Berry's Creek is a tributary of the Hackensack River in the New Jersey Meadowlands in Bergen County, New Jersey. The creek watershed contains a diverse array of wetlands, marshes, and wildlife. The creek runs through a densely populated region and has been subject to extensive industrial pollution during the 19th and 20th centuries. Several companies discharged toxic chemicals into the creek in the 20th century, and these chemicals have remained in the sediment. The creek has the highest concentrations of methyl mercury of any freshwater sediment in the world. Portions of the creek watershed are Superfund sites, and cleanup projects began in the late 20th century.