It is not possible to predict if the recent orca sightings in the Tauranga harbour area will continue.

See video below filmed by Swim with Dolphins owner Graeme Butler of the orca in Tauranga harbour. This photo by Grant Jellyman.

In the last week, sightings of the orca have been regular with people taking to the water to get close to the animals.

This occurred on Sunday, when Papamoa surf lifeguards used their IRB and earlier on January 14, as seen in the video below.

New Zealand orca expert Dr Ingrid Visser says it is impossible to tell when the marine mammals will appear close to shore in the region.

'It's completely unpredictable; the animals are drawn by their food sources,” says Ingrid, who notes they are hunting for rays.

The orca pods seen in the last week have measured in groups of three or four and she says this is consistent with the group average of about 6-12 in New Zealand waters.

Ingrid tracks the orca movements as this provides much knowledge of these creatures.

'How long they live for, whether they have babies, how often they have them; do they survive.”

One orca Ingrid is tracking is a calf with a chunk bitten off its fin. This was seen in the Bay of Islands area on December 29 and she says it's a good one to follow because it is easily recognisable.

If people see this, or any other orca, Ingrid asks that they contact her on 0800 SEEORCA.