Resistance board weirs are innovative monitoring structures first used to manage Pacific salmon stocks in Alaska. The versatility, functionality, and reliability of resistance board weirs has increased their popularity recently, and designs and applications have been adapted to manage a variety of fishery stocks nationwide. Their inherent advantage is direct enumeration of fish passage, which provides highly accurate, real-time escapement counts. Additionally, they can be used to actively trap and process fish, block or segregate species, or passively monitor for returning tag detections.

Simple, yet functional design leads to straightforward construction, installation, monitoring, and maintenance. Choosing the right site is critical, yet installation can occur in a short period of time, even in remote locations. The ability of resistance board weirs to collapse under high flow/debris levels allows them to resist ‘blow-out’, often when rigid weir structures are lost. Cramer Fish Sciences has been custom designing weirs to match specific project objectives and achieve desired results for over 15 years.