Mystic Island, New Jersey, United States [CDP]; population was 7,400 in 1990; housing units was 4,679 in 1990; location is 39°34'N 74°23'W; land area is 7.67 square miles (4,908 acres); water area is 0.15 square miles (97 acres); FIPS code is 49560 [SourceCBP]