Mysterious Sea Pickles Invading West Coast in Bizarre Bloom

Sea pickles, or pyrosomes, growing up to 2 feet in length are being found in large numbers in the eastern Pacific. University of Oregon

Mysterious creatures called sea pickles are showing up in large numbers on the West Coast. These organisms are actually conglomerations of zooids—small, multicellular organisms—which come together into tubular shapes that in this case stretch from about 6 inches to 2 feet long, according to EarthFix, an offshoot of Oregon Public Broadcasting.

Normally these animals, also known as pyrosomes, are found in tropical waters, and they also are bioluminescent, meaning they produce light. (Pyrosome is derived from the Greek pyro for "fire" and soma for "body.") Not very well-studied, they can stretch up to 60 feet long, and look something like a living wind sock.

But this spring they began appearing in the eastern Pacific, from Oregon to Alaska, in quantities never before seen—numbers so large that they've led fishermen to abandon fishing in certain areas. One researcher pulled up 60,000 of them in 5 minutes using a net, National Geographic reports.

These bumpy little sea pickles are basically harmless and feed on algae and small particulate matter in the ocean. But scientists worry that they might all die at the same time, which could lead to a mass of decaying organic matter, which would suck oxygen out of the water and perhaps create a dead zone. Indeed, rotting organic matter (specifically plankton and algae) is what causes the Gulf of Mexico dead zone; this algae thrives on nutrient runoff from the Mississippi River.

"Why they're here now is unknown at this point," Jennifer Fisher, a research assistant with Oregon State University's Hatfield Marine Science Center, tells EarthFix. "We've had warm ocean conditions over the past couple years, and something has brought them here. They're just flourishing. It's just very unusual to find them so close to shore, so evenly distributed and so abundant."

Scientists are seizing the chance to study the animals, which are normally rare, and hence known to some as the "unicorn of the sea."

Hilarie Sorensen, a graduate student at the University of Oregon who is part of a new research team set up to study the bloom, told The Guardian, "If we continue to see this many, what impact will it have on the ecosystems here, and what economic impact on the fisheries? There are so many unknowns at this point, it really is a remarkable bloom.

"Right now," Sorrensen said, "we are scrambling to learn as much as possible while we have the opportunity."