Diseased dolphins use muscles as energy source to survive, study suggests

Researchers analysed the metabolism of bottlenose dolphins.

Researchers looked at bottlenose dolphins (Owen Humphreys/PA) (PA Archive)

Diseased dolphin populations use their muscles as an energy source to survive, new research suggests.

Researchers from the University of Aberdeen, Medical University of South Carolina, Georgia Institute of Technology and the Technical University of Denmark analysed the metabolism of dolphins as part of the study.

They compared the blood profile of diseased bottlenose dolphins with the blood profiles of healthy bottlenose dolphins from wild populations at Charleston Harbour and the Indian River Lagoon in the US.

The research found that dolphins in poorer health had lower levels of amino acids, the building blocks for muscles, and may use those building blocks to substitute the shortfall in energy they have to fight the disease.

Human activities can disrupt the foraging ability of these animals, reduce their food intake, and can impact how much energy they can invest in reproduction or growth

Dr Davina Derous, University of Aberdeen

The study found that diseased dolphins may be put at an increasing risk of starvation due to man-made factors including tourism and shipping.

It is hoped that by increasing the understanding of dolphins’ physiology, conservationists can better assess how to mitigate the risks posed by human activity.

Dr Davina Derous from the University of Aberdeen’s School of Biological Sciences, said: “This study gives us vital insight into how diseased animals regulate their metabolism and how further impact by humans activities may cause even more issues to their health.

“Energy metabolism plays a key role in our ability to understand the consequences that human disturbances might have for the conservation of whale and dolphin species.

“Human activities can disrupt the foraging ability of these animals, reduce their food intake, and can impact how much energy they can invest in reproduction or growth. Predicting these ecological consequences is limited by our understanding of cetacean energy metabolism and what a healthy dolphin looks like.

“Human activities can impact the health of dolphins to such a degree that it can even lead to less offspring being born. To prevent this, we are measuring the health of dolphins by estimating how much fat they have.

“This is the same principle as in humans where we don’t have enough fat stores, the body tries to survive by shutting down non-essential mechanisms such as our ability to reproduce.

“However, in dolphins we have found that only looking at their fat stores does not give us the full picture about their health, as they also use fat stores to keep them warm, to dive and for buoyancy.

She added: “We desperately need novel health markers if we want to protect these precious species. Our study is the first step towards finding those novel health markers.”

The study was funded by the US Office of Naval Research, and is published in Comparative Biochemistry & Physiology.