2.1. Study Site and Sampling
Epifauna (hereafter referred to as epifauna) were assessed in intertidalZostera capensis beds in Langebaan Lagoon on the west coast of South Africa (Map 1; 18°03’E, 33°08’S). Part of the West Coast National Park and designated a RAMSAR site for its ecological and conservation significance, the lagoon is an important wetland and layover for migratory birds (Christie, 1981; Compton, 2001; Day, 1959). It is approximately 15 km long and 4 km wide and opens into a bay with a mouth to the sea in the north. There is no freshwater inflow from rivers, instead freshwater input occurs through groundwater seepage during the rainy season (Whitfield, 2005). The lagoon experiences a spring tidal range of 1.8 m at the mouth to 1.5 m at the head (Day, 1959). The benthic substrate of the lagoon mainly consists of sandy sediment. In addition to Zostera capensis , various algal species and salt marsh grass (Spartina sp.) comprise the vegetation within and around the lagoon edge (Schils et al., 2001).
Sub-populations of seagrasses from five sites: Centre Banks, Klein Oesterval and Oesterval (closer to the lagoon mouth), Bottelary and Geelbek (further away from the mouth) were sampled in this study (Fig. 1). The sites were selected based on a priori knowledge of their position in the lagoon that displayed consistent and high seasonal and interannual Z. capensis coverage (Lawrence, 2023, in review ).