Should the situation not improve, the EU could resort to banning fisheries imports, as it has done in the past with Guinea, Cambodia and Sri Lanka.
The announcement comes after a thorough analysis and a series of discussions with Thai authorities since 2011.
The Commission concluded that Thailand is not doing enough, and has denounced the country's shortcomings in its fisheries monitoring, control and sanctioning systems.
European Commissioner for Environment, Maritime Affairs and Fisheries, Karmenu Vella, stated: “Our EU rigorous policy on a harmful practice such as illegal fishing, together with our genuine capacity to act, is paying off.
"I urge Thailand to join the European Union in the fight for sustainable fisheries. Failure to take strong action against illegal fishing will carry consequences.”
Steve Trent, Executive Director of the Environmental Justice Foundation (EJF), also commented: “Thai authorities exert very little control over their fishing vessels, with many activities illegally damaging fish stocks and the marine environment, and this is linked to some of the most exploitative and inhuman working conditions documented anywhere. These conditions include the use of slaves and extreme violence. It is time for the Thai government to take swift action to control the Thai fleet and end this environmental and human crisis.”
The decision starts formal talks with the Thai authorities as they move to taking the necessary corrective measures.
They will be given six months to implement a corrective tailor-made action plan.
South Korea and Philippines De-Listed
In contrast to the situation in Thailand, the EC announced that South Korea and the Philippines have carried out appropriate reforms of their legal systems and are now equipped to tackle illegal fishing.
Previously the EC had given a 'yellow card' to Korea in November 2013 and the Philippines in June 2014.
Mr Vella remarked: "By using our market weight the EU is getting important players on board. Both Korea and the Philippines have taken responsible action, amended their legal systems and switched to a proactive approach against illegal fishing."
As a result of the action taken by Korea and the Philippines, the EC has stopped formal discussions with the countries' authorities.
The Environmental Justice Foundation, which has documented a large number of Korean-flagged vessels operating illegally in West Africa, welcomed the move today de-listing South Korea.
Mr Trent commented: “Korea’s efforts to stop illegal fishing are unprecedented in the region and demonstrate a clear intent to deliver national and international leadership to combat IUU fishing which devastates marine environments, biodiversity, fish stocks, livelihoods and food security.
"Flag States need to maintain a firm grip on their distant water fleet, and we hope that other States will follow Korea’s lead. The actions taken by Korea since 2013 clearly demonstrate the global impact of the proactive steps taken by the EU and European Commission, through the EU IUU Regulation, to drive out pirate fishing from global supply chains.
"In the last 12 months Korea has taken huge strides away from poor performance to becoming a leading nation in the fight against IUU fishing with innovative and deterrent measures. The Korean industry, in particular Korean fishing vessel operators, must match the intention of their Government, make sure they abide by the law and become an exemplary distant-water fleet.”
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