PopSci U: Seven of the Country's Coolest SciTech Courses

Dyeing for Jelly: The jellyfish absorbs dye released in front of it, which makes its movements easier to see.  Christoph Gerigk, courtesy GEO

So You Want to...Dive with Jellyfish?

Where: Dawson Lab, University of California at Merced
What You’ll Learn: The evolutionary reasons behind jellyfish swarms and how they energize the ocean
Job Prospects: Marine biologist, evolutionary ecologist
Typical Assignment: Swim alongside 10 million golden jellies in an island lake in the Pacific

The schedule for the grad students and postdocs in the Dawson Lab this year sounds like an extended spring break, with scuba diving, snorkeling and speed-boating in places like the Gulf of Mexico, the California shoreline and the island nation of Palau. But the work they’ll do—trying to explain what the lab’s namesake, evolutionary biologist Michael Dawson, calls “the dark energy of the oceans”—is far from trivial.

Dawson and his students hope to solve one of the most puzzling aspects of the world’s oceans: where they get all their energy. Ocean mixing is the process whereby turbulence and currents redistribute heat and bring nitrogen, carbon and other elements from one part of a body of water to another. But scientists have done the math, and to see mixing to the degree they do, the ocean must be getting extra energy from some unknown source.

One candidate is the jellies. In swarms, the movements of even small animals might have a serious effect. And Palau’s Jellyfish Lake, a 12-acre sea landlocked from the ocean some 15,000 years ago and now home to millions of golden jellies, is the perfect laboratory for testing that theory. If the sum of the animal-created turbulence has a strong enough mixing effect here, then it might have a comparable effect in the oceans. Last year, Dawson’s team and its California Institute of Technology collaborators, funded by the National Science Foundation, became the first to suggest the link between jelly-swarm turbulence and ocean energy. The students spend six to 10 hours a day for months at a time in the water, swimming alongside the jellies and measuring the velocity of the tiny eddies they create as they make their twice-daily migration across the lake. It’s one of the few places in the world where researchers can get this close to an entire population of jellyfish.

Jelly Junkies: Researchers use a particle imager to measure the nutrients and other particles stirred up by the jellies’ swimming.  Christoph Gerigk, courtesy GEO