A biological oceanographer at Stanford University, Kevin Arrigo, has been studying remote sites in Antarctica for nearly two decades. His research has been focused on what experts call an "oasis in a desert of ice." These areas are so inaccessible that even those scientists who theorize various study hypotheses about them may not have ever laid eyes on them.
Arrigo visited a handful of such areas with formations called polynyas. These formations derive their name from the Russian language word translating as "hole in the ice". The can be found typically along the coast, on an expanse of open seawater that is enclosed by the continental shelf and floating sea ice.
Arrigo's new research found that the abundance of phytoplankton, the most important determinant of productivity in these polynyas is iron. The iron traces found there were being pumped into them by glacial meltwater. Due to a warming planet, intensification of glacial melting leads to a formation of these polynyas formations in coastal Antarctica. This is one of the few benefits effects of climate change found by scientists so far. According to the researchers, Antarctica is likely to become more productive and that could create ripple effects for the food chain.
Arrigo explained that certain varieties of phytoplankton are tiny microorganisms that stay at the base of the marine food chain. The marine organisms can thrive on this food resource, protected along the coast in areas where the ocean waters are cleared of sea ice by strong winds. This carve out a suitable enclave for marine organisms, unlike the rest of the cold and frozen Antarctic region.
Satellite images of the show and abundance of phytoplankton around Antarctica, Arrigo said. Traditional oceanographic measurements like primary production and chlorophyll levels were combined with recent satellite work by other research groups that study glacial melt, added Scott Doney, a scientist at H.T. Harvey & Associates, an environmental consultancy.
By using satellite data accumulated between the years 1997 and 2014 for 46 polynyas areas located around the Antarctic coast, the scientists were able to detect a strong link between the extent of glacial melt from adjacent glaciers and productivity levels. The conclusion of these studies, Arrigo said, is that productive polynya appears where the glacial meltwater is enriching polynya with iron. Iron, according to scientists, is a nutrient with a role in phytoplankton growth.
