Sheppard, J.N. and MacKay, C.F., 2018. Using historic land cover data to predict estuarine macrobenthos characteristics in South Africa.
Human socioeconomic activities affect natural environments worldwide. Coastal environments like estuaries are especially threatened by the disproportional population growth and development taking place within the coastal zone. Within semiarid South Africa, and especially within the KwaZulu-Natal (KZN) Province, estuaries face human development pressures from a growing coastal population ranging in socioeconomics and types of natural resource use, and many systems are degraded. Although estuary management is well legislated, it is slow to be implemented. Unlike biophysical data, land cover data (historical–present) for KZN's coastal zone is readily available. Of interest was whether land cover is related to estuary ecological condition. If so, there is potential to use land cover characteristics around estuaries in future development of a tool for short-term interim management that addresses common management challenges including a paucity of historical ecological information, money, and expertise. In a novel approach for this region, land cover and biophysical (water physicochemical, sediment, and estuary macrobenthic invertebrates) data sets for seven of the province's estuaries for three points within a 30-year period (1980–2010) were examined. Land cover around these estuaries ranged from seminatural, agriculturally dominated to highly urbanized systems. Macrobenthos communities within the systems showed a similar distinction in terms of taxonomic dominance, although species richness and abundances were variable. Land cover within the 20-m contour line was found to be a very strong predictor of estuary macrobenthos characteristics, with a subset of 8 land cover types and five invertebrate species identified in this study for use as potential future indicators.