Center for Marine Biodiversity and Conservation

Thiamine Deficiency Complex is an emerging health concern for California’s Chinook salmon (Oncorhynchus tshawytscha). Low egg thiamine concentrations contribute to the condition being expressed in newly hatched fry leading to increased rates of early mortality. Increased rates of mortality in early life stages could further jeopardize already depleted populations of Chinook salmon in California’s river systems. In 2020, a study of egg thiamine concentrations at Coleman National Fish Hatchery and Livingston Stone Fish Hatchery revealed nearly 50% of the sampled populations contained egg thiamine concentrations below 5 nmol/g which is the egg thiamine concentration threshold for 95% fry viability. This study assesses egg thiamine concentrations from Chinook salmon sampled in the Klamath River Basin during their 2020 and 2021 annual spawning migrations. The study will also assess relationships between egg thiamine concentration and other variables including water temperature and distance of migration, and it will also evaluate relationships between egg diameter and egg thiamine concentration.

See the media created for this project here: https://storymaps.arcgis.com/stories/b49ec1acfdc9435dabeeca0c2606eda1