A controversial offshore migrant detention centre on Christmas Island is to reopen, Australian Prime Minister Scott Morrison announced Wednesday, as he doubled down on hardline policies after a historic legislative defeat.

Some 8 million tonnes of plastic garbage - bottles, packaging and other waste - is dumped in the sea every year, killing marine life.

Asian markets headed into the weekend on a positive note yesterday, with Tokyo again propelled by the weaker yen but the dollar edged back slightly in the afternoon following its recent surge against global currencies.