Police escort injured orca as experts work to free it from crayfish line

An injured Orca had a police escort through the Waitemata Harbour as marine experts try to free it from a cray-pot line.

It ran into trouble near Whangarei three days ago and its chances of survival are dropping by the day.

It's a race against time to disentangle the distressed orca.

"If we don't get the line off then there's zero chance of survival," marine biologist Ingrid Visser said.

She has spent the past three days attempting to free the orca from the cray pot line it became tangled in near Tutukaka in Northland on Sunday night.

They thought they'd lost track of it, but shortly after midday on Thursday, a whale-watching vessel from Auckland Whale & Dolphin Safari spotted it near Auckland's North Head and tipped off police.

A crowd gathered as it passed the wharf at Devonport. Police and the Department of Conservation spent the afternoon shadowing it as it moved through the harbour and making sure nobody came too close.

"His family is here in the harbour too which is why we're asking people to stay a respectful distance away and legally they're not allowed to go any closer than 50 metres, but we're asking everybody to double that distance," Visser said.

Newshub followed the orca around on Thursday from Westhaven to Island Bay. In that time it rarely went above 4 knots, but the average orca swimming speed is 8 knots. That shows just how much this injury is impeding it.

If the nylon rope and buoy tangled around his right pectoral fin can't be removed, it's likely the orca will die of blood loss or blood poisoning.

"As he swims forward, the buoy, which is about the size of the coconut, is pulling and the nylon line is embedded in the flesh, and it's cutting him whilst he's moving forward, so slowing down is taking a bit of pressure off the fin," Visser said.