14 DAY TRIAL // Echinoderms, a group of animals that includes sea stars, sea urchins and sea lilies, are apparently more proficient at collecting and storing the dangerous greenhouse gas carbon dioxide than previously thought. A group of experts announces that it has just finished the first-ever study to look at the contribution that these animals bring to the overall capacity of the world's seas and oceans to trap and store massive amounts of CO2, Nature News reports.
Generally, as experts study the carbon cycle in the planet's waters, they look mostly at plankton, or similar, small-size organisms that drift in the upper layers of the seas. These life forms indeed contribute extensively to carbon sequestration, as it was proven on numerous occasions. They consume a lot of carbon during their life times, and take the chemical down to the bottom of the sea when they die and sink. The greenhouse gas is then stored on the sea or ocean floor as calcium carbonate, which is a stable substance.
The recent investigation was conducted by a team of researchers led by former University of Southampton undergraduate student Mario Lebrato. The expert is now a PhD student at the Leibniz Institute of Marine Science, in Germany. He suspected that echinoderms also stored CO2, but found out that there were no studies to quantify their exact contribution to the overall carbon cycle in the oceans. “The funding for this was initially derived from my pocket because nobody believed in the echinoderm [carbon] contribution,” Lebrato says. During the research, he and his colleagues collected samples from all five echinoderm main classes: sea stars (Asteroidea), sea urchins (Echinoidea), brittle starts (Ophiuroidea), sea cucumbers (Holothuroidea) and sea lilies (Crinoidea).
Results indicated that these organisms trapped and stored about 0.1 gigatonnes of carbon dioxide per year. This may not seem like much, but the view is changed when considering that human activities generate about 5.5 gigatonnes of CO2 annually. “Echinoderms are found in all ecosystems at all depths worldwide and have bodies that can be composed of more than 80% calcium carbonate […] so we were almost expecting a result like this,” Lebrato adds. Further details of this work can be found in the latest issue of the scientific journal ESA Ecological Monographs.