Environmental changes along the southern Cape coast, South Africa during the last millennium: evidence from diatoms

The dynamic nature and ecological diversity of the southern Cape coast of South Africa is directly related to the interaction of various climatic systems with the landscape. This makes it a vital region for scientific investigations into environmental changes. The extraction of sediment cores from the coastal lakes within the Wilderness Embayment provides a unique opportunity to assess environmental changes over the last millennium. The intention is to create a high temporal resolution study to present a detailed pattern of climatic variability in an extremely sensitive environmental region. The preliminary analysis of fossil diatom deposits, which are typically well preserved in the sediment record, indicate two periods of significant change. The first period appears to be associated with temperature fluctuations experienced between 0.7 - c. 0.33 ka; whereas the second period (0.33 ka – present) indicates a combination of extreme climatic shifts and the later impacts of human activities within the catchment. This study demonstrates that diatom analysis of lake sediment can provide very detailed information, hampered only by inconsistent sediment accumulation.