Keith Lightbody won the Threatened Species category and the Our Impact section.
The competition and exhibition is in its 11th cycle and WA Museum chief executive Alec Coles said the museum was proud to have hosted the exhibition from its inception.
"Each year, the exhibition has brought more magnificent images of our spectacular natural environment to a growing audience," Mr Coles said.
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READ NOW"The competition promotes excellence in nature and landscape photography. It offers a compelling reason for photographers of any age and genre to engage in documenting our beautiful bioregion."
Lightbody won the Our Impact section with his work Salinity by Twilight.
"During winter, this perched lake near Quairading gains water that runs down from surrounding paddocks which have all been cleared for crops," he said.
"Without any exit creeks, it's still and slowly evaporates during summer, with salt growths and crystals forming on the dead trees."
Judges said the unusual shapes and appealing colours attracted the viewer's attention.
"Social Drinking is my submission for the Threatened Species category. It shows two Baudin's black cockatoos engaging together as if in mid-conversation, plus a Carnaby's black cockatoo alongside," Lightbody said.
"There was no wind and it was more than 30 degrees by 8am, so both Baudin's and the Carnaby's black cockatoos from the local flocks came down from the trees to the farmer's pond near Nannup for a social drink. A few also had a quick rinse before heading off to look for food."
The 2014 Australian Geographic ANZANG Nature Photographer of the Year is a free exhibition at the WA Museum until June 1.