A new report raises concerns that when fishing vessels "go dark" by switching off electronic tracking devices, in many cases they are doing so to mask the taking of illegal catches in protected marine parks and restricted national waters.
In the report released Monday by Oceana, an international conservation group, authors Lacey Malarky and Beth Lowell document incidents of fishing vessels that disappear from computer screens as they shut off collision-avoidance beacons near restricted areas, only to have them reappear days or weeks later back in legal fishing grounds.
"This practice of vessels going dark is really widespread on a global scale," Malarky tells NPR.
Malarky and Lowell used Global Fishing Watch, which aggregates automatic identification system, or AIS, signals to give an unprecedented view of global fishing activity. AIS signals can be viewed by the public through such websites as Vesselfinder.com.