Using the Right Tool for the Job: Gear Types Used in Western Washington to Monitor Outmigrating Juvenile Salmonids

As juvenile monitoring efforts become increasingly focused toward salmon recovery, effectively collecting data at levels commensurate with the importance of these stocks is critical. The ability to detect changes in long-term trends and assess recovery can be improved greatly by carefully choosing the proper equipment to fulfill study objectives. Every trapping method has its pros and cons in a given situation. The four main gear types currently employed by WDFW include: inclined plane screen traps (scoop traps), rotary screw traps, permanent weirs, and temporary fence weirs. Site availability and importance of the stock (s) being monitored help dictate whether 100% capture traps (e.g., temporary fence weirs and permanent weirs) are appropriate. Whereas partial capture traps (e.g., scoop traps and rotary screw traps) can be used in almost any situation. With over 30 years of trapping outmigrating juvenile salmonids we have continually adapted these commonly used designs to accommodate the small to large (~1-40,000 cfs) rivers we have been tasked with monitoring. In this presentation we will explore the when, where, which, how, and why when considering a monitoring study in a particular watershed.