SCIENTISTS at a Tees Valley biotechnology firm have developed a system that could extend the lives of a fish that costs up to £150,000.

Environmental biotechnology company CBio has developed a system which uses live bacteria to clean ponds inhabited by koi fish.

The fish can be killed by the ammonia they themselves excrete and previously many have died while traditional systems deal with the problem.

But the technology developed by scientists at the firm, based at Preston Farm Business Park, in Stockton, means a pond can be made safe for the fish in only two days.

CBio managing director Ben Hoskyns said: “Koi excrete ammonia and, when that builds up, it will turn a pond toxic.

“The traditional way of dealing with this is through a filtration system where water is pumped up to a filter box.

“Bacteria colonise the filter box gradually over time and turn the ammonia into harmless nitrates.

“But this process of bacterial colonization can be a lengthy process and during that time fish can die because there’s not been enough time to build up the right amount of bacteria.”

With the CBio system, millions of friendly bugs are instantly released into the ecosystem of the pond and destroy the ammonia.

Stockton-based fish expert Paul Fretter, who runs Teesside Koi and Aquatics in Stockton, said: “People can become very attached to koi, they will come to the surface and eat from your hand. They are not like river fish which shy away. They are friendly and intelligent and can live for up to 45 years if well looked after in a large pond.

“Koi are also very expensive – the most expensive we stock are £800, but they can reach £150,000.

“Even if you only have a small pond, the cost of a dose of bacteria is nothing compared to the financial loss of a couple of fish.”

CBio, also known as Cleveland Biotech, has been based in the North-East since 1992.

The company breeds a variety of naturally-occurring micro-organisms from which products are then formulated for use in the degradation of specific wastes.

The firm is working on projects involving pollution control in the UK, Europe, the US, South America, Middle and Far East and the Pacific region.