NPS

Many nonnative animals and plants, such as Thespesia populnea, are observed in Biscayne National Park

John Donne wrote that "no man is an island," and the same can be said for National Parks. While all parks are affected to some extent by what goes on in adjacent areas, the situation is magnified in a marine park where water flowing across boundaries can provide easy access for pollutants, exotic species, and large numbers of visitors not confined to traditional throughways like trails and roads.