Traffic through Canada’s biggest port fell during the first half of the year, hit by weak industrial activity at home and slackening demand for commodities in Asia, another sign of trouble for the nation’s sputtering economy.Following a record year for the Port of Vancouver in 2015, cargo fell 5.9 percent to 66 million metric tons in the six months to June from the same period in 2015, the port said in a statement. Shipments of all major commodities declined except for grains. Exports of thermal coal for power plants in Asia plummeted 39 percent. Meanwhile, a slowdown in industrial activity in western Canada hit volumes of machinery, vehicles, and construction materials, which fell 12 percent. A weaker Canadian dollar also affected consumers, leading to a decline in imports of household goods, it said. Canada’s natural resources-dependent economy is struggling to emerge from a slump having expanded by 1.2 percent since May 2014, the slowest two-year pace outside a recession in at least six decades. Disappointing data on trade and employment has stoked speculation policy makers will need to add even more stimulus if things don’t improve