Boat anchor damages large area of transplanted coral off Florida Keys

About 20 colonies of critically endangered elkhorn coral off the Florida Keys were severely damaged recently by a dragged boat anchor, scientists say.

The damage was done in a 10-square-meter portion of Pickles Reef off the ocean side of Key Largo, which contains coral that survived Hurricane Irma, but was no match for careless humans.

Alice Grainger, with the Coral Restoration Foundation, a Keys conservation group that has been rebuilding the reef by transplanting offshore nursery-reared coral specimens onto it since 2007, said the impacted section is the “only part on all of Pickles that has large elkhorns like this anymore.”

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Elkhorn coral is shown damaged and detached from its base on Pickles Reef in Key Largo. Scientists believe a boat anchor caused the damage. Coral Restoration Foundation

Scientists consider elkhorn coral a “keystone” species, meaning it is essential to reef building. But, years of exposure to pollution, bleaching, storms and boat damage have devastated their populations, as well as populations of other species like staghorn coral. That’s why scientists and volunteers at the Coral Restoration Foundation have been busy planting them.

The damaged colonies were planted in 2014, Grainger said. The damage was discovered by a group of divers who were checking on newly planted corals.

“It is devastating to think that these corals survived Hurricane Irma only to be wiped out by someone carelessly dropping an anchor on the reef,” Jessica Levy, restoration manager at CRF, said in a statement.

Levy added that anchor damage is not uncommon on the reef, and remains a significant problem, despite educational outreach efforts by groups like CRF, as well as government agencies like the National Oceanic and Atmospheric Administration.

Pickles Reef even has mooring balls for boaters to connect to so they don’t drop anchor. It was actually a missing mooring ball that led divers to conclude that the damage they witnessed was caused by an anchor.

“It is evident from the damage assessment and a missing mooring buoy that a boat dropped its anchor and proceeded to drag the anchor over this critical site,” Grainger said in a press release.

The CRF operates within and under a permit from the Florida Keys National Marine Sanctuary, which is part of NOAA, and anchoring on coral is illegal in the sanctuary, which covers all of the Keys.

Levy urged boaters to use mooring balls, and if none are available or they are missing, to look for a sandy shallow spot away from coral and seagrass to anchor their vessels. And, once anchored, “ensure your anchor is set and will not drag,” she said.

The original story incorrectly reported the size of the damaged area as 10 square acres. It is 10 square meters.

David Goodhue covers the Florida Keys and South Florida for FLKeysNews.com and the Miami Herald. Before joining the Herald, he covered Congress, the Environmental Protection Agency and the Department of Energy in Washington, D.C. He is a graduate of the University of Delaware.