Of the refuge's 47,000 acres, 78% is salt marsh. Salt marsh is the most productive land on earth- twice as productive as even the richest farm fields. This makes salt marshes a very important nursery for young fish, and a great buffer to the upland coastline for nor’easters, hurricanes, and strong waves. It is also nesting habitat for coastal songbirds such as Salt Marsh and Seaside Sparrows, and feeding grounds for many species of ducks, geese, herons and egrets. You might notice that most of the salt marsh appears to look the same, and that is because only a few plant species, which are specially adapted to tolerate salt water, are capable of growing here.