Evaluating Salivary Cortisol as a Non-Invasive Alternative to Blood in Beluga Whales (Delphinapterus leucas)

Beluga whales (Delphinapterus leucas) reside in Arctic waters, which are ground-zero for climate change. While it is difficult to study wild beluga health, animals under professional human care provide opportunity to gather important data on beluga physiology. The gold standard for monitoring health is blood; however, non-invasive sample matrices offer alternative approaches for rapid, easy, and repeated sampling. This study aimed to determine if beluga salivary cortisol is a relevant alternative to blood by 1) comparing cortisol in saliva vs. blood and 2) determining if construction-related drilling sounds result in a detectable increase in salivary cortisol. Paired saliva and blood samples were collected from three trained whales at Mystic Aquarium over 1 year. Saliva was also collected during exposure to drilling noise. Salivary cortisol was measured using a Cayman Chemical Cortisol ELISA Kit. A single animal showed a significant correlation between blood and saliva cortisol (R=0.721; p=0.019), yet no significant relationship was detected in the total data. The monthly average salivary cortisol was 78.15 +/- 51.20 pg/mL. During noise exposure, two whales had increased cortisol (265.52 and 173.96 pg/mL). While saliva shows promise for monitoring cortisol, more work is needed to determine the blood and saliva relationship and investigate individual variation in physiology. This work contributes to the development of saliva as a non-invasive sample for monitoring health which can be applied experimentally within aquaria to help us understand beluga physiology.

Presentation Preference: Poster

Primary Presenter: Emily Charles, University of Alaska Anchorage (ercharles@alaska.edu)

Authors:

Emily Charles, University of Alaska Anchorage  (ercharles@alaska.edu)

Dr. Laura Thomspon, Mystic Aquarium, University of Connecticut, Department of Marine Sciences  (lthompson@mysticaquarium.org)

Dr. Tracy Romano, Mystic Aquarium, University of Connecticut, Department of Marine Sciences  (tromano@mysticaquarium.org)