International Dredging Review

International Dredging Review

Mitigation for the deepening project at Miami Harbor is complete after the deepening was completed in September 2015 and the Corps said in December recent monitoring shows the mitigation features functioning successfully.

The mitigation includes almost 17 acres of seagrass and 12 acres of artificial reef. Surveys conducted one year after construction of the artificial reef show positive signs – sea life and habitat colonization. Post-construction reports of the seagrass mitigation site show new seagrass recruitment growth and a 97 percent survival of planted plots.

Recent post-construction monitoring reports also provide a complete assessment and characterization of the sea floor communities during and after project work. The reports compare monitoring data to preconstruction surveys and information and provide observations of project-related and natural sediment settling throughout construction. Scientists also mapped the extent of project-related sediment during construction which measures 252.4 acres across the hardbottom middle and outer reef areas. Results of the monitoring show that sediment levels have either dissipated or are dissipating in most areas.

The majority of the impacts on coral were attributed to regional-scale disease outbreak.