Regenerative Ocean Farming: Can We Farm Underwater?
Written By Nicole Zhu
Edited By Brianna Beckham
On land, farming is wide stretches of soil, the steady rumble of tractors, and the slow patience of sun, rain, and care. The scent of earth, rain feeding the crops, tomatoes and herbs ripening into a fresh salad, eggs cracking into an omelet, bacon sizzling alongside—a true farm-to-table feast.
Now picture that underwater. The plentiful garden fruits are replaced by ribbons of green seaweed stretching toward the light. Oysters line the rocks below, filtering the ocean with every breath. This new vision, known as regenerative ocean farming, has begun to make waves. As demand for seafood rises, traditional aquaculture alone is projected to fall short, risking further biodiversity loss. According to Planet Tracker, regenerative ocean farming could generate an additional 45 million metric tons of seafood. But what exactly is it? And will we need to start thinking about farmers of the sea?
At its core, regenerative ocean farming means growing food and other resources using the ocean’s natural systems. Shellfish like oysters, clams, and mussels act as natural purifiers, improving water quality. Seaweed farms capture carbon on a massive scale; a single acre of kelp can absorb twenty times more carbon dioxide than a forest of the same size on land. Some farms combine methods in what is called integrated multi-trophic aquaculture, where multiple species support one another in a closed-loop system. Waste from one species becomes sustenance for another, mimicking the balance of wild ecosystems.
The potential extends far beyond food production. Regenerative ocean farms can restore habitats, slow coastal erosion, and create artificial reefs that support marine life. As climate change continues to erode shorelines and weaken coral ecosystems, these systems may become vital tools for ecological recovery and long-term resilience.
Photos from pexels.com. Curated by Kailey Klibansky (kk995@cornell.edu).
Still, the idea is not without challenges. Because the practice is relatively new, scientists are still uncovering its unintended consequences. Seaweed farms rely on ropes and synthetic infrastructure that can leach pollutants or entangle sharks, rays, and turtles. Large-scale cultivation also risks spreading invasive species or fostering disease. In some cases, farmed seaweed has even outcompeted reef-building corals, starving them of nutrients and space.
Others, however, are working to ensure regenerative ocean farming builds bridges rather than barriers. Bren Smith, founder of the nonprofit GreenWave, envisions a model that “breathes life back into the ocean while feeding local communities.” His approach relies on simple, low-cost underwater scaffolding that is easy to replicate. The farms tread lightly, leaving room for fishing, boating, and swimming. Smith notes that his designs have never led to marine mammal entanglements. GreenWave also collaborates with Indigenous groups, including the Native Alaska Conservation Foundation, to restore kelp beds and herring stocks that are vital both ecologically and culturally.
Economically, the promise is striking. The World Bank estimates that farming seaweed in just five percent of U.S. waters could support up to 50 million jobs across related industries. In Denmark, Joachim Hjerl of Ocean Harvest sees regenerative farms as a way to stabilize incomes for coastal fishers. By combining fishing, farming, and even eco-tourism, he argues, communities could build a more resilient ocean economy. Regenerative farming shows great promise, offering not only a path toward food security but also a blueprint for sustainable livelihoods protecting both people and the planet.
Nicole Zhu ‘28 is in the College of Agriculture and Life Sciences. She can be reached at nz274@cornell.edu
