Algal lipids open a window into climate records Analysis of algal lipids in both lakes and on the sea surface can help scientists to reconstruct past temperature records, from which new insights can be drawn into the likely future evolution of the climate. We spoke to Dr Jaime L. Toney and Dr Antonio Garcia-Alix about their research into using algal lipids to extend human instrumental records further back in time A type of
lipid produced by algae, alkenones are highly responsive to water temperature, and have long been used as fossils to reconstruct past climate records. Based at the University of Glasgow in the UK, Dr Jaime L. Toney is the Principal Investigator of the ALKENoNE project, an ERC-backed initiative aiming to analyse these lipids and build more detailed climate records. “The main objective in the project is to record temperature and precipitation from a number of lakes in Canada in a quantitative way, so that we can extend human instrumental records further back in time,” she explains. The number of double bonds in alkenones varies according to the water temperature at the time the algae were growing; Dr Toney and her colleagues are analysing alkenones from over 100 lakes in Canada, which she says have some interesting features. “These lakes have salinities which range from being completely fresh to having four times the salinity of ocean water. Because they are spread across a large latitude range, they also have a large temperature gradient of about 9 degrees,” she outlines. This variability allows researchers to calibrate the biomarkers or lipids that are found in the lakes to all these different environmental conditions, which is a key part of the project’s agenda. The main factor that complicates temperature
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BECS PhD student and Nuffield Placement summer intern splitting lake sediment cores. ©Jaime L. Toney, PI of ERC-funded ALKENoNE project. calibration with respect to lakes is that researchers need to know the time of year at which these compounds were produced. “For instance, if the algae are producing these compounds in the Spring, then you’re going to be recording temperatures from Spring, if they’re producing them in Summer, then you’re going to be recording temperatures from Summer, and so on,” explains Dr Toney. Previously Dr Toney
developed a temperature calibration by collecting water samples from different depths within a single lake, now she aims to investigate whether this calibration is applicable to this larger set of lakes in Canada. “Ultimately we’d like to understand the algae that produced these alkenones in sufficient depth to come up with a single calibration that can be used regardless of location,” she says.
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