Whales and the oil and gas industry have co-existed in Taranaki for decades.

Blue whales - the world's largest animal - have been found in abundant numbers in a proposed seabed mining area in Taranaki.

Marine mammal expert Leigh Torres made a presentation to the Environmental Protection Authority (EPA) in Wellington on Wednesday on the results of a recent survey in the South Taranaki Bight, which found a blue whale population of at least 68.

The EPA is meeting to hear arguments for and against an application from miner Trans Tasman Resources (TTR) to mine millions of tonnes of iron sands off the coast of Patea. TTRs first application was rejected in 2014.

SUPPLIED A baby blue whale filmed nursing off the Taranaki coast observed by Leigh Torres and her crew last year was likely a world-first.

Torres, a professor from Oregon State University professor who has carried out research in Taranaki waters in collaboration with the Department of Conservation, said seabed mining will have a severe impact on the whale population in the area.

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* Blue whale research begins off the Taranaki Coast

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* Aerial footage of baby whale feeding in New Zealand waters believed to be a first



"The likely impacts of seabed mining are increased noise in the area, which could seriously affect the whales and their primary prey which is krill," she said.

"The mining will be noisy and whales' hearing is crucial to them, they rely more on it than they do eyesight.

TTR The 66 square kilometres off the South Taranaki coast where Trans Tasman Resources have applied to mine iron ore.

"But it's the sediment created from uplifting the sand that could affect the krill which would in turn affect the whales feeding."

Torres and her team observed 68 individual whales over 32 sightings during nine days this year, more than twice the number of whales they observed last year when they captured world-first footage of a calf feeding from its mother.

Torres said that whales are generally seen by the scientific community as being migratory animals, but her study so far indicates that the population they've been following have made South Taranaki their home.

Trans Tasman Resources/YouTube TTR's project overview video, explaining how the mining will work.

"All we really know for certain at this stage is that the South Taranaki Bight is very important to this population," she said.

"We've observed them surface-feeding but we also hear them through hydrophones calling to each other almost daily. So we know they're there a lot of the time."

Torres said the team had identified mating calls from males which indicated the whales were staying around to breed.

Although TTR has offered certain mitigation strategies to protect the whales, such as deploying its own hydrophones to monitor the population, Torres said it wasn't enough.

"The evidence I've presented at the hearing supports the argument of the opposition to the mining," she said.

"But my own personal opinion is that the mining is not worth the risk to the whales."

Oil and gas activities have operated with the Taranaki region for decades as New Zealand's only oil-producing basin, but Torres feared the effects of adding mining to the mix could do cumulative damage.

This is Trans Tasman Resource's second application to the EPA to mine more than 50 million tonnes of iron-laden sand per year from a 66 square kilometre area off the coast of Patea.

The company's application was rejected in 2014 amid concerns of a lack of knowledge as to the environmental effects of their proposal.

When they applied last year the EPA saw a record number of submissions flood in against the proposal - more than 17,000 - in an effort spearheaded by New Zealand anti-mining group Kiwis Against Seabed Mining.