reconstructing-relative-sea2

Recently there has been a growing interest in the relationship between climate and sea level change and a realization that human-induced global warming may accelerate the rate of sea-level rise. Understanding past patterns of sea-level change is important on local (e.g. for coastal management and engineering), regional to national (e.g. national future sea-level predictions) and global scales (e.g. for understanding polar ice sheet history). Relative sea-level curves have been constructed for a substantial portion of northern hemisphere coastline; however, to date, few curves have been presented for the southern hemisphere. Holocene sea-level records for the eastern and western coastlines are incomplete in extent and coarse in resolution. South African sea-level research has therefore relied largely on global records as a benchmark.

reconstructing-relative-sea

In the southern African context, the application of foraminifera as biological indicators has been restricted to studies of stratigraphy, temperature change, sedimentology and marine records. A successful a pilot study was conducted, whereby vertical zonation of salt-marsh foraminifera at a single site was established and relative sea-level form the past 1200 years reconstructed using transfer functions (Strachan et al., 2014). Here, an established sea-level proxy was introduced to determine proof of concept for South African sea-level research. This technique has the potential to contribute to our incomplete understanding of past sea-level change along the southern African coastline. Additional sites have been selected along the east and south coast of South Africa to apply and further develop this technique, including the Knysna Lagoon, the Keiskamma and Kei estuaries, and Lake St Lucia in Maputaland.