Mapping the physical environment

Often there is not enough biological information to map the distribution of plant and animal communities accurately. 

To improve accuracy, characteristics of a physical environment are used to predict where plant and animal communities occur in marine environments.

Remote sensing technology

The first step in characterising the physical environment often uses remote sensing technologies such as satellite imagery, aerial photography and multi-beam echo sounder, to map the seafloor without data gaps. 

Analysis of satellite and aerial photography are used in clear waters, while multibeam echo-sounder technology is used where light cannot penetrate to the seafloor, which is often the case for the Northern Territory's (NT) muddy waters. 

Multibeam echo-sounders collect hardness and depth data for the seafloor. Hardness shows the nature of the seafloor, such as the substrate type (like rock, sand or mud). 

Depth data allows a wide range of topographic characteristics to be calculated, resulting in seascape maps.

Water columns

The characteristics of a water column above the seafloor is important for mapping the physical environment.

Scientists use hydrodynamic models to map the strength and direction of currents, exposure time due to tides and the fate of sediments when moved by currents. 

Others use water quality data to understand the fate and interaction of nutrients in the water column, how salinity changes across an area, light quality and suspended sediment relationships.

Spatial analysts, including habitat mappers, compile and model all the available environmental data to create maps that show areas with similar environmental and seascape characteristics.

Mapping physical characteristics is a step towards creating broad scale maps that describe the marine environment. 

These maps are valuable in many aspects of marine spatial planning. 

The maps also help identify data gaps and design biological sampling programs for additional benthic community and single species sampling programs.

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Last updated: 27 June 2017