Yet just 2.4 per cent of the ocean is fully or highly protected, and more than one-third of fish populations are harvested at biologically unsustainable levels. With 70 per cent of stocks fished at full capacity, overfished, or recovering, entire aquatic ecosystems are at risk. ‘Right now, we are hammering marine species from every possible angle,’ says Chris Graham of the Marine Conservation Society. With wild fish stocks at their limit, aquaculture now provides the lion’s share. Satellite monitoring has begun to expose the shadowy world of unregulated, long-distance fishing fleets – often invisible to official data.