Fishing in murky waters: Cargo ships from around the world are moving untracked in African waters, where the rise of a new fishing activity affects everything from local biodiversity to piracy

THE VERACRUZ SHOULDN'T simply disappear. This is no small fishing boat but a 108m-long, 3,755 gross tonnage, refrigerated cargo ship built in 1977. Yet every time it crosses the sea border from Namibia to Angola it seems to do exactly that, as its operators switch off the automatic identification system (AIS) tracking signal. 'Going dark' contravenes the international treaty for Safety of Life At Sea (SOLAS) rules for ships like this of over 300 gross tonnage.