[Image above] Example of an oyster reef in North Carolina. In recent years, governments, conservation groups, researchers, and oyster growers in states along the U.S. Atlantic and Gulf coasts have started seriously investing in oyster restoration projects. Credit: Carolina’s marine lab, Flickr (CC BY-NC-ND 2.0)
When I think about the effects of climate change on marine habitats, coral is usually the first example that comes to mind.
Corals are marine invertebrates that play an important role in reef building. In recent decades, corals have experienced massive bleaching events in response to warming waters. Many of these corals have subsequently died, leading entire reef ecosystems—on which people and wildlife depend—to deteriorate.
Images of bone-white corals that have undergone bleaching events are widespread, and many people are aware of the work being done to support coral restoration (even ceramics are involved!). Fewer people, though, know about the loss of another marine animal that is also vital to global ocean health—oysters.
Oyster is the common name for several different families of salt-water bivalve mollusks that live in marine or brackish habitats. While these mollusks are commonly known for their ability to produce pearls, they play a much more important role in the ecosystem than generating pretty jewelry.
“Oysters are a crucial component of global ocean health. These animals filter and clean the surrounding water and provide habitat, food, and jobs. In some places, oyster reefs can serve as barriers to storms and tides, preventing erosion and protecting productive estuary waters,” the National Oceanic and Atmospheric Administration explains on its website.
Oysters were once plentiful in coastal areas throughout the United States, but decades of overfishing, habitat loss, pollution, and disease proved devasting for the mollusks. Now, oyster populations are at historic lows.
Fortunately, oysters are resilient animals that, under the right conditions, can rebuild productive reefs quickly, often in two to five years. And thanks to recent initiatives by governments, conservation groups, researchers, and oyster growers in states along the U.S. Atlantic and Gulf coasts, significant progress is already being made toward oyster reef restoration.
This Monday, Virginia-based television station WAVY-TV published an article on the restoration work being done by Lynnhaven River NOW, a nonprofit organization in Virginia Beach, Virginia. One of their recent projects not only aids in oyster restoration but also resolves a longstanding eyesore in the local community—a 60-foot-high pile of concrete off I-264.
WAVY-TV first reported on the massive pile of concrete in 2019, when the recycled concrete business that oversaw the rubble was taken to court for violating the city height ordinance. To prevent the concrete from going into a landfill, the business made a deal with Lynnhaven River NOW, which began moving the rubble into the Lynnhaven Inlet to serve as a substrate for oysters to settle on.
“It’s a substitute for oyster shells, which are in very rare supply these days,” says Brent James, Lynnhaven River NOW oyster projects coordinator and notable trees coordinator, in the WAVY-TV article.
An article on The Virginian-Pilot explains that the new reef of crushed concrete—5,000 tons—will be built in stages, in partnership with the Chesapeake Bay Foundation, the city of Virginia Beach, and the National Fish and Wildlife Foundation. The concrete will be distributed by blowing it from a barge into the water at great force to build a foot-high reef, which you can see in the video below.
The project fits into the larger Chesapeake Bay Watershed Agreement, a landmark accord signed in 2014 that establishes goals and outcomes for restoration of the Bay, its tributaries, and the lands that surround them. It will contribute to the agreement’s goal of 152 acres of restored oyster reef in the Lynnhaven River.
While this project was the first time Lynnhaven River NOW used recycled concrete in oyster restoration, the use of concrete as a substrate is established in the literature. Learn more about the use of concrete and other alternative substrate materials for oyster restoration in this open-access article.