A collaborative expedition to investigate oceanic manta ray deaths in migration corridor

We're busy preparing for a collaborative 1,100 nautical mile expedition hosted by Free Range Ocean aboard 50ft sailing vessel FREERANGER will depart Whangārei, Aotearoa New Zealand bound for Nukuʻalofa, Tonga, subject to a suitable weather window around 1 June 2026.

The expedition will support pioneering research by two New Zealand-based marine conservation initiatives, Manta Watch Aotearoa New Zealand and Citizens of the Sea. 

The voyage will follow part of a newly emerging migration corridor for endangered oceanic manta rays between New Zealand and the Southwest Pacific Islands, helping researchers investigate a concerning pattern of manta ray deaths south of the Tonga identified through satellite tagging.

Picture: Manta Watch New Zealand

Along the way, the crew will also collect environmental DNA (eDNA) samples to help build a wider picture of biodiversity across these remote ocean waters. 

Manta Watch Aotearoa New Zealand shines a light on the lives of endangered oceanic manta rays through research, tagging and community sightings.

Over the past six years, Manta Watch NZ’s small research team led by Lydia Green has helped uncover groundbreaking data about this lesser-known manta population, including evidence that Aotearoa serves as an important feeding and breeding ground for oceanic manta rays. 

These animals biannually migrate between Aotearoa New Zealand and the Southwest Pacific Islands, travelling further and diving deeper than any other manta population are known to do - redefining what was thought possible for the species. 

But the discoveries have also revealed a growing crisis. Using satellite tagging technology, researchers have identified a concerning pattern of manta ray deaths occurring south of Tonga. 

The expedition will follow the migration route travelled by Aotearoa New Zealand’s oceanic manta population to investigate what threats the animals are encountering and why mortalities occur as they traverse multi-jurisdictional fisheries and high seas regions. 

The research will contribute to ‘blue corridor’ initiatives, which aim to create greater protections for migratory ocean species. Researchers hope the expedition will strengthen the scientific case for international marine protections across the Southwest Pacific and help prevent the extinction of one of the ocean’s most enigmatic species.

“Not many people know that we have Oceanic Mantas in New Zealand,” says Manta Watch NZ founder and marine biologist Lydia Green. “These seven-metre giants have been quietly moving through our waters for generations. But we are seeing signs that these incredible animals are dying outside of New Zealand waters. We need to understand what is happening out there and what is driving these deaths before it is too late.”

Picture: Citizens of the Sea

Citizens of the Sea is building a global picture of ocean biodiversity through sailor-collected eDNA samples. By collecting tiny traces of genetic material shed by marine life into the water, the project is helping reveal what lives beneath the surface of some of the world’s most remote and under-sampled ocean regions. 

For sailors, the method is simple but powerful: collect a water sample on passage, filter it using a field kit, and return it for laboratory analysis. For researchers, the resulting data can provide a snapshot of biodiversity across vast bluewater routes that are rarely surveyed by conventional science.

During the expedition, the crew of FREERANGER will collect eDNA samples along the route from New Zealand to Tonga, contributing to a growing dataset that can help identify species presence, biodiversity patterns and potential ecological change across the Southwest Pacific. 

“This season we have a record number of crews collecting samples from across the Southwest Pacific. It’s growing year on year and the project has become a flagship example of people-powered ocean science: practical, scalable and designed for participation by the cruising community,” says Citizens of the Sea Operations Manager Erin Bomati. “By enabling sailors to gather meaningful scientific samples while already at sea, we’re helping turn bluewater passages into opportunities to expand ocean knowledge in places where research vessels cannot always go.”

Picture: Jadamama Crew 2025 Citizens of the Sea

The ocean remains vastly under-observed, especially across remote bluewater routes where marine life, island nations and sailing vessels are already connected by movement. S/V FREERANGER, the 50ft sailing vessel owned and operated by Free Range Ocean founders Duncan Copeland and Larissa Clark, was connected with the manta research team through The International SeaKeepers Society’s DISCOVERY Programme, which links privately owned vessels with participating scientific initiatives as part of its wider mission to advance oceanographic research at sea.

For this expedition, FREERANGER is being used as a shared platform to bring researchers, conservation initiatives, storytellers and sailors together — gathering useful data, sharing knowledge and demonstrating how ocean passages can contribute to real-world marine protection.

Free Range Ocean also hosts a free, open-access Ocean Citizen Science Directory, helping sailors, coastal communities and other ocean users find credible projects they can support around the world.

During the passage, the crew will contribute to additional ocean citizen science initiatives, including offshore observations and other wildlife observation reporting.

“This expedition brings science, storytelling and seamanship together aboard one moving platform,” said Larissa Clark, co-founder of Free Range Ocean and first mate aboard FREERANGER. “It shows how a relatively small ocean-going sailing vessel can help connect local conservation initiatives, marine researchers, storytellers and communities - and turn a passage into something useful for the ocean. We hope it proves valuable for ocean research and also encourages more sailors to see their own voyages as opportunities to contribute.”

“As skipper, my first responsibility is to get the team safely along this route, but the wider purpose is to help document a part of the ocean where important things are happening and very few people are watching,” said Duncan Copeland, FREERANGER skipper and Free Range Ocean co-founder. “After more than 20 years working in international fisheries monitoring and enforcement, I know how difficult it can be to understand what is happening across remote, multi-jurisdictional waters. If oceanic manta rays are dying south of Tonga, as the tagging data suggests, better information is urgently needed about the conditions and pressures they may be encountering there. Sailing vessels cannot replace dedicated research ships, but they can add huge value by putting experienced eyes, useful tools and credible observations into places that are otherwise rarely seen.”

Environmental scientist and award-winning photographer and filmmaker Sam Campbell will join the crew as expedition storyteller, documenting the science, scale and human experience of the journey and helping translate the research into visual stories for public, media and partner audiences.

The expedition is recognised as a SeaKeepers DISCOVERY Programme expedition and is connected to Free Range Ocean’s partnership with Island Cruising Pacific Rally 2026, which is helping bring citizen science and practical environmental guidance to cruising boats heading into the Pacific Islands. It forms part of Free Range Ocean’s wider UN Ocean Decade-endorsed work to increase participation in ocean citizen science.

“Private vessels represent an untapped resource for advancing marine science and conservation efforts. When vessel owners partner with research organizations, their boats become floating laboratories that can access remote areas and contribute valuable data to our understanding of ocean health.”- Melissa White, Director of South Pacific for The International SeaKeepers Society.

The voyage is expected to be at sea during UN World Ocean Day on 8 June 2026, putting its message of ocean action into practice in the bluewater itself.

The expedition is made possible through volunteer effort, in-kind contributions and support from Another World Adventures, This Chapter PR and the Manta Watch New Zealand crowdfunding community.

The 1,100 nautical mile voyage to Nuku’alofa, Tonga, via Minerva Reef, is the first leg of Bluewater Pathways 2026, a Free Range Ocean expedition series that explores the living routes that connect ocean life, island nations and citizen science across the Southwest Pacific.

After Tonga, FREERANGER will continue through the Southwest Pacific, with further Bluewater Pathways activity being planned for Fiji, Vanuatu, New Caledonia and Australia between May and November 2026.

For more information contact us on: hello@freerangeocean.org

Read more about the plans here: https://www.freerangeocean.org/post/south-pacific-expedition-2026-beneath-the-surface-of-a-bluewater-corridor