Drawing the future of phytoplankton in a changing ocean

Phytoplankton development is strongly linked to the dissolved iron availability in the surface waters. Iron’s behavior is sensitive to warming, stratification, acidification and de-oxygenation. In a changing ocean, these processes in addition to nutrient co-limitation interactions with iron biogeochemistry will all strongly influence phytoplankton dynamics. This paper establishes the potential future shifts in multiple facets of iron biogeochemistry, from cellular physiology to ocean circulation. Possible impacts of these multiple changes on diatoms and trichodesmium are illustrated in the figure below. This work warns us on the urgent need to improve our present knowledge of the micronutrient cycle forcing, in order to better predict their future behaviors.

17 Hutchins
Figure: Interactive influences of the changing ocean iron cycle on diatoms and nitrogen-fixing cyanobacteria. Iron biogeochemistry will respond to global change-related warming (red), increased light (yellow), acidification (black), loss of oxygen (green), and lowered inputs of the nutrients nitrate (white), silicate (grey) and phosphate (blue). This will have direct consequences for the growth and physiology of both phytoplankton groups, as well as indirect effects on critical resource supply ratios (boxes). Important components of the marine iron cycle responding to environmental change include inputs from dust, complexation by organic ligands, redox chemistry, and biological availability (orange). Click here to view the figure larger. (adapted from Hutchins and Boyd 2016, with thanks to J. Brown for graphics)


Hutchins, D. A., & Boyd, P. W. (2016). Marine phytoplankton and the changing ocean iron cycle. Nature Climate Change, 6(12), 1072–1079. DOI: 10.1038/nclimate3147

Latest highlights

Science Highlights

Different fates of four poorly soluble trace elements in the Pacific Ocean

Zheng and co-authors present the full-depth distributions of aluminum, lead, manganese and copper in the western South Pacific.


Science Highlights

Internal tides, energetic dynamical processes that generate particle nepheloids at different depths

In this study, Barbot and co-authors identified the sites where internal tides are responsible for sediment resuspension…


Science Highlights

Greenland’s floating ice tongues, sources of dissolved lead to the Arctic

Using helium and neon as tracers for subglacial meltwater, Krisch and colleagues found that subglacial discharge is a source of dissolved lead.

Science Highlights

Debate on the dissolved nickel bioavailibility in surface waters

John and co-authors tackle one of the known paradoxes regarding trace metal cycles in the ocean…