The Arctic Ocean experiences a two-week algal bloom every spring as the winter darkness subsides and sea ice starts to thin. This algal bloom is capable of fueling the whole food web for the entire year while acting as a CO2 sink, removing carbon dioxide from the atmosphere.
The bad news is that recent experiments have shown that plankton can switch from acting as a sink to acting as a source of CO2 when water temperatures exceed 5 C. With increasing evidence that the Arctic Ocean will experience 5 C temperatures in the coming years, an international team of researchers, led by the Director of The University of Western Australia (UWA)’s Oceans Institute, Winthrop Professor Carlos M. Duarte, has issued a warning about the dangers we are facing.
Professor Duarte notes that resolving the role of plankton as a source or sink for CO2 is vital when considering the carbon budget of the planet. It’s also a fairly time-sensitive issue, as 5 C temperatures aren’t far away.
“In the open Arctic Ocean warming at this level will be experienced in a few decades, although projections are being constantly revised due to changes being more rapid than anticipated,” Professor Duarte told MST in an email.
Temperature is unlikely to affect the length of the spring algal bloom, but Professor Duarte explained that there is concern that temperature will affect the timing of the bloom.
“There is evidence, published in 2012 and 2013, that blooms may now be happening under ice…however, the magnitude of the bloom will be constrained by nutrient supply, which is likely to be reduced with freshening of the Arctic,” he said.
Professor Duarte’s team will return to the Arctic again in April and July.
“In April we continue to monitor the magnitude of the spring bloom and possible changes in the structure of the plankton community,” he said. “In both cruises we will continue to monitor the role of plankton in the CO2 balance to detect the shifts expected with warming.”
To learn more:
- Read the news release: Arctic ecosystem about to tip over on climate change
- Check out this related article: Global warming affects Arctic and Antarctic regions differently
- Find the latest study, here: Seasonal patterns in Arctic planktonic metabolism (Fram Strait – Svalbard region)
Copyright © 2013 by Marine Science Today, a publication of Marine Science Today LLC.