2020 marks four years since Cambodia’s government took a crucial step towards protecting the country’s coral reefs, seagrass and coastal fisheries by establishing its first marine protected area (MPA) in the picturesque Koh Rong Archipelago.

Central to this achievement were intensive consultations and surveys by Fauna & Flora International (FFI) and government partners, ensuring that social, economic and ecological concerns were incorporated into the final protected area design. Creating the new MPA was, however, just the first step, and after four years of locally led management there are critical questions to ask, such as: what effect have these measures had on the Koh Rong marine ecosystem; and are populations of key fish species recovering? In April 2019, a survey team from FFI, alongside local partners Song Saa Foundation and Kuda Divers, dove into the archipelago’s deep, blue waters to find the answer.

Diving in

The expedition divers surveyed 20 permanent monitoring sites across the coral reefs of Koh Rong and also ventured to Cambodia’s distant outer islands to see how these unprotected areas were faring compared to the existing MPA. They collected data on reef fish, coral condition, seabed composition and on invertebrates such as sea urchins.

The fish surveys required scuba-divers to multi-task by swimming along a transect (just a humble measuring tape) and counting the fish that crossed their path, focusing on species of ecological and economic importance. In Cambodia, we concentrate on parrotfish, an important family of grazing herbivores; and grouper, which are top predators in a healthy coral reef ecosystem. Whilst these fish were recorded at worryingly low levels, suggesting intense fishing pressure, their numbers do appear to be gradually increasing since surveys began in 2010. Considering all species together, the numbers of fish observed provided more room for cautious optimism, with populations either stable or increasing.

The team used transects to record fish and invertebrate species. Credit: Matt Glue/FFI
The team used transects to record fish and invertebrate species. Credit: Matt Glue/FFI

Whilst some divers counted teeming fish and navigated armies of bristling urchins, others were recording the abundance and condition of coral species – critical information when assessing reef health. The results presented a mixed picture: significant areas of healthy coral were observed, but there was also evidence that certain types of coral have almost disappeared from Koh Rong. Large “boulder” corals were widespread, whereas species of “branching” corals (ideal refuges for juvenile fish and small invertebrates) appeared scarce.

Signs of recovery

So, what do these results tell us about the impact of the MPA on Koh Rong’s coral reefs?

We cannot be certain, but it seems that the different habitats within the MPA are at least stable. Management measures, in place since 2016, appear to have prevented further decline of this heavily pressurised ecosystem and its vital small-scale fisheries. Much work remains, however, with historically overfished parrotfish and grouper populations still showing only the most tentative signs of recovery, and there is evidence of illegal fishing continuing within the archipelago’s waters.

Grouper are important predators in coral reef ecosystems. Credit: Roger Bruget
Grouper are important predators in coral reef ecosystems. Credit: Roger Bruget

FFI, the fishing communities of Koh Rong, the Cambodian government and other partners are continuing to work on strengthening locally driven management of the MPA, which came under heightened legal protection as a national park in 2018. With support from the Blue Action Fund, the Prince Albert of Monaco II Foundation, the Levine Family Foundation and Arcadia – a charitable foundation of Lisbet Rausing & Peter Baldwin, FFI and partners will continue to build on the early signs of success in Koh Rong, and seek to replicate this approach elsewhere in Cambodia’s coastal waters. We are optimistic that, the next time a scuba survey team dives into the Koh Rong Archipelago, there will be further signs of coral reef stability and recovery.

Read the report here.