Shallow urban lakes record industrial history over the last century: a paleolimnological study of three lochs in Greater Glasgow, Scotland, United Kingdom

Globally, freshwater ecosystems are increasingly facing anthropogenic stressors. One such stressor is urban development which not only alters land use but also increases pollutant loads to aquatic systems. Shallow freshwater lakes in urban areas are susceptible to excess nutrients and other contaminant inputs, leading to degraded water quality and ecosystem change. In this study, we applied a paleolimnological approach to investigate lake-ecosystem changes in suburban areas in response to historical anthropogenic stressors. The city of Glasgow, Scotland, is renowned as one of the major centers for the Industrial Revolution in the United Kingdom (UK), and three lakes situated in and around the city were investigated to reconstruct the historical changes surrounding the lake ecosystems. Diatom microfossils, supplemented with plant and insect macrofossils, and geochemical elements, were analyzed as indicators of chemical and ecological change in the lakes over the last 150 years. Two lakes in heavily industrialized urban catchments were found to have evident signs of eutrophication with the greatest ecological change seen in the lake with high hydrological connectivity. The third lake had a different management history due to private land ownership and did not show a clear sign of eutrophication. The study highlights the potential of paleolimnology for exploring the history of urban waterbodies. It suggests that local land-use history and degree of connectivity are important considerations in assessing the onset, degree and nature of environmental change and can result in lakes with varying types of anthropogenic stressors and variable impacts, even within the same small geographical region. This variation needs to be taken into account when designing lake-specific eutrophication management strategies.