Reuters A southern right whale, known in Spanish as ballena franca austral, jumps off the water in the Atlantic Sea, offshore Golfo Nuevo, near Argentina's Patagonian village of Puerto Piramides, June 17, 2011.
Blue whales were seriously hunted in the Southern Hemisphere at the height of the whaling period which led to a dramatic population decline.
Scientists from New Zealand's NIWA, led by marine ecologist Dr Leigh Torres, saw the blue whales while on a research expedition in the South Taranaki Bight. The researchers hope to collect data to increase knowledge of blue whale population in the region.
In the past week, the research team has counted 50 blue whales in the area. Dr Torres said it was "exciting" for see the giant sea creatures in New Zealand and start the process of gathering important data.
The scientists were able to identify their blue whales' prey on the surface and beneath the ocean with the aid of hydroacoustics.
In 2013, Dr Torres published a scientific paper exploring the possibility of blue whales foraging ground in the Bight. Her research showed that the blue whale population in the area was greater than previously thought.
According to the Herald, there has been an increasing number of blue whale sightings reported which may be caused by large clouds of plankton coming from a prominent upwelling system. The abundance of plankton in the area may have attracted more blue whales.
Scientists have long thought blue whales were only travelling through New Zealand during migration. Dr Torres explained that blue whales need to consume large amounts of plankton to support their energy needs.
Dr Torres added that there have been confirmed reports of "blue whale foraging grounds" outside of Antarctic waters in the Southern Hemisphere.
Sea Shepherd collides with Japanese whaling ship
Meanwhile, a video of the collision between the anti-whaling ship Sea Shepherd and a Japanese harpoon vessel has been released to the public. Both the Sea Shepherd and the Japanese Institute of Cetacean Research have released footage with statements that the other did it intentionally.
A shipping expert watched the video of the collision and concluded that the encounter was "probably unintentional." Marine risk consultant John Riding analysed both videos and declared the collision was not intentional. Mr Riding, who is based in Wellington, said the videos show a classic example of "interaction."
Mr Riding explained though Radio NZ that when two ships move in the water together, the two hulls may get pulled together as the water passing between the vessels move faster. He pointed out that the Sea Shepherd's hull was clearly sucked in to towards the Japanese ship.
The release of the collision videos came following the Sea Shepherd's accusations against the Japanese whaling ships of launching attacks on Bob Barker and Steve Irwin, both vessels in the Southern Whale Sanctuary on Feb 1.
Australian Environment Minister Greg Hunt has launched an investigation into the collision.
A southern right whale, known in Spanish as ballena franca austral, jumps off the water in the Atlantic Sea, offshore Golfo Nuevo, near Argentina's Patagonian village of Puerto Piramides, June 17, 2011.