The Cathlamet pound net (fish trap) project is the modern-day model for deploying this uber-selective gear type.

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Final 2017 report....

A total of 7,129 salmon and steelhead were caught; about 2,000 Chinook and 1,000 steelhead were tagged. The Wild Fish Conservancy’s very preliminary analysis of post-release survival of the tagged fish to McNary Dam was 99.6 percent for Chinook and 94 percent for steelhead.

“We were thrilled with these results,” Tuohy said
https://www.nwcouncil.org/news/blog/pound-net-experiment-on-the-lower-columbia-december-2017-report/