Few ecosystems punch above their weight quite like seagrass meadows. These humble underwater pastures, spanning over 300,000 square kilometers across six continents, quietly perform a remarkable array of ecological services. They stabilize shorelines, shelter marine life, and sequester carbon at rates up to 40 times greater than terrestrial forests. Yet, like so many unsung heroes of the natural world, seagrasses are in retreat. Since the late 19th century, nearly 30% of their global area has vanished, and at least 22 of the world’s 72 known species are in decline. The loss carries grave consequences: without seagrasses, coastal fisheries falter, carbon sinks shrink, and the ocean grows more acidic.
This World Seagrass Day, however, brings a rare dose of optimism. A new ‘how-to’ handbook offers a practical guide for restoring these beleaguered ecosystems. Published by the Anthropocene Institute’s ocean program, the handbook is grounded in a restoration effort at California’s Elkhorn Slough. Scientists from Sonoma State University, the University of California, Santa Barbara, San Francisco State University, and the University of California, Davis, orchestrated an eelgrass revival there that saw restored meadows expand 85-fold in just three years. The findings, published in Ecological Applications, offer a replicable model for global restoration efforts.
Seagrass restoration has long been an arduous endeavor, often plagued by poor survival rates and slow growth. But the Elkhorn Slough project provides a playbook for success. The researchers identified optimal planting conditions—light availability, current flow, and sediment stability—that significantly boost establishment rates. One of their more surprising discoveries was the role of sea otters. By preying on crabs that uproot seagrass shoots, these charismatic predators improve the odds of restoration success, highlighting the interconnectedness of marine ecosystems.
The handbook translates these insights into actionable steps for community groups and conservationists worldwide. It arrives at a critical moment. With seagrass meadows helping to mitigate climate change by capturing 83 million metric tons of carbon annually, their restoration is an imperative, not a luxury. Each square meter generates up to 10 liters of oxygen per day, sustaining marine biodiversity while buffering against ocean acidification.
Beyond their ecological virtues, seagrasses offer tangible economic benefits. Healthy meadows underpin commercial fisheries and fortify coastlines against erosion, reducing costly storm damage. The economic value of their services is estimated at $22,832 per hectare per year—yet their contributions remain largely overlooked in global conservation agendas.
The United Nations’ designation of March 1 as World Seagrass Day is a step toward greater recognition. But real progress requires action, not just awareness. This new handbook equips communities with the tools to turn the tide on seagrass loss. If its lessons are widely adopted, the quiet resurgence of seagrass meadows may yet become one of conservation’s great success stories.
