New research could help solve the long-standing problem of monitoring the health of farmed Atlantic salmon.
It is hoped the technology will boost salmon farming
It is hoped a new "DNA chip" will save the salmon industry thousands of pounds and conserve dwindling stocks.
The chip technology, developed by scientists at three UK universities, aims to provide a more reliable assessment of the condition of fish.
Farmers and conservationists currently rely on the general appearance of salmon as an indicator of their health.
Atlantic salmon, seen as the most important farmed fish in the UK, are a disappearing species in the wild.
They are particularly vulnerable to infection because of the dramatic changes they go through, known as smoltification, which enable them to live in both fresh and salt water.
As a result, assessing their health and performance using conventional measures such as temperature and blood protein levels has proved difficult.
The chip, the result of a four-year study by scientists at the Universities of Stirling, Aberdeen and Cardiff, aims to identify changes in gene activity to flag up potential problems.
The experts said it was too early to tell if the chip would become a commercial success.
Chris Secombes, from Aberdeen University, said: "We have identified hundreds of genes that are increased or decreased following infection, many of which may be indicators of disease.
"We have also looked at what other factors impact on these genes, such as nutrition.
"We are now working to encode this information onto a chip which could help farmers monitor the health and performance of their stocks through methods such as changing their nutritional intake."
The study, known as Salmon Traits (Transcription Analysis of Important Traits in Salmon), was also taken forward with ARK Genomics at the Roslin Institute and researchers at the Norwegian School of Veterinary Science.
It received funding from the Biotechnology and Biological Sciences Research Council.