Multi-decadal trends in oceanic biodiversity
At the ocean basin scale biodiversity of pelagic zooplankton copepods is related to temperature and an increase in warming over the last few decades has been followed by an increase in diversity. There is also a direct link between diversity and the size-structure of the zooplankton community. The overall diversity patterns of pelagic organisms, peaking between 20° to 30° latitude north or south, follow temperature gradients in the world's oceans. Similarly, phytoplankton show a relationship between temperature and diversity which is linked to the phytoplankton community having a higher diversity but an overall smaller size-fraction and a more complex foodweb structure (i.e. microbial-based versus diatom-based production) in warmer, more stratified environments. The parallel decrease in size-structure of pelagic organisms with increasing diversity may have implications for marine ecosystem services such as smaller-sized fish communities and reduced carbon drawdown (PNAS (2010) 107: 10120-10124).
Read more: Beaugrand, G., Edwards, M. and Legendre, L., 2010. Marine biodiversity, ecosystem functioning and carbon cycles. Proceedings of the National Academy of Sciences of the United States of America, 107:10120-10124
Relationships between the spatial distribution and long-term latitudinal changes in the diversity of calanoid copepods in the extratropical North Atlantic. Diversity was measured by first-order jackknife performed on the Gini coefficient. Left panel: mean spatial distributions (1960-2007) of copepod diversity and mean residence time above 50 m of sinking copepod particles (in days). Right panel: long-term latitudinal changes in copepod diversity and mean residence time above 50 m of sinking copepod particles. Based on (PNAS (2010) 107: 10120-10124).
