Climate change threatens freshwater fish

Jan 10, 2014
Climate change threatens freshwater fish
Murdoch researchers examine a site in the Blackwood River catchment.

(Phys.org) —New research has revealed that Western Australia's drying climate will impact fish migrations, putting further pressure on a number of native freshwater fish species.

Scientists from Murdoch University's Freshwater Fish Group and Fish Health Unit said the new paper shows there is a clear relationship between river flow and the spawning migrations of potamodromous fishes (those that migrate within river systems).

"Australia's south west has seen major reductions in rainfall since the 1970s, leading to a decline in surface flow of around 50 per cent," said lead author Dr Stephen Beatty.

"The ongoing flow reductions will result in these migrating less and cause a loss of suitable spawning habitat. As a result, declines in their abundances can be expected."

Scientists conducted a four year study, focusing on the Blackwood River, to track the migrations of the Western Pygmy Perch, Balston's Pygmy Perch, Western Minnow and the Nightfish. The researchers then assessed the relationship between fish migrations within rivers and the variable environmental conditions.

"The amount of surface discharge was the best predictor of the strength of the annual spawning migrations of most species," Dr Beatty said.

"With surface flows projected to continue to diminish in this region, our findings have major consequences for the future of these fish species."

Dr Beatty said that as top order consumers, these fish species play an important part in the wider ecosystem. By feeding on larvae, these species also help control troublesome insects such as mosquitoes and midges.

The study painted an equally grim picture of the drier season, when the seek refuge in pools of water. The researchers predict that the amount and quality of refuge pools will also continue to decline due to climate change.

With rapid population growth and salinity also putting pressure on aquatic ecosystems, Dr Beatty said it was important that all Western Australians consider their water use.

"Every effort should be made to ensure that existing stressors are addressed and that abstractions of surface and groundwater consider the sensitivity of fishes to changes in hydrology," he said.

The study will be published in an upcoming issue of the journal Global Change Biology.

Explore further: Saving vulnerable Australian fish species

More information: onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-2486

add to favorites email to friend print save as pdf

Related Stories

Saving vulnerable Australian fish species

Jan 08, 2014

Nearly one year into a study on the three rarest fish species in WA's south-west zone is already yielding invaluable data to aid in developing action plans that may save their future.

Researchers name new fish species

Apr 16, 2013

(Phys.org) —Researchers from Murdoch University's Freshwater Fish Group & Fish Health Unit and South Australian Museum have officially named Australia's newest freshwater fish: the Little Pygmy Perch (Nannoperca ...

Researchers develop new model to assess fish passage

Dec 20, 2013

Fishes, such as salmon, who must swim upstream to their birthplace to spawn are often impeded by obstacles like dams and roads that crisscross rivers and streams. A team of researchers from the University of Georgia and the ...

Recommended for you

India's ancient mammals survived multiple pressures

12 hours ago

Most of the mammals that lived in India 200,000 years ago still roam the subcontinent today, in spite of two ice ages, a volcanic super-eruption and the arrival of people, a study reveals.

User comments : 0

More news stories

Deadly human pathogen Cryptococcus fully sequenced

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...