In Australia and around the world, barriers such as dams are believed to be the cause of a significant decline of freshwater fish stocks over the past half-century. This is because they interfere with fish reproduction cycles by stopping the fish from migrating to spawn.
Now, some engineers from UNSW Sydney have come up with a brilliant invention to tackle this issue.
An ingenious invention
“If we could reconnect our rivers and give fish the ability to navigate our rivers safely, we would see more breeding and healthier native fish populations in our rivers.”
The engineers have developed what they call a tube fishway. This device functions by pumping fish at high velocity through a tube running over any dam or weir barriers to getting the fish safely into the water on the other side.
"Freshwater fish populations have declined by more than 80% over the last four decades across the globe. This is partly due to the hundreds of thousands of our dams, weirs and barriers stopping their movements,” said in a statement professor Richard Kingsford, Director of the Centre for Ecosystem Science, from UNSW School of Biological, Earth and Environmental Sciences
A cost and eco-friendly development
The device further ensures the fish are protected by also pumping a cushion of water. The invention is inexpensive, eco-friendly as it requires very little energy. Easy adaptability to the local environment is another important aspect of it.
“Our numerical modelling work shows that this system will work reliably for pipes at least one meter in diameter, lifting fish more than 100m vertically. This is potentially a game changer in the ecological management of large dams,” said UNSW Engineering’s Adjunct professor Bill Peirson.
The invention, however, didn't turn up without complications. Getting the fish over lower barriers was easy, but higher ones compromised the fish's lives. As such, the team is now looking for gentler ways of getting the fish over large dams.
The engineers are determined to find a solution that will help the fish while ensuring the function of the original river structure is not diminished. “There’s no reason why we can’t have dams and healthy river systems at the same time,” Peirson concluded.