Virtually all marine life depends on the productivity of phytoplankton — microscopic organisms that work tirelessly at the ocean’s surface to absorb the carbon dioxide that gets dissolved into the upper ocean from the atmosphere.
Through photosynthesis, these microbes break down carbon dioxide into oxygen, some of which ultimately gets released back to the atmosphere, and organic carbon, which they store until they themselves are consumed. This plankton-derived carbon fuels the rest of the marine food web, from the tiniest shrimp to giant sea turtles and humpback whales.
Now, scientists at MIT, Woods Hole Oceanographic Institution (WHOI), and elsewhere have found evidence that phytoplankton’s productivity is declining steadily in the North Atlantic, one of the world’s most productive marine basins.
In a paper appearing today in Nature, the researchers report that phytoplankton’s productivity in this important region has gone down around 10 percent since the mid-19th century and the start of the Industrial era. This decline coincides with steadily rising surface temperatures over the same period of time.
Read more at Massachusetts Institute of Technology
Image: Retrieving an ice core section from the drill barrel during a west Greenland snowstorm, west Greenland Ice Sheet. CREDIT: Sarah Das (WHOI)