website templates

Hello Everyone,
My name is Jason John and my research focuses on the physiology of swimming and diving in marine mammals and birds. As a grad student in Terrie Williams' lab at University of California Santa Cruz (UCSC), I've had the opportunity to work with over a dozen different species in environments ranging from Florida in the summer to Antarctica in the winter.

In my research I examine the adaptations that allow marine mammals and birds to not only survive, but also thrive in an environment that most mammals are incredibly ill-adapted for. Recently, new opportunities have emerged with breakthroughs in miniaturized instrumentation that can be deployed on free-ranging mammals to monitor physiology and acceleration. These instruments allow us to record and study how they move and interact with the environment around them in an effort to understand their unique physiological adaptations. When combined with ecological modeling, we can better predict the needs of these species and how they will respond to disturbances in their environment.


Swimming and diving in West Indian manatees

Quantifying the effects of swim speed and diving on locomotion costs for a threatened marine mammal species. Learn more...


Physiology in extreme conditions

Current and upcoming research looking at the physiological adaptations enabling survival in Antarctica. Learn more...


Beluga whale energetics

Measuring the cost of resting, swimming, and diving in beluga whales to better understand the impacts of disturbances.
Learn more...


Energetics and Acceleration

Examining the metabolic cost of swimming and diving and calibrating an accelerometer metric for assessing those costs in the wild. Learn more...