There are two ways to remove coal from the ground: surface mining and underground mining. Surface mining is used when a coal seam is relatively close to the surface, usually within 200 feet. The first step in surface mining is to remove and store the soil and rock covering the coal (called the overburden).
Pearl oysters are not closely related to true oysters, being members of a distinct family, the feathered oysters (Pteriidae). Both cultured pearls and natural pearls can be extracted from pearl oysters, though other molluscs, such as the freshwater mussels, also yield pearls of commercial value.
Oyster seed is an oyster that is transplanted to another location for the purposes of commercial grow-out or restoration. Seed can be produced from a hatchery or harvested from the wild. The type of seed you will start with in this program is spat-on-shell or cultched oysters produced from a hatchery. In producing spat-on-shell in the hatchery, whole oyster shell is first dried out on land in order to remove organic material that could degrade water quality in the setting tanks.