European Union border monitors say the number of illegal migrants arriving by sea in Greece has boomed and will keep doing so if Turkey does not take action.The Frontex monitoring group announced 50 percent more made the journey in the first half of this year, compared with the same period last year. And Athens says Ankara took back only a fraction of those smuggled through its lands on their way to Europe. Frontex Deputy Executive-Director, Gil Arias Fernandez, said: “As long as the Turkish authorities do not cooperate, the situation will not become much better, so this is a crucial element.” Greece forms a particularly porous border for Europe. Including more than 1000 islands, it is difficult to control. More than 35,000 illegal migrants reportedly made it there in the first six months of 2009, from places like Afghanistan and Iran. And Frontex says with the lure of a better life so strong, if nothing is done, no doubt many more will attempt the trip.