A major international ocean-science expedition has begun across the Pacific Ocean, bringing together researchers from Australia and Pacific nations to investigate how the ocean is changing and how those changes could affect climate, ecosystems and communities.

The research voyage aboard Australia’s RV Investigator began on September 27, 2026, and is scheduled to continue until December 16. The expedition will travel from Lautoka in Fiji toward Wellington and ultimately Hobart, conducting measurements across a large section of the Pacific Ocean.

Survey From the Equator to the Antarctic

The expedition will follow a transect along approximately 170°W, extending from the tropical Pacific toward the Antarctic ice edge.

Scientists will conduct measurements from the ocean surface to its deepest layers, examining physical, chemical and biological conditions.

The region is particularly important for climate research because the western Pacific is experiencing significant changes associated with warming oceans, ocean acidification and Antarctic ice loss.

At the same time, large parts of the region remain relatively poorly observed compared with some other parts of the world’s oceans.

Measuring Ocean Change

One of the primary objectives is to determine how the ocean’s physical and chemical properties are changing.

Researchers will collect information on temperature, salinity, carbon-related processes, nutrients and biological conditions.

These measurements can help scientists understand how heat and other properties move through the ocean and how the marine environment responds to a changing climate.

The observations will also contribute to long-term datasets used to assess climate trends.

Improving Climate Models

The expedition is expected to provide information that can improve global climate models.

Ocean observations are particularly important because the ocean absorbs and stores large amounts of heat and carbon.

Better measurements can help scientists improve estimates of how the climate system is evolving and strengthen regional projections.

The data collected during the voyage will contribute to global climate research, including information relevant to IPCC assessments.

Pacific Researchers Take Part

The expedition also has a strong capacity-building component.

Four early-career Pacific researchers, including two from Fiji, are joining the voyage through partnerships involving the Pacific Community and the Partnership for Observation of the Global Ocean.

They will gain practical experience in ocean observation, scientific research and data collection.

The programme is intended to help strengthen long-term scientific capability within Pacific island nations that face significant climate-related risks.

70 Science Participants

The voyage includes approximately 70 science participants across its two legs, along with additional ship crew.

Researchers and specialists from more than 15 institutions worldwide are participating.

The multidisciplinary nature of the expedition allows scientists working in different fields to collect complementary observations during the same voyage.

Climate Risks for Pacific Communities

Pacific island countries are particularly exposed to climate-related changes.

Rising sea levels, warmer oceans, changes in rainfall and shifts in extreme weather can affect infrastructure, water supplies, fisheries, agriculture and coastal communities.

Better information about ocean conditions can help Pacific countries strengthen climate adaptation planning and make decisions about infrastructure and marine-resource management.

The research therefore has practical relevance beyond the scientific community.

Looking Beneath the Ocean Surface

A major feature of the expedition is the collection of full-depth measurements.

Scientists will examine conditions from the surface down through deep-ocean waters.

This is important because climate-related changes are not restricted to the ocean surface.

Heat, freshwater and chemical changes can move through different layers of the ocean, influencing circulation and marine ecosystems.

Long-term measurements help scientists identify changes that may otherwise be difficult to detect.

Additional Climate Research

The voyage also includes projects examining atmospheric and biological processes.

One project is developing an automated seabird-detection system that can operate aboard the research vessel.

Another will study clouds, precipitation and atmospheric chemistry across the southern Pacific.

Together, these projects will provide information about interactions between the ocean, atmosphere and marine ecosystems.

Building Long-Term Ocean Records

The 170°W route has been surveyed previously, including by research vessels in 2001, 2009 and 2016.

Repeating measurements along similar routes allows scientists to compare current conditions with historical observations.

Such repeated observations are particularly valuable for identifying long-term changes rather than short-term fluctuations.

A Critical Climate Dataset

The latest expedition comes as the Pacific faces increasingly important climate challenges.

Ocean warming, acidification and changes in ice conditions are affecting the broader climate system and marine environments.

The new observations will provide scientists with additional evidence for understanding these processes.

For Pacific nations, the information could also support planning for future climate risks.

The Research Continues Through December

The voyage is scheduled to continue for almost three months, with the first leg running from Fiji to Wellington before the vessel continues toward Hobart.

Scientists will collect and process observations throughout the expedition, while the final research outcomes are expected to be published several months after the voyage is completed.

The expedition represents a major investment in understanding the changing Pacific Ocean and its role in the global climate system.

By combining deep-ocean measurements, climate observations and participation from Pacific researchers, the mission aims to strengthen both scientific knowledge and the region’s ability to prepare for a changing climate.