Leatherbacks from above

A first-hand account written by Upwell Observer, Sharon Hsu. Sharon Hsu is currently a grad student at Moss Landing Marine Labs with the Vertebrate Ecology Lab. Her research uses stable isotope analysis to determine foraging areas of nesting leatherback females in Costa Rica. She holds a BS in Ecology, Behavior, and Evolution from UC San Diego.

We’re only 650 feet high – technically still on earth – but it’s a whole new world up here. A rare break from the low clouds that are typically present in the region during August provided the perfect opportunity to search for leatherback turtles. On 15-16 August, I joined Upwell’s partners at NOAA, Scott Benson and Karin Forney and Katherine Whitaker for aerial surveys of marine turtles and mammals between Monterey Bay and San Francisco with Aspen Helicopters, Inc. pilot Kevin Ellington.

Connected by headsets to drown out the noise, we watch humpbacks dive, count sharks and molas by the hundreds. We record sea state, note patches of red tide, and spot currents of jellies, the primary food source for critically endangered west Pacific leatherbacks. The sea is hypnotic, and we fall into a routine of calling out our findings as we fly from Monterey up toward the Farallones. 

And then…. “I’ve got a turtle!” There’s an immediate adrenaline surge. The pilot circles around until we confirm the sighting. As a new observer, this is the most nerve-wracking moment - is it really a leatherback? Did I just call out for a large mola or maybe a very round sea lion? I’m familiar with all these species, but this is also my first aerial view of them. The team is amazingly coordinated. Someone confirms the sighting, the pilot zeros in on the turtle, and we record a visual size measurement, sex, general location and direction. In two days, we confirmed a total of five leatherback sightings.

Aerial surveys of marine turtles and mammals between Monterey Bay and San Francisco, CA during 15-16 August.

Aerial surveys of marine turtles and mammals between Monterey Bay and San Francisco, CA during 15-16 August.

I am more than thankful to be part of this project with such broad implications for sea turtle conservation! These flights are part of a preliminary survey to gear up for the field season next month as the team from NOAA and Upwell Turtles prepares to tag leatherbacks to learn more about diving behavior and at-sea movements of these critically endangered marine turtles. These data will support ongoing efforts to mitigate incidental entanglement of turtles in fixed gear nearshore fisheries.