Over 47% of the 25,500 acre Great Marsh Area of Critical Environmental Concern has been protected through land conservation efforts. Conservation began with government entities using eminent domain in the early 1900s, and now emphasizes partnerships between federal, state, and non-profit organizations. Recent conservation projects in Essex County have used funding from various sources to purchase land through bargain sales and fee interest, with a focus on protecting buffer areas and upland surrounding wetlands from development. Engagement opportunities through programs like osprey tracking help involve the public in conservation work in the Great Marsh.