When you think of terrifying monsters that might inhabit the Great Pacific Garbage Patch, what do you think of? Mutant sharks? Pissed-off squid? Rabid barnacles? (Well, ok, probably not rabid barnacles.)

Nope. The scariest inhabitant of the Great Pacific Garbage Patch is this.

White plastic with Halofolliculina ciliates on it

Photo by Hank Carson

Meet Halofolliculina. It is a single-celled organism - a ciliate - about the size of a sesame seed with teeny tiny devil horns. (They are actually pericytostomial wings, not devil horns, but I won't tell if you don't.) My collaborators Hank Carson and Marcus Eriksen found these little buggers living on plastic debris floating way offshore in the western Pacific, which wouldn't be terrifying in itself since a lot of strange critters live on plastic debris (see our paper for a complete list). But Halofolliculina is a pathogen that causes skeletal eroding band disease in corals, and this piece of debris was headed towards Hawaii.

Coral with skeletal band eroding disease.

A coral with skeletal eroding band disease. You can see Hallofolliculina ciliates forming a dark band at the margin between the live tissue and exposed skeleton. Photo: Andrew Bruckner

Unfortunately, Hank and Marcus didn't save the corals of Hawaii by capturing these Halofolliculina. Skeletal eroding band disease was discovered in Hawaiian corals back in 2010. While It's not know how this disease got to Hawaii, a lot of plastic trash washes up on Hawaii, and it's possible that some of that trash had Halofolliculina living on it.

Along with Halofolliculina, there are all kinds of creatures living on plastic debris that wouldn't normally be able to survive floating in the middle of the ocean. Along with the usual members of the North Pacific rafting community - gooseneck barnacles, bryozoans, rafting crabs - we found brittle stars, sea spiders, and even a shipworm that was probably really unsatisfied living on plastic. Essentially, the trash acts like tiny little islands, with small pieces hosting only a few species, and large pieces (like tangled fishing nets) hosting many more.

Dead baby triggerfish in human palm

A juvenile triggerfish Canthidermis maculata found associated with a bleach bottle. Photo: Hank Carson

We aren't sure what the impact of all these "misplaced" species is on the open ocean, or whether plastic was the sole vector that introduced skeletal eroding band disease to Hawaii. But plastic does not belong in the ocean, and we have really got to stop putting it there. No more cushy homes for devil ciliates!

Want more? You can read the paper here or here. And as always, I'm happy to answer your questions in the comment thread.