Archaeologists have found an ancient fish trap near Esperance, the first to be recorded in the area, which is believed to have been used up to 1000 years ago.
The trap is made up of a series of rocks placed across a tidal creek east of the south coast town and would have been supported by wooden stakes and covered in netting to catch passing fish.
A research team uncovered the fish trap while surveying the area.
Doc Reynolds, a traditional owner of the area and chairman of the Gabbie Kylie Foundation which organised the expedition, said the site was well known among indigenous people.
"The old fellas had a very complex understanding of the seasons, tides and animal behaviour and were able to harvest a catch with great skill and efficiency," he said.
Archaeologist David Guilfoyle said the rock structure harnessed the natural tidal cycles of the estuary by trapping fish as they moved in and out with the tides.
"It is difficult to determine how long these traps have been used, but we guess at least over the last 500 to 1000 years," he said.
Similar rock structures have recently been found elsewhere in the South West, including Albany.