National Intertidal-Subtidal Benthic NISB Habitat Distribution Map Series

The National ECM Key Habitat Distribution Map Series were derived from the NISB
Habitat Map created by the University of Tasmania for a partnership between the
Department of Climate Change and the National Land and Water Resources Audit. It
supports the DCC/Audit partnership by providing a nationally consistent set of the
available mapping data that show the distribution of habitats that occur between the
approximate position of the highest astronomical tide mark (HAT) and the location of
the 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 by
Geoscience Australia. The resulting map data set forms a core component of the ECM
National Habitat Map Series.
The habitat classes include: coral reef, rock dominated habitat, sediment dominated
habitat, mangroves, saltmarsh, seagrass, macroalgae and filter feeders (e.g. sponges), as
defined in the NISB Habitat Classification Scheme. The scheme is designed to support
the development of marine ‘ecoregions’ or bioregional subregions. Details of the
scheme and the process of its development are available in National Intertidal/Subtidal
Benthic (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 Habitat
Distribution Map Series were derived from the NISB Habitat Map in order to produce
maps 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, new
fields were created listing the presence, absence, unknown distribution or nonapplicability
of 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), sediment
dominated habitats (Class 2.0.1), seagrass dominated habitats (Classes 1.2.2.4 and
2.0.2.1), 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 comparing
mapped data sets of multiple scales, as is the case for this compiled and derived data
set. The two derived information products were generated to provide a simplified
spatial representation of the broad distribution patterns of each of the key habitats
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across large areas. These derived products are designed to enable the visualisation of
the habitat distributions at the regional and national extents. It is extremely important
to note that they are definitely NOT able to be used to calculate areas of habitat
types.