Opera House reef set to revive harbour

The latest extension at the Sydney Opera House will go underwater with a new artificial reef set to explore ways to improve marine life in the harbour.

The NSW government announced a three-year project on Tuesday to suspend an imitation reef off Bennelong Point, which will kick off with a count of fish numbers in the water around the iconic landmark later in the year.

Following the survey, the new reef, made up of nine hexagonal shaped modules hanging in the water, will be installed.

Researchers are hopeful the reef will spark positive change.

"Across Sydney Harbour over 50 per cent of the shoreline has been replaced by seawalls to protect infrastructure from storms and erosion," lead researcher UTS Professor of marine ecology David Booth said in a statement on Tuesday.

The artificial reef trialled at the Opera House could help restore natural marine habitats and rebalance biodiversity around the harbour, he said.