The US government abolished 40-year-old constraints on crude oil exports in December. But since then less US oil has been put on ships headed abroad. Volumes of US crude exported by tanker have declined 5 per cent in 2016 to an average 325,000 barrels a day, according to Clipper Data, a market intelligence service. Waterborne exports were 342,000 b/d in the first three months of 2015. The oil industry hailed the ability to freely trade US crude as the dawn of a new era in global energy. The data so far suggest a big net addition to supplies will be slow in coming, however. The US was already sending hundreds of thousands of barrels per day to Canada before the broad export ban was lifted. The Canada trade has become less profitable this year and exports elsewhere have yet to make up the difference. Abudi Zein, Clipper Data’s chief executive, said: “Lifting the export ban has firmly tied the US into the global market but the world wasn’t waiting for US crude.” As US lawmakers debated the oil export law, Line 9B, a Canadian pipeline, was reversed in December so crude could flow over land from west to east. Line 9B will eventually carry as much as 300,000 b/d to Quebec province, diminishing Canada’s demand for oil imported by tanker.