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Strachan, K.L.; Hill, T.R.; Finch, J.M.; Barnett, R.L., and Frenzel, P., 2017. Distribution of salt-marsh foraminifera in two South African estuaries and the application as sea-level indicators. The global mean sea level is rising as a result of climate change and is likely to affect millions of people. It is essential to understand and quantify regional relative sea-level variability to be able to predict future changes. Proxy evidence is necessary for extending our understanding of past sea-level changes beyond the industrial era, and salt-marsh foraminifera have become an important tool for reconstructing late Holocene sea-level changes. In South Africa, little is known regarding the distribution of salt-marsh foraminifera and their use as sea-level indicators, thereby limiting their application in sea-level research. This study therefore describes the distribution of living and dead surface foraminifera from two study sites along the SE South African coastline. The full surface dataset has been compiled from 139 samples that are used to describe the contemporary distribution of salt-marsh foraminifera. Cluster analysis is used to define four biozones; high marsh, middle marsh, low marsh, and mudflats. In the high marsh, where environmental conditions reach the survival threshold, a greater abundance of agglutinated foraminifera occurs. In the low-marsh zone, where subaerial exposure is restricted and environmental conditions are usually stable, a greater diversity of calcareous species occurs. The tidal mudflats have the highest diversity of calcareous assemblages with some agglutinated taxa present. Distributions of living foraminiferal populations are similar to the population distributions of dead foraminifera at both sites in the low-marsh and mudflat zones. In the high-marsh zones, however, the living-to-dead ratio and distributions are different, which could be a result of different influences of environmental variables along with seasonal variations. This study provides insights into foraminiferal distributions along the SE coastline of South Africa, which will be useful for interpreting late Holocene sea-level changes. [ABSTRACT FROM AUTHOR]

Silva, R.; Martínez, M.L.; Hesp, P.; Catalan, P.; Osorio, A. F.; Martell, R.; Fossati, M.; Miot da Silva, G.; Mariño-Tapia, I.; Pereira, P.; Cienfuegos, R.; Klein, A., and Govaere, G., 2014. Present and future challenges of coastal erosion in Latin America. The coastal zones of Latin America have many landforms and environments, including sedimentary cliffs, deeply incised estuaries, headlands, barrier coasts and low lying, muddy coastal plains. These forms will respond differently to the expected changes in climate and associated sea level rise, which may produce coastal erosion in the future. Considering the coasts of Latin America overall, erosion is not yet a serious threat, although it is widespread and it is severe in some parts. Major erosion problems are frequently associated with human intervention in sediment supply, with poor planning or with the morphodynamic nature of the coast. Permanent erosional processes, locally or regionally, are caused by tectonic subsidence, deforestation and the fragmentation of coastal ecosystems, land use changes and sediment deficits because of infrastructure built along the coast. In this article we analyse coastal erosion in Latin America and the challenges it presents to the region. We first highlight the relevance of Latin America in terms of its biodiversity; then we describe the population at risk, demographic trends and economic growth throughout the low lying coastal zones. We also examine the vulnerability of the region by analyzing the resilience of key coastal ecosystems after exposure to the most frequent hazards that affect coastal zones in Latin America, namely tropical cyclones, sea level rise, ocean acidification, earthquakes and tsunamis. Finally, we discuss seven case studies of coastal erosion across Latin America. We close the study by pinpointing the main areas of concern in Latin America and explore possible strategies to overcome erosion and thus sustain economic growth, minimize population risk and maintain biodiversity. [ABSTRACT FROM AUTHOR]