Long-Term Monitoring at East and West Flower Garden Banks: 2019 Annual Report

This report summarizes fish and benthic community observations and water quality data collected from East Flower Garden Bank (EFGB) and West Flower Garden Bank (WFGB) in 2019, along with nearly 30 years of historical monitoring data. EFGB and WFGB are part of Flower Garden Banks National Marine Sanctuary (FGBNMS), located in the northwestern Gulf of Mexico. The annual long-term monitoring program began in 1989 and is funded by the National Oceanic and Atmospheric Administration’s FGBNMS and the Bureau of Ocean Energy Management, with support from the National Marine Sanctuary Foundation. In 2019, mean coral cover was 55% within the EFGB one-hectare study site and 60% within the WFGB one-hectare study site. Mean macroalgae cover was 33% within the EFGB one-hectare study site, which differed significantly from the 21% mean macroalgae cover within the WFGB one-hectare study site. Mean coral cover has increased significantly at WFGB and remained stable at EFGB since 1989. Mean macroalgae cover has increased significantly at both banks since 1999. Mean coral cover within repetitive photostations has increased significantly since 1989 at both banks. The Orbicella spp. complex, listed as threatened under the Endangered Species Act, accounted for the majority of the coral cover within the one-hectare study sites. Sea urchin density was 1.25 and 28.08 individuals per 100 m2 at the EFGB and WFGB one-hectare study sites, respectively. The reef fish community was comprised primarily of the families Labridae and Pomacentridae. For commercially and recreationally important species, grouper density was higher within the EFGB one-hectare study site while snapper density was higher within the WFGB one-hectare study site. During 2019, water temperatures on the reef exceeded 30oC for six non-continuous days at EFGB and ten non-continuous days at WFGB. Coral bleaching at both banks was less than 1% at the time of surveys. A significant monotonic increasing trend in seawater temperature was detected at both banks from 1990 to 2019, indicating ocean temperatures have risen at FGBNMS over the past three decades. The results of this report highlight the importance of long-term monitoring efforts by providing one of the longest records of coral reef health in the Gulf of Mexico and Caribbean region.

Key Words

benthic community, coral ecosystem, coral reef, fish community, long-term monitoring, Flower Garden Banks National Marine Sanctuary, Gulf of Mexico, marine protected area, water quality