A device called Nemo will shed light on small-scale fisherfolk

FISH ARE being plundered from the ocean at an alarming rate. According to the UN Food and Agriculture Organisation some 90m tonnes of commercial catch are hauled from the sea every year. And that is only for legitimate, commercial fishing vessels. Even setting aside the huge amount of illegal fishing that goes on, few authorities monitor the activities of the 50m or so fisherfolk who operate small boats in local waters with the aim of feeding their families, or of selling their catch harbourside or into local markets. So an attempt is now under way to collect some of these missing data.

The combined catch of such small-scale fishing could be half as much again as the reported global catch, according to Michel Dejean, director of sustainable fisheries for CLS Group. CLS is a subsidiary of France’s space agency that, among other things, helps monitor, via satellite, the transponders on large fishing boats operating around the world. (Those that switch off their transponders are tracked by radar.)

For small craft, though, CLS requires something simpler and cheaper. This is where the group’s experience in another area has come in useful—for the organisation also tracks marine birds and sea mammals, and for this it employs low-powered transponders. Engineers at CLS have used that expertise to come up with Nemo, a self-...