From cytometry to macroecology: a quarter century quest in microbial oceanography

A quarter of a century has passed since the contemporary ecological role of water column microbes was first articulated. It was also about a quarter of a century ago that 2 other seemingly unrelated developments first appeared: the application of flow cytometry for analysis of marine microbes and the statistical approach of macroecology for the analysis of complex ecological systems. These two developments now meet at the interface of microbial oceanography. The combination of these developments, termed cytometric macroecology, provides an avenue to explore general theories of ecology and biogeography, as well as a means to address environmental issues of long-term change. This case study examines the abundance of picoeukaryotic phytoplankton from weekly to multiyear time scales and from local to global space scales. Cytometric macroecology identifies patterns of regularity arising from flexible contingent circumstances, some of which-like anthropogenic disruptions-are of special interest because they appear outside the bounds of natural variability.