<P> During the first half of the sixteenth century, Spaniards discovered the vast and luscious pearl oyster beds that existed on the Caribbean coast of Venezuela, particularly in the vicinity of Margarita Island . Indigenous slavery was easy to establish in this area because it had not yet been outlawed; therefore, indigenous peoples were captured and often forced to work as pearl divers . Since violence could not protect the efficiency of the slave trade, coastal chieftains established a ransoming system known as the "rescate" system . </P> <P> As this system continued to grow, more and more oyster beds were discovered along the Latin American coast, including near Riohacha on Colombia's Guijara Peninsula . However, due to over exploitation of both indigenous labor and the oyster beds, the Spanish pearl economy soon plummeted . By 1540, previous Spanish settlements along the coast had been abandoned as the Spanish looked elsewhere for more labor and newer markets . The pearl industry was partially revived in the late sixteenth century, when Spaniards replaced indigenous labor with African slave labor . </P> <P> Oyster harvesting methods remained relatively the same along the coast and varied depending on the divers' conditions, the region's topography, and a Spanish master's work demands . </P> <P> On Margarita Island, small zones were inspected in advance by the divers, who relied mostly on lung power to dive and resurface from the ocean . Once those small zones had been depleted of their oysters, the men on the boat - which usually included a dozen divers, a Spanish navigator, a diving chief, an oarsmen, and a foreman - moved on to the next oyster bed . To retrieve the pearls, the divers carried a small net that had one end tied to the boat and the other end tied to the fishing net . The shells that they extracted were usually placed in this basket, but for dives of greater depth, the divers also had to wear stones tied to their bodies as they submerged into the ocean . The stones acted as a ballast until they resurfaced, where the divers then untied the stones from their bodies . The divers would receive a slight break to eat and rest and continue this work until sundown, where they all presented their catch to the foreman, return to the Spanish ranchería to have some dinner, and then open the oyster shells . </P>

Who did some cultures use for pearl diving because of the dangers