An international team of researchers has found climate change is negatively impacting the Californian wild salmon population and it should serve as a warning to Australia.
Associate Professor Sally Thompson, from the Centre for Water and Spatial Science in The University of Western Australia's School of Agriculture and the Environment, was a co-author of the study led by the University of California and published in Proceedings of the National Academy of Sciences.
"Salmon are important in north-west America as they have indigenous significance, are a valuable commodity and essential for nutrient cycles in the forests," Associate Professor Thompson said.
"Salmon breed in rivers, mature in the ocean and then return to the streams they were spawned in to have their own babies, but California had a one-in-a-1000-year drought from 2011 to 2014."
Researchers found during the drought, streams that usually saw an increase in flow in November only began the winter flow in January.
The low water levels caused the upper reaches of the streams to be cut off and the fish could not return to places to spawn.
The lack of access caused breeding failure for several salmon species in rivers across northern California.
"Because salmon were not born in those locations, it potentially means we will not see them return," Associate Professor Thompson said.
"Our study shows that the range where the valuable Californian salmon population lives is shrinking because of the impact of the drought."
Associate Professor Thompson said the findings should act as a warning as climate change events, such as droughts and bushfires, which occur in California are often mirrored in Western Australia.
"Australia's rivers are shrinking because of variable and declining rainfall," Associate Professor Thompson said.
"We don't have wild salmon, but we do have migratory fish such as lampreys that need access to freshwater to breed."
