New eDNA Study Shows Alternative Approach to Monitor Endangered Delta Smelt Population

 
San Francisco, CA – The Delta Smelt, a small pelagic fish endemic to the San Francisco Estuary, has experienced a significant decline in population abundance over the past few decades. Current ecosystem conditions are inhospitable to native species, and population abundance issues have restricted “take” under the State and Federal Endangered Species Act. New alternative approaches are needed to monitor the population recovery of the Delta Smelt.
 
Environmental DNA methods provide a solution to visual survey limitations, as they unambiguously identify target organisms and are sensitive to trace amounts of DNA in sampled material. To use Delta Smelt eDNA information effectively in a regulatory context, a mathematical model is required to establish the relationship between DNA detection and the three main variables that influence the detection of DNA particles in a unidirectional or tidally influenced aquatic system (see related { artemis package } and publication ).
 
Focused experiments have been designed to fill in the most pressing gaps in our current knowledge needed to inform our existing models and test performance under realistic field conditions. These methods provide a cost-effective and feasible way to monitor the population of endangered Delta Smelt and other cryptic species without impacting them directly.
 
Experiments conducted are described in project report submitted to U.S. Bureau of Reclamation.
 
Quantifying Fish Biomass X Distance from Environmental DNA Samples in a Hydrodynamically Complex Environment