In response to numerous permit violation complaints and threats of litigation regarding the Miami Port dredging project, the Florida Department of Environmental Protection (FDEP) performed site inspection dives on July 22 and 23, 2014. A 39 page FDEP report issued on August 18, details significant coral mortality and habitat destruction caused by silt generated from the dredging activities.
The FDEP divers found up to 5 ½ inches (14 cm) of silt smothering coral colonies along 100’s of meters of reef. The report concludes “The observed sediment cover has had a profound effect on the benthos. There were no scleractinian or octocoral recruits or juveniles less than 3 cm in maximum dimension observed along the assessment transects at the Inner and Middle Reefs…” The survival of impacted scleractinian corals and octocorals in size class < 10 cm is highly unlikely; according to the FDEP observation, the sediment layer has resulted in anoxic conditions.
Larger size classes of scleractinian corals, octocorals, and sponges were also adversely affected by project-related sedimentation, and impacts to these larger organisms is considerable. More than half of the larger scleractinian corals (> 10 cm in max dimension) observed had partial mortality caused by sediment accumulation, which can increase diseases in corals through infections in the affected areas.
“Summer is the time of year during which recruitment occurs for the majority of benthic organisms; corals, octocorals, and sponges that have been impacted by sediment accumulation will have much less energy for reproduction. Additionally, the situation is worsened by the fact that the hardbottom substrate is now covered with a layer of sediment that will prohibit larval settlement and attachment,” the report said. “Lost reproductive output and recruitment resulting from this impact will have long-lasting effects on the impacted areas of reefs and hardbottom. The cohesive nature of fine sediments suggests that the sediment cover may persist for some time and have even more profound effects on the ecological function of the communities.”
On August 18, 2014 the FDEP issued a Notice of Violation Warning Letter giving the ACOE 14 days to address needed corrective actions. If not, The Army Corp of Engineers is facing a $ 10,000/day fines for the project related damage.
Press Release, August 20, 2014