Florida’s Brevard County is embarking on a large-scale environmental dredging project for the Indian River Lagoon.
Decades of excessive pollution has overwhelmed the natural resilience and assimilative capacity of this National Estuary. This legacy of pollutant load contributed to record breaking algae blooms in 2011 and 2012, loss of 60% of the seagrass beds, and unusual mortality of dolphins, manatees, pelicans and other shorebirds.
The northern half of the lagoon’s length is sheltered from the ocean by a barrier island with few inlets, spaced 90 miles apart, thus most pollution that gets into the lagoon, stays in the lagoon. Excess nutrients feed algae blooms.
When algae die, they settle on the lagoon bottom in a thick, black, decaying sludge that smothers seagrass and all other benthic life and competes with aquatic organisms for oxygen. This organic rich ooze, known locally as Muck, negatively impacts water clarity, water quality, biodiversity, fisheries abundance and navigation.
Brevard County, Florida is conducting an aggressive restoration strategy for the lagoon that will reduce excess nutrient inputs, remove the legacy load of muck, restore the lagoon’s natural filtration systems (oysters, clams and wetlands) and ensure that sound research is the basis of these efforts.
The County Environmental dredging to remove a legacy of pollution stored in muck deposits is critical to overall success of Brevard County’s lagoon restoration strategy.
Brevard County plans to remove accumulations of muck from the lagoon by dredging.
In July 2014, muck dredging began to come to fruition with a $10 million appropriation from the Florida Legislature. The County moved swiftly to contract with a team of consultants to design and permit five high priority muck removal areas and contracted with a team of researchers at Florida Institute of Technology (FIT), per Legislative intent, to document and analyze ecological responses of the national estuary to muck removal. Pre-dredging data collection and scientific studies are already underway.
Dredging consultants quickly collected field data necessary to prepare and submit permit applications to state and federal regulatory agencies. State permits for the first two sites, major muck deposits off Palm Bay and Cocoa Beach have been approved. Federal permits are pending with active dialogue on appropriate permit conditions. Bid documents preparation is underway with dredging anticipated to begin in April, less than 1 year after the Legislative appropriation.
A second year of funding is currently being considered by the Florida Legislature. If approved, these additional funds will expand muck removal at the first 5 sites, as well as continue physical and biological lagoon monitoring and analysis by FIT researchers.
The estimated cost to complete muck removal from the first 5 sites is $55 million and is anticipated to require 3 years of implementation time.
First year funds are anticipated to remove approximately 160,000 cubic yards of muck. Second year funds are anticipated to remove approximately 550,000 cubic yards of muck and begin permitting for future priority sites within the Brevard portion of the Indian River Lagoon, the Banana River Lagoon and associated tributaries. Third year funds would complete muck removal from the first 5 sites, complete permitting for Fourth year sites, and begin permitting for sites to be dredged in future years.
The Indian River Lagoon is a national treasure, spanning a unique mixing zone between temperate America and Florida’s sub-tropics, that harbors a record-breaking 4000 different species of plants and animals, over 100 endangered or threatened species, and many recreationally and commercially important fisheries.