The Redfield ratio at 80

Image credit: PHOTOTAKE Inc. / Alamy

In 1934, Alfred Redfield discovered that the ratio of carbon to nitrogen to phosphorus is a nearly constant 106:16:1 throughout the world's oceans, in both phytoplankton biomass and in dissolved nutrient pools. This insight has proved invaluable in understanding marine biogeochemical cycles, but, 80 years later, subtle variations to this ratio have emerged. In this Web Focus, we present a collection of research and opinion pieces that examine nutrient dynamics across ancient and modern changing environments.



Eighty years of Redfield p849


The outstanding lifespan of the canonical Redfield ratio has shown the power of elemental stoichiometry in describing ocean life. But the biological mechanisms governing this consistency remain unknown.



Redfield's evolving legacy pp853-855

Nicolas Gruber & Curtis A. Deutsch


The ratio of nitrogen to phosphorus in organic matter is close to that in seawater, a relationship maintained through a set of biological feedbacks. The rapid delivery of nutrients from human activities may test the efficacy of these processes.

The elements of marine life pp855-856

Noah J. Planavsky


Today, the ratio of carbon to nitrogen and phosphorus in marine organic matter is relatively constant. But this ratio probably varied during the Earth's history as a consequence of changes in the phytoplankton community and ocean oxygen levels.


News and Views

Ocean chemistry: Biogeochemical regimes in focus pp862-863

Raymond N. Sambrotto


The ocean's biological pump transfers carbon to long-term storage in deep waters and sediments. Two inverse modelling studies describe the export of organic matter throughout the surface layer of the world's oceans in exceptional detail.



Large-scale variations in the stoichiometry of marine organic matter respiration pp890-894

Tim DeVries & Curtis Deutsch


The elemental composition of marine organic matter varies systematically at large scales. Simulations of the ocean circulation and observations of ocean chemistry reveal close links between light and nutrient availability and stoichiometry.

Global-scale variations of the ratios of carbon to phosphorus in exported marine organic matter pp895-898

Yi-Cheng Teng, François W. Primeau, J. Keith Moore, Michael W. Lomas & Adam C. Martiny


The ratio of carbon to phosphorus in marine phytoplankton biomass varies by ecosystem. Biogeochemical modelling suggests that organic carbon exported to depth shows similar variations in stoichiometry.


From the archives


News and Views

Ocean science: Balancing ocean nitrogen

Wolfgang Koeve & Paul Kähler


The ocean's nitrogen budget has escaped quantification. A modelling study shows how a small shift in the nitrate-to-phosphate uptake ratio of phytoplankton has a large effect on calculated nitrogen fixation rates.



Processes and patterns of oceanic nutrient limitation

C. M. Moore, M. M. Mills, K. R. Arrigo, I. Berman-Frank & L. Bopp


Photosynthetic microbes, collectively termed phytoplankton, are responsible for the vast majority of primary production in marine waters. A synthesis of the latest research suggests that two broad nutrient limitation regimes dictate phytoplankton abundance and activity in the global ocean.



Strong latitudinal patterns in the elemental ratios of marine plankton and organic matter

Adam C. Martiny, Chau T. A. Pham, Francois W. Primeau, Jasper A. Vrugt, J. Keith Moore, Simon A. Levin & Michael W. Lomas


The elemental composition of marine organic matter is used to infer a variety of oceanic ecosystem processes. A compilation of observational data suggests that elemental ratios differ substantially from the Redfield ratio, but exhibit a clear latitudinal trend.

Magnitude of oceanic nitrogen fixation influenced by the nutrient uptake ratio of phytoplankton

Matthew M. Mills & Kevin R. Arrigo


The ratio of nitrogen to phosphorus in phytoplankton varies greatly with taxa and growth conditions. An ecosystem model suggests that the relative abundance of fast- and slow-growing phytoplankton controls the amount of new nitrogen added to the ocean.

Nature: An ecological aspect of the Gulf Stream

Alfred C. Redfield




The acceleration of oceanic denitrification during deglacial warming

Eric D. Galbraith & Markus Kienast


The marine nitrogen cycle was altered during the transition from glacial to interglacial conditions. An analysis of δ15N records throughout the world's oceans suggests that rates of denitrification in the water column accelerated during the last deglaciation.

Nature Communications: Human-induced nitrogen–phosphorus imbalances alter natural and managed ecosystems across the globe

Josep Peñuelas et al.


Nature: Ocean nutrient ratios governed by plankton biogeography

Thomas S. Weber & Curtis Deutsch




Nature: Natural proportions

Paul G. Falkowski & Cabell S. Davis


Redfield ratios: the uniformity of elemental ratios in the oceans and the life they contain underpins our understanding of marine biogeochemistry.

Extra navigation