Key Facts:
- millions of people across the Pacific depend on tuna for food, jobs and national income, with ocean sensors now helping fishers understand the changing conditions that affect where tuna are found.
- temperature sensors attached to commercial fishing gear measure temperatures hundreds of metres below the ocean surface, providing data from depths satellites cannot observe.
A UNSW-led partnership is using ocean temperature sensors to help Pacific fishers navigate changing tuna behaviour, while providing vital data for fisheries management and climate forecasting.
Across the Pacific, millions of people depend on tuna for food, jobs and national income. As climate change alters ocean temperatures, however, the fish are shifting, creating growing uncertainty for the communities and economies that rely on them.
Now, a UNSW Sydney-led research program is helping Pacific nations adapt by turning commercial fishing vessels into ocean observing platforms.
The Integrated Marine Observing System and Fishing Vessels as Ships of Opportunity Observing Program (FishSOOP), led by UNSW, works with the commercial fishing industry to gather invaluable ocean observations.
Commercial tuna fishing vessels are equipped with Moana temperature sensors attached directly to nets and lines which automatically measure subsurface ocean temperatures, as the gear is used during normal fishing operations.
Following the program's success in Australian waters, FishSOOP is expanding its reach to work with fishing vessels in the Pacific through a partnership with SPC (the Pacific Community) recognising the critical importance of tuna fisheries to Pacific Island nations.
"Tuna fisheries are critical to the region's economy, food security and livelihoods. However, tuna stocks are increasingly under threat from climate change, which is expected to alter their distribution and abundance, creating uncertainty for communities that depend on them," said Professor Moninya Roughan, an oceanographer from UNSW.
"Because tuna is such a priority across the Pacific, SPC immediately recognised the potential for this program to make a real difference.
"By partnering with the Pacific tuna fleet to collect ocean observations, including temperature data, the program will improve understanding of changing ocean conditions, support better fisheries management, strengthen climate forecasting such as El Niño and extreme weather events, and ultimately help protect the livelihoods of people across the Pacific."
Looking beneath the surface
Although oceans cover more than 70% of the Earth's surface, it remains remarkably under-observed.
Prof. Roughan said that while satellites provide invaluable information, they only measure temperatures in the ocean's top centimetre, while commercially important fish such as tuna live hundreds of metres below the surface.
"Satellites tell us what's happening at the surface, but that's not necessarily what's happening where the fish actually are.
"Commercial fishing vessels, however, travel these waters every day and, if appropriately instrumented, can fill these gaps. Unlike traditional research vessels, which are expensive and can only survey limited areas for short periods, fishing vessels can routinely collect observations across vast areas while carrying out their normal operations," Prof. Roughan explained.
The sensors record temperature, pressure, location and time as fishing gear moves through the water. Within minutes, the information is transmitted via satellite, processed automatically and returned to participating fishers. This can inform the operations of the fishing vessel while also making information available to improve fisheries management and understanding of changing ocean conditions.
Each time fishing gear is deployed, Moana sensors collect temperature data that helps Pacific fishers understand conditions hundreds of metres below the surface. Temperatures at depths of 200-400 metres can differ from surface temperatures by 3-5°C, and fishers are using this information to identify cooler water and temperature gradients associated with better fishing conditions.
"It is giving fishers visibility into conditions they previously couldn't see, effectively helping them to stop 'fishing in the dark'," Prof. Roughan said.
"Some Pacific fishing companies have found the data valuable enough to request sensors for additional vessels or purchase their own equipment. This industry co-investment is an encouraging indication that fishers see practical value in the observations."
Better forecasts, safer communities
The benefits extend well beyond fisheries.
Ocean observations collected by FishSOOP are shared in real time through the World Meteorological Organization's Global Telecommunication System, making them immediately available to forecasting agencies around the world.
Those observations improve estimates of subsurface ocean heat, a critical factor in predicting tropical cyclones, marine heatwaves, ocean circulation and climate variability.
"Getting better information about ocean heat content improves our ocean and atmospheric models," Prof. Roughan said.
"That ultimately improves forecasts of tropical cyclones, storms and drought, helping communities prepare for extreme weather."
The data also help researchers better understand marine heatwaves and coastal ocean processes, while fisheries managers can combine ocean observations with catch information, where fishers choose to share it, to better understand how changing ocean conditions affect fish stocks.
Built on trust
One of the project's greatest successes has been the relationship between scientists and fishers.
Rather than simply collecting data from industry, the program was designed so participating fishers receive the information first, allowing them to better understand the ocean conditions influencing their catches.
Prof. Roughan said the approach has created genuine trust.
During a visit to Papua New Guinea, she found herself aboard a fishing vessel with a Filipino captain, a Korean fishing master, Papua New Guinean fisheries staff and observers, and colleagues from SPC based in the Solomon Islands and New Caledonia.
One Filipino captain pulled out a folder containing printed ocean temperature reports generated by the program and showed them to another fisher.
"I couldn't understand what they were saying," Prof. Roughan said. "But when they'd finished talking, the other captain gratefully took the equipment and installed it on his own vessel.
"It was a powerful reminder that the program's greatest advocates had become the fishers themselves. They're using the data. They expect the data. If they don't receive it, they contact us.
"They really care about the ocean because their livelihoods depend on it. They also have an extraordinary depth of knowledge about the relationship between ocean conditions and their catch. Bringing that knowledge together with science makes both stronger."
From curiosity to global impact
Prof. Roughan admits the project began with a simple research problem.
"I actually started it because I needed more observations for my own coastal ocean research."
Today, the program supports commercial fishers, fisheries managers, weather agencies and scientists, while contributing to improved climate and ocean forecasting across the Pacific.
Since launching in 2017, the international network has grown from a handful of vessels in Australia and New Zealand to around 500-600 commercial fishing vessels operating across the Western and Central Pacific, the Indian and Southern Oceans, Brazil and Canada. The network also has collaborators in Europe, the USA, Caribbean and Africa doing similar work as part of the Fishing Vessel Observation Network.
Professor Roughan believes this is only the beginning.
"The vision is a truly global network of 10,000 commercial fishing vessels helping us better understand the ocean, and ultimately, helping communities everywhere that depend on it."
