Science activity

The inner ear bones of fish, or otoliths, grow continuously and their chemistry reflects the water conditions that a fish has experienced throughout its life. In this project, researchers used in-situ chemical analysis to determine the oxygen isotopic composition of otoliths, which can reflect the water temperature that a fish has experienced. They applied this method to archived adult Delta Smelt otoliths from multiple different water years spanning the time from before and during the recent drought. Using these data, they investigated the relationship between delta smelt abundance and environmental parameters, such as water temperature. More specifically they investigated whether delta smelt are able to find temperature refuges, even in drought years.