The largest and most ambitious marine fieldwork season ever undertaken in the New Zealand subantarctic is providing valuable insights on the vulnerable native species living there.

The Department of Conservation (DOC) has wrapped up a bumper summer field season where for the first time, rangers, scientists, independent researchers and other staff were stationed on all five of the remote subantarctic island groups – Bounty Island, Antipodes Island, Snares Island, Auckland Islands and Campbell Island.

DOC Marine Bycatch and Threats Manager Kris Ramm says much of the work focused on filling knowledge gaps for species as well as maintaining and fixing important field infrastructure.

“The subantarctic islands are remote and hard to reach; undertaking work down there requires a lot of careful coordination. Things such as the COVID-19 pandemic, Cyclone Gabrielle and other external factors have all impacted our work programme on the islands in recent years, so we’re thrilled to have been able to complete successful trips to each of these islands this year.”

New Zealand’s subantarctic islands represent one of the last great wildernesses anywhere in the world and are located hundreds of kilometres to the south and southeast of the mainland. They are home to a range of rare species, such as Antipodean and Gibson’s albatross, which breed nowhere else on earth. The islands are managed by DOC as national nature reserves, the highest possible conservation status. They have also been honoured with World Heritage status, meaning they represent the best of the world’s natural heritage and rate alongside the Grand Canyon and Mount Everest.

The research and monitoring programme will help us to understand the health of vulnerable native species such as hoiho/yellow-eyed penguin, New Zealand sea lion/pakake/whakahao, Gibson’s and Antipodean albatross/toroa and other seabirds, Kris says.

“For many of these species, the subantarctic region represents their last stronghold. It’s important we understand the threats and challenges they face so we can better focus our efforts.

“Some of the research programmes such as the Antipodean albatross work, have been going on for decades. That’s a lot of useful data chronicling the health of a species and gives such a valuable insight into how we can better advocate for them and other species when they’re traversing international waters.”

While it will take some time for the full suite of monitoring data to be analysed from the season, so far there are some trends emerging, Kris says.

“The number of sea lion pups born on the Auckland Islands had a slight increase from the extraordinarily low year last year, but not to the extent we would have expected. On Campbell Island, pup mortality continues to be high with up to 89% of sea lions dying in their first few weeks of life. While the precise reasons for this remain unclear, many pups on Campbell Island appear to die of a combination of exposure and starvation.”

The number of southern royal albatross also appears to have declined. Teams are still working through exact population estimates, Kris says.

Teams were also getting samples for baseline monitoring of wildlife health, which Otago University are testing for pathogens including avian influenza viruses.

Highly pathogenic avian influenza (HPAI) has not been detected in the New Zealand subantarctic region or Oceania, including New Zealand, Australia and the Pacific. However, it has been reported on islands in the subantarctic Atlantic Ocean and the Antarctic Peninsula in recent months.

Alongside the species work, teams of rangers were also undertaking repair work to key field infrastructure such as roofs and boardwalks and building maintenance.

It takes a lot of people and coordination to pull off a field season in an area as remote as the New Zealand subantarctic, and it was great to have the support of so many, Kris says.

“The season was challenging with strong winds, rain and low cloud. Despite this, across many different teams -- from those undertaking field maintenance, to biosecurity checks before departure, to those out collecting wildlife data, and of course the skipper and crew of the transport vessel, Evohe -- it’s been a huge effort.”

This marine programme is largely funded by fisheries levies through the Conservation Services Programme with the aim of monitoring the impact of commercial fishing on native species and identifying ways to mitigate this impact.

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