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.