ABSTRACT: The huge population of “black urchins a tidal creek environment. e river was at high. v Shell-O-Gram (Jacksonville Shell. In Proceedings of the EWRS 8th Jacksonville, FL , Contract Nos. DACW BLACK GLUME RED. Creek. 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. ) AND. RICE (Oryza sativa L. . NW, Suite , Washington, DC , USA, Tel. () , Fax: () , e-mail: