Acidic oceans shrink plankton

摘要

As oceans take up more carbon dioxide, their increasing acidity could be decreasing the weight of one of the most abundant calcium-producing marine phytoplankton. Low pH is known to interfere with phytoplankton calcification and reduce their weight in the lab, but the impacts of ocean acidification in the wild have not been clear. Sebastian Meier, now at the University of Kiel in Germany, and his colleagues collected Emiliania huxleyi (pictured) particles between 1993 and 2005 from surface sediments in the Mediterranean Sea. The authors compared the weights of the plankton with data from sediment cores stretching back more than 10,000 years. The team found that the weight of E. huxleyi has been decreasing since 1993, and during the study period reached its lowest value in the past 10,000 years.