Some kind of diatom of the Chaetoceros species. There’s a prize for anyone who can identify it more specifically in the comments.
Tali Treibitz, a member of our scientific party from Scripps Institution of Oceanography and UC-San Diego, will spend the trip testing her experimental underwater microscope-camera for visualizing small-scale particles. This camera attaches to the CTD rosette (the rack we use to collect seawater samples
Some kind of coiled diatom. Why would a diatom form as a coil? Diatoms are weird.
and basic data about ocean temperature, salinity, and some other variables; more on this later) and takes microscopic images of the water that passes it by. She can use it to count particles, get some sense of their composition, and even to identify some species of phytoplankton. Note the scale bar: features on the order of a micrometer, or about 40 millionths of an inch, are clearly visible.