Deep reefs

The deep reefs of Ningaloo

Deep reef or ‘‘mesophotic’ ecosystems occur where low amounts of light reach the seafloor in deeper water but light dependent organisms such as corals and algae still grow. Generally, these habitats are found in water depths of 30 to 40 metres, but records also exist of mesophotic reefs occurring in depths of up to 150 metres. The deeper waters of Ningaloo are known to support abundant, highly diverse, filter-feeding communities – which have been identified as important ecological values in the Ningaloo Marine Park’s Management Plan.

Mushroom corals, called Cycloseris distorta, found in water depths of 40 metres at Ningaloo in 2017 during a deep reefs field survey.

Ningaloo Outlook (2015-2020) revealed the hidden deeper areas of the seafloor with much of the first phase of the project concentrating on collecting data to map the extent of deep-water reef areas of Ningaloo and characterise the habitats found. This was carried out by exploiting the characteristic signals produced by sonar, coupled with data collected from video and Autonomous Underwater Vehicle (AUV) field deployment. Find out more about what the team achieved between 2015-2020, click here or read our Ningaloo Outlook Highlight Report.

Research forming part of the next phase (2020-2025) of the Ningaloo Outlook deep reefs work will continue to involve the use of remotely recorded imagery using ROVs and remote camera deployments. Instead of more mapping, the team, lead by Dr John Keesing, will move to gaining a  better understand the dynamics and ecology of deep-reef communities. In particular the team will look at how stable these habitats are and what processes are important in maintaining them. The function of the deep reefs habitats will also be determined by examining what assemblages of fish and invertebrates inhabit and make use of them This will help determine their importance to the overall reef system and how they are linked to the shallow reef system.

Future Scientists

A key element of the Ningaloo Outlook partnership continues to be the opportunity to train our future scientists, providing them with a range of skills and opportunities to set them apart. Logan Hellmrich joined the deep reefs team in January 2021 and will undertake work towards a PhD degree at Curtin University studying the ecological functioning of selected deep reef habitats off Ningaloo.