Two giant steel pinnacle-shaped "reef towers", each more than 12m tall and weighing 90 tonnes, were sunk at sea off Perkins Beach, with installation completed on Thursday, Minister for Agriculture Adam Marshall said.

This type of artificial reef is perhaps the main way the NSW Department of Primary Industries returns the proceeds of its Recreational Fishing Fee (colloquially known as a licence fee) to the fishers who pay it.

The structure will allow fish to accumulate and feed on marine flora and fauna growing, creating a fishing hot spot, the minister said.

Mr Marshall said these structures would support a wide variety of fish species and will improve conditions for fishers for years to come.

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"The steel structure is the skeleton of a new thriving fish community, providing shelter for species popular with recreational fishers and a variety of attaching marine organisms," he said.

"The other six reefs constructed to date have produced very positive results, coming alive with species like yellowtail kingfish, bonito and blue mackerel."

Mr Marshall said the decision was made after "extensive" seabed mapping and community consultation, and the reef was deployed 2.4km offshore and 2.5km south of the Five Islands Nature Reserve.

But when we contacted the Mercury's fishing columnist Gary Wade to discuss the new artificial reefs, he said he was "stunned" - he hadn't heard this was happening.

It may have been a surprise, but it was a pleasant one.

"Recreational fishers will be delighted to hear this has happened," Wade said.

"It's good to see the money we pay for the recreational fishing fee being returned to us in facilities, rather than just being taken for general revenue.

"This is a good use for our fishing fee money.

"These kind of things draw tourists to the Illawarra and there are plenty of rec fishers out there."

Details about the artificial reef and its location are online at the NSW DPI recreational fishing pages.