Hidden worlds

By Marianna Karagiannis

I've always felt a strong urge to collect things. Much like a squirrel, I am always gathering and sorting and storing my treasures. Thankfully, this turns out to be a useful habit for a scientist, although perhaps not what you're looking for in an officemate (sorry). Today, I'd like to share some of my most recent treasures from sea!

The ocean is full of worlds that most people never get to see. There are of course environments like charismatic hydrothermal vents, crusted in the most extreme life imaginable. There's the videos of the creatures of the deep, staring at cameras with eyes that have never seen light. But, much closer to home, there are beauties and curiosities that we push back without so much as a glance. These microscopic worlds of the water and mud can be spiky and sticky, squishy and crunchy, and can glisten like diamonds of the sea. Let's take a look at the world of plankton.

Plankton are, by definition, drifters. They go where the water takes them, lacking the ability to swim against the current. Phytoplankton are the "plant-like" plankton, the primary producers of the open ocean that use photosynthesis to build their bodies that turn the water green and brown and red. Zooplankton are the animal plankton, which can include the tiny copepods and water fleas, but also any of the bigger animals that float rather than swim, including jellyfish. Zooplankton can also be other heterotrophs like radiolarians and foraminifera, protists that feed off smaller plankton. Just to round us out, there are also bacterioplankton and mycoplankton (marine fungi), but our plankton collectors are only catching the big things so you'll have to wait until another day to hear about those.

Over the past few weeks, as we've been collecting sediment cores and sinking particles, I've started sifting through to see what our eyes are missing. Mud is never just mud, and each sinking particle is its own universe. In my sorting, I've found foraminifera shells, radiolarians, copepods, microscopic worms, pteropods, diatoms, dinoflagellates, and everything else I read about in a textbook but didn't give much thought. Over the next few weeks, as we collect photos, I'll write more posts explaining exactly what these creatures are and why we're collecting them, but for now I'll leave you with a first glance to remind you of the beauty of our planet and a reminder to appreciate the little things.