We have pioneered the use of diatoms as indicators of environmental change in lake sediment cores (Battarbee et al. 2001) and we are therefore in a strong position to provide clients with an expert service.

Most commonly diatom slides are produced after treatment of the sediment with hydrogen peroxide to remove organic matter. Slides are then counted using a light microscope with a magnification of x1000. Diatom diagrams are produced showing the change in species composition through time from the past to the present day. If required we can use the changes in diatom composition to provide reconstructions of water chemistry (pH, TP or salinity) using transfer functions and other statistical techniques. We have also developed techniques enabling diatom records to be used to assess the extent to which lakes have deviated from their reference condition, as defined by the EU Water Framework Directive (Bennion & Simpson, 2011).

Consultancy projects involving these methods have included an analysis of diatom records from sediment cores across Scotland to assess their eutrophication status for SEPA (Bennion et al. 2004), analysis of diatoms in sediment cores from Norwegian lakes to define reference communities and the degree of ecological change for the Norwegian Institute for Water Research (Bennion et al. 2010), and most recently the combination of sediment trap and sediment core records to assess the extent to which acidified lakes in the UK uplands have recovered from the effects of acid deposition (Battarbee et al. 2014)

(Below) The diatom record of Loch Lomond, North Basin, Scotland showing the recent increase in diatoms indicative of enrichment (those shown in red)
Loch Lomond diatoms
References

Battarbee, R.W., Jones, V.J., Flower, R.J., Cameron, N.G., Bennion, H., Carvalho, L. & Juggins, S. (2001). Diatoms. In J.P.Smol, H.J.B. Birks & W.M. Last (eds), Tracking Environmental Change Using Lake Sediments. Volume 3: Terrestrial, Algal, and Siliceous Indicators. Kluwer Academic Publishers, Dordrecht, The Netherlands, pp. 155-202.

Battarbee, R.W., Simpson, G. L., Shilland, E. M., Flower, R. J., Kreiser, A., Yang, H., & Clarke, G. (2013) Recovery of UK lakes from acidification: An assessment using combined palaeoecological and contemporary diatom assemblage data. Ecological Indicators, 37, 365-380.

Bennion, H. & Simpson G.L. (2011) The use of diatom records to establish reference conditions for UK lakes subject to eutrophication. Journal of Paleolimnology, 45, 469-488.

Bennion, H., Fluin, J. & Simpson, G. (2004). Assessing eutrophication and reference conditions for Scottish freshwater lochs using sub-fossil diatoms. Journal of Applied Ecology, 41, 124-138.

Bennion, H., Clarke, G., Goldsmith, B. & Battarbee, R.W. (2010) Diatom analysis of three Norwegian cores. Report to the Norwegian Institute for Water Research, Project Number O-28428. ECRC Research Report No. 142.

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