Since returning from our March winter expedition, the large amount of laboratory work is now underway. We have collated a large variety of measurements, both physical and chemical, to help us assess the environmental conditions and water quality. These measurements were obtained using a Secchi disk, probes, water sampler and nets to determine the physical and chemical properties of the water. Our overall aim is to build a picture of the algal community activity and water quality conditions in Lake Baikal, and importantly aim to find any localised areas of eutrophication and climate change impacts on this unique ecosystem.
After collating and cataloguing all the water column samples, sediment core material and sediment trap samples the exciting part of science (as well as the incredible fieldwork expedition of course!) now begins. From the three sampling sites, a total of 180 samples where collected from within the water profile alone. The water column was sampled at depths of 1m, 3m, 5m, 10m, 20m, 30m, 50m, 100m and 180m, at sites situated along a transect (from the Neutrino scientific site to a site close to one of the biggest mills in Russia). These were taken for phytoplankton and diatom, total phosphorus, dissolved organic carbon, nutrients and major ions, photosynthetic pigments (carotenoids and chlorophyll a derivatives), zooplankton, chlorophyll a, diatom silicon isotope, diatom oxygen isotope, and anion analyses.
Nutrient concentrations are very low in Lake Baikal, and therefore only small additions of nutrients (Nitrogen, phosphorus and Silicate) can stimulate algal growth and productivity. Currently, water chemistry analysis is underway within the laboratory facilities at the University of Nottingham. To begin with the filtered nutrient and major ion water samples are being analysed on the Ion Chromatography (IC) for Nitrates. In addition to this, the Total Phosphorus and Silicate analyses on the water samples are near to completion.
From the water samples, the factors driving the modern-day algal community and silicon isotope composition of diatom shells will be investigated, in order to look back through time within the sediment core samples and help us understand past primary productivity (palaeolimnological reconstructions). Thus, the present is the key to the past, and there will be more to follow shortly on our laboratory progress…