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UncertaintyWhat are the potential impacts on wild sturgeon from mixing of genetic stocks as part of broodstock and larval fish rearing mitigation efforts?
ThemeFish propagation
Sources Recommendations for the 2014 Program Amendment from ODFW, WDFW, Cowlitz I.T., USRTF, USFWS
Criticality Level Priority
Rationale Five population units of white sturgeon are distinguished in the Columbia River: Lower Columbia, Mid-Columbia, Snake, Upper Columbia, and Kootenai. The Upper Columbia, Kootenai, and Snake population units are at risk because natural recruitment is sporadic and inadequate. These three population units span the areas where supplementation and translocation will take place. Typically just a few white sturgeon are used as broodstock in hatchery programs because of difficulties in capturing and maintaining maturing broodstock and achieving synchronous maturation. These constraints, along with low or non-existent natural recruitment, mean that genes from hatchery fish are likely to be disproportionately represented in future generations. Translocation of adults may also reduce genetic diversity if the population units they are introduced into have small natural spawning populations. The capture and subsequent rearing of naturally produced larvae is a promising new approach to white sturgeon conservation. Analyses have shown that naturally produced larvae originate from multiple parents and are genetically diverse. This is a new method, so refinements in where, when, and how to collect larvae plus how best to rear and release them are needed. Among hatchery propagation, translocation, and capture of naturally produced larvae, the latter appears to be the best strategy for maintaining genetic diversity. Uncertainties, however, about the genetic consequences of all of these approaches on wild sturgeon populations exist. To resolve them, it will be important to periodically monitor the genetic diversity of the white sturgeon population units where sturgeon recovery efforts have taken place.

last updated: Jan 27, 2016