Water, water, everywhere
Published: Nov 16, 2017Living Coasts - a giant water treatment plant with some penguins on top...
People know Living Coasts as Torquay’s coastal zoo – a compact site on the water’s edge with pools for penguins, seals and other aquatic species. We walk around, admire the animals from above and below the waterline, then go to the café for tea and cake. But how does Living Coasts actually work? How does all that water come and go, move around, stay clean?
Living Coasts is essentially a giant water treatment plant with some penguins on top. It’s built around a super-skimmer, a large octagonal chamber where ozone enriched bubbles remove organic compounds such as food and waste particles from water in a process called protein skimming. The Living Coasts skimmer is the height of a two storey house and more than 5 metres across; when it was built it was one of the largest in the country.
Water Services Technician Derek Youd can reel off some impressive statistics: “We hold 1.7 million litres of seawater taken from the Bay in a closed system of interconnected pools and circulated by two 55kw pumps. The system can process 825,000 litres an hour - that’s 19,800,000 litres a day, which means that the entire water volume is cleaned 12 times a day.” The waste is diluted and given 24 hours of ultra violet sterilization to kill any harmful bacteria before being returned to the Bay.
The technology was tried and tested when Living Coasts was built; 15 years on, it’s a bit out-dated. Which is not to say that it is no longer fit for the job – just that things have moved on. But that’s the march of progress. Draining down the super-skimmer is a major task that can reveal problems, or future problems. But it’s also a fascinating insight into the guts of this extraordinary place.
Derek looks after the pumping, filtering and cleaning of 1,700 tonnes of water. He knows every millimetre of the hugely complicated system. Visitors see the habitats and the animals. Staff and volunteers know some of what lies beneath. Derek sees deeper still, to the systems that are at the heart of Living Coasts. His territory is the noisy subterranean world of the plant room.
A computer system called SCADA records trends and patterns and helps Derek to predict changes. The variables are many and tricky to juggle: the quality of the water is everything - visitors rightly expect clear water for perfect viewing. What can influence the system?
“This is a living system modified by weather, seasons and animal life. The look of tanks can change over the course of a day. Rain adds fresh water to our mainly saltwater system and makes it go cloudy. Fine sand from Penguin Beach goes into suspension and reduces visibility. Summer sunshine causes microscopic plant-life to grow and water to evaporate. Even feeding our animals an oily fish like salmon can upset the system, as it will break down the foam in the super-skimmer.
“Most people who visit us have only experienced indoor aquarium environments with controlled lighting and crystal-clear filtered water. We use sea water drawn directly from the Bay, which means we can have algae, seaweeds, crabs and even plankton! Living Coasts’ tanks are a closer representation of the sea than most places you will visit.”
Five pools - some up to 3 metres deep – arranged on different levels connected by hundreds of metres of pipe hold seawater. The only tank to hold fresh water is the waders’ estuary.
The filtration system computer can be monitored and accessed remotely; alarms can be sent out to lap-tops and mobile ‘phones. It’s clever stuff, but then it needs to be: ultimately, the health and welfare of the birds, mammals and fish in the attraction rely on it. So, thanks Derek and everyone else who looks after the system – Living Coasts would be nothing without you!