In 2023, North Carolina sank 1,700 tons of concrete pipes and manholes at AR-305; the material added fish habitat off the coast of Beaufort

Did you know one of the busiest fishing spots along the East Coast was once a sewage system? In July 2023, North Carolina’s Division of Marine Fisheries sunk around 1700 tons of concrete pipes and manholes into the seafloor at AR-305, a location approximately 28 miles off Beaufort. According to a WCTI12 report citing state fisheries officials, AR-305 now includes four vessels and more than three acres of recycled concrete pipe habitat, making it one of the busiest fishing and diving destinations on the North Carolina coast.

The idea of recycling construction waste to create new ecosystems is very simplistic and easy to understand. For a whole generation who have grown up with the ‘reduce, reuse and recycle’ mantra, this is one of the few examples where this phrase can be taken literally, turning concrete rubble into homes for the grouper and amberjack.

The science behind artificial reefs


While artificial reefs can look like simply dumping waste into the sea, there’s real science behind where and how the structures are placed. NOAA scientists surveyed 31 artificial reefs across a 125-mile stretch of North Carolina’s coastline, including the waters around AR-305, using echosounders mounted on a research vessel.

According to NOAA’s National Centers for Coastal Ocean Science, fish density was tied more closely to a reef structure’s vertical relief, essentially its height, than to its horizontal footprint, and isolated, single structures tended to host more fish than ones placed close together. That finding helps explain why AR-305 combines several vessels with scattered concrete piles rather than one dense cluster, creating a more varied habitat.

Artificial reefs don’t always work

Although artificial reefs can look like a quick fix, they don’t always work. A 2020 meta-analysis of 39 peer-reviewed studies, published by Paxton and colleagues in the journal Frontiers in Marine Science under the title “Meta-Analysis Reveals Artificial Reefs Can Be Effective Tools for Fish Community Enhancement but Are Not One-Size-Fits-All,” found that artificial reefs can match natural reefs in fish density, biomass and diversity, but largely depending on where they’re placed and what they’re built from. The researchers caution that artificial reefs shouldn’t be treated as a universal fix for lost fish habitat.

AR-305 has held up well against that caution. It remains a popular spot for anglers targeting snapper, grouper, amberjack and triggerfish, and a sought-after dive site thanks to its sand tiger sharks and decades-old shipwrecks. AR-305 is just one piece of a much larger system: North Carolina maintains 72 artificial reefs statewide, which officials describe as crucial spawning and foraging habitat for commercially and recreationally important fish species. The state’s Artificial Reef Program is funded in part through an annual $500,000 grant from Coastal Recreational Fishing License revenues, and plans call for roughly one new reef enhancement project per year, spread across the state’s coastal regions. Overall, AR-305 is a clever way to repurpose waste that would otherwise have gone to a landfill, and NOAA’s research backs up its effectiveness. Still, the lesson from Paxton’s team stands: artificial reefs work only when they’re sited and built with care, and North Carolina’s project is a solid example of getting that balance right.