The Importance of Sustaining Oceanographic Biogeochemical Time-Series Programs

Today, there are ›160 ship-based biogeochemical time-series around the world, the longest a few decades old. Observations from these remarkable platforms have led to a better understanding about ocean processes and ecosystem variability. They are one of the most valuable tools available to characterize and quantify ocean carbon fluxes, productivity, biodiversity, and how these are linked to our changing climate. Time-series have detected significant changes in the ecology and biogeochemistry of our global oceans, from reductions in oxygen concentrations and changes in ocean acidity, to plummeting fish abundances related to ecological shifts. Coastal time-series are already observing shifts in the timing and magnitude of the delivery of dissolved and particular organic carbon from land. Ongoing observations will allow for more accurate forecasting on how the predicted intensification of the global hydrologic cycle will alter organic matter fluxes on continental margins. Time-series have also put under the microscope microorganisms living in the ocean. Together, these discoveries have reshaped our understanding of biogeochemical fluxes in the ocean.

Time-series are critical in differentiating between natural climate variability and changes induced by anthropogenic forcing. It has been suggested that, to discern shifts resulting from climate change, regular observations of ›20 years are needed. While the number of ship-based sites seems impressive, many ecosystems are not being sampled. The cost of maintaining sites is a significant factor in the success of a time-series, and even well-established sites, such as CARIACO, CalCOFI, ESTOC, DYFAMED, Station P, BATS and HOT, face uncertain funding futures. To ensure the continuation of time-series, it is increasingly important that their scientific objectives be linked to benefits that their data can offer to society. Initiatives, such as the Global Ocean Observing System, will help define and integrate observations, data analysis, and modeling of the ocean. By pooling together time-series data from around the world, as the IGMETS effort is currently doing, it will be possible to assess changing biogeochemistry and ecosystem dynamics at regional and global scales, and to predict how future climatic conditions may affect important resources. In this presentation, we will provide an overview of some of the necessary elements needed for maintaining a ship-based, biogeochemical time-series. We will also discuss some of the remarkable scientific discoveries derived by using time-series facilities around the world.