Pyrosomes are gelatinous, tube-shaped animals that have become increasingly abundant in the California Current, but we still know surprisingly little about their role in marine food webs and carbon cycling. In this study, we investigated how much they eat, how much they poop, and what happens to that poop as it sinks through the ocean. We found that individual pyrosome colonies produce approximately 1,300 fecal pellets per hour, which sink at an average speed of 47 meters per day. When abundant, pyrosomes can consume nearly 30% of daily offshore phytoplankton production, making them important grazers in an otherwise food-limited environment. We also found intact diatoms in their fecal pellets, confirming that pyrosomes consume these tiny algae and contribute to silica cycling. Together, these findings show that pyrosomes can export substantial amounts of carbon and silica from surface waters. However, their pellets sink relatively slowly, leaving plenty of time for this material to be recycled before reaching the deep ocean. As pyrosomes become a recurring feature of the California Current, understanding their feeding and poop production is increasingly important for figuring out where ocean carbon goes and how long it stays there.
