Large-scale ocean connectivity and planktonic body size

However, the role that abundance and body size plays in determining spatial patterns of diversity remains unclear. Here, we analyze spatial community structure - beta-diversity - for several planktonic and nektonic organisms spanning from prokaryotes to small mesopelagic fishes collected during the Malaspina 2010 Expedition. beta-diversity were compared to surface ocean transit times derived from a global circulation model, revealing a significant negative relationship that is stronger than environmental differences.

Estimated dispersal scales for different groups show a negative correlation with body-size, where less abundant large-bodied communities have significantly shorter dispersal scales and larger spatial species-turnover rates than more abundant small-bodied plankton. Our results confirm that the dispersal scale of planktonic and micro-nektonic organisms is determined by local abundance, which scales with body size, ultimately setting global spatial patterns of diversity.