Global median phytoplankton concentration

Value 0.56 mg/m^3
Organism Biosphere
Reference Boyce DG, Lewis MR, Worm B. Global phytoplankton decline over the past century. Nature. 2010 Jul 29 466(7306):591-6.PubMed ID20671703
Method To estimate regional Chlorophyll trends, researchers divided the global ocean into ten regions, in which similar variability in phytoplankton biomass was observed in response to seasonality and climate forcing (Behrenfeld, M. J., Boss, E., Siegel, D. A. & Shea, D. M. Carbon-based ocean productivity and phytoplankton physiology from space. Glob. Biogeochem. Cycles 19, 1–14 (2005).) (Fig. 3a). To capture the range of potential Chl trajectories, regional trends were estimated from generalized additive models (GAMs) as linear functions of time on a log scale in three different ways: (1) continuous (linear trend), (2) discrete (mean year by- year estimates), and (3) smooth functions of time (non-monotonic trend). This approach is comprehensive: it allows both the quantitative (magnitude) and qualitative nature (shape) of trends to be estimated.
Comments The global meta-analytic mean rate of Chl change (1899-2009) derived from individual regional model estimates was -0.006±0.0017 mg/m^3/year (P<0.0001 Fig. 3b), representing an annual rate of decline of ~1% relative to the global median chlorophyll concentration (~0.56 mg/m^3).
Entered by Uri M
ID 105536