Recovered fishing buoys send ocean observations from Mozambique
A peer-reviewed pilot study repurposed recovered tuna-fishing buoys as short-term ocean observation platforms off Mozambique. Satellite links carried acoustic measurements to shore, where they were combined with environmental monitoring and diver surveys. The demonstration establishes a working observation stream, while its brief deployments leave ecological baselines and absolute biomass unresolved.
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A second use off Bazaruto
Recovered tuna-fishing equipment supplied ocean measurements during a pilot off the Bazaruto Archipelago, an island group on Mozambique’s Indian Ocean coast. The peer-reviewed study used refurbished buoys with downward-facing echo sounders, which send sound into the water and measure the returning signals. The devices came through ReCon, a recovery programme run by the Spanish marine technology company Satlink. Field deployments took place in 2025, using both anchored instruments and controlled drifting surveys.[1]
Satellite data and diver observations
The combined dataset contained 393 acoustic measurements with timestamps. Depth-layer observations totalled 1,281. Positions and acoustic data travelled by satellite to shore. At the Bazaruto Center for Scientific Studies, a Mozambican marine research centre, the buoy series were aligned with existing weather and ocean measurements. Divers also surveyed large marine animals at the sites. Their observations supplied biological context for the acoustic signals; the surveys did not calibrate those signals into an absolute mass of fish.[1]
Short series captured day and night
Fixed instruments returned acoustic series lasting between 51.5 and 96.2 hours per site. Relative acoustic values were 20–40% higher at night, and the researchers described exploratory coincidences with environmental changes. These short deployments demonstrated that the reused instruments could feed an observatory under remote field conditions. They could not establish a normal ecological baseline, assess reef health or determine fishing impacts. Longer deployments, repeated sampling and independent biological calibration remain requirements for those ecological uses.[1]
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