After several years of assessment, planning and coordination by local volunteers, and multiple state and federal natural resource managers, Mill Brook, a 381-acre section of Scarborough Marsh Wildlife Management Area was restored in 2005. Mill Brook salt marsh had been degraded by man-made ditches and upland land uses. Ditches were first constructed in the 1600s to facilitate the growth of salt hay by farmers, and additional ditches were dug in the 1960s, in a misguided attempt to reduce mosquito populations. Drainage ditches reduced the biological vitality of the salt marsh by limiting the frequency and duration of salt water wettings by the tides. Land-use activities on nearby uplands, including housing developments and golf courses, also negatively impacted Mill Brook by concentrating polluted freshwater run-off on the marsh surface. In recent years, Phragmites, a highly invasive plant, also appeared in Mill Brook.