Figure 11.5 Changes in the distribution of fish in the North Sea. (a) From 1977 to 2003, the temperature of the water at the bottom of the North Sea increased by 2°C. (b) Surveys of fish trawls from 1985 to 2006 found that the total number of fish species collected per year in the North Sea increased from 60 to approximately 90. (c) The total number of fish species collected per year was positively correlated with the average sea temperatures during the previous 5 years.

Data from J. G. Hiddink and R. ter Hofstede, Climate induced increases in species richness of marine fishes, Global Change Biology 14 (2008): 453–460.