The artificial reef would be the sixth the government has installed along the NSW coast.

The reefs are designed to enhance recreational fishing opportunities by attracting a large number of fish to the area. 

Last week the government called for tenders from companies keen to build the structure, which would be located around 2.4 kilometres off Perkins Beach at Windang.

Read more: Merimbula reef heads offshore

The reef will be made of steel modules and could be as large as 12 metres high and 15 metres long. 

A spokeswoman for Primary Industries Minister Niall Blair said the changes in fish populations had been monitored at other artificial reef locations – including at Shoalhaven and Merimbula.

“Results from other sites have shown that fish abundance at the new reef site rapidly increases soon after the reef is installed,” the spokeswoman said. 

“The complex design of the reefs combines high relief (height off the structure off the seafloor) with a large surface area with caves and crevices where fish and other marine organisms may settle. 

“This means the reefs are highly productive locations that support very high fish abundance.”   

The spokeswoman said the reef off the Illawarra coastline was expected to be in place by the middle of next year and should start attracting some fish varieties almost immediately.

“A small number of fish species will rapidly colonise the structure within weeks of its completion to take advantage of the new reef space and shelter that it provides,” the spokeswoman said.

“Over time, the number of species will continue to increase and produce more fish through natural fish recruitment cycles and monitoring has shown that as many as 50 fish species may eventually take up residence on a single reef. 

“This process can take up to three to five years.”