Shooting at blue whales from a small boat to obtain tissue samples was one of the tasks for Nelson-based marine scientist Carlos Olavarria in a breakthrough research voyage to the Ross Sea earlier this year.
The seven-week voyage, run by the Antarctic Blue Whale Project, was undertaken by the Nelson deepsea trawler Amaltal Explorer, which carried an 18-strong international science team.
The ship was chartered by the Australian Government and scientific co-ordinator Victoria Wadley described the expedition's results as "successful beyond our wildest dreams".
It was the first time acoustic science has been used to track vocalising whales and the team was delighted with the progress made in surveying the population of the world's largest animal, and the largest to have ever lived.
Dr Olavarria, who was on board as an observer, photographer and sampler, is to describe the voyage in an illustrated talk for the Nelson Science Society on Tuesday night.
He said his observer role was spotting whales from the ship's upper bridge, using special binoculars and angle boards so they could be tracked. As photographer he took pictures so that the whales could be individually identified through their distinctive pigmentation patterns near the dorsal fin.
"As sampler my work involved the collection of small pieces of skin for genetic analyses, using a dart propelled by a modified rifle, which floats in the surface of the water after hitting the whales and bouncing back."
The acoustic techniques enabled scientists to track the whales at long distances, sometimes hundreds of kilometres, reducing search time and producing much greater data than before.
He would use pictures, video and graphics in his presentation, which would review the history of blue whale exploitation in Antarctica, highlighting the specie's conservation values, and describe the survey, Dr Olavarria said.
"Finally I'll talk a bit about New Zealand blue whales."
It is estimated that up to 300,000 blue whales were killed during the commercial whaling area, with the population reduced to between a few hundred and a few thousand.
It remains on the critically endangered list.
The expedition, which ended in mid-March, obtained tissue samples from 23, and established photo ID for 57.
The talk is on Tuesday night at 7.30pm in room A211 at NMIT, with access off the Alton St carpark. All welcome. Non-members $2.
- © Fairfax NZ News