Recent wildfires that occurred in August 2020 along the California Central Coast have generated a mosaic of burned and unburned watersheds. This project uses a paired sampling design, pairing burned and unburned streams within four watersheds. Spatially isolated sites within each watershed have been selected to ensure juvenile salmonids cannot move between the burned and unburned sites. This project will measure the concentrations of heavy metals in stream water and fish muscle tissue from burned and unburned streams within each watershed. The behavior of juvenile salmonids from burned and unburned streams will be compared for predator avoidance and recognition of natal stream water. The expression of genes associated with normal olfactory function and natal homing will be compared between fish from burned versus unburned streams. If the release of heavy metals by fire disrupts juvenile salmonid olfaction, then fish from burned streams are expected to exhibit weaker predator avoidance, impaired recognition of natal stream water, and reduced gene expression. Collection of field data during summer 2021 is important because the cohort of juveniles currently rearing in streams will experience the altered chemical environment created by recent fires most strongly.

Approved