Story at a glance
- Coastal dolphins living in proximity to the United States, South America and Australia are exhibiting signs of a freshwater skin disease.
- Australian researchers discovered that the disease is actually caused by environmental factors.
- As climate change affects water quality and weather patterns, the fatal disease is likely to spread.
Nahiid Stephens, a veterinary pathologist, got out of her boat, she told the Guardian, trying to make a plan to euthanize a female adult dolphin in distress and suffering from skin lesions.
“She literally just died at my feet. That has stayed with me. I’ll never forget that moment. It was horrific,” Stephens, a co-author of a new paper on a freshwater skin disease, told the Guardian. “How can you not get upset about dead dolphins?”
The study published in Scientific Reports revealed the environmental factors behind the fatal disease in dolphins who were exposed to freshwater. Australian researchers studied dolphin necropsies and tissue sampling in two coastal communities where heavy rainfall had affected marine habitats.
Cetaceans — aquatic mammals such as whales or dolphins — are unable to survive for long periods of time in fresh water. If these animals become trapped in such water or their environment is heavily affected by rainfall, they can develop a skin disease, which may lead to ulcers and lesions affecting almost three-quarters of the animals' body. The disease can be as severe as a third-degree burn and may lead to bacterial, fungal or algal infections, which can be fatal.
“We couldn’t believe that such a severe, rapidly developing disease could be anything other than infectious … but ultimately, it is an environmentally caused disease,” Stephens told the Guardian. “Their skin is just as sensitive as ours, and possibly even more so – it would be incredibly painful.”
Global warming is influencing precipitation patterns that carry fresh water and even surface runoff to the ocean. As climate change increases the frequency and intensity of storms and other natural phenomena, the risk to dolphins will increase, according to the study.
“We can only say there’s a pattern, a trend – but it’s gathering strength,” Stephens told the Guardian.
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