Abstract
Two river instream hydrokinetic (RISEC) devices were installed in the Kvichak River, Alaska in 2014 to demonstrate the ability to generate hydroelectric power. Fish and wildlife were monitored nearby to describe their presence and to document any negative effects from the devices. Fish were monitored using underwater video cameras and lights mounted to each device; wildlife (birds and mammals) were monitored using shore-based surveys by trained biologists and technicians. Both devices were installed near the village of Igiugig, submerged in the river until sitting on the river bottom, and operated intermittently in August and September.
Fish were present at each device and were seen travelling upstream, travelling downstream, and milling. Most observed fish were salmon and salmonids (Oncorhynchus spp.) and moved freely around each device. No fish were detected moving through the turbine part of the larger device, which was manufactured by the Ocean Renewable Power Corporation. At the smaller device, manufactured by Boschma Research, Inc., one lamprey (Lampetra spp.) was detected moving downstream through the part of the device housing the turbine. Overall, salmon were clearly less abundant at the devices than along the edges of the river nearby and showed no negative effects from the devices. Wildlife consisted almost entirely of birds, had no contact with or negative effects from the devices, and showed no behavioral changes when nearby.
The fish monitoring design was also meant to test the ability to use underwater cameras to monitor fish in the type of conditions found on the Kvichak River. Cameras were able to detect fish from 10 to 15 feet away, depending on water clarity; this range allowed coverage of 1/3 of the ORPC device and of the entire entrance and exit of the BRI device. In the daytime, ambient light was sufficient for fish detection; at night, lights placed nearby allowed video recording to continue with no loss of effectiveness. All cameras and lights were fixed directly to the devices in a design finalized once on site, and were powered from shore. Cameras and lights were able to be started within 1 to 12 hours after deployment of each device, and operated effectively thereafter with no breakdowns.
Camera images were recorded on shore at a temporary recording station, where footage could be viewed in real time during daily site visits by trained technicians. Imagery was then transferred to a laptop computer and reviewed nearby in Igiugig. A subsample of 10 minutes was reviewed from each hour of video footage (from each camera); most of these 10-minute blocks were able to be reviewed within two days of original recording. Video imagery was recorded during all operation time by the ORPC device and 72% of the operating time by the BRI device.
Overall, fish were seen at rates of less than one fish per 10-minute block of video reviewed at each device. This rate was likely a function of the device placement (relatively far offshore, in water that was deeper and faster than other parts of the river channel), and timing (after the peaks of both the juvenile and adult sockeye salmon [O. nerka] run). More detailed aspects of fish presence and behavior are reported below.