white yellow and black butterfly fish swim over a coral reef


Monitoring reef fish populations on the east and west coast

Monitoring reef fish supports reef management and helps AIMS scientists understand the influences of ocean currents, natural and anthropogenic disturbances, and climate change on reef fish populations and their ecology.

AIMS can compare fish diversity and abundance right across tropical Australia, thanks to the combination of our east coast surveys and our comprehensive assessment of coastal, nearshore, oceanic atolls and shoals from Ningaloo to Darwin.

On the east coast, the AIMS Long-term Monitoring Program (LTMP) has been monitoring fish populations on the Great Barrier Reef for over two decades.

The work has revealed distinct inshore, mid-reef and outer shelf communities on the Reef. These communities also vary with latitude within the area monitored─between Lizard Island and the Capricorn–Bunker reef system.

Fish communities on each reef change little over time unless a major disturbance, such as a cyclone, an outbreak of crown-of-thorns starfish or major coral bleaching, causes changes in the seabed community.

Our early survey work identified key regions of biodiversity, providing advice for the Great Barrier Reef Marine Park Authority's Representative Areas Program and the subsequent re-zoning of the Great Barrier Reef Marine Park in 2004.

The Long-term Monitoring Program also monitors the effects of zoning on target fish species, such as coral trout, and biodiversity in general. Findings suggest that coral trout are bigger and more numerous in protected areas than in reefs that are open to fishing.

Deep-water habitats are increasingly targeted for fishing as new technologies make them more accessible. AIMS uses baited remote underwater video cameras to monitor these deeper water fish communities These systems provide new insights, which help managers identify areas that need protection.

In Western Australia, our team has been monitoring fish communities over the past two decades in collaboration with various industry, university and state government institutions.

Underwater visual surveys have shown distinct fish communities at remote oceanic atolls and isolated coastal reef environments, with limited genetic mixing between reef systems. They have also found that these fish communities react strongly to natural disturbances such as cyclones and coral bleaching, with key groups declining rapidly with declines in coral cover.

The Western Australian team has also combined resources and expertise with east coast team members to cover marine environments in difficult-to-access and deeper sites using baited remote underwater video stations to complement visual surveys.