Bycatch mortality from gillnets and different standard harvest methods impedes the restoration of Endangered Species Act (ESA)-listed salmonids and industrial fishing alternatives when ESA-take limits are exceeded.
To profit wild salmon, threatened ecosystems, and coastal fishing communities, Wild Fish Conservancy and native industrial fishermen performed a post-release survival examine within the Decrease Columbia River Sub-basin to judge the potential of another industrial gear—particularly, an experimental pound internet entice—as a stock-selective, sustainable harvest method. Increasing upon the 2016 pilot examine, a modified entice was constructed and operated beneath a wide range of tidal phases, gentle ranges, and climate circumstances between August 26th and September 29th, 2017.
Using a mark-recapture methodology with Passive Built-in Transponder (PIT) tags, post-release survival from the entice was estimated by evaluating tag detections at upstream dams to that of a management supply of fish; whole catch, catch-per-unit-effort, and covariates of recapture possibilities have been analyzed. Preliminary outcomes exhibit that pound internet traps can successfully goal commercially viable portions of hatchery-reared Fall Chinook (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch) whereas lowering rapid and post-release bycatch mortality of ESA-listed species relative to standard industrial gears.
All through the 33-day take a look at fishing interval, the experimental entice captured and launched 7,129 salmonids. Relative post-release survival ranged from 94% for steelhead trout (Oncorhynchus mykiss) to 99% for Chinook salmon. These outcomes recommend that fish traps might present a sustainable different to standard industrial gears, enabling environment friendly harvest of focused salmon shares and restoration of ESA-listed shares blended inside salmon fisheries.