Researchers have long known that some marine animals, such as plankton, play big roles in the carbon cycle, but a new study shows that a long-ignored family of marine animals, the bottom-dwelling echinoderms, also do their part in the carbon cycle.
Members of the echinoderms—sea stars, sea urchins, brittle starts, sea cucumbers, and sea lilies—capture and store 0.1 gigatons of carbon annually (or 100 million tons), according to a new study in ESA Ecological Monographs. Although only about 1.8 percent of the amount of carbon humans pump into the atmosphere every year, the number is massive and surprising.
“I was definitely surprised by the magnitude of the values reported in this study, but [the study’s] approach seems sound, so the reported numbers are probably fairly accurate,” palaeoceanographer Justin Ries of the University of North Carolina at Chapel Hill told Nature.com.
Reis says further research should look at the effect of ocean acidification—caused by marine systems storing higher levels of carbon—on the echinoderms.
“If the echinoderms end up being disproportionately susceptible to ocean acidification then it’s conceivable that the dissolving of echinoderm-derived sediments will be one of the earliest effects of ocean acidification on the global carbon cycle,” says Ries. “In fact, maybe it already is.”
Citation: Mario Lebrato, Debora Iglesias-Rodriguez, Richard Feely, Dana Greeley, Daniel Jones, Nadia Suarez-Bosche, Richard Lampitt, Joan Cartes, Darryl Green, Belinda Alker (2009) Global contribution of echinoderms to the marine carbon cycle: a re-assessment of the oceanic CaCO3 budget and the benthic compartments. Ecological Monographs. doi: 10.1890/09-0553.
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