Decades of overfishing and the international demand for cheap seafood mean Thai boats are increasingly turning to slave labour as fishermen flee worsening working conditions, a rights group said…Thai waters are one of the world's most over-fished regions, and Thai boats now catch just 14 percent of what they caught in the mid-1960s, according to the London-based Environment Justice Foundation (EFJ).To remain profitable, boats are forced to stay at sea for longer and go further afield than ever before. Some unregistered "pirate" boats are fishing the waters of other countries, also fuelling demand for modern-day slaves, the EJF said in a report…