A Bradley Air Services Avions de Transport Regional ATR-42-300 on behalf of First Air, registration C-GULU performing freight flight 7F-5850 from Kugluktuk,NU to Yellowknife,NT (Canada) with 2 crew, was approaching the top of descent into Yellowknife when the crew received a low left fuel indication and requested priority handling due to low fuel. The low left fuel light extinguished subsequently extinguished. The aircraft continued for a safe landing at Yellowknife. Canada's TSB reported the aircraft landed with 800lbs of fuel remaining. Due to a fuel pump failure in Kugluktuk the crew had been unable to uplift fuel at Kugluktuk.