MILLIONS of fish could be saved from being used in toxicity tests thanks to scientists from the region.

Scientists at the University of York have helped develop a new test for contaminants in water which avoids using live fish.

The new procedure – which uses gill cells from rainbow trout grown in the laboratory – is not only more sustainable but also more cost effective, researchers say.

Every year, more than a million fish are used for toxicity testing and scientific research in the EU alone, and around 400 fish are needed for a single fish early-life stage test.

Such toxicity tests are often required by regulatory authorities for new chemical substances, as fish are particularly sensitive to contaminants in water at the start of life and as they begin to grow.

The team say they can now predict the growth of the fish using the cultured gill cells, combined with existing computer modelling, after just five days of experiments.

Dr Roman Ashauer, from the university’s environment department, said: “The issue is that animal testing is ethically controversial and expensive.

“Traditional testing requires a huge number of animal tests which is not practical. You need a test that you can do quickly and in the lab and at low cost.

Dr Ashauer said the technique could have wider applications and reduce the need for experiments on animals.

“We think it can also be used for rats and mice, anything that we want to test the effects of growth on. The general idea behind this kind of model can be transferred to small mammals,” he said.

The results have been published in the journal Science Advances.