Observing Planktonic Ecosystems: Needs, Capabilities, and a Strategy for the Next Decade

We review the current state of our capabilities for the systematic sustained observation of ocean ecosystems, concentrating primarily on planktonic ecosystems. First, we describe the structure of ocean ecosystems – from the nutrients that support primary production, up through the plankton, and then through the various predators, from juvenile finfish to whales, sea lions and humans. We try to draw a picture of the ocean ecosystem (and related biogeochemical cycles) as complex, dynamic systems embedded in the equally complex and dynamic system represented by physical ocean processes. We describe the properties of ecosystems that biologists need to observe and understand, if they are to forecast the future behaviour of ocean ecosystems. Second, we identify the major users and uses for sustained observations of marine ecosystems. Third, we summarize how ocean ecosystems are observed from ships, trying to get across the need to describe the 'texture' as well as the dynamics of ocean ecosystems. Fourth, we review and present examples of the main components of emerging ecosystem observing systems. Finally, we discuss the gaps in existing capabilities and suggest a strategy to guide the development of sustained observations of planktonic ecosystems over the next decade.