About 20 per cent of the global seafood catch is harvested illegally, and now the areas where it is happening can be spotted faster on a that uses satellite radar imagery. The digital map, created by the (GFW) non-profit organisation, is revealing previously undetected fishing fleets operating in coastal waters across the oceans.
Regulations vary by country, but commercial-size vessels must generally have Automatic Identification System (AIS) transponders fitted so they can be tracked. However, those engaged in illegal fishing can simply turn off their AIS so no one knows where they are.
Satellite-based radar can theoretically be used to find ships without their AIS turned on, and in 2020 GFW used satellite data to detect a “dark fleet” fishing in Korean waters. But the large amount of time needed to analyse images meant it was only possible to focus on small areas.
Advertisement
Now, more affordable processing power makes better global oversight possible, says , director of research and innovation at GFW, who has been working with the US Department of Defense’s Defense Innovation Unit (DIU) on the project.
“Instead of asking human beings to look through specific satellite images we think may be important – which may take several hours per image – we can use computer-vision algorithms to look through every single satellite image we record in a matter of minutes,” says  at the DIU.
GFW processed AIS data to get known ship locations, then sifted through petabytes of information from the European Union’s two to extract the signatures of vessels in coastal waters. Comparing the two data sets revealed the areas where vessels are operating “dark” without AIS on. Kroodsma says the limit is the Sentinel satellite sweeps across the globe, which update every 12 days.
“We have processed about six years’ worth of data from Sentinel-1, and, on the map, we are currently showing data from 2022,” says Kroodsma.
The map allows viewers to zoom in on specific areas or see activity by incognito vessels in nearshore waters across the globe on a colour scale. A vessel not broadcasting its position isn’t necessarily engaged in illegal activity, though, says Kroodsma, because AIS can be turned off for reasons such as safety in areas of high piracy or for law enforcement.
More work will still be needed to uncover the vessels’ identities to catch those fishing illegally after the event, but GFW is getting closer to its goal of monitoring all the vessels all the time.
The map could help coordinate efforts against illegal fishing and tell law enforcement agencies where to patrol, says Steve Trent, founder and CEO of the . “Uncovering high-risk areas where dark fleets operate and gaining knowledge about their behaviours allows scarce resources to be used where they are the most needed and policy-makers to protect vulnerable areas,” he says.
Trent says that the maps will be even more effective if accompanied by greater transparency on details of fishing permits, vessel ownership and identification. If these details are made public, illegal operators can be identified and action can be taken again them, he says.
