Human-induced climate change isn't just changing the way rising seas interact with the shores, there's plenty going on underneath the waves as well.  As oceans get warmer, it seems that phytoplankton - those microscopic organisms that make up the bottom of the food chain - are retreating to the poles along with the cooler water to which they're accustomed.

The results are from a new study that appearsin the Proceedings of the National Academy of Sciences that sought to determine how phytoplankton would react to anthropogenic climate change over the coming century.  Researchers studied 87 different species of microscopic marine plants found in the North Atlantic, looking at the organisms' mean historical range from 1951 to 2000, and projections of what oceans will be like from 2051 to 2100.

"The main results of the study were that we found that when the climate changes it was not just the temperature that was changing and impacting phytoplankton but it was also all the ocean circulation and the conditions in the ocean surface, such as nutrients and light, that have an ecological impact," said co-author Andrew Barton, a researcher at Princeton University, working at the US National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Laboratory.

Some species would move faster than others, and some might not move at all.  But overall, the change is projected to happen much more quickly than has been seen from looking at historical data for these marine species.

Many ocean species are already stressed from over-fishing and hunting.  The next step will be to determine how the change in plankton will impact species moving up the food chain.

"The plankton are the seas' life-support system and any changes in where they occur will not only affect the distributions and abundance of other life in the sea upon which we depend, but will also influence the ecology of our entire planet with consequences for us all," said scientist Dr. Richard Kirby, who wasn't involved in this study but has long researched he oceans' food systems in his work as "the plankton pundit".  He notes that this new study "adds to a growing body of evidence already describing large-scale, climate-induced changes in the distribution, abundance and seasonality of the plankton around the globe."