Global warming has long been blamed for the huge rise in the world's jellyfish population. But new research suggests that they, in turn, may be worsening the problem by producing more carbon than the oceans can cope with.
Research led by Rob Condon of the Virginia Institute of Marine Science in the US focuses on the effect that the increasing numbers of jellyfish are having on marine bateria, which play an important role by recycling nutrients created by decaying organisms back into the food web. The study, published in the journal Proceedings of the National Academy of Sciences, finds that while bacteria are capable of absorbing the constituent carbon, nitrogen, phosphorus and other chemicals given off by most fish when they die, they cannot do the same with jellyfish. The invertebrates, populating the seas in ever-increasing numbers, break down into biomass with especially high levels of carbon, which the bacteria cannot absorb well. Instead of using it to grow, the bacteria breathe it out as carbon dioxide. This means more of the gas is released into the atmosphere.