In a head-twirling scenery, the Dutch-owned, second-largest fishing vessel in the world, FV Margiris, has dumped more than 100,000 dead fish into the Atlantic Ocean off the coast of France.

Annick Girardin, France's marine minister, described the photographs of the dead fish – which created a floating blanket of carcasses found by environmental activists – as "shocking," and has urged the national fisheries monitoring authority to initiate an inquiry.

Virginijus Sinkevicius, the European Commissioner for the Environment, Oceans, and Fisheries, has also stated that he is looking for “exhaustive information and evidence about the case”.

According to the Pelagic Freezer-Trawler Association (PFA), called the occurrence "very rare," and explained that the spill was a result of a tear in the trawler's net on Thursday. 

In a statement, it added that “In line with EU law, this has been recorded in the vessel’s log book and reported to the authorities of the vessel’s flag state, Lithuania." It also divulged the dead fish would be deducted from the vessel's quota. The vessel is owned by the Dutch business Parleviliet &Van der Plas.

The French section of the campaign organization Sea Shepherd was the first to publish photographs of the leak, which showed a dense coating of blue whiting, a subspecies of cod used to mass-produce fish fingers, fish oil, and meal, covering the ocean's surface. According to the report, the spill contained over 100,000 fish and spanned an area of around 3,000 square meters.  

Environmentalists have slammed trawlers like the Margiris for using drag nets more than a kilometer long and processing the fish in aboard factories.

Following activist demonstrations, the Margiris was forced to depart Australian seas in 2012. The trawler had a quota to haul 18,000 tonnes of fish from the sea, but it was stopped by Tony Burke, the then-Labor environment minister, after a public uproar.

According to marinetraffic.com, the vessel was still fishing off the French coast on Friday.