De Pere dam on lower Fox River during spring sturgeon spawning season. Photo by Rob Elliott, USFWS.

A protection plan for lake sturgeon that spawn below the De Pere dam on the lower Fox River, Wis., was implemented successfully in 2008, marking the start of what is hoped will be a steady recovery of the population that spawns in this historically important sturgeon river.

After several years of on-going discussion and negotiation coupled with continued data collection and analysis by U.S. Fish and Wildlife Service personnel, a plan for the protection of lake sturgeon habitat below the De Pere dam on the lower Fox River was agreed to by representatives from the Service’s Green Bay Fisheries Office and Green Bay Ecological Services Office, the Wisconsin DNR, the US Army Corps of Engineers, and Thilmany Papers Nicolete Mill which hold a FERC license for hydroelectric generation at this site. The “Protection Plan” was a requirement the Fish and Wildlife Service and Wisconsin DNR had requested as a condition of a new FERC license issued to the Nicolet Mill for continued hydroelectric generation. 

The Plan prescribes how Thilmany Papers will work in cooperation with the agencies and the USACE to ensure that adequate flow conditions for successful sturgeon reproduction are maintained throughout the spawning season each year.  The protection plan specifies a minimum water elevation in the pool above the dam which, when combined with the use of flashboards, directs adequate flow of water over the target habitat during the critical spring reproduction period.  When river flows are not adequate to provide both this minimum flow and full power generation, then the Nicolet Mill will decrease hydroelectric generation as needed to maintain the minimum pool elevation and thus direct the necessary minimum flow over the spawning habitat. 

This was the first year of implementation under this protection plan.  Regular communication among all parties was and remains a key to success of this effort.  As occurred this year, the plan calls for staff from the Green Bay NFWCO and ES Field Office, and the Wisconsin DNR to be in regular communication with Nicolet Mill operators and the USACOE during the critical sturgeon reproduction season.  Service and State biologists also provided training to Nicolet Mill operators so they could assist with sturgeon observations during the spawning period.  The USACE also installed a real-time on-line gage station so that all parties could better monitor the flow conditions and react to incoming changes in flow.  Fortunately, flow was adequate during most of the 2008 spawning and larval incubation season.  There were only a few days when Nicolet Mill needed to reduce generation to maintain needed flows, and in those days, the Mill was very proactive in anticipating the need for reducing generation and shutting down turbines in time to prevent dewatering of the habitat.  The Plan was implemented and worked just as intended. All parties will continue to meet on an annual basis prior to the spawning season each year to discuss details of operation, communication and implementation for the coming spawning season.

Protection of this habitat for sturgeon reproduction has opened the door for recovery of the sturgeon population spawning in the lower Fox River.  Prior to this plan, the only habitat used by this population frequently became dewatered during the egg and larval incubation period, reducing survival of eggs and larvae.  Though the 25-75 adult sturgeon that currently return to spawn in this river are few compared to the thousands that historically spawned at this site, they might be capable of supporting  a natural population recovery given suitable environmental conditions.  Implementation of this protection plan also now creates opportunities to implement other rehabilitation efforts for sturgeon in this important Lake Michigan tributary. Contact: Rob Elliott, USFWS, Green Bay NFWCO, robert_elliott@fws.gov.