The Sydney Opera House is one of Australia's most recognisable landmarks, and soon it could also be home to a whole new underwater ecosystem.

Researchers are looking to build an artificial reef in Sydney Harbour next to the Opera House, to try to enhance biodiversity of the marine area.

The team says that Sydney Harbour has a huge proportion of built environment, such as seawalls to protect the area from storms and erosion.

"In some cases these have been around for over a century, and they're made of lovely sandstone, but they just don't offer the habitat that was there," said David Booth from the University of Technology Sydney. "The goal of this project is to see if we can enhance that."

"We believe initiatives like the artificial reef that will be trialled at the Opera House could help restore natural marine habitats and rebalance biodiversity."

The researchers have been investigating the current marine diversity around the area for over two years, and the results could be better.

"It's certainly not in horrible shape at the moment, there are quite a number of species, but that doesn't mean they are doing well," Booth said.

"Habitats are limited … a large dockland area or sea wall where there used to be mangroves, there aren't many [fish] left."

The design itself is going to be fairly subtle, with various levels of complexity, and sizes for the creatures.

"It's about creating productive habitats and understanding how marine life use structures, it's like making apartment blocks," said David Lennon, a reef designer who's been hired to work on the project.

"We understand marine life need different entranceways, rooms, gaps to walk and move. We're just like underwater architects and town planners. It's like building a city, and to have a vibrant city you need a diversity of habitats."

Opera House Reef Project / UTS

Although the designs haven't been finalised, the artificial reefs are likely to be in cubic or spherical type shapes, and each about a metre (3.2 feet) long.

Either way, we're really excited to see how this project turns out, and we hope the fish like their new, prime real estate!

"In designing the Opera House, Jorn Utzon was strongly influenced and inspired by nature," says Sydney Opera House Environmental Sustainability Manager Emma Bombonato.

"Projects such as this enable us to continue that legacy by inspiring greater community awareness of the marine environment around Bennelong Point and contributing to local biodiversity."

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