The $205 million dredge project to deepen Port Miami has spread a blanket of silt and clay over the bay bottom that is smothering coral and damaging sea life, state environmental inspectors have found.
In a letter Monday, the state Department of Environmental Protection warned the U.S. Army Corps of Engineers, which is managing the project, that work is violating state permits, churning up too much sediment and having a “profound effect” on the sea floor. The agency gave the Corps two weeks to respond.
“A fast response to this issue may minimize long-lasting impacts,” an inspection concluded.
The warning follows a similar complaint last month from the Biscayne Bay Waterkeeper watchdog group, which threatened to sue in September unless work is cleaned up.
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“The amount of sediment building up is horrifying,” said Waterkeeper executive director Rachel Silverstein. “We believe there is a way this project can be done better and that’s simply not being done right now.”
Late Tuesday, the Corps said it was still reviewing the letter and will adapt work based on findings.
“The Corps’ goal is to meet the congressionally mandated mission to improve the infrastructure at the port in the most environmentally and economically sustainable way,” a statement said. “To date, we have relocated approximately 1,000 healthy corals from the edge of the channel prior to dredging and are placing hard limerock substrate which will become more than nine acres of coral reef.”
Last month the state sent divers to inspect the area around the dredge after regular weekly reports showed sediment building up, said Danielle Irwin, deputy director of DEP’s Division of Water Resource Management. County officials had also raised concerns, she said. Environmentalists have long worried, saying two years of blasting and digging could wipe out coral, sea grass and other sea life.
Divers found a moonscape, with sediment extending beyond the channel, about a half a foot deep in places.
The fringes of some coral colonies had already started dying. Some smaller colonies showed signs of stress, divers found. And despite being months into coral’s summer spawning season, no baby coral were found. Sediment had also buried the bases of sponges, causing them to break off and die.
Inspectors also discovered that large boulders placed in the channel to provide places for young coral to grow as part of a mitigation effort had crushed existing coral and sponges when they were dropped.
An artificial reef created to hold coral transplanted from the channel was dusted with a layer of sediment. Water had become so thick with silt and clay that it created “anoxic conditions” in which very little oxygen reached the bay bottom.
Great Lakes Dredge and Dock, which is performing the work, did not respond to an email request for comment.
The dredge will ultimately scoop up about six million cubic yards of bottom from the port’s main shipping channel to make way for new monster ships sailing through the expanded Panama Canal in 2015. Altogether, dredging will consume about seven acres of reef, including five undisturbed acres at the mouth of the channel.
The Corps had originally planned on transplanting only threatened species of coral. But after the Waterkeeper organization and Tropical Audubon sued in 2011, the Corps and Miami-Dade County agreed to transplant coral from more than 16 acres that included any colonies larger than 10 inches, as well as 1,300 measuring between four and 10 inches.
Critics worry monitoring practices, which state inspectors confirmed are not working, will never be enough. State inspectors also say sediment has become so uniform, it may last and cause even more profound damage.
“If the Corps and [Great Lakes Dredge & Dock] can stall, hem and haw long enough, they will get the project done,” said Dan Kipnis, a fishing captain and one of the plaintiffs in the Waterkeeper lawsuit. “We will be left holding the bag as Miami-Dade County ultimately is responsible for the damages and remediation as per the contact agreement between PortMiami and the Corps. Something is definitely wrong with this system.”
Port officials did not respond to a request for comment by late Tuesday.
As early as April, two months before work started, state officials noted violations on how work is monitored and offered the Corps assistance. Those violations remain, Irwin said, but the two agencies are working to resolve them. One simple solution being worked out will put divers with rulers in the water to measure the sediment rather than rely on complicated devices, she explained.
“It’s very simple, straightforward and quick to do,” she said.