Effects of copper exposure on the olfactory response of Delta smelt (Hypomesus transpacificus): Investigating linkages between morphological and behavioral anti-predator response

Start/End: February, 2018 to January, 2020

One factor that could be involved in the recent decline in San Francisco Bay-Delta fish populations is the presence pollutants such as copper, which can disrupt the fishes’ sense of smell. Since fish rely on their olfactory system to find prey, avoid predators, as well as cue mating behaviors, this could have serious consequences. While copper has been documented in the Bay at levels known to be toxic to many fish species, researchers do not know what levels of copper are toxic to the olfactory system of key species such as delta smelt.

This study aims to address the question of how contaminants—specifically copper—can affect the ability of delta smelt to detect specific odorants and conduct essential behaviors.

The project will have two main goals:

  1. Evaluate the anti-predator behavior of Delta smelt in response to alarm cues.
  2. Explore the effects of copper exposure on the anti-predator behavior and morphology of the olfactory rosette of Delta smelt.

The data can be integrated into the conceptual models that have been developed by managers of the state and federal agency and the Interagency Ecological Program to better prioritize the mechanistic and ecological effects of pollutants in the San Francisco Estuary.

Research Mentor: Swee J Teh, University of California, Davis
Community Mentor: Shawn Acuña, Metropolitan Water District of Southern California