Functioning Coral Reefs in the Indo-Pacific Respond to Local Management
By Stuart Campbell, Deputy Director of Rare in Indonesia
This blog summarizes a recent paper published by Emily Darling et al. in Nature Ecology & Evolution. The study showcases data collected on coral reefs in the Indo-Pacific, along with related policy and management findings. It includes 2,584 surveys from 2014 to 2107 (a global mass bleaching event with coral reef loss) from 44 countries — from East Africa to South East Asia, the Coral Triangle, and the Pacific. Stuart is a co-author of the study.
When it comes to news about coral reefs, it’s easy to feel doom and gloom, not hope. But based on the most extensive study of its kind, in which I and nearly 100 coral reef scientists took part, we found that functioning coral reefs in the Indo-Pacific still exist — and as my colleague and the study’s lead author, Emily Darling, observes, “It’s not too late to save them.” That is, if we can manage them effectively against threats like climate change and overfishing.
This new publication offers critical perspectives that advance and support our work at Rare in both protecting and managing reefs for improved fisheries catches and food security for coastal inhabitants. If you leave with just one takeaway from the study, it’s that we urgently need to sustain large, complex corals that maintain ecosystem structure, and take immediate action to limit warming to 1.5 Celsius. Many of the functioning reefs were found in climate cool spots — areas with longer time windows between bleaching events due to thermal elevations in sea surface temperatures.
But what’s interesting to Rare, and those of us applying a behavioral approach to addressing coastal overfishing and other threats, like climate change, is this: Reefs influenced by human populations, markets, and agricultural use were associated with a lower abundance of competitive stress-tolerant and generalist corals. This data suggest that local behavior change — which mitigates direct human impacts (e.g., exploitative activities, destructive fishing) or limits agricultural runoff’s impacts — could drive positive environmental change by promoting the structurally complex and calcifying reefs needed for marine ecosystems to thrive. These results support Rare’s global approach through Fish Forever of pairing local, community-based management with behavioral insights and social marketing principles to drive this change.
It’s telling that local management actions, through no-take reserves and restricted management (like restrictions on fishing gears), were associated with higher total coral cover and greater abundance of stress-tolerant, generalist and weedy (non-competitive) corals. To that point, the study recommends local coastal fisheries management as a critical policy and management strategy to help sustain a network of functioning reefs in the Indo-Pacific and avoid ecosystem collapse in the face of increasing climate change impacts.
If you leave with just one takeaway from the study, it’s that we urgently need to sustain large, complex corals that maintain ecosystem structure, and take immediate action to limit warming to 1.5 Celsius.
And these findings further suggest that the type of management approach applied is critically important for sustaining coral reef function. Notably, local management didn’t increase the abundance of branching and plating competitive corals, which are crucial for reef-building. This is consistent with expectations that such corals are often susceptible to extreme heat events and bleaching mortality, which can swamp any potential benefits of local management. The results did suggest, however, that fishing gear restrictions had similar increases in coral abundance to fully no-take areas.
For corals, any management that reduces destructive practices can have direct benefits for coral survival and growth. This paper, which I also co-authored, evidences how coral cover increased with reduced destructive fishing in Karimunjawa National Park, Indonesia (a Rare Fish Forever site).
The study substantiates Rare’s approach to more responsible fishing — encouraging fisher behaviors that drive support and adoption for ‘rules’ that communities vigorously enforce and comply with. It validates that such an approach can lead to a higher abundance of the total coral cover relative to unmanaged sites — even after accounting for climate disturbances and other environmental conditions. And it bolsters our aim to build a movement that dramatically changes the way communities protect their coastal waters and influences the way entire nations and regions manage their fisheries.
