Photograph proof of whale's journey

A chance photograph taken by the public has helped researchers show a southern right whale has travelled more than 600km from the Auckland Islands to Coastal Otago in a few weeks.

It is the first time researchers have been able to show photographically that a southern right whale travelled from the subantarctic to mainland New Zealand.

University of Otago marine science research fellow Dr Will Rayment said hopefully this match was the tip of the iceberg, as work had just begun developing a catalogue of southern right whale photographs.

Ultimately, the catalogue would log each whale and its history.

So far, more than 25,000 photographs have been taken during more than four years of research.

The whale photographed by Mark Stevenson off Blackhead on August 21 was identified quickly because of its distinctive pale mottled appearance, he said.

Most of the whales are dark grey.

It had been photographed by researchers in the Auckland Islands on August 5.

Initial indications from that trip showed the population was healthy and growing in the islands, so proof they were visiting the mainland gave impetus to the work scientists were doing on habitat, Dr Rayment said.

"If we know the same whales prefer the same habitat, then the work we are doing down there is really relevant to what is happening on the mainland."

Doc marine ranger Jim Fyfe said the match was quite significant and highlighted the value of people photographing and reporting sightings of the whales.

To report a sighting of a southern right whale call 0800 362-468.