Phytoplankton change in the North Atlantic

A marked increase in global temperature over the last century was confirmed by the second Assessment Report of the Intergovernmental Panel on Climate Change1. Here we report significant positive and negative linear trends from 1948 to 1995 in phytoplankton measured by the Continuous Plankton Recorder survey in the northeast Atlantic and North Sea that might reflect a response to changing climate on a timescale of decades. Spreading of unusually cold waters2 from the Arctic might have contributed to the decline in phytoplankton north of 59o N. Further south, phytoplankton season length and abundance seem to have increased.