Jump to content

Sink Or Swim: Eight Fish Who Guard The Health Of Millions


mrmoshe

Recommended Posts

Sink or swim: eight fish who guard the health of millions

THEY are not angel fish, but they are Sydney's guardian angels.

In a small brick shed in the Southern Highlands eight tiny fish stand guard, 24 hours a day, seven days a week, over the water flowing to more than 4 million people.

Like the canaries that once sniffed the air in coal mines, the Australian rainbow fish are living proof that the city's water is safe.

If they don't like what they are swimming in, they have the power to shut down much of Sydney's supply system.

Although the Sydney Catchment Authority routinely tests for a wide range of impurities, the checks only guarantee water quality at the moment they are conducted.

Khanittha Poonbua, a project engineer with the authority, said the the three centimetre fish provided continuous evidence that all is well.

Their high-tech aquarium looks more like an automatic teller machine, or a space-age oven. Each lives in its own compartment, little bigger than a compact digital camera.

Every minute a litre of water is pumped into the testing station at Broughtons Pass, near Appin. "We watch how they react, how they behave," Ms Poonbua said.

Electrodes sense "bioelectronic signals" emitted whenever the fish inhale through their gills. The information is fed into a computer programmed to recognise their normal respiration rates.

A screen displays the information. If the computer ever detects that at least five fish - a majority of those on guard - are breathing abnormally and are in distress, it will automatically trigger an alarm and order gates to close, shutting off the flow in canals carrying water to Sydney.

"The fish," Carl Broockmann, the authority's projects delivery manager, said, "have a big responsibility. They are our front line of defence. They won't tell us what is wrong, but they will tell us something is wrong."

So the alarm will also cause a water sample to be collected for engineers to analyse and identify the problem.

Two of the fish monitoring stations are now testing water flowing to Sydney via open canals from the Avon, Cataract, Cordeaux and Nepean dams which supply a fifth of Sydney's needs.

With public roads crossing the catchments and canals, a fuel spill from a road accident, a sewage overflow or even a terrorist attack could contaminate the water.

Warragamba Dam's water, fed to Sydney via pipes, is considered less of a risk.

Every two weeks the fish, working under the Animal Care and Ethics Committee's approval, are exchanged and given a holiday in a conventional glass aquarium.

Fortunately, Mr Broockmann said, the only alarms triggered by the fish have been caused by technical glitches, such as electrical faults and pump failures.

post-1685-1205535559_thumb.jpg

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...