In the restored waters of Kep: how the Cambodian archipelago became a marine sanctuary

A “Hope Spot” at the edge of the world — Recognized by legendary oceanographer Sylvia Earle, the marine area of the Kep archipelago now represents one of the most remarkable conservation success stories in Southeast Asia.

Base Marine Conservation Cambodia - Koh Ach Seh

Behind this silent miracle: eighteen years of relentless effort by a pioneering NGO, concrete structures placed on the seabed, and the return of dolphins.

An archipelago on the brink

Just a decade ago, the waters surrounding the thirteen islands of the Kep archipelago, at Cambodia’s southern tip, were the scene of a silent ecological disaster. Bottom trawlers methodically scraped seagrass meadows, tore apart coral reefs, and depleted the last specimens of marine megafauna. Local fishers returned empty-handed. Dugongs had disappeared. Irrawaddy dolphins—classified as “Endangered” on the IUCN Red List—had become little more than rare ghosts glimpsed in the distance.

It was in this context of devastation that Marine Conservation Cambodia (MCC), founded in 2008, became the very first organization to actively work on marine conservation in Cambodia—initially in the Koh Rong archipelago, and later in Kep province, where it established operations from 2013–2014 onward.

Concrete structures against trawling

MCC’s strategy is based on an innovation that is as simple as it is effective. The organization’s scientists and volunteers deploy what they call “Conservation and Anti-Trawling Structures” (CANTS): four-ton concrete blocks placed on the seabed to physically block trawl nets and boards, create artificial reefs for marine life, and provide refuge for endangered Irrawaddy dolphins.

This project won the National Geographic Society’s Marine Protection Prize in 2018, recognizing the most effective and promising ocean protection initiative.

The results, now measurable, exceed even the most optimistic expectations. After deploying more than 350 habitat restoration structures over the past five years, seagrass regrowth now exceeds 2,000 hectares, and iconic large species—dugongs and dolphins—have returned to these waters.

The return of ghost species

On monitoring team screens, the data tells a story once thought lost. Local fishers report larger catches and more frequent sightings of threatened species such as dugongs and Irrawaddy dolphins—a finding confirmed by MCC monitoring data, which records measurable increases in biodiversity and biomass.

Field surveys by MCC teams have also documented the return of the Irrawaddy dolphin (EN), the Indo-Pacific humpback dolphin (VU), and the dugong to the waters of Kep and Kampot—species many believed had been permanently driven from these shores.

Seagrass meadows, the green lungs of the ocean, are also experiencing a spectacular revival. MCC mapping covering 35,820 hectares recorded, by mid-2023, approximately 6,399 hectares of seagrass, 1,202 hectares of algae, 440 hectares of bivalve beds, and 65 hectares of coral reefs. Kep’s seagrass meadow has proven to be the largest in Cambodia and one of the most diverse, with ten species of seagrass identified.

Recognition: a “Hope Spot” designated by Sylvia Earle

On April 1, 2019, international recognition finally arrived. The Kep archipelago was declared a “Hope Spot” by the international NGO Mission Blue, in recognition of MCC’s conservation efforts in preserving the region’s unique seagrass meadows and sensitive marine species. Mission Blue, an alliance founded by legendary oceanographer Dr. Sylvia Earle, designates Hope Spots as places on Earth that are “critical to ocean health.”

The Marine Fisheries Management Area (MFMA) of the Kep archipelago, established at the national level in April 2018 after four years of intensive work, was one of the drivers behind this international recognition. MCC is an active member of the provincial technical management committee, contributing to boundary demarcation, combating illegal fishing, research, and community initiatives.

An international coalition to save the Khmer sea

Behind every concrete structure placed on the seabed, behind every monitoring mission, lies a complex network of partnerships. In addition to support from Cambodia’s Ministry of Agriculture, Forestry and Fisheries and the Fisheries Administration, MCC receives backing from the French Development Agency (AFD) and, since 2024, major funding from the Asian Development Bank. MCC has been mandated by the Ministry of Agriculture and funded by the ADB to deploy 5,000 structures along the Cambodian coast, from Kep to Kampot, Kampong Som, and Koh Kong.

Koh Ach Seh

MCC is now recognized as a key actor in community-based marine restoration and ocean governance in Cambodia, combining science, community leadership, and policy action to restore marine habitats, reduce illegal fishing, and support sustainable fisheries.

Hope, a tangible reality

What the Kep archipelago demonstrates to the world goes beyond a simple Cambodian case study. The restoration and expansion of seagrass meadows, the increase in fish biomass, and the reappearance of key indicator species—seahorses (Hippocampus spp.), dugongs (Dugong dugon), Irrawaddy dolphins (Orcaella brevirostris), and marine turtles—attest to a restored ecological resilience.

In these waters once thought dead, life has reclaimed its place—not by miracle, but through the determined will of men and women who chose to believe that the ocean, if given the chance, could remember itself.

Sources: Marine Conservation Cambodia, Mission Blue / Sylvia Earle Alliance, Asian Development Bank, International Conservation Fund of Canada (ICFC), National Geographic Society, IUCN Red List, Global Rewilding Alliance.