An international team of researchers will visit the region of the North Atlantic Ocean affected by ash from the eruption of Eyjafjallajökull in an effort to determine the impact the volcano had on the ocean biology.
Aboard the UK’s Royal Research Ship Discovery, the team will make their second cruise to study the region, the first after the volcano Eyjafjallajökull erupted in April and May of this year. The team will return to the area they had previously studied to assess how phytoplankton blooms have developed in lieu of the volcano.
“We will be doing further biological experiments at sea in the Iceland and Irminger Basins during this five-week cruise,” said Professor Eric Achterberg who will be leading the cruise. “In particular we will add volcanic ash collected on the first cruise to seawater samples (and also add iron separately) to study the response of phytoplankton. This work is built into our original programme and provides a unique opportunity to determine the biological effects of volcanic ash inputs to the ocean.”
Ocean Biology 101
Phytoplankton are responsible for much of the oxygen present in Earth’s atmosphere, half of the total amount produced by all plant life. They are the basis for many of saltwater and freshwater food webs, most notably the food chain of phytoplankton feeding krill feeding baleen whales.
Phytoplankton are also able to fix large amounts of carbon within the water, making them very important to the carbon cycle. Subsequently phytoplankton are especially important as is their ability to live and reproduce.
However many regions of the ocean have a limited availability of iron which limits the productivity of phytoplankton. Scientists from the National Oceanography Centre, Southampton, NOCS, demonstrated that the high-latitude North Atlantic Ocean might be one such region.
The sub-polar region of the Atlantic Ocean is a globally important region due to its role as a carbon sink and an area where deep-water formation takes place. Any lack of iron could cause a diminishment of carbon fixation in the water and represent an inability for the ocean to extract and store carbon from the atmosphere.
The first cruise made by scientists this year to the region just south of Iceland and east of Greenland took place just before and during the eruption of Eyjafjallajökull. Their original purpose was to determine biological and chemical conditions in the ocean before the large annual spring phytoplankton bloom started, but they also managed to observe the large input of volcanic ash into the ocean.
Their return will allow them to assess how phytoplankton blooms have developed as well as give them the chance to investigate whether phytoplankton in the area were limited due to a lack of iron or whether the volcanic ash – thought to be capable of providing a significant source of iron – supplied enough iron to sustain the spring bloom.
“It will be really interesting to return to the region where we observed significant ash inputs earlier in the year,” said Dr Mark Moore from SOES, who led the first cruise. “We are very fortunate to be able to go back and see whether there is an effect on ocean productivity.”
The team set sail from Avonmouth on July 4 and is scheduled to return to the UK on August 11. An expedition blog can be seen here with a daily blog, photos and more information about the cruise and its aims.