These juvenile lake sturgeon, captured near Ontonagon River in Lake Superior, were examined, tagged and released. - USFWS photo

(left to right) Ed Baker, Michigan DNR; Henry Quinlan, USFWS; and, Gene Mensch, Keweenaw Bay Indian Community, about to release the lake sturgeon back in to Lake Superior. - USFWS photo

To help restore the ecological integrity and fishery potential of Lake Superior, fishery agencies developed the Lake Sturgeon Rehabilitation Plan for Lake Superior.  Many agencies are collaborating to protect and rehabilitate sturgeon populations per this plan.  One collaborative effort got underway this fall. 

Lake sturgeon have been absent from the Ontonagon River for nearly 100 years.  In 1998, sturgeon returned to the Ontonagon River via stocking by the Michigan DNR.  Sturgeon have been stocked each year since -- with the exception of 2003 and 2005.  The fish stocked were collected as eggs from the nearby Sturgeon River, also a tributary to Lake Superior.  The number of fish stocked ranged from 2,000 – 6,500 annually.  Prior to release, a microscopic piece of metal (coded wire tag) was injected into snout of each of the five-to-eight inch long sturgeon.

Surveys of the progress of this rehabilitation effort have been limited in scope and conducted primarily in the river.  This year, the Keweenaw Bay Indian Community, Michigan DNR, GLIFWC and U.S. Fish and Wildlife Service collaborated to conduct a pilot survey in Lake Superior waters near the mouth of the Ontonagon River.  The agencies are interested in gathering more information to evaluate stocking progress and to describe the status of lake sturgeon in Lake Superior near the Ontonagon River.

The USFWS R/V Chub served as the platform for the gill net survey work.  To minimize capture of non-target species, nets were set and lifted at roughly 12 hour intervals.  Weather was a concern as wind and cold can cause problems on Lake Superior in late October.  We were able to lift nets on three occasions during the week, which was less than hoped, but this allowed the agencies to initiate the first of what is hoped will be a long-term cooperative venture.

Despite being able to set only 8,000 feet of net, we captured six juvenile lake sturgeon.  The young, sharp-scuted fish ranged from 15 to 27 inches long.  Four of the six sturgeon captured had coded wire tags, positively identifying them as stocked fish.  Coded wire tags were not detected from the two largest fish, although they are likely stocked fish as well.  This is consistent with experience in the St. Louis River, MN/WI, where tag detection in stocked fish decreased as fish size increased.  A thumb-nail size piece of tissue was collected from the fins of all fish.  This will be genetically analyzed by Michigan State University to determine the origin of the fish without coded wire tags.  The sturgeon were tagged and released.  If these fish are captured during future Lake Superior survey work, agencies will obtain data on the growth and movement of these fish.