Tight Temporal Consistency of Coral Mass Spawning at the Flower Garden Banks, Gulf of Mexico, from 1997-2003

Abstract

Mass spawning by the hard corals of the Flower Garden Banks National Marine Sanctuary has been studied for over a decade. In this report we present observations by a single set of experienced observers on spawning events extending over seven years, on spawning activity, lack of activity and coordination within and between species. This compilation shows that the spawning times of each species are extremely consistent during major events, with onset and hiatus often predictable to within seven minutes, and in some species to within two minutes. In addition to the extraordinary degree of temporal regulation, the other striking feature of the spawning schedule is the uniqueness of most spawning windows. With the exception of Diploria strigosa, each of the major spawning species—Colpophyllia natans, Montrastraea cavernosa, M. annularis, M. faveolata, M. franksi and Stephanocoenia intersepta—has a unique window of time in which it and no other coral species releases gametes. Spawning times for the 2005-2008 seasons are predicted based on these findings.