Construction of Western Australia's first artificial reefs have reached the halfway mark.

Two artificial reefs are expected to be built by early February and will be placed in the southwest region's waters later that month or in March.

Fisheries Minister Norman Moore said one of the reefs would be established near Bunbury and the other off Dunsborough in Geographe Bay to create a habitat for nearshore fish.

"These purpose-built reefs have been proven elsewhere to produce environmental benefits by supporting a diverse marine community and, over time, will provide recreational fishers with new, accessible and safe fishing locations," he said.

Regional Development Minister Brendon Grylls said about 580 tonnes of concrete and 20 tonnes of steel were needed for the two specially designed reef structures, to be provided by companies in the region.

Mr Moore said researchers would monitor the new reefs to assess their effectiveness.

"Recreational fishers would need to allow time for the reefs to begin hosting significant biodiversity," he said.

The $2.38 million project has been funded with $1.86 million over four years from the Royalties for Regions program and $520,000 reinvested by the state government from funds collected through recreational licence fees.