Coral conservation programmes in Bali, Indonesia: restoration of degraded reefs and localised socioeconomic benefits.

Abstract

Coral reefs, the “ocean’s rainforests”, are valued at over US $1 Trillion globally through the provision of ecosystem services such as including food production, biogeochemical cycling and tourism. Over the past several decades, these ecosystem services have been threatened by anthropogenic threats, which continue to cause a worldwide decline in coral reef biodiversity, functioning and habitat structure. Even with global warming limited to 1.5oC (the IPCC’s most optimistic scenario), the projected future for coral reefs is bleak, and this is expected to cause devastating impacts on the human communities who depend on coral reef health for their livelihoods. In locations where coral reef degradation has already occurred, some local communities have established restoration programmes which utilise tools such as artificial reef deployment, coral propagation and marine protected area establishment, which aim to restore some of the ecosystem benefits associated with healthy natural reefs. Indonesia has experienced widespread coral reef degradation in recent decades and coral reef restoration programmes have been established across the archipelago as a response to this, with the nation now being recognised to have more of these programmes than any other country in the world. A substantial proportion of this reef restoration work is concentrated in the island of Bali. Despite the large number of these programmes on the island, very few monitor the health of their reefs, and even less publish research papers which assess if their work has resulted in tangible ecological and social benefits. My PhD aimed to evaluate the extent to which coral reef restoration programmes in Bali have restored reef ecology, ecosystem functioning and generated localised social benefits. The primary research location was in Tianyar, north east Bali, on a coral reef restoration programme which had deployed over 20,000 artificial reef units at the end of 2023. Additionally, several other secondary coral restoration sites in Bali were also assessed as part of this research, which allowed comparisons between each of them. To assess biological community structure, this research employed various ecological surveying techniques (such as remote under water video to quantify fish communities and photoquadrats to quantify benthic communities). To assess ecosystem functioning, water samples were taken to test for inorganic nutrients, and sediment (surface and sediment trap) samples were taken to test for particulate organic carbon. To assess the generation of social benefits from coral reef conservation programmes, semi structured interviews and focus group discussions were held with stakeholders in three different coral reef conservation regions in Bali. My results showed that fish communities on artificial reefs became similar (ecologically equivalent) to those on a nearby CR over a 3 year period, whilst benthic populations remained quite different. I found that artificial reefs showed some resemblance to CRs in terms of functioning, but were not functioning fully as natural reefs. My findings also showed coral reef restoration can lead to localised social benefits through additional marine tourism, and can also promote the generation of pro- environmental behaviours within the community, through education and empowerment of local leaders which create ‘ocean empathy’ amongst their people. Overall, the findings of my PhD found that coral reef conservation programmes in Bali have been effective in capturing some of the benefits of natural CRs, although they were not yet shown to act as a direct replacement for the natural reefs which they may aim to replace. More work is needed to assess the benefits of coral reef conservation programmes over longer time scales.