Scientists Survey Fiordland Waters For Microplastics & Marine Invasive Species

On Saturday October 16th, 2021, an interdisciplinary team of marine scientists returned from a week-long research expedition and sampling cruise in Fiordland / Te Moana o Atawhenua onboard MV Strannik of Strannik Ocean Voyages sailing out of Milford Sound.

The work involved surface tows using a manta trawl for microplastics and a modified cruising speed net to collect eDNA (environmental DNA) samples, and oceanographic measures of temperature, salinity, turbidity and depth. Searching for microplastics is a world first in Fiordland, and as Aotearoa New Zealand is dealing with more marine invasive species, this work will also support the detection of opportunistic invasive species such as the nuisance macroalga Undaria pinnatifida.

Surveys took place in Milford Sound, Bligh Sound, George Sound and the coastal area of the Tasman Sea in favourable weather. The overall objective was to identify a baseline as nobody has ever monitored these waters for microplastics, and there is lack of information on potential marine pests in that area. The team was composed of scientists from Blue Cradle, the Cawthron Institute, the Institute for Environmental Scientific Research (ESR), the University of Otago, and hosted a teacher from Fiordland College, recommended by Fiordland Marine Guardians. Working under two Ministry of Business, Innovation and Employment (MBIE) funded Endeavour Programmes, Marine Biosecurity Toolbox and Aotearoa Impacts and Mitigation of Microplastics (AIM2), this expedition was the second coordinated under Blue Cradle’s overarching objective to make these expeditions more accessible and inclusive for the community, working with schools, iwi and other relevant institutions.

Blue Cradle had organised several outreach events for this expedition, in close coordination with the local community in Te Anau, but unfortunately due to Covid level 2 restrictions all these events have been cancelled. Future outreach is planned later in 2022, to showcase early results and provide ocean literacy educational opportunities for the local community.

James Nikitine, Founding Director of the Blue Cradle Foundation: “Te Moana o Atawhenua / Fiordland is a truly unique and magical place, a treasure not only for Aotearoa New Zealand but for the world. Knowing that we can impact the marine environment here, by our human actions, is a scary thought. Microplastics are definitely in the ocean, and the water in the ocean circulates a lot. This mission is fundamental to find out if they’re in Fiordland, and if so, help understand where they come from. As for Undaria and other marine invasives, we need to develop early warning systems, and eDNA tools are becoming more and more easy to use and efficient. Finally, we are committed to the community here as we’ve been welcomed. We want to bring this knowledge to the youth / rangatahi of the region. We’ll be back here with early results and outreach activities."

Dr Olga Pantos, Senior Scientist at the Institute of Environmental Science and Research (ESR), and co-lead of the national AIM2 (Aotearoa Impacts and Mitigation of Microplastics) project joined the team to examine the presence of microplastics in the surface waters.

Two of the objectives of the AIM2 project are to examine the levels of microplastics in Aotearoa’s environments and the potential impacts that they pose. This expedition brought those 2 things together in one place, as one of the risks posed by marine plastics is the transport of non-indigenous species into areas they ordinarily wouldn’t get to if they were attached to natural materials due to the high resistance and lightweight nature of plastics - two of the two properties that have made plastics so successful and pervasive in our environments. Pantos says that “this work was of particular importance in this area of Aotearoa which is considered remote and fairly untouched by human activity. However, finding pieces of plastic floating in the surface waters - just the ones we could see with the naked eye - really brings home that there is no ecosystem now untouched by our plastic footprint. Seeing these pieces and then within hours seeing pods of humpback whales playing and feeding in the same area, knowing full well when they take a mouthful they’re also ingesting plastics is heartbreaking”. Although some larger pieces of plastic were seen in the samples when they were collected the focus now is on the lab work required to determine the levels and types of microplastics (<5 mm) that aren’t easily seen.

Dr Anastasija Zaiko and Associate Professor Xavier Pochon, of Nelson’s Cawthron Institute and University of Auckland, joined the expedition in their capacity as senior researchers in the national Marine Biosecurity Toolbox Programme.

Zaiko says the expedition’s goals align perfectly with the Marine Biosecurity Toolbox’s mission to “develop science-based tools and technologies that empower governments, tangata whenua, industry and the public to effectively mitigate biosecurity risks”. During this cruise, our team managed to assemble a ‘floating laboratory’ enabling the near real-time analysis of environmental DNA samples that included the targeted detection of Undaria pinnatifida as well as the DNA sequencing of entire marine communities to get a snapshot of the biodiversity present in these fiords. Luckily, Undaria was not detected in the subset of samples analysed onboard. We are now taking a closer look at the sequencing data to verify whether this or other non-indigenous species occur in the studied area. Our future aspiration is to hand over the operationalized molecular toolkit for routine marine pest diagnostics by biosecurity practitioners, tangata whenua, students and environmental enthusiasts in the region.”
 

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