In an address to the UN General Assembly, he described the practice as a fundamental threat to sustainable fisheries and damaging to the economies of developing nations.
Bradshaw chairs the High Seas Task Force, a group of ministers and NGOs working together to combat illegal fishing.
The UNFAO says the number of overfished stocks has tripled in the past 30 years and its assessment of fish stocks in March showed little improvement on past trends. Some 16% of fisheries are overexploited and 52% are fully exploited. Seven per cent are depleted and only 1% are recovering from depletion.
The Marine Stewardship Council noted in its annual report that the IUU market is worth up to $15bn. Surveillance patrols have helped reduce sightings of IUU vessels.
Chief executive Rupert Howes said the UNFAO’s guidelines for eco-labelling of fisheries set “a credible international minimum”. He hailed “tremendous progress” in the development of MSC-certified fisheries, with the number of MSC lines set to “increase dramatically” in coming months.