Mystery over Port River dolphins’ disappearance and death, as another dead dolphin calf washes up at Seaford

The mystery case of the dead baby dolphin on a suburban beach follows a spate of deaths and disappearances in the Adelaide Dolphin Sanctuary – and yet another young male is ailing.

A disturbing discovery at Seaford is yet another sign that all is not well for dolphins in Adelaide metropolitan waters.

While a dead baby dolphin appears to be unrelated to a spate of recent deaths and disappearances in the Adelaide Dolphin Sanctuary, a young male calf from the Port River pod has dolphin lovers worried.

The August death of 12-year-old dolphin Tallula followed the disappearance of two male dolphins, Doc and Twinkle in June and July. Both dolphins had suffered injuries from fishing tackle and their condition appeared to deteriorate as a result.

Jenni Wyrsta of Port River Dolphin Watch said Hunter, a six-year-old male from the same area had been losing weight and behaving strangely in recent weeks.

“They all spent a lot of time together,” she said. “It is important we find out what caused the three to lose weight and pass away, with this fourth dolphin showing he is losing weight too.”

Ms Wyrsta has been asking park rangers and vets if there could be something in the water causing these problems, or a shortage of food.

“We have seen a dramatic drop in the number of dolphins in the river,” Ms Wyrsta said.

“We go on the Dolphin Explorer cruise regularly and of late have only seen one or two dolphins on these two-hour cruises. When I first started dolphin watch 12 years ago, we would see up to 36 dolphins on these cruises.”

Port River dolphins Hunter and Doc, in happier, healthier times. Doc has been missing for months after becoming ill and thin. Now Hunter is going the same way. Picture: Jenni Wyrsta

Whale and Dolphin Conservation Society regional science and education manager Dr Mike Bossley said he was deeply concerned about the health of the pod.

So far Tallula’s autopsy and test results on specimens from Doc, taken before he disappeared, have not revealed the source of the problem.

Further south, Nicky Falkiner of Seaford Meadows made the gruesome discovery of the dead baby dolphin on the beach Friday morning.

She reported the body to the authorities, who collected it for autopsy at the SA Museum.

“Something is a bit amiss,” Ms Falkiner said. “I don’t believe it’s an isolated incident.”

A spokesman for the Environment and Water Department said the National Parks and Wildlife Service confirmed one common dolphin had washed up at Seaford beach.

This is a separate species from the bottlenose dolphins in the Port River.

“The animal is believed to be very young and has no visible signs of injury. It is most likely it died of natural causes,” he said.

He said common dolphins are rarely seen in the Adelaide Dolphin Sanctuary, and several are washed up on Fleurieu beaches each year

Environment and Water Minister David Speirs launched an investigation into the potential causes of recent dolphin deaths in the Adelaide Dolphin Sanctuary in August, following the death of dolphin Tallula.

It is expected to take months before it is known what is affecting the health of the dolphins in the Port River and Barker Inlet.