Salinity Tolerances and Biomarkers of Salt Stress in Longfin and Delta Smelt

R/SF-55
Start/End: January, 2013 to June, 2015

This project seeks to identify salinity tolerances of two listed fish species – longfin smelt and delta smelt. Experiments focused on newly hatched and post-45-day-old smelt. The work shows that both smelt species, at this age, are able to survive and grow in salty waters. The Delta Science Fellow also conducted experiments on adult delta smelt. These experiments looked at how changes in water salinity might affect delta smelt’s responses and physiology, in order to determine if salinity tolerance influences their presence in the low salinity zone (<6ppt), where fluctuations are common.

Part of this project is to identify biomarkers through fluorescent staining of gill cells and acclimatory responses of salinities from ≤6 ppt to 10 ppt. Physiological responses and biomarkers may provide scientists and managers a means to monitor species’ exposures to different water salinities. Results from this project may further what is known about the species’ life history requirements, particularly the timing and speed at which smelt can transition from fresh to saline conditions.

Research mentor: Swee Teh, UC Davis

Community mentor: Randall Baxter, California Department of Fish & Wildlife