New research has revealed that significant damage has occurred to Miami’s coral reefs from a 16-month dredging operation at the Port of Miami that began in 2013. The study was performed by researchers from the University of Miami Rosenstiel School of Marine and Atmospheric Science and published in the August 2019 online issue of the journal Marine Pollution Bulletin.
The study revealed that sediment buried between half to 90 percent of nearby reefs, resulting in widespread coral death. It is estimated that over half a million corals were killed within 500 meters of the dredged channel and that the dredging impacts may have spread across more than 15 miles of Florida’s reef tract.
“Coral reefs worldwide are facing severe declines from climate change,” said Andrew Baker, associate professor of marine biology and ecology at the UM Rosenstiel School and senior author of the study. “If we want to conserve these ecosystems for the generations that come after us, it’s essential that we do all we can to conserve the corals we still have left. These climate survivors may hold the key to understanding how some corals can survive global changes. We have to start locally by doing all we can to protect our remaining corals from impacts, like dredging, that we have the ability to control or prevent.”
Florida’s reef tract is the only nearshore reef in the continental United States, and coral cover has declined by at least 70 percent since the 1970’s. Staghorn corals, which were once common in shallow water, have declined an estimated 98 percent and are now threatened species under the Endangered Species Act.
The authors also found that sediment plumes, which are milky clouds of suspended dredging sediment visible from space, had a high correlation between being visible on satellite data and predicting where dredging impacts killed coral.
Study co-author wrote that, “This connection allowed us to predict impacts beyond where ship-based monitoring was taking place, and showed that dredging likely damaged this reef several kilometers away. While this same relationship may not apply in all projects, this is a remarkable finding that further establishes Earth-observing satellites as independent monitoring tools to fill in gaps where data are otherwise not available.”
The study reveals just how impactful dredging is on ocean environments even when it is not directly dredging on coral environments. Hopefully if any good can come out of this, future dredging can use this research to establish whether widespread death may be caused to surrounding marine environments if dredging is proposed for a certain area and future death of reef systems can be prevented.