How Does Seawater’s ‘Stickiness’ Affect Marine Microbes at the Foundations of the Global Food Chain?

1 February 2018

Scientists have been awarded grant funding of almost $1 million (US Dollars) to measure the effect of how changes in the viscosity – or ‘stickiness’ – of seawater impacts the smallest types of marine life. Funded by the Gordon and Betty Moore Foundation in the US, the two-year project will be led by Professor Stuart […]

Scientists have been awarded grant funding of almost $1 million (US Dollars) to measure the effect of how changes in the viscosity – or ‘stickiness’ – of seawater impacts the smallest types of marine life.

Funded by the Gordon and Betty Moore Foundation in the US, the two-year project will be led by Professor Stuart Humphries from the University of Lincoln, UK, in partnership with colleagues from the Scripps Institution of Oceanography at UC San Diego in the US.

The team will examine the scale differences in the viscosity (the measure of the resistance of a fluid to flow – which we often perceive as a liquid’s ‘stickiness’) of seawater. Viscosity of seawater will vary in different parts of the ocean because of temperature changes, polymers released by microscopic plants known as phytoplankton, and the contents of cells released when the smallest marine microbes die.

Marine biologists will measure these small differences and their effects on bacteria, which are a major part of marine ‘foodwebs’, a term used to describe the feeding relationships in an ecosystem where many food chains interconnect to create a food network.

The team will develop a new underwater microscope to be able to visualise the polymers released by plankton and conduct experiments to investigate the effect on bacteria as they begin to congregate to feed on this material. Laboratory research will take place in Lincoln in the UK while the microscope will be developed at the Scripps Institution of Oceanography at UC San Diego. Fieldwork will be located at the Scripps Institution of Oceanography and Hawaii.

Professor Humphries said: “Interactions between microbes such as bacteria and phytoplankton drive nutrient cycling and food webs in our oceans, and ultimately influence biogeochemistry – the overall term we use to encompass chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment – on a global scale.

“The surprising impact of tiny bacteria on large-scale processes in the oceans is mainly driven by the sheer number of individual interactions that occur between cells. The results generated by this project will improve our understanding of marine microbial interactions in localised areas, but will also help inform global biogeochemical and climate models that rely on accurate estimates of bacterial productivity.”