Restoring the ocean, from kelp forests to coral reefs

Marine rewilding is the large-scale restoration of ocean ecosystems by recovering lost species, habitats, and ecological processes. Unlike traditional marine conservation, which often focuses on protecting what remains, rewilding actively seeks to restore what has been lost, returning apex predators like sharks, rebuilding destroyed oyster reefs, replanting seagrass meadows, and creating conditions for natural recovery. The concept draws on terrestrial rewilding principles but adapts them for the unique challenges of the ocean environment.

Ocean ecosystems are among the most powerful carbon sinks on Earth. Seagrass meadows store carbon up to 35 times faster than tropical rainforests, and kelp forests can capture and sink substantial quantities of organic carbon to the deep ocean. Restoring whale populations enhances the biological pump that moves carbon from the ocean surface to the deep sea. Rebuilding marine ecosystems is therefore not just a biodiversity goal, it is one of the most cost-effective natural climate solutions available.

Several projects stand out for their scale and impact. The recovery of humpback whale populations following the end of commercial whaling demonstrates that marine megafauna can recover given protection. Seagrass restoration in Virginia, USA, has seen meadows return to over 9,000 acres from near-zero following a community-led seeding program. Oyster reef restoration projects in South Australia have reversed functional extinction of eradicated reefs within years. In California, sea otter reintroduction has driven kelp forest recovery by controlling sea urchin populations.

Marine protected areas (MPAs) are fundamental to rewilding because they remove the primary pressures, fishing, disturbance, and pollution, that prevent ecosystems from recovering naturally. Strictly enforced no-take MPAs consistently show higher fish biomass, greater species diversity, and more complex food webs than unprotected areas. The global 30x30 target, protecting 30% of the ocean by 2030, aims to create a network of MPAs large enough to allow genuine ecological recovery rather than just slowing decline.

There are many ways that ordinary people like you can support marine rewilding. Reducing plastic use and preventing pollution reaching the ocean removes pressure from marine habitats. Supporting sustainable seafood choices reduces overfishing pressure. If you live near the coast, volunteering with seagrass seeding projects, citizen science monitoring programs, or beach and intertidal habitat surveys contributes directly. Campaigning for stronger MPA designation and enforcement, and supporting organizations working on marine restoration, creates the political conditions for rewilding at scale.