Northward shift of plankton

Plot Grouped

Over the last 50 years there has been a gradual increase in the number of warm water plankton species occurring in the North Atlantic and the North Sea.  Warmer water copepod species (crustaceans) have moved northwards by 10° of latitude (~1000 km).  This has been matched by a gradual decline in cold water species of plankton.  This mass northerly movement has been related to rise in sea surface temperature (SST) in the North Sea. 

The charts above show this change in the biogeographical distribution of warm water and cold water species.