Trends in phytoplankton over space and time Global observing for phytoplankton? A perspective

Environmental changes primarily caused by humans are putting our biosphere under growing pressure. The most optimistic predictions indicate that this will continue for decades, potentially much longer. Managing global ecology through these challenges requires knowledge of what species are present and how their populations are changing. Yet for vast areas of the ocean, the abundance of most species is simply unknown and not monitored. The failure to monitor means conclusions about their global ecological status cannot be robust. Yet, this ignorance delays and limits any response. These changes are, however, disrupting the commercial and indigenous harvest of essential food resources as well as many other ecosystem services important to human well-being. While the global community has made significant progress on designing a monitoring program, there remain significant gaps, hurdles and other challenges to be overcome. Here, we consider some of these challenges and provide specific recommendations regarding potential next steps toward a minimum global monitoring program for plankton.