E/V Nautilus Begins Final 2026 Expedition to Unsurveyed Deep-Sea Habitats Near Hawaii
The Ocean Exploration Trust's research vessel has embarked on a 20-day mission to map never-before-seen ridges and seamounts in the Papahānaumokuākea National Marine Sanctuary.
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On September 22, the Ocean Exploration Trust’s Exploration Vessel (E/V) Nautilus set sail on a 20-day expedition to explore previously unsurveyed deep-sea habitats around the Hawaiian Islands and within Papahānaumokuākea National Marine Sanctuary. This is the final expedition of the 2026 season, and it targets two distinct regions: the eastern portion of the sanctuary itself, and abyssal plain habitats lying southwest of the Main Hawaiian Islands.
The mission will employ a standard suite of deep-ocean tools: a remotely operated vehicle for close-up inspection and sample collection, multibeam seafloor mapping to build high-resolution bathymetric charts of the terrain, and telepresence systems that let scientists on shore participate in real-time decision-making. What distinguishes this particular expedition is the target geography—never-before-seen ridges and seamounts that have sat below the surface without systematic survey, in a region where even basic depth data can be decades old.
The Papahānaumokuākea Marine National Monument is one of the largest protected marine areas on Earth, stretching across more than 1.5 million square kilometers of the central Pacific. Its deep waters and isolated seamounts create habitats that remain poorly understood—ecosystems that may host species found nowhere else, adapted to conditions of permanent darkness, crushing pressure, and chemical regimes that differ sharply from surface waters. The eastern portion of the sanctuary, where Nautilus will focus part of its effort, represents a transition zone between the better-studied main islands and the vast protected expanse to the northwest.
The expedition also carries a new piece of equipment: a Quokka eDNA sampler from the Australian National Science Agency, which Nautilus Live notes will be deployed during the mission. Environmental DNA sampling collects genetic material shed by organisms into the water column—fragments of skin, scales, waste, and other trace materials—allowing researchers to detect species presence without physical capture. For deep-sea work, where animals may be sparse and some are fragile enough to be damaged by traditional collection methods, eDNA offers a way to build species inventories that complement what ROV cameras can observe directly.
The abyssal plain habitats southwest of the main Hawaiian chain present a different set of questions. These are flat, deep seafloor regions lying at depths of 3,000 to 6,000 meters, far below the reach of sunlight and largely shaped by sediment deposition from above. What life exists there, and how it is distributed across apparently featureless terrain, remains an open question. Seamounts rising from these plains can create localized upwelling and current patterns that concentrate nutrients, making them biological hotspots in an otherwise sparse environment—exactly the kind of feature that systematic mapping is designed to locate.
By the time Nautilus returns, the 2026 season will be complete. The data collected—bathymetric maps, video surveys, physical samples, and genetic records—will feed into ongoing efforts to understand how deep Pacific ecosystems are structured, how they connect to one another, and what might be required to manage them as human pressures extend even into these remote depths. For a region that has been protected on paper for years, the expedition represents a step toward understanding what that protection actually encompasses.