Copper River salmon are an important resource for subsistence and commercial fisheries. The goal of this project is to provide an estimate of relative abundance as soon as salmon are committed to migrating upriver. These estimates help managers decide when to open or close the fisheries to meet escapement goals, while providing a sufficient number of fish for subsistence and commercial harvesters.
Technicians from the Native Village of Eyak manually counted salmon echo traces from the computer screen, using two separate echograms that use color to show target strength and upstream/downstream angle. Simultaneous use of these two echograms allows quick recognition of the targets of interest, i.e., large upstream moving fish. This simple technique proved to be fast and can be learned quickly without requiring prior experience in hydroacoustics.
Given the remote location, it was important to develop remote control and data access capabilities to minimize the requirement of on-site presence of staff. Data were transmitted in real-time through a wireless Ethernet connection from the streamside echo sounder to a data acquisition computer in a trailer parked 1 km away. This computer was connected to the Starband® satellite system, allowing us to access and to control the data acquisition computer and sonar system from any computer connected to the internet.
References
Mueller, A. M., and D.J. Degan. 2004. Indexing the inseason abundance of salmon in the lower reaches of the Copper River Delta, 2004 Annual Report. USFWS Office of Subsistence Management, Fisheries Resource Monitoring Program, Annual Report No. 04-506, Anchorage, Alaska.
Degan, D. J., K. van den Broek, and A. M. Mueller. 2005. Indexing the inseason abundance of salmon in the lower reaches of the Copper River Delta, 2005 Annual Report. USFWS Office of Subsistence Management, Fisheries Resource Monitoring Program, Annual Report No. 04-506, Anchorage, Alaska.