NORTHGATE <NGX> QUEBEC ORE RESERVES DECLINE Northgate Exploration Ltd said year-end 1986 ore reserves at its two Chibougamau mines in Quebec fell to 8,141,150 short tons grading 0.077 ounce gold a ton and 1.63 pct copper from year-earlier 8,462,000 tons grading 0.077 ounce gold ton and 1.67 pct copper. The company said it launched a 700,000 dlr exploration program at the mines to increase production and ensure the operations' continued long life. Ore production totaled 650,653 tons last year, it said, estimating year-end reserves contained about 627,000 ounces of gold and 265 mln pounds of copper.