Barbleheads Unite: Developing an Acoustic Monitoring Network for Green Sturgeon

At the time that green sturgeon were petitioned for listing under the Endangered Species Act, very little was known of their basic biology; let alone the intricacies of their coastal migrations and population structure.  With initial seed funding and the cooperation of a large group of researchers, we developed an extensive monitoring program for subadult and adult green sturgeon along the West Coast.  Fish were tagged with acoustic transmitters in natal rivers and during summer aggregations in estuaries.  At the same time, extensive arrays of acoustic receivers were being deployed for monitoring of salmonids in a variety of rivers and along the coast from California to Alaska.  Salmon researchers shared data from sturgeon detections and these data provided insights into green sturgeon spawning periodicity, rates of movement, population structure, and habitat use.  This information was an invaluable resource for the later identification of critical habitat and for ongoing threats assessments mandated by the Endangered Species Act.  In our view, the key to success of this program was twofold.  First, funds for sturgeon were made available at a time when even greater resources were being expended to monitor salmon using the same technology. Second, and perhaps more importantly, both salmonid and sturgeon researchers along the West Coast achieved data-sharing on a large spatial scale.  Thus, information key to its management was gained for a species that inconveniently crosses from freshwater to salt, across state and international boundaries, and through the jurisdictions of numerous agencies.