Marine habitat mapping

The Centre for Marine Science and Technology (CMST) has expertise in:

• Seafloor and river habitat mapping and modelling
• Marine fauna detection
• Autonomous and remotely operated platforms

Seafloor and river habitat mapping and modelling

CMST has developed specialist algorithms and software for optimising echo-sounder data for seafloor habitat mapping. The centre has expertise and experience at processing different mapping technology, including multibeam (Fig 1) and single beam echo-sounders, sidescan sonar (Fig 2), to produce maps of depth, backscatter, substrate, habitat and species distribution.

Fig. 1: Example of Multibeam backscatter draped over a 3D depth model. Inserts show stills from underwater video data collected.

Fig 2: Example of processed sidescan sonar image (in grayscale) draped over aerial photograph along a 50 m stretch of riverbank. This imagery was used to identify areas of riverbed complexity for fish, such as underwater tree branches.

Marine fauna detection

Multi-beam echo-sounders can also be set up to record data from the water column at the same time as seafloor surveys. Fig. 3 shows an example of multibeam echo-sounder data collected and processed by CMST to map a fish aggregation and the seafloor habitat in 3D. Combining seafloor and fisheries surveys is a cost-effective approach in marine resource management.

Fig. 3: Seafloor and water column backscatter data from a multibeam survey of Samsonfish (each > 1m length) schooling above a ship wreck.

Water column data can be used to produce maps of water column targets, such as fish or seeps. Fig. 4 shows an example map of water column backscatter from a single beam survey of an Australian Marine Park. This map was used identify “hotspots” of fish activity without the need for invasive techniques, which can be important when managing marine parks.

Fig 4: Map of relative spatial distribution of water column backscatter data (areas of high backscatter in red and low in green), where a “hot-spot” of fish presence has been identified.

Multibeam imagining sonars are useful for underwater detection of marine fauna. Some examples projects include crocodiles and dolphins (See videos below).

Autonomous and remotely operated platforms

CMST has carried out various marine science studies using data collected on different platforms, including ROV (Fig 5), AUV, Wavegliders.

Fig 6. CMST’s Senior Technician Malcolm Perry with Curtin University’s School of Earth and Planetary Science’s Blue Robotics ROV