The ear bones from two whales stranded in the Far North are being examined by an expert to see if seismic testing caused the marine mammal deaths.
At least four whales have stranded on Far North beaches in the past six weeks, raising concerns from hapu and environmentalists that sonar and seismic surveying for oil and gas off Northland's west coast could have contributed to the deaths.
Members of Ahipara Komiti Takutaimoana extracted the ear bones from a sperm whale that washed up on Ninety Mile Beach on August 13 and a baleen whale that was found at Tauroa (Reef Point) near Ahipara on August 21. A spokesman for the Te Rarawa group said seismic or multi-beam sonic mapping were being undertaken northwest and southwest of Ahipara at the time of the strandings.
The bones were sent to Professor Ewan Fordyce, from the geology department at Otago University, who was to examine them to see if there was any sign of seismic, sonar, or other human intervention that might have caused the deaths. Professor Fordyce said he could have answers by today.
He said it was possible to tell if human factors had impacted on the whales by checking the ear bones, with breaks or fractures tell-tale signs.
Otago University associate professor of zoology Liz Slooten said earlier this year that sonar and seismic surveying for oil and gas off Northland's west coast could lead to more whale strandings and leave some species of whales and dolphins effectively deaf and blind.
Dr Slooten said it might be impossible to say what seismic or sonar testing was being carried out and exactly where because of secrecy surrounding the process.
But, Norwegian oil giant Statoil says while it can't guarantee no whales and dolphins will be harmed when it carries out seismic surveying for oil off Northland's west coast, it has not seen any marine mammal deaths in its 40 years of exploration around the globe.
Statoil is preparing to carry out testing in 9818.88sq km in the Northland Basin after being granted a permit by the Government.
Exploration vice-president Pal Haremo said Statoil took the potential impact on marine mammals seriously and the company followed all international and local regulations wherever it operated.
"We are planning to start acquisition of seismic data in our Northland permit in December 2014. We are conducting a Marine Mammal Impact Assessment (MMIA) covering the licence area. A part of this study is to identify and mitigate risks before we start acquisition."