Nearly 200 pieces of concrete now rest about 90 feet beneath the Atlantic Ocean at Harm's Ledge, roughly 25 miles off the Mayport jetties, where a new artificial reef is beginning its transformation from discarded construction material into marine habitat. Culverts, pipes and other concrete structures were loaded onto a barge and deployed at the site in late June. Over time, their exposed surfaces and openings are expected to attract marine growth while providing fish and invertebrates with places to feed, spawn and take refuge. The project is Jacksonville's first major artificial-reef installation in several years, and organizers hope it will serve as the foundation for a renewed, long-term reef-development program in Northeast Florida.
For local anglers, the reef's potential can be explained more simply: Fish are drawn to structure. Captain Rick Ryals said fish may begin investigating artificial-reef material almost immediately, though different species move into new habitat at different rates. He expects the Harm's Ledge reef to become increasingly productive as marine growth develops. Ryals said concrete is particularly attractive to grouper, while snapper, amberjack, barracuda and cobia are also among the species that could use the structures. King mackerel, tuna, wahoo and sailfish may be drawn to the activity surrounding the reef. Anglers may begin seeing activity around the structures within a couple of months, he said, although the reef could take a year or more to become well established.
Turning surplus concrete into marine habitat, the new reef was built with materials that might otherwise have gone unused. Rinker Materials and Phillips Heavy Civil Construction Co. donated the concrete, while Mobro Marine provided marine construction services.
Artificial reefs are built from durable materials that provide the hard surfaces and complex spaces often missing from a sandy ocean bottom. Marine organisms can attach to the material, beginning a gradual process that creates shelter and feeding opportunities for larger animals. The Jacksonville Offshore Sport Fishing Club began supporting reef placements in the late 1950s or early 1960s, Ryals said, and more than 300 placements have been made since then using materials such as concrete culverts and retired vessels. Ryals emphasized that this process is especially important off Northeast Florida, where artificial reefs have become an essential part of the offshore fishery. “Without the reefs, there would be no offshore fishing,” he said.
Materials intended for artificial reefs must be reviewed, cleaned and prepared before deployment. Ryals said vessels and other structures are inspected and positioned so they do not create navigational hazards.
The Harm's Ledge project, a community effort, began taking shape in early 2025, when the Jacksonville Offshore Sport Fishing Club and the nonprofit Think It, Sink It, Reef It developed a concept using donated concrete. A grant application followed, along with coordination among local, state and federal agencies, private companies and community organizations. Funding came through a grant partnership involving the Florida Fish and Wildlife Conservation Commission (FWC) and the U.S. Fish and Wildlife Service. The Jacksonville Waterways Commission and other partners also participated, and veteran artificial-reef project manager Joe Kistel coordinated the deployment. Harm's Ledge is named for Gus Harms, an early member of the Jacksonville Offshore Sport Fishing Club. Its location provides room for new marine habitat while remaining accessible to properly equipped offshore boats.
Organizers expect the reef to benefit more than marine life. As the site develops, it could create additional opportunities for recreational fishing and diving while supporting businesses connected to Northeast Florida's marine economy. Charter operators, marinas, tackle shops, hotels and restaurants can benefit when healthy offshore destinations attract anglers, divers and visitors.
Those potential benefits reflect the broader goals of artificial-reef development throughout Florida. According to FWC, artificial reefs can increase fish habitat, expand recreational fishing and diving opportunities and generate socioeconomic benefits for coastal communities. Depending on their location and design, other artificial-reef projects can help replace hard-bottom habitat lost to beach renourishment or vessel groundings, regenerate oyster reefs and protect shorelines. Florida has one of the most active artificial-reef programs among the 15 Gulf and Atlantic coastal states involved in reef development. Since the 1940s, more than 4,548 planned public artificial reefs have been placed in state and federal waters off Florida's coast, according to FWC. The agency's Artificial Reef Program provides financial and technical assistance to coastal governments, nonprofit organizations and state universities to construct, monitor and assess reefs.
At Harm's Ledge, the ecological results will not appear all at once. Colonization begins as organisms attach to the concrete, and a fully developed reef community takes time to form. Ryals' confidence in the project comes from decades of experience with artificial reefs off Jacksonville. Although the new structures may look stark on the ocean floor today, he expects them to become productive habitat as fish and marine growth take hold.
This recent project is part of a much longer reef-building history. The Harm's Ledge installation joins numerous artificial reefs previously placed off Northeast Florida. In 2000 and 2001, 500 dome-shaped concrete structures known as Reef Balls were deployed between Jacksonville and St. Augustine to form the Charles H. Kirbo Memorial Reef. Volunteers, including students from Mandarin High School, helped construct those reef components. Supporters hope the new project will similarly leave a lasting mark, and that it will be the first of additional deployments rather than a stand-alone effort. Jacksonville Waterways Commissioner Marc Hardesty said the project's impact will extend beyond the marine habitat itself. “The benefits of this reef will be felt for decades by anglers, divers, marine businesses and future generations who enjoy Northeast Florida's offshore waters,” Hardesty said in a statement, according to a June 28 report from Action News Jax.
For anglers and divers, the reef, located at latitude 30° 22.109′ N and longitude 80° 54.028′ W, could eventually become another offshore destination. For the organizations behind it, the larger value will be measured by what develops beneath the surface, and whether this installation leads to a lasting regional reef program. What now lies on the seafloor as a collection of concrete culverts may, in time, become a thriving link in Northeast Florida's marine ecosystem.
