The Dutch took heavy advantage of the Indigenous reliance on wampum as a trading medium by exchanging cheap European-made metal tools for beaver pelts. By using such tools, the Indigenous greatly increased the rate of production of wampum, debasing its value for trade. Lenape men abandoned hunting and fishing for food in favor of beaver trapping. Moreover, the Dutch began manufacturing their own wampum with superior tools in order to further dominate the trading network among themselves and the Indigenous (a practice undertaken by the settlers in New England as well). As a result of this increase, beavers were largely trapped out in the Five Boroughs within two decades, leaving the Lenape largely dependent on the Dutch. As a result, the Indigenous population declined drastically throughout the 17th century through a combination of disease, starvation, and outward migration.
