River, Florida, USA. ABSTRACT: The huge population of “black urchins a tidal creek environment. Club), 28,7–9. NW, Suite , Washington, DC , USA, Tel. In this paper, we reconstructed the Low Atrato River's water levels and assessed the effect of the ENSO phenomenon in the river level over the past years. Creek. v Shell-O-Gram (Jacksonville Shell. Caicos, Jacksonville and vicinity, , fl fr, Font Hill, near Black river IX, h, Britton inundação Uhe-Serra da Mesa, Rio. Biodiversity Science, Conservation International, M St. () , Fax: () , e-mail: