When you're on a fishing boat, you may see flocks of birds following in your track, hoping to catch a snack. Now scientists say they can use those birds' behavior to track illegal fishing boats.
Here's how it works: Researchers attached data recorders to the backs of 169 albatrosses (信天翁) in the Southern and Indian oceans. The devices weighed only an ounce and a half, but they included a GPS and were able to detect the presence and intensity of radar signals coming from boats. That information was then transmitted by satellite, so the researchers could track the location of the birds and thus the radar-emitting boats in real time.
The scientists then cross-checked that data against the known locations of boats, gathered from a system that boats use to declare themselves, called the Automatic Identification System (AIS). And differences appeared frequently.
More than a third of the times the birds' recorders detected radar signals, and therefore a boat, no such boat appeared in the official log (航海记录)—meaning that the vehicles had likely switched off their Automatic Identification Systems—something the researchers say probably happens in illegal fishing operations.
The work suggests birds could be an effective boat-monitoring tool—as long as illegal fishing operations don't target the birds. Fortunately, such a task would be difficult.
“Around fishing vessels, you can get hundreds of birds at any one time that are all flying around. So it's not really possible to target a specific bird. And the birds with recorders on are not marked in any way. So it's difficult for fishermen to pick out a specific bird," said study author Samantha Patrick, a marine biologist at the University of Liverpool.
Patrick's bigger concern is that albatrosses often get hooked on fishing lines. And though regulations have been established to protect against that happening—with success—illegal boats don't necessarily obey. So scientists might be underestimating the risk posed to albatross populations. But this system could mean that those illegal boats may have a tougher time flying under the radar.
