Water movement within a fringing reef flat, Orpheus Island, North Queensland, Australia

Abstract

A technique to examine through reef water movement by direct tracing using fluorescent dyes is described. Results from an experiment conducted on the sand dominated fringing reef flat at Pioneer Bay, Orpheus Island, North Queensland, indicate net seaward water movement velocities in the order of 40 m day-1, and considerable vertical mixing. A conceptual model of water movement is proposed in which dispersive type water movement is predominant when the reef flat is submerged, with advection being more significant when the reef flat is exposed. The application of the method to the study of the mechanisms of diagenesis is discussed and water quality rather than water agitation is suggested as being the principal reason for most rapid lithification being reported as occurring near the sediment water interface.