An international research crew is scheduled to arrive at Great Barrier Island this afternoon to investigate ocean plastic pollution, viewing the island as a key catchment area for mainland waste.
The voyage, organised by the UK-based nonprofit eXXpedition, departed Westhaven Marina in Auckland early this morning aboard the 70-foot sailing ketch Windshift.
The vessel is bound for Aotea, followed by the Bay of Islands and Tonga.
It is the only New Zealand departure among ten planned global missions over the next 18 months.
The 10-woman crew, led by Rowan Henthorne, includes international scientists, educators, a professional maritime crew, and an Auckland student.
The primary mission is to map plastic pollution back to its land-based sources to inform local policy.
Henthorne said the stop at Great Barrier Island is a critical part of their research.
The crew will partner with Sustainable Coastlines New Zealand to conduct a local cleanup and analyse the collected debris.
“The way that the prevailing winds and the currents come out of the Hauraki Gulf mean that actually a lot of the waste that’s coming from Auckland actually travels through,” Henthorne said.
“Great Barrier Island actually almost acts a bit like a land net in terms of catching the items that are drifting in the currents out of the Gulf. So it will be really, really interesting to see what we find there.”
The crew uses a surface-gliding device called a manta trawl to collect plastic fragments from the water.
These fragments are then analysed using an FTIR machine on board to determine their polymer type and chemical degradation.
“It sends a signal into the plastic and then we can figure out which fragments, what kind of plastics they are and what materials and what items they may have come from,” Henthorne said.
“We might get a signal that says that plastic has become oxidised. And that’s an indication that it’s been in the water for a long time and been weathered, whereas newer pieces of plastic would come up as primarily just their polymer type.”
By distinguishing between fresh runoff and weathered ocean plastics, the expedition aims to provide evidence that drives practical solutions.
Henthorne noted a previous expedition in Antigua traced paint and resin chips in the water directly back to local boatyards, informing new maritime waste management policies.
The volume of ocean plastic has grown exponentially since Henthorne previously crossed the North Pacific in 2018.
“It’s quite staggering to think about the amount of plastic pollution we saw there and that’s only increased tenfold in that time,” she said.
“It’s more important than ever to be providing the data and the evidence needed to help areas find local solutions to plastic pollution.”
All data collected by the Windshift crew is uploaded in real time to the Marine Debris Tracker website.
The information is open-source and synthesised by the University of Georgia to assist local partners in environmental planning.
