Invertebrate Responsible for Rise in Carbon Sink in Antarctica
25.02.2011 - Atmosphere & Space, Water & Oceans, Flora & Fauna, Antarctic
In a recent study published in Current Biology, a group of researchers studied collections of a filter-feeding marine invertebrate, Cellarinella nutti, which date back to 1901. The organisms are helping sequester more carbon from the atmosphere on the ocean seabed.
Numbers of the organism had been growing steadily until 1990, when scientists noticed its numbers double. According to David Barnes of the British Antarctic Survey (BAS), “This is one of the few pieces of evidence that life in Antarctica has recently changed drastically” since the organisms are “taking more carbon dioxide out of circulation and locking it away on the seabed.”
The rapid growth of C. nutti reflects a similar growth of phytoplankton, which is their primary food source. Phytoplankton relies on CO2 dissolved in the seawater from the atmosphere for subsistence. Once C. nutti eats the phytoplankton, it incorporates the carbon in its skeleton and other tissues. The parts of its body that the animal loses over the course of its life then sink to the seabed, taking the carbon along with it. This shift to an increased carbon capture and storage, the scientists say, might result from an increase in wind speeds over the last decade.
This study, the researchers believe, is one of the first to link two global phenomena – the hole in the ozone layer and the greenhouse effect – and highlight the impact of one on the other. Although the impact of the changes in C. Nutti should remain limited, “the combination of ice shelf losses and sea ice losses due to climate change and the effect of ozone loss-induced wind speeds offer some hope for much-needed carbon sequestration to the seabed in the Southern Ocean," according to Barnes.
