A sea creature normally found in the tropics has suddenly exploded in the ocean off the Oregon coast.

Scientists are baffled by this massive bloom of pickle-shaped pyrosomes that are clogging the nets of researchers and fishermen. No one knows exactly why they’re here, but many suspect it has something to do with a blob of warm water that’s been hanging out off the West Coast for the past several years.

Researchers are studying the ocean conditions to learn more about their habitat and running experiments to figure out what they’re eating.

Read the full story from EarthFix.