Bleak Prime was rich in a variety of metals and minerals, including carnacite, leading to the establishment of a mining facility, dubbed "The Flower". Unfortunately, carnacite releases toxins when exposed to atmosphere, requiring the use of pressure suits and atmospheric structures.
When the Marmosans became a Dominion subject race in 2373, the Dominion also occupied Bleak Prime, stationing a number of Vorta to administrate the mining operations. Problems arose when exposure to the processed carnacite weakened the Vorta's allegiance to the Founders. Once this was discovered by the Female Changeling, Bleak Prime was abandoned. (DS9 short story: "Change of Heart")