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Increasing salinity inland has meant the mussels are mostly restricted close to where rivers meet the coast.

Lymbery said the main purpose of the university’s latest study out of the Harry Butler Institute was to get a better understanding of the mussel’s habitat preferences with a view towards future translocation or even captive breeding.

“Which is what they do in the United States and Europe. Freshwater mussels are in decline everywhere,” he said.

“They like to be close to the riverbank, they like fine sediment rather than rocky or pebbly substrate and they like to have debris in the water, branches that have fallen.

“We’re working with the Water Corporation to see where the mussels can live in their assets like drains and compensation dams.

“We’re having to think fairly laterally because we’re running out of water.”

River flows have fallen 70 per cent in the past 50 years after a massive drop-off in annual rainfall for the South West since 1970.

The reduction in water has meant there are rivers and lakes which dry out in summer and autumn when they previously would not have.

The dry conditions have seen a big drop in invertebrate species across 17 Wheatbelt lakes going from 300 to a bit over 100 between 1998 and 2011.

“All our animals are adapted to dry season pools but they’re becoming fewer in number, smaller in size,” Lymbery said.

“Summers are getting hotter and longer, mussels and everything else have to survive in those refuge pools longer.

“That’s going to be the major problem going forward, that’s why we’re starting to look at artificial structures that might serve as dry season refuge pools, not just for mussels but freshwater fish.”

The South West has 11 native species of freshwater fish, relatively few, but nine of them are endemic.

It’s a trait similar to other Mediterranean climates around the world that tend to be “arks” for unique species.

A recent paper from University of Western Australia researchers examined where the 11 species were likely to still be able to survive come 2080 in a drying climate.

Two fish, the trout galaxias and the WA salamanderfish, a relic from when Australia was part of the supercontinent Gondwanaland, are predicted to have no habitat left in the next 58 years.

Five other fish will lose 80 per cent of habitat and there was a “coldspot” identified in the Shannon River Basin in the Great Southern region.

About 93 per cent of the coldspot is within already established protected areas, like national parks.

Most of the surviving fish species would be present in the coldspot but only 26 per cent of surrounding areas where they could also continue to exist in the region is covered by conservation reserve boundaries.

The authors suggested just having protected species status or protected areas in isolation may not be enough to conserve the different species.

“Instead, a multi-pronged approach is likely to be more effective, using a combination of protected areas, controlling alien species, and enabling the allocation of adequate environmental flow,” they said.

“The results of this study indicate that changes in species distributions as a result of climate change should be considered in the design and implementation of protected area networks.”