NASA satellites detected a 1% annual drop in Northern Hemisphere phytoplankton from 1998–2012. These invisible ocean plants drive 25% of human CO₂ absorption and anchor the entire marine food chain.
Oceans in the Northern Hemisphere have become a little less crowded. A new study led by NASA researchers has found populations of the microscopic marine plants, phytoplankton, have decreased in recent years. Individual phytoplankton are invisible to the human eye but they can be detected from space by looking at the color of the oceans. Using a NASA model in combination with ocean satellite data, scientists observed in the Northern Hemisphere a one percent decrease of phytoplankton per year between 1998 and 2012. Phytoplankton are the first level of the food chain. So they feed fish but also larger mammals including whales. Plus phytoplankton are just like trees, absorb carbon dioxide and emit oxygen. So there is a constant exchange between the ocean and the atmosphere of gas. In fact, the ocean absorbs about 25% of the carbon dioxide that is emitted by humans. We don't know whether the decrease will keep on going but what we know is that this decrease could likely have an effect on carbon dioxide in the atmosphere and the food chain.