Now four of seven Port River dolphins born this breeding season found dead

OF the seven dolphin calves born in the Port River so far this breeding season, only three have survived. The others are suspected of being hit and killed by boats — and conservationists are demanding swift action.

• Boaties urged to be careful around three new baby dolphins
• Anger at state of Port River following baby dolphin deaths
• Speeding boats are killing our Port River dolphins
• Jetskiers caught doing doughnuts in Adelaide Dolphin Sanctuary

A BABY boom — the biggest in 11 years — is taking place in the Port River but it has come with a heartbreaking twist.

Of the seven calves born so far this breeding season only three have survived.

The other four babies have mysteriously died and are suspected of being hit and killed by boats.

At least one of the calves, Holly, has been confirmed as a boat death.

Three-week-old dolphin calf CK was found dead yesterday.

Her body was being pushed around by her mother Oriana.

It will stay with Oriana for up to a week to allow her to grieve and then will be collected by conservationists to determine a cause of death.

Mum Oriana and dead calf CK. Picture: Sharon Sharp

An adult dolphin, who has not yet been identified, was also found dead at Garden Island on the same day.

A recent report by the South Australian museum found that 17 out of 35 dolphin fatalities in the past 13 years were caused by speeding boats.

Conservationists are now demanding that boaties keep at least 150m away from any mother and calf to protect the babies and any others born this breeding season, which is expected to finish this month.

Baby calf Holly was killed by a speeding boat. Picture: Marianna Boorman.

Adelaide dolphin expert Dr Mike Bossley said he was “gutted” that yet another baby had died.

He called on authorities to crack down on hoons and review the speed limits within the Adelaide Dolphin Sanctuary, particularly given the vulnerability of the three surviving calves. The limit currently varies from 4 knots (7km/h) to unlimited.

Dr Bossley said after more than 30 years of watching over and researching the dolphins, he considers himself their “grandfather”.

Dr Mike Bossley in Port Adelaide. Picture: Sam Wundke

“This makes me feel like the dolphins are part of my family and makes me particularly concerned for their welfare,” he said.

“Adelaide is incredibly lucky to have dolphins living almost in the heart of the city but this proximity exposes them to numerous threats.

“It is essential that we do all we can to ensure their safety in the future.”

Conservationist and dolphin-watcher Marianna Boorman said there also needed to be better speed-limit signage and education for people going out on the water.

“We are really excited there is a dolphin baby boom in the Port River this season but we are still very concerned about the wellbeing of these calves,” Ms Boorman says.

“The last baby boom was back in 2009. There were 11 calves born and only five survived their first year.

“This season, we have had seven calves born so far and already four have not survived.

“Boats and jet skis travelling at excessive speed, doing doughnuts and changing directions erratically should not be permitted in the Adelaide Dolphin Sanctuary.”