is lake sturgeon a threatened species in Michigan?
Yes. Michigan has listed lake sturgeon as threatened since 1994. The state has stocked the Ontonagon River since 1998 as part of a long-term restoration effort.
