KEY POINTS:
A pod of dolphins stranded in an Auckland river this morning are heading back out to sea.
DoC marine ranger Karl McLeod said the 18 dolphins that were stranded in less than 1 metre of water this morning have cleared the mouth of the Tamaki River, near the Half Moon Bay marina.
He said it took an hour to shepherd the dolphins over a shallow area under the motorway bridge.
He said DoC staff and volunteers are being stood down but one boat will stay near the dolphins to monitor their situation.
Dolphin rescuers had been eagerly awaiting high-tide in the hope that the 18 dolphins would be freed from the Tamaki River.
Department of Conservation staff and Coastguard were on the banks of river, monitoring the situation.
About 1pm, Coastguard's northern region chief executive Dean Lawrence said the Dolphins had left the swimming hole and were on their way out to sea.
Mr McLeod said earlier this morning there was concern about one of the dolphins which had rolled on to its side and appeared to be stuck in the mud.
Mr McLeod said staff did not want to get into the water unless absolutely necessary because that would put stress on the bottle nose dolphins.
The dolphin managed to roll and free itself from the mud.
"We don't want to interfere with their natural inclination," Mr McLeod said.
He said dolphins feed on small fish like mullet and herrings and were likely chasing food when they misjudged the tide and got stuck.
University of Auckland biologist Rochelle Constantine said the dolphins are part of a larger 500-600 pod that travels between the Bay of Plenty and Northland.
She said each one has been numbered and is part of a study that has been going since 1993.
Dr Constantine said some of the dolphins would be 14 years old, up to 3.5m long and weigh up to 400kg.
"That's part of the reason we don't want to get into the water," she said.
Dolphins are often seen feeding amongst mangroves and "scooting through the mud on their bellies," Dr Constantine said.
Mr McLeod said the tide was coming in and the dolphins - with the help of Coastguard - will be shepherded back to the coast, north of St Heliers.
Ellerslie motorway police officer Kevin Smith said he had moved about 12 people on after they pulled up on the motorway to watch the dolphins.
"Everyone stops to see what's going on and the next thing there's a nose to tail. It's a shame because it would make a nice photograph but you've got to look at the safety," Mr Smith said.
