What Mollusks Know About Sea-Level Rise: Billion Oyster Project’s Unique Approach to Urban Climate Resilience
Bold headlines warning about the dangers of rising sea levels flood our inboxes: the threat looms over coastal cities, putting infrastructure, jobs, and, most importantly, lives at risk. For the 40 percent of the U.S. population who live on or near the shoreline, the question of what can be done about sea-level rise is increasingly relevant. And the answer may have a shell and a salty flavor.
Oysters have proven to be so much more than just a food to enjoy at happy hour: the little mollusks play a significant role in fostering climate resilience in coastal cities. Billion Oyster Project, a nonprofit based in New York City, is working to combine the restoration of oyster reefs with the education of city youth to build lasting resilience against the plague of sea-level rise and broader climate change.
Why does ocean health matter in the first place? More than 95 percent of the ocean remains unexplored by humans. What we do know is that it moderates climate and weather patterns by absorbing and redistributing heat across the planet. Currents bring warm water and heat to the otherwise cold temperate zones while bringing cool water to chill the otherwise unbearably warm tropical regions. Without this regulation, these places would barely be habitable. Entire economies depend on the ocean for goods, services, transportation, and trade, all of which contribute $9 trillion to U.S. GDP and $2.5 trillion to global GDP annually. More than three billion people worldwide depend on the ocean for food and medicinal ingredients.
Sea level rise is an increasingly important indicator of an ocean in distress, which is why understanding its causes is crucial. Driven by greenhouse gas emissions and a warming planet, melting polar ice and thermal expansion are the biggest contributors to sea level rise. As land-based glaciers and ice sheets melt rapidly due to global warming, the meltwater returns to the ocean, increasing the ocean's total volume. Thermal expansion goes back to basic science: heated particles have more energy to push one another apart, causing the material to expand in volume. As the ocean water absorbs heat from global warming, its volume rises.
Recent reports on the consequences of rising sea levels feel inescapable. In Miami, ocean water seeps into city streets as people attempt to drive to work; in Coastal Louisiana, unusually high storm surges wipe out entire wetlands that the local economy depends on; in Southern California, saltwater from rising sea levels has contaminated underground freshwater aquifers that supply local communities with water. Some places are expected to see a rise of up to 18 inches by 2050, which would further threaten infrastructure, jobs and industry, freshwater supplies, and marine habitats.
The good news is, the outlook isn’t entirely underwater. Innovators can learn from the ocean itself and the biodiverse forces that keep it thriving.
By nature, oysters are a keystone species, meaning they have a disproportionately positive impact on their habitats. While they won’t mitigate the causes of sea level rise, without oysters, coastal ecosystems would be significantly less healthy and resilient. They clump together on the ocean floor to form complex structures that provide a habitat and protection for smaller marine species, supporting biodiversity. As filter feeders, oysters flush water through their bodies, removing excess nutrients and algae. This feature helps clear the water and allows for sunlight to reach greater depths, supporting more species. Their ornate framework also absorbs wave impact and traps sediment to stabilize the coast, protecting against sea-level rise and erosion. The Billion Oyster Project sees the unique abilities of oysters as crucial to helping heal the ocean.
In 2014, amid growing concerns about sea-level rise and historic pollution in the New York Harbor, the Billion Oyster Project was founded to restore oyster reefs in hopes of bringing the Harbor back to life. Pete Malinowski, a teacher at the New York Harbor School and the organization's founder and CEO, recognized the potential benefits of oyster reef restoration at this site, particularly for water purification and mitigation of sea-level rise impacts. As the name claims, the Billion Oyster Project was created with the goal of restoring one billion oysters in the New York Harbor by 2030. When a reef contains one billion oysters, it reaches the threshold of being fully self-sustaining while also supporting nearby ecosystems, setting a durable positive feedback loop in motion. As of 2026, the organization has restored over 200 million oysters and counting.
In addition to its reef restoration, the nonprofit acknowledges the importance of community engagement and education in building enduring solutions. Its mission statement reads: “We believe students protect what they feel connected to.” Since 2014, it has partnered with public schools to engage over 66,000 students through STEM curriculum at multiple levels, teacher webinars, outdoor learning experiences and days of service, and research opportunities, among other educational resources. The nonprofit also partners with local restaurants, businesses, government, policymakers, and other local organizations to further advance its goal of environmental sustainability for the New York City community and beyond.
The Billion Oyster Project teaches us that urban resilience in the face of climate change requires a seamless combination of education and restoration, and that neither is mutually exclusive. While planting oyster reefs may not address the root causes of sea-level rise, healthy marine ecosystems can provide a buffer as problems like flooding and storm surges become increasingly severe. The continued stewardship between communities and their ecosystems is necessary for the planet’s survival.
Not everyone has to restore one billion oysters in their marine waterways to mitigate rising sea levels; it can start at a much simpler level. Studies show that environmental education cultivates ecological quality, aligning with Billion Oyster Project’s foundational understanding of education in environmental resilience. Individuals can educate themselves about keystone species in local marine ecosystems and partner with organizations that protect vulnerable areas. Students can start clubs on campus to involve peers and professors in educational and environmental restoration opportunities. Billion Oyster Project offers a myriad of resources for students, educators, and passionate individuals curious about oyster reef work. Advocating for healthier oceans will benefit everyone, as restoration and education have proven to be the secret sauce for climate resilience.
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