INTERNATIONAL: Dutch-owned trawler FV Margiris, the world's second-biggest fishing vessel, shed over 100,000 dead fish into the Atlantic Ocean off France, forming a floating carpet of carcasses which was spotted by environmental campaigners.

The spill, which happened in the early hours of Thursday ,February 3, was caused by a rupture in the trawler's net, said by fishing industry group PFA, which represents the vessel's owner. In a statement, the group has called the spill a "very rare occurrence".

The French arm of campaign group Sea Shepherd first published images of the spill, showing the ocean's surface covered by a dense, layer of blue whiting, a sub-species of cod, which is used by the industry to mass-produce fish fingers, fish oil and meal.

Sea Shepherd France has said it doubted the incident was an accident. Lamya Essemlali, head of the campaign group in France, her NGO was inclined to believe the fish were deliberately discharged.

The EU regulation has been implemented so that the group can reduce the non-selective fishing methods because it's very demanding, time-consuming and costs money for a fishing vessel to go back to port and unload the bycatch, and then go back at sea," Essemlali has explained. The temptation is big for these vessels at sea without any witness, any control, to just throw overboard all the bycatch.

France's Maritime Minister Annick Girardin mhas called the images of the dead fish "shocking" and said she had asked the country's national fishing surveillance authority to launch an investigation into the accident.

Trawlers like the Margiris use drag nets measuring over a kilometre in length and process the fish in on-board factories, a practice heavily criticised by environmentalists.

Sea Shepherd points to the practice as "driving dolphins to starvation" and forcing them to hunt closer to the coasts, in turn leading the sea mammals to get trapped in fishing nets and dying of asphyxia.

Thousands of dead dolphins have washed up on France's Atlantic coast over the past years. Such high numbers of the mammals are affected that local populations are at risk, marine biologists say.

Following protests by activists denouncing super trawlers, the Margiris was forced to leave Australian waters in 2012.

Traffic data by marinetraffic.com on Friday showed the vessel, which is owned by the Dutch company Parleviliet & Van der Plas and sails under the flag of Lithuania, was still engaged in fishing activities off France's coast.