An Investigation of Benthic Epifauna to Support Classification and Mapping of Outer Shelf Ecosystems in KwaZulu-Natal

Abstract

Ecosystem classification and mapping are foundational steps for effective ecosystem-based marine spatial planning, marine ecosystem assessment and integrated ocean management. The aims of this study were to interrogate and refine existing ecosystem classification and maps using quantitative data for epifaunal communities and to investigate the potential physical drivers which may contribute most to the distribution patterns of these ecosystem types. A total of 27 sites between Pennington and Ballito on the east coast of South Africa, including unconsolidated sediment, mixed and reefs habitat types, in the 48 to 85m depth range, was examined. Epifauna data were quantified from seabed imagery collected by remotely-operated vehicle covering more than 13 130 epifaunal individuals counted representing over 170 morphospecies from five taxa. Multivariate analyses of data from 17 sites surveyed in southern KwaZulu-Natal (KZN) revealed that epifauna at unconsolidated sediment sites were significantly different to that occurring on either mixed or reef substrates and epifauna occurring on mixed substrates were also significantly different to those occurring on reefs. Epifauna at mixed sites were more similar to epifaunal assemblages at reef sites than epifauna at unconsolidated sediment sites.