Every day, wildlife conservationists are developing new technologies and techniques that mitigate human footprint and foster a more prosperous future for our ecosystems. Here in South Carolina, our local eco-stewards at the South Carolina Department of Natural Resources (SCDNR) work tirelessly to protect our waterways, wildlife, and all stocks of our natural resources. When it comes to oyster conservation efforts, the South Carolina Oyster Recycling and Enhancement (SCORE) program leads the way.

Recently, the SCORE program has introduced a new technology that is changing the conservation game by combating erosion, cultivating new oyster reefs, and cleaning our coastal waters simultaneously. These superhero structures, called Manufactured Wire Reefs (MWRs), are making waves in the field - here’s what you need to know about them.

Effective conservation always begins with one thing: identifying and understanding the problem. The funny thing about oyster habitat conservation is that every state's problem is different, so solutions must be area-specific. 

To understand how MWRs are making a difference in South Carolina, let's first look at how oyster reefs naturally form. Oysters go through several stages during their development: Spawning, Larval Stage, Settlement, Juvenile Stage (Spat), and Maturity. During Spawning, adult oysters release millions of microscopic larvae into the water, hoping they find their way to a suitable hard surface. In the larval stage, these microscopic oysters use tiny hairs, called cilia, to swim around our coastal rivers and creeks, searching for food and a place to settle. After about 3 weeks, they find a hard surface and attach themselves (this is when MWRs come in to play!). Once attached, they undergo a metamorphosis and transform into juvenile oysters, or “spat,” and grow for 1-3 years before reaching maturity. The time it takes for oysters to mature depends on a handful of factors like habitat, food availability, water temperature, salinity, environmental conditions, etc. Most notably, suitable hard substrates promote quicker, healthier growth for oysters, while poor substrate availability and unfavorable settlement can slow down their development. 

Here in South Carolina, we are fortunate to have an abundance larval oysters, but what we lack is an abundance of hard, calcium rich surfaces for these larvae to settle on. Sure, Oysters can grow on wooden dock pilings or even on a single rock sticking out of the Pluff Mud, but what they thrive on are Calcium-rich, hard substrates such as old, recycled oyster shells - this is where MWRs come into play.

MWRs are composed of 3 environmentally friendly materials: a wire mesh framework, recycled oyster shells, and a bit of coconut husk. The wire mesh framework and recycled oyster shells' importance are somewhat intuitive, but coconut husk? Why use that? Coconut husk or "coir" is a naturally occurring, renewable resource that is biodegradable and eco-friendly. Its use helps reduce reliance on synthetic materials which could degrade and release harmful microscopic waste into our waterways. Additionally, coir promotes healthy sediment accumulation on the shore-facing side of the MWR, stabilizing the structure and providing an excellent environment for the growth of our resident Spartina grasses. Lastly, coir's natural resistance to decay and ability to withstand harsh, salty marine conditions add to the MWRs overall durability and makes it an even more viable structure.

The robust design and thoughtful components of MWRs create a stable, effective, and sustainable foundation for oyster reefs to begin their life cycle. When fully built, MWRs are about 5 feet long and expose nearly 15 square feet of viable, hard substrate for larval oysters to attach to. This hard substrate is made entirely of recycled oyster shell that have been cleaned, quarantined, and picked through by the SCORE program, making it one of the best settlement locations in our waterways. Many of these recycled oyster shells come from local restaurants, events, or festivals, and have now been repurposed for ecological benefit - how awesome is that!

Just last week, our team was able to take another day off from work and help give back to our ecosystems by visiting Kiawah’s Mingo Point: an area that suffers from intense shoreline erosion and lack of hard substrates - a perfect MWR deployment site. The area was rich in Spartina Grass and Fiddler Crabs, but lacked oyster beds and hard, calcium rich substrates where spat can attach themselves. With few oyster reefs near by, the shoreline at Mingo Point is eroding quickly, harming spartina grass habitat. The MWRs planted last week will serve as the foundation for new oyster reefs, building a solid foundation for that section of the Kiawah River’s localized ecosystem. Egrets, Blue Crabs, Redfish, and up to 130 different native species will rely on this new section of river as a food source, protection for their young, and a water filtration system.