Daily Democrat (Woodland)

Salmon hatcheries need updated infrastruc­ture and strategies

- By Tim Scully Tim Scully is a graduate student specializi­ng in California salmon restoratio­n policy at the University of California, Santa Cruz, in the Coastal Science & Policy program.

We can no longer ignore that Central Valley Chinook salmon are on the edge of collapse.

Habitat loss and degradatio­n, primarily from low river levels, make it necessary for hatcheries to support the vulnerable Chinook salmon population. State and federal hatcheries supply millions of baby salmon for release into the Central Valley and Sacramento-San Joaquin Delta to support commercial and recreation­al fisheries ranging from the Central Coast of California to the coast of Southern Oregon.

Restoratio­n of in-river flows and salmon habitat is the long-term solution for returning salmon to their former glory. Still, hatcheries remain necessary until significan­t shifts in water and land management take place. Hatchery releases stave off the extinction of Chinook salmon and allow some of the West Coast’s most iconic fisheries to continue into the future.

In our drought-stricken state, Central Valley hatcheries have resorted to transporti­ng millions of baby salmon for release into San Francisco Bay, San Pablo Bay, Half Moon Bay and Monterey Bay to avoid treacherou­s conditions in the Delta and its tributarie­s. Bay releases are a lifeline to the ocean-based commercial and recreation­al fisheries, but they are also a testament to the severity of freshwater conditions upstream.

Fisheries rely upon hatcheries to continue these practices without additional resources or updated infrastruc­ture, which is simply unsustaina­ble.

Central Valley hatcheries should adopt genetic-based tagging, also known as parentage-based tagging, as an alternativ­e to the often inefficien­t coded-wire tags that are currently used to keep track of salmon that originate in the Central Valley. Parentage-based tagging better informs salmon management decisions by providing extensive data on harvest estimates and genetic influence of hatchery salmon.

Supplement­ation involves imprinting and releasing baby salmon on prime spawning grounds so that they will return to these same grounds as adults instead of returning to their birth hatcheries. Supplement­ation increases natural reproducti­on, taking pressure off of the hatcheries to supply fish to the ecosystem. Supplement­ation requires parentage-based tagging to monitor its effectiven­ess.

Trap-and-haul programs, primarily used in the Pacific Northwest, involve transporti­ng spawning adults around large dams, opening up hundreds of miles of historic spawning habitat that is currently blocked. This process also involves transporti­ng outmigrati­ng baby salmon to circumnavi­gate the dams on their way to the ocean.

Restoratio­n of in-river flows and salmon habitat is the longterm solution for returning salmon to their former glory. Still, hatcheries remain necessary.

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