Sharmila Pal, graduate student at the University of South Carolina, studies organic carbon, or dead particles, sinking from the surface ocean to the deep ocean. (Photo: Haley Smith Kingsland)

Dr. Kevin Arrigo is a Professor in the Department of Environmental Earth System Science at Stanford University. He is the Chief Scientist for NASA’s ICESCAPE (Impact of Climate change on the Eco-Systems and Chemistry of the Arctic Pacific Environment) mission this summer onboard US Coast Guard Cutter HEALY.

We’re surrounded by a green broth of life. The single-celled algae called phytoplankton are so dense that our instruments disappear from sight a mere few feet after we plunk them into the water.

A few days later, we sample the same area and find…nothing. Or almost nothing.

Phytoplankton are the staple food that sustains much of the Arctic marine ecosystem. The bread of the sea. But where did it all go?

That’s what Sharmila Pal, a graduate student of Claudia Benitez-Nelson (University of South Carolina), wants to find out.

In the Arctic, phytoplankton take advantage of the few months of sunshine and ice-free conditions in the spring and summer to grow to extraordinary numbers. So dense are these “blooms” that they completely overwhelm the ability of the grazers, mostly shrimp-like copepods, to consume them (just picture a cow with an entire pasture to itself). The phytoplankton that don’t get eaten will eventually sink after they suck the surface ocean dry of nutrients. Some of this energy-rich salad will decay as it sinks, but because the Arctic Ocean is so shallow, a lot of it reaches the bottom.

We’re just not sure how much.

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