New York, Oct 16 (IANS): Researchers have developed an instrument that can analyse specific compounds called metabolites in dolphin breath to diagnose and monitor problems in them.

Invasive techniques such as skin biopsies and blood sampling, which are the most effective ways to test the health of the marine mammals, are difficult to perform, the study noted.

"Studying dolphins' health is about more than preserving their populations - the popular mammals can also serve as sentinels for overall ocean health," said co-researcher Cristina Davis from the University of California, Davis in the US.

Exhaled breath contains compounds called metabolites that can hint at a person's diet, activity level, environmental exposures and disease state.

The researchers designed an insulated tube customised to trap the breath exhaled from the blow hole of the bottlenose dolphin.

They tested it on dolphins both in the wild and under human care.

The scientists established baseline breath profiles of healthy animals and identified changes in the breath of animals affected by disease or other factors.

The study appeared in the journal Analytical Chemistry.