The refuge is a habitat for number of native bird species including the endangered yellow-shouldered blackbird, locally known as mariquita de Puerto Rico or capitán.

[2] Caborrojeños Pro Salud y Ambiente, a local civic group, runs a visitor center in the salt flats area.

The refuge has also been declared a BirdLife International Important Bird Area (under the name Suroeste de Puerto Rico) and was the first Caribbean site to be added to the Western Hemisphere Shorebird Reserve Network (WHSRN).

Some of the bird species found in the refuge include the American kestrel (Falco sparverius), the smooth-billed ani (Crotophaga ani), the black-necked stilt (Himantopus mexicanus), the yellow or mangrove warbler (Setophaga petechia), the Adelaide's warbler (Setophaga adelaidae), the troupial (Icterus icterus) which was introduced from Venezuela, the semipalmated plover (Charadrius semipalmatus), the Wilson's plover (Charadrius wilsonia) and the Puerto Rican woodpecker (Melanerpes portoricensis).

[6] Native plants found in the refuge include the cobana negra (Stahlia monosperma), the pipe-organ cactus (Cephalocerus royenii), the West Indian birch (Bursera simaruba) and the guayacan (Guaiacum officinale).