Geomorphic features

Geomorphologic features are categorical descriptors of the shape of the seabed that range in scale from thousands of km2 (e.g. basins) to tens of m2 (e.g. sand waves, Heap and Harris 2008). Geomorphologic features themselves do not directly affect biodiversity, but since they are associated with depth, substrate hardness, current velocity, and productivity, they can be useful surrogates to link seabed structure and the distribution of benthic communities. In their most general sense, raised geomorphic features such as banks and ridges are more likely to support richer and more abundant epifaunal assemblages, while subdued features such as plains and valleys are more likely dominated by infauna and detritivores (Przeslawski et al. 2011). In particular, canyons and seamounts have been identified as biological hotspots of diversity and endemism due to their capacity to provide complex habitats with increased production relative to surrounding features (Williams et al. 2006, Schlacher et al. 2007, Bouchet et al. 2014), although this is not always the case (Samadi et al. 2006).  Geomorphology is the foundation of most Key Ecological Features, including tributary canyons in the North, the ancient coastline and various shoals in the North-West, and the carbonate banks and terrace system overlapping both regions.

Certain raised geomorphic features such as banks and shoals are associated with hard substrate. Species composition often varies dramatically between consolidated (i.e. hard) and unconsolidated (i.e. soft) substrate (Williams and Bax 2001, Beaman and Harris 2007), with hard substrates generally acting as habitat to a larger proportion of sessile suspension feeders and soft sediments as home to infauna and a larger proportion of small, discretely motile invertebrates.

Use the interactive map below to explore how geomorphic features vary around Australia's coastline.  

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