Time series of annual linear growth increments from 12 Montastrea annularis (E. and S.) collected at the East Flower Gardens Bank reef in the northwestern Gulf of Mexico have a common pattern. This is best expressed in an index master chronology (average by year of the annual percentage deviations from the mean of each coral.)

Comparisons with time series of environmental data indicate that coral extension rates vary positively with seasonal (February through May - 4 months) surface water temperature and negatively with annual discharge of the Atchafalaya River. We propose that secular variations of water temperature and other parameters are the major long term controls of coral growth in the area. Our data do not support the view that sinking of the Flower Gardens reef, caused by catastrophic collapse of the underlying substrate, has been a prime influence on the corals.