Historical incorporation of barium in the reef building coral Montastrea annularis at the Flower Garden Banks, north-west Gulf of Mexico

Annual growth bands of Flower Garden Banksʹ Montastrea annularis skeletal material were analysed for barium (Ba), a principal drilling mud component, to evaluate its potential as an indicator of water quality changes caused by oil and gas exploration and production in the northern Gulf of Mexico. The data did not indicate a Ba trend related to documented hydrocarbon exploration activities. Increased concentration variability after 1960 may, however, attest to environmental change. This variability does not correlate with a 23% decrease in average annual growth rates observed between 1957 and 1979 at the Flower Gardens.