In the early years, the colony was highly dependent on the import of staples from England and was supported by the investments of a number of wealthy immigrants. Certain businesses were quick to thrive, notably shipbuilding, fisheries, and the fur and lumber trades. As early as 1632, ships built in the colony began trading with other colonies, England, and foreign ports in Europe. By 1660, the colony's merchant fleet was estimated at 200 ships and, by the end of the century, its shipyards were estimated to turn out several hundred ships annually. In the early years, the fleet principally carried fish to destinations from the West Indies to Europe. It was common for a merchant to ship dried fish to Portugal or Spain, pick up wine and oil for transport to England, and then carry finished goods from England or elsewhere back to the colony. This and other patterns of trade became illegal following the introduction of the Navigation Acts in 1651, turning colonial merchants who continued these trading patterns into "de facto" smugglers. Many colonial authorities were merchants or were politically dependent on them, and they opposed being required by the crown to collect duties imposed by those acts. In 1652, Massachusetts General Court established the "Hull Mint" established by John Hull and Robert Sanderson producing the pine tree shilling.