Chinook Salmon Conservation Physiology
Chinook salmon is a native anadromous species and the largest of Pacific salmon. In California adults migrate throughout the year as four seasonal runs. Commonly referred to as a cold-water species they are currently facing population declines due to multiple factors such such as anthropogenic habitat alterations (e.g. dams) and a changing climate (e.g. warming water temperature). Our lab aims to understand their physiology to better inform management actions taken in California and across the west-coast.
Latitudinal variation in thermal physiology -- PhD Candidate Ken Zillig
Due to their life-history strategy, Chinook salmon exist as a collection of populations, particular to their river systems. How these populations differ from each other can inform how we understand salmonid adaptation as well as provide insight into how to best manage this plastic species. This project is looking specifically at temperature, and how different populations of Chinook may exhibit varying thermal physiologies and whether these variations are a result of local adaptation.
Current work has explored populations from California, Oregon and Washington with an eye towards testing populations from British Columbia or Alaska. Comparing populations via a common-garden framework will enable an accounting of the potential for this species to cope with future environmental change.
Physiology of Chinook salmon smolts in the San Joaquin River -- PhD Student Leah Mellinger
Spring-run hatchery Chinook salmon smolts released in the San Joaquin river have been experiencing high mortality rates and low returns. Smolts have been held in cages in locations shown to be areas of high mortality by previous telemetry studies for acclimatization and then physiological testing of mRNA expression of sublethal stress and possible pathogen infections. By combining assessments of pathogen load and stress markers linked to water quality, we should be able to glean greater insight into potential mechanisms underlying observed mortality patterns. It is hypothesized that higher mortality rates (outside the initial release) are due to accumulated sub-lethal stress stemming from degrading environmental conditions in the San Joaquin River.
Chinook Salmon Battle Creek Acoustic Tagging Study -- Amanda Agosta
In April 2019, our team tagged 700 Fall-run Chinook salmon parr at the Coleman National Fish Hatchery. This study looks to compare survival rates between two release sites: directly at the hatchery release site or 70 miles down river at Scotty’s Landing. Past telemetry information has shown the highest mortalities to be within the first 100 miles of travel from the hatchery release site. Releasing further down river may potentially decrease mortality by predators during outmigration.