Investigators: Alexa Kownacki, Dr. Dave Weller, Dr. Nick Kellar, Dr. Eunha Hoh, Dr. Nate Dodder, Dr. Leigh Torres

This project aims to better comprehend common bottlenose dolphin population health off the coast of California. The marine ecosystem off of California is highly productive and home to a diversity of cetacean species. Common bottlenose dolphins (Tursiops truncatus) occur as two genetically differentiated ecotypes off of California, a coastal ecotype and an offshore ecotype. Common bottlenose dolphins are an important study species and serve as indicators of marine ecosystem health because their range and diet overlaps with human populations. Furthermore, they inhabit an area highly impacted by human use, from industry to recreation.

Because coastal dolphins are subjected to many anthropogenic threats, including oil spills, vessel traffic, and noise and chemical pollution, it has become increasingly important to study and assess their health. In contrast to this nearshore ecotype, the offshore bottlenose dolphin ecotype occupies a dramatically less urbanized environment, and does not experience the same level of anthropogenic threats as the coastal ecotype does. By using photography—both from a small boat and UAS (unmanned aerial systems), blubber hormone analysis, and gas chromatography, we analyze and quantitatively compare the health of these two ecotypes. With these tools, we are able to evaluate body condition via body measurements and visualization, stress levels via blubber cortisol levels, and contaminant levels via halogenated organic compounds presence. These dolphins may serve as an indicator species for both commercial fisheries and environmental toxins because their preferred prey are commercial species in California. As a highly nomadic population, common bottlenose dolphin are an ideal study species in relation to how human-induced disasters—such as oil spills—affect marine life. Information gathered from this study will inform conservation management of recreational and industrial activities.

Collaborators:

Dr. Dave Weller, Marine Mammal & Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration

Dr. Nick Kellar, Marine Mammal & Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration

Dr. Eunha Hoh, Environmental Health, Graduate School of Public Health, San Diego State University

Dr. Nate Dodder, Environmental Health, Graduate School of Public Health, San Diego State University

Dr. Leigh Torres, Department of Fisheries and Wildlife, Marine Mammal Institute, Oregon State University, Hatfield Marine Science Center

 

Funders:

The Science, Mathematics And Research for Transformation (SMART) Scholarship established by the Department of Defense (DoD)

Southwest Fisheries Science Center, NOAA Fisheries, National Oceanic and Atmospheric Administration

This project aims to better comprehend common bottlenose dolphin population health off the coast of California. The marine ecosystem off of California is highly productive and home to a diversity of cetacean species.