This article was first published by RNZ
- Taranaki Offshore Partnership (TOP) is deploying three marine mammal detection devices in the South Taranaki Bight
- It will use hydrophones to capture whale and dolphin vocalisations
- Data will be used to help better understand potential impact of wind turbines on marine mammals in the area
- Pigmy blue whales, blue whales, southern right whales and dolphins are present in the Bight
- TOP hopes to build 70 wind turbines standing 230m tall
- They will generate up to 1GW of power, about 11 percent of New Zealand’s electricity needs
Marine mammal detection devices being deployed in the South Taranaki Bight will capture valuable information about the potential impact of wind turbines on whales and dolphins, an offshore wind energy operator says.
Taranaki Offshore Partnership - which wants to build 70 turbines in the area - is positioning three Passive Acoustic Monitoring devices on the seabed for 12 months.
An upwelling of currents from the South Island triggers plankton blooms in the South Taranaki Bight which a variety of whales feed on, and there is resident population of pygmy blue whales.
TOP environmental 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 the baleen whales - the really big ones - present in the bight.
“We want to know where they are, so that we can then develop some much more targeted surveys to understand their behaviour, how they use the area, where they are and how many there are.”
The devices, which were blessed by Ngāti Ruanui iwi members on Thursday - carried hydrophones to detect vocalisations from marine mammals that would be recorded an held in onboard computers and retrieved when they were brought to the surface.
Blue whales, pygmy blue whales and southern right whales would be their principal target, but the activity of other whale species and dolphins would also be captured.
Lane said it was important work.
“We are talking about building structures in the offshore environment and there’s obviously going to be disturbance to other life there when we put the gear in, so it’s really important to understand what’s there and what potential impacts might be, and then we can begin to design mitigation measures and ways to avoid harm.”
A lot of work had been done around mitigation practices overseas, Lane said.
“So, say during construction they can look at techniques like creating bubble curtains, air bubble curtains, around the construction area and what that does is it attenuates the noise, so it stops the noise propagating nearly as far.
“And you could have active listing devices in the water at the time [of construction] and that would detect if whales or dolphins were approaching the area, so then work on the site could be slowed or shut down.”
Any turbines would be spread wide enough apart that there was no concern whales could not move between them, Lane said.
Australian company Jasco Applied Sciences was responsible for the devices which were being deployed by New Plymouth Underwater.
TOP development manager Tega Ogbuigwe said the study was not an example of greenwashing.
“Absolutely not. As part of our work we care for the environment and we’re pleased to be pioneering this one of a kind study, first such study here. This was part of really caring for the environment, gathering all the information we need, so that this project is fit for purpose for the area and not damaging the environment.”
Ngāti Ruanui iwi member Clive Tongaawhikau, who carried out the blessing, said the iwi was still considering the merits of offshore wind.
“I sit in some of those hui and I think there is a mixed view to be honest, but we are sitting and talking and we have good healthy conversations, so once we come out of that we’ll have a clearer view because there’s no clear insight yet because there’s still a ying and yang about the whole thing. Some people think it will add value.”
The pilot study would help make that picture clearer.
“Absolutely, that’s why I am here. If I thought it was something sinister I wouldn’t be helping this. I believe in my heart these people are putting this together to have a look at what’s happening out there for the tamariki and mokopuna of Tangaroa, and that’s a good thing.”
TOP believed its $50 billion project could eventually generate up to 1GW of power and provide about 11 percent of New Zealand’s electricity needs. It was projected to create 2000 jobs during the construction phase and 150 permanent local operational and maintenance positions.
The partnership hoped to begin a three to four year construction and commissioning stage in 2030, regulatory environment permitting.
TOP was not the only company expressing interesting building offshore wind capacity in the South Taranaki Bight, with BlueFloat Energy and Wind Quarry Zealandia also involved in the area.
By Robin Martin of RNZ