Study to better understand impacts of wind turbines on marine mammals

A blue whale in South Taranaki Bay.
photo: Photo courtesy of Leigh Torres

• The Taranaki Ocean Partnership (TOP) is deploying three marine mammal detection devices in South Taranaki Bay.
• It will use hydrophones to capture the calls of whales and dolphins
• Data will be used to help better understand the potential impacts of wind turbines on marine mammals in the region
• Dwarf blue whales, blue whales, southern right whales and dolphins can be found in the bay
• TOP wants to build 70 230-meter-high wind turbines
• The plants will produce up to 1 GW of electricity, about 11% of New Zealand’s electricity needs.

Marine mammal detection equipment being deployed in the South Taranaki Bay will capture valuable information about the potential impacts of wind turbines on whales and dolphins, an offshore wind operator says.

The Taranaki Offshore Partnership plans to build 70 turbines in the area and will place three passive acoustic monitoring devices on the seabed for 12 months.

Upwelling currents from the South Island trigger large plankton blooms in South Taranaki Bay, which are fed by several species of whales, and the area is also home to small blue whales.

TOP environment manager Alison Lane said the first-of-its-kind study would allow the joint venture between Copenhagen Infrastructure Partners and the New Zealand Super Fund to better understand baleen whales, or the very large whales, in the bay.

“We want to know where they are so we can do more targeted surveys to understand their behavior, how they use the area, where they are and how many there are.”

Alison Lane, top environmental manager.
photo: RNZ/Robin Martin

The device, which was blessed by members of the Ngāti Ruanui tribe on Thursday, carries a hydrophone that detects the calls of marine mammals, which will be recorded and saved to the ship’s computer to be retrieved when they are raised from the water.

Blue whales, pygmy blue whales and southern right whales are their primary targets, but they also capture the movements of other whale species and dolphins.

Ryan said it’s important work.

“We’re talking about building structures in offshore environments, and when we put equipment in there, that’s obviously going to cause disturbances to other organisms that are there, so it’s really important to understand what’s out there and what the potential impacts might be, and then we can start to design mitigation measures and ways to avoid harm.”

Ryan said a lot of work has been done overseas to mitigate climate change.

“So, during construction, they can look at techniques like creating bubble curtains, air bubble curtains around the construction area, which can attenuate the noise and stop it from traveling further.

“And you can have active tilt devices in the water while construction is going on, so you can detect if a whale or dolphin is approaching the area and slow down or stop construction on site.”

Lane said the distance between any turbines is wide enough so there is no concern that whales won’t be able to move between them.

Tega Ogbuigwe, TOP Development Manager.
photo: RNZ/Robin Martin

Australian company Jasco Applied Sciences is responsible for the equipment deployed by New Plymouth Underwater.

TOP development manager Tega Ogbuigwe said the study was not an example of greenwashing.

“Absolutely not. As part of what we do we care about the environment and we are delighted to be spearheading this unique study, the first of its kind here. It’s all part of really caring about the environment, gathering all the information we need so that the project is fit for purpose for the area and doesn’t damage the environment.”

Ngāti Ruanui tribal member Clive Tongaawhikau, who performed the blessing, said the tribe was still considering the merits of offshore wind.

“I’ve been in some of the meetings and to be honest I think there’s a mix of opinions, but we’re sitting down and having healthy conversations so once we get out of this we’ll have a clearer picture because there’s no clear insight right now because there’s still a yin and yang to this whole thing. Some people think this is going to add value.”

This pilot study will help provide more clarity on this situation.

“Of course, that’s why I’m here. If I thought it was something sinister, I wouldn’t be helping. I believe in my heart that these people are putting this together to see what’s happening to the tamariki and mokopuna in Tangaroa, and that’s a good thing.”

Ngāti Ruanui tribal member and South Taranaki District MP Clive Tongaawhikau blesses a Jasco marine mammal monitoring device at Underwater’s Moturoa headquarters in New Plymouth.
photo: RNZ/Robin Martin

TOP believes its $50 billion project could eventually generate up to 1GW of electricity, meeting about 11% of New Zealand’s electricity needs. The project is expected to create 2,000 jobs during the construction phase and 150 permanent local operations and maintenance positions.

If the regulatory environment permits, the partnership hopes to begin a three- to four-year construction and commissioning phase in 2030.

TOP is not the only company to have expressed interest in building an offshore wind farm in the South Taranaki Bay, with BlueFloat Energy and Wind Quarry Zealandia also involved in the region.