On Board the Dixmude - Armed and stony-faced, six black-clothed members of Senegal's marine special forces board the Chinese fishing boat, alerted by radio that it may be operating illegally.Identity papers are demanded and the cargo is inspected: one of the crew members is not on the manifest of the "Casimir", which departed from Hong Kong, and their fishing licence has expired.The scene is a simulation, but for the Senegalese inspectors and commandos the reality is all too familiar, as west Africa battles flagrant poaching in its waters and the threat of piracy on the high seas."We just received the information that there was a boat fishing illegally. They gave us its last position and the speed of the vessel and we came over immediately to intercept them," explained Mamadou N'Diaye, the head Senegalese commando present.Senegal has three patrol vessels harboured in Dakar, and the intervention team launched from the "Ferlo" to begin their assessment.These 10-day regional exercises, baptised African NEMO (Navy's Exercise for Maritime Operations), are conducted by French marines playing the role of the baddies from France's vast Dixmude aircraft carrier.They aim to leave the problem-solving to the forces of more than 20 west African countries involved in the project, as they step up their battle against maritime criminality."We went from tactical training of teams boarding the boats, to lifesaving at sea, to how to make the centres put into place by the Yaounde process work," said the Dixmude's Captain Jean Porcher.The Yaounde process was adopted in 2013 as a code of conduct by west and central African nations to share intelligence and coordinate intervention against illegal fishing, drug trafficking and piracy on Africa's west coast, but progress has been slow.Fish without borders Embarking from Togo on September 10, the Dixmude, a vast 199-metre-long warship, has carried out half-a-dozen exercises with the navies of the Gulf of Guinea, aimed at reinforcing the sovereignty of national waters and protecting a vital source of food for the population.African coastal states lose around $1.3bn per year to illegal and unreported fishing, according to the European Union."Fish don't know how to read maps, they don't recognise borders, and neither do pirates," Admiral Christophe Prazuck, chief of the French navy, said at the opening of a conference in Dakar on Tuesday which will close this year's exercise."Around 90% of world trade is done by sea. In the Gulf of Guinea, there are 2 000 boats, and their security is fundamental for prosperity," Prazuck told journalists.The "Casimir" was boarded because its captain was uncooperative when contacted by radio, and was escorted to Dakar's port for further inspection.That is not always feasible in a region that lacks patrol boats and dedicated military and customs staff trained in illegal fishing patterns, according to environmental organisations such as Greenpeace, leaving nations such as Mauritania and Sierra Leone particularly vulnerable.Niger Delta threat The day after the "Casimir" exercise, the team took back a boat snatched by pirates. Although currently less of a problem in the upper section of west Africa, the discovery of important oil and gas deposits off Senegal and Mauritania may one day attract criminals to their waters.World piracy has been on the decline since 2012 after international naval patrols were launched off East Africa in response to violent attacks by mostly Somali-based pirates.But the focus of concern has shifted to the Gulf of Guinea, where a new class of pirates - mostly offshoots of militant groups from the Niger Delta - have become active.Since 2013, maritime cooperation has been a mixed picture, said Senegalese Rear-Admiral Momar Diagne. While one regional centre agreed upon in the Yaounde process is operational in Pointe-Noire, Congo, another in Abidjan has yet to open.