Plankton respond to warmer seas

A study of populations of North Sea plankton, published this week in Nature, suggests that annual phenological cycles—such as migration and blooming—are changing as the ocean warms. The study found that not all species are affected in the same way, so that peaks that once occurred together or in close succession are now moving apart—a breakdown of ecosystem synchronicity that could, warn the authors, have major consequences in years to come.

Martin Edwards and Anthony Richardson, both based at the Sir Alister Hardy Foundation for Ocean Science, Plymouth, UK, examined the effects of increasing sea temperature on the annual productivity cycles of 66 plankton taxa, which they categorized into five functional groups: diatoms, dinoflagellates, copepods, non-copepod holozooplankton, and meroplankton.

Using data collected from the central North Sea by the continuous plankton recording program every month from 1958 to 1992, the pair was able to form a picture of shifting seasonal ...