Balancing Conservation and Harvest Objectives: a Review of Considerations for the Management of Salmon Hatcheries in the U.S. Pacific Northwest

Abstract

The U.S. Pacific Northwest (PNW) has one of the largest suites of hatchery programs for anadromous salmonids in the world, with about 500 programs producing about 325 million juvenile fish. A total of about 0.7 million Pink Salmon Oncorhynchus gorbuscha, 21 million steelhead O. mykiss, 50 million Chum Salmon O. keta, 32 million Sockeye Salmon O. nerka, 41 million Coho Salmon O. kisutch, and 182 million Chinook Salmon O. tshawytscha are released annually from PNW hatcheries. These fish provide for robust, sustainable fisheries, and their production and release are designed to meet legal agreements, international treaties, and treaty trust responsibilities. However, this level of hatchery production is often assumed to have negative effects on the conservation of U.S. Endangered Species Act–listed salmon populations in the region. A review of the development of best management practices to balance the conservation and sustainable fisheries goals for PNW salmon hatcheries indicates that to be successful every hatchery program must (1) be scientifically defensible and relate to both published standards and statistically relevant outcomes, (2) have well‐defined and documented goals with explicit biological and operational specifications, and (3) have protocols in place that enable managers to respond adaptively to new information. The focus should be on the biological integrity of the populations being propagated in or influenced by the hatchery environment, as opposed to the management of the physical facilities. Complete documentation for a proposed hatchery action component should include items ranging from hatchery location and water source(s) to all aspects of animal husbandry and harvest and the management plans for adult returns. The current science for items should be described and the choice of an action component justified in terms of either the scientific or policy basis of the expect outcome. Where appropriate, complete monitoring and evaluation plans for the proposed actions need to be described.

Expanding Partnerships and Innovations to Implement Reform of a Large Columbia River Hatchery Program

“…Historically, the success of this hatchery was measured by adult contributions to ocean and in‐river harvest. However, definitions for “hatchery success” have evolved (Flagg ) and been redefined for most salmon and steelhead O. mykiss hatcheries in the state of Washington and other areas as a result of large‐scale hatchery reform recommendations provided by the Hatchery Scientific Review Group (HSRG ).…”

Large-scale parentage-based tagging and genetic stock identification applied in assessing mixed-stock fisheries and hatchery brood stocks for coho salmon in British Columbia, Canada

“…Production from hatcheries is currently an important factor contributing to abundance for many species of Pacific salmon (Ruggerone and Irvine 2018), with the objectives of either increasing fishery harvest or supplementing production for populations of conservation concern. Harvesting hatchery production may come at a cost to unenhanced wild populations if both hatchery and wild populations are exploited in mixed-stock fisheries (HSRG 2014;Flagg 2015). Ideally, fisheries and hatchery production should be managed in such a way as to ensure that wild populations are safeguarded and harvest attributed to both wild and hatchery-origin parents is sustainable.…”

Ecological implications of changing hatchery practices for Chinook salmon in the Salish Sea

“…Salmon are anadromous, typically migrating to the ocean in their first or second year of life, and returning to spawn as adults 1-6 yr later. As the primary target for both commercial, recreational, and treaty fisheries in southern British Columbia and the states of Washington, Oregon, and California, Chinook salmon (Oncorhynchus tshawytscha) represent the majority of hatchery production in this region (Naish et al 2007, Flagg 2015. Ecologically, salmon provide prey subsidies to marine and terrestrial predators, including grizzly bears and killer whales (Schindler et al 2013).…”

“…Populations of avian (e.g., cormorants, Collis et al 2001, andgulls, Osterback et al 2013) and marine mammal predators (e.g., seals, Lance et al 2012) are also supported by migrations of juvenile salmon from rivers to the ocean. As the primary target for both commercial, recreational, and treaty fisheries in southern British Columbia and the states of Washington, Oregon, and California, Chinook salmon (Oncorhynchus tshawytscha) represent the majority of hatchery production in this region (Naish et al 2007, Flagg 2015. Chinook salmon are also iconic species throughout their range, with profound cultural significance to indigenous North Americans.…”