Rising Sea Temperatures Killing Vital Algae Phytoplankton levels fell 40% in the last 60 years By Nick McMaster, Newser Staff Posted Jul 28, 2010 6:59 PM CDT 29 comments Comments This undated handout image provided by Karl Bruun, Nostoca Algae Laboratory, shows a number of marine diatom cells (Rhizosolenia setigera), which are an important group of phytoplankton in the oceans. (AP Photo/Karl Bruun, Nostoca Algae Laboratory, courtesy of Nikon Small World) (Newser) – Rising sea temperatures are killing phytoplankton, the microscopic organisms that feed the lower rungs of the food chain in the world's oceans and create much of our oxygen, scientists say. Researchers at Dalhousie University in Nova Scotia used a combination of old records and newer satellite images to determine a 40% drop in algae since 1950 and a drop of about 1% annually over the last century. "A global decline of this magnitude? It's quite shocking," said a lead author of the study in Nature. "This is the tip of the iceberg, in some respects," added the researcher. "Phytoplankton are key to the whole ecosystem. In terms of climate changes, the effect on fisheries, we don't know exactly what these effects will be." The Wall Street Journal and the Los Angeles Times have more details.