One Fish, Two Fish: Using Fixed Electronic Fish Counting Systems for Real Time Monitoring of Freshwater Species

In keeping with the meeting’s theme, an integral part of current and future fisheries management is the concept of adaptive management, which requires real time monitoring of freshwater species and the use of technologies such as electronic fish counting systems. In the past, counting the number of fish migrating through a stream involved numerous hours of observation in the field. Now, a variety of fixed electronic fish counting technologies are in use worldwide in systems ranging from small tributary streams to large rivers, like the Columbia River. Because most counters are implemented as part of long-term monitoring projects, peer-reviewed studies on the methods and operational considerations for using electronic fish counters are uncommon. New fisheries technology often requires troubleshooting and modification in the field before it can produce consistent and reliable data. Due to the diversity of fluvial environments, electronic fish counting installations may necessitate a unique configuration based on local conditions such as flow, turbulence, swimming velocity of fish, and fish behavior. This symposium will address general questions regarding the current status of electronic fish counting systems:

• What are the strengths and weaknesses of the different fish counting systems (resistivity, optical, video and hydroacoustic)? 
• Where are these systems in operation and what species are targeted? What types of in-river structures are used?
• What information has been gathered to validate the performance of electronic fish counting systems?
• What are examples of trends that have been detected using fish counters? What can we learn from data collected using these systems? How can these data be used to inform management decisions?