Image Credits: Restoring oyster populations benefits local ecosystems and may help mitigate climate change’s impacts on coastal communities. That’s why groups like Orange County Coastkeeper are working to reintroduce native oysters to coastlines throughout the US. Photo courtesy of Jonathan Wilker/Purdue University
Audio Editing by: Marie Hogan Blurb by: Amanda Neslund Script by: Marie Hogan
Oysters’ Role in Living Shorelines
Oysters can serve as an important environmental solution to shoreline restoration. Oyster reefs can provide habitat for hundreds of marine species, improve water quality (as an adult oyster can filter up to fifty gallons of water a day), and protect against erosion and storm surges. Oysters also help stabilize sediments and wave energy, which reduces coastal erosion and the impacts of sea-level rise. As filter feeders, oysters help remove excess nutrients from the water and maintain healthy water quality. This ecosystem service is especially important with urban and agricultural run-off entering waterways, as oysters filter excess nitrogen, which can help prevent harmful algal blooms. Oyster restoration is important for conservation as well, as within the past two hundred years nearly 85% of global oyster reefs have been lost from over harvesting, wetland loss, human development, pollution, and other anthropogenic factors. Oyster reefs also serve as natural flood control and sea-level rise solutions, and compared to man-made solutions like seawalls and levees, oyster reefs are more cost-effective and less disruptive to the environment. Oyster reef restoration is now being used for coastlines throughout the US, including New York, Moss Landing, and Newport Beach.
Orange County Coastkeeper’s Approach
Orange County Coastkeeper has led the shoreline restoration in Newport Beach since 2017, re-introducing both native Olympia oysters and native eelgrass. To build a habitat where oysters could settle in Upper Newport Bay, Coastkeeper and its volunteers hand-sewed over 500 bags, using coconut coir, to transport 40,000 pounds of Pacific oyster shells. Many of the oyster shells were donated by local restaurants. Coconut coir is a natural fiber, allowing Orange County Coastkeeper to avoid introducing any plastics during the restoration process. Since the initial restoration, CoastKeeper has been monitoring the restored oyster beds yearly and found signs of healthier and more sustainable coastline.
The Orange County Coastkeeper has also worked to restore eelgrass in the Upper Newport Bay. Eelgrass is a shallow coastal seagrass and foundational species, as it provides habitat and food for many juvenile fish, lobsters, and shellfish. Eelgrass has been targeted for restoration because it provides many critical ecosystem services from oxygen production and nutrient cycling, to providing “carbon service” as it absorbs carbon which helps fight ocean acidification. In 2012, Orange County Coastkeeper worked in collaboration with the Department of Fish and Wildlife staff at the Back Bay Science Center to plant 0.3 acres of eelgrass. The goals of their restoration were to increase the diversity or abundance of native species, establish a sustainable eelgrass habitat, and restore the economic value of the recreational and commercial fishery in the Bay. The Coastkeeper’s efforts have been successful: Upper Newport Bay now has over one acre of eelgrass habitat.
Claire Arre is the Orange County Coastkeeper’s Marine Restoration Director. In her role, she manages the shoreline restoration program and works to restore the health of Orange County waters. Arre graduated from California State University, Long Beach with a Bachelor of Science in Marine Biology and received her Master of Science degree in BIology from California State Polytechnic University, Pomona. In her free time, Claire volunteers at Cabrillo Marine Aquarium as a Whale Watch naturalist.
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Ethan: I’m Ethan Elkind, and you’re listening to Climate Break: Climate Solutions in a hurry. Today’s proposal: Using oysters and other native species to protect coastlines against climate change-induced storm surges and erosion. Claire Arre, Marine Restoration Director at Orange County Coastkeeper, explains.
Claire Arre: Looking forward to what the climate is going to do to our coastal ecosystems, our problems are going to build on top of each other, so we need to find better solutions.
Claire Arre: Oysters filter water, help water quality, and they really are kind of a natural wall barrier. And so that’s actually why we call it a living shoreline project — so it makes our shorelines more resilient to things like erosion, as well as sea level rise.
Ethan: Traditionally, we’ve used human-made structures to protect coastlines, but they’re expensive to maintain and can sometimes increase erosion over time. Arre says that in the face of climate change, we need a new approach.
Claire Arre: Unlike things like riprap or bulkheads — that humans really have to protect and they don’t really create a lot of habitat — oysters have the ability to really create a living space and they will continue to move up the shoreline, creating a wider bed as sea level rises. And the hope is, well, we can overcome some of that squeeze.
Ethan: To learn more about how Orange County Coastkeeper is using native species to bolster shorelines from climate change and to get involved with similar projects in your area, visit climatebreak.org.