National Intertidal-Subtidal Benthic NISB Habitat Distribution Map Series

The National ECM Key Habitat Distribution Map Series were derived from the NISBHabitat Map created by the University of Tasmania for a partnership between theDepartment of Climate Change and the National Land and Water Resources Audit. Itsupports the DCC/Audit partnership by providing a nationally consistent set of theavailable mapping data that show the distribution of habitats that occur between theapproximate position of the highest astronomical tide mark (HAT) and the location ofthe outer limit of the photic benthic zone (approximately at the 50-70 m depth contour).This area is broadly equivalent to the “inner” and “mid-shelf” regions identified byGeoscience Australia. The resulting map data set forms a core component of the ECMNational Habitat Map Series.The habitat classes include: coral reef, rock dominated habitat, sediment dominatedhabitat, mangroves, saltmarsh, seagrass, macroalgae and filter feeders (e.g. sponges), asdefined in the NISB Habitat Classification Scheme. The scheme is designed to supportthe development of marine ‘ecoregions’ or bioregional subregions. Details of thescheme and the process of its development are available in National Intertidal/SubtidalBenthic (NISB) Habitat Classification Scheme Version 1 (Mount, Bricher and Newton,2007).The 10 km and 50 km tiles distribution maps that form the National ECM Key HabitatDistribution Map Series were derived from the NISB Habitat Map in order to producemaps at resolutions that are easy to interpret at state and national extents. For each state,two layers were produced, one with 10 km and one with 50 km tiles. In each layer, newfields were created listing the presence, absence, unknown distribution or nonapplicabilityof the Habitats of Interest (HOI). The HOI are rock substrate (Class 1.2),unconsolidated substrates (Class 2.0), coral habitat (classes 1.1 and 1.2.2.3), sedimentdominated habitats (Class 2.0.1), seagrass dominated habitats (Classes 1.2.2.4 and2.0.2.1), mangrove dominated habitats (Class 2.0.2.2) and saltmarsh dominated habitats(Class 2.0.2.3).There are technical geographic and cartographic issues that arise when comparingmapped data sets of multiple scales, as is the case for this compiled and derived dataset. The two derived information products were generated to provide a simplifiedspatial representation of the broad distribution patterns of each of the key habitatsNational ECM Habitat Map Series User Guide_v7.doc 30/04/2008 Page 32 of 156 across large areas. These derived products are designed to enable the visualisation ofthe habitat distributions at the regional and national extents. It is extremely importantto note that they are definitely NOT able to be used to calculate areas of habitattypes.