New research suggests jellies play a more valuable role in food webs and carbon storage than scientists previously thought.
A new study in the AGU journal Global Biogeochemical Cycles estimates how much carbon gelatinous sea creatures store in their bodies and where that carbon goes. The results show that 3.7–6.8 billion metric tons of organic carbon can be traced back to jellies each year, an amount on par with the United States’ 2018 carbon dioxide emissions. Mass jelly die-offs (called jelly-falls) alone could increase estimates of the total carbon that reaches the bottom of the ocean by 35%, according to the study. Ultimately, a substantial portion of that carbon could end up stored on the ocean floor.
The study adds to a growing body of evidence that jellies, long considered a nuisance and a symbol of collapsing ecosystems, play a valuable role in ocean ecosystems.
A New Perspective on Jellies
A broad category of ocean critter with a bad reputation, the vast array of jelly-like animals known as gelatinous zooplankton include jellyfish, comb jellies, and salps, which drift freely on ocean currents for at least part of their lives. Jellyfish are often cast as the villains of the sea, notorious for their sting and for gumming up boat motors. Their growing numbers are also typically invoked as a dire sign of overfishing and emptying oceans because they reproduce quickly, can thrive in warm temperatures and chemical conditions other animals find hostile, and are particularly numerous when larger predators aren’t around to keep their numbers in check.