The subpopulation of White Sturgeon (Acipenser transmontanus) inhabiting the transboundary reach of the Columbia River has experienced chronic recruitment failure for several decades.  This population has been the focus of an international recovery effort since the early 2000s.  The purpose of this project is to augment the recovery effort by pursuing the following goals:

Goal 1:  Inform decisions for Transboundary Reach White Sturgeon conservation and management.
Under this goal the project will assist with periodic stock assessment surveys intended to track population status, hatchery supplementation success, and monitor the impacts of the recreational fishery.  In addition to survey participation, the major contributions of this project will be to a) determine maturation rates in hatchery fish for use in population models to predict responses to changes in stocking strategies or fishery management; and 2) assess the conservation risks associated with spontaneous autopolyploidy by screening wild adults and hatchery releases for rates of 8N, 10N, and 12N ploidy states.  This project will also contribute to this goal by developing and maintaining the upper Columbia White Sturgeon data management system.

Goal 2: Index natural recruitment and monitor the success of experimental releases to test recruitment failure hypotheses.
Under this goal we intend to redesign and implement fall recruitment surveys that in their current form have failed to detect any age-0 juveniles (either naturally produced or from experimental releases of larvae and age-0 juveniles) in nearly 20 years.

Goal 3: Determine if larval drift distance and drift rate influence recruitment.
While there are many potential factors contributing to recruitment failure in the transboundary population, this project is focused on assessing the role of larval drift rate and extent using modeling and field experimental approaches (e.g., larval translocation).

In 2023, our specific tasks include: 1) the development of a study plan and methods for monitoring low levels of recruitment to the fall age-0 life stage generated using estimated gear retention and encounter rates; 2) implementing age-1+ setline surveys to monitor for natural recruitment and success of previous experimental releases; 3) implementing experiments for estimating larvae drift rates, and 4) monitoring ploidy of age-1+ juvenile White Sturgeon captured during setlining.