In the last decade, the Indonesian Government has made mangrove restoration part of the country’s national agenda. In response to huge mangrove loss and degradation the Government, with support from national and subnational government stakeholders, has set a target of restoring 50,000 ha of mangroves by 2024. The recovery of mangrove forests as a blue carbon sink, commonly achieved through mangrove plantation, is one of the aims of the government’s policy but the effectiveness of those projects to abate carbon emissions is still in question.

A recent study of the Institute for Marine Research and Observation (IMRO) – Ministry of Marine Affairs and Fisheries led by Dr. Sidik, aimed to help quantify the effectiveness of mangrove restoration in abandoned aquaculture ponds in Bali.

The research featured mangrove development through plantation and non-plantation methods in abandoned shrimp ponds. IMRO then monitored their growth and carbon capture from 2011 onwards. The study found that mangrove restoration in abandoned aquaculture ponds can generate climate mitigation benefits from biomass growth but also sediment accumulation where ‘blue carbon’ is also stored.

The findings demonstrated that by removing some man-made aquaculture structures such as pond dykes and gates, water flow into the ponds can help to naturally and rapidly regenerate mangrove ecosystems, without the need for plantation.

The success of IMRO’s study shows that restoring natural hydrology and water flows in mangrove ecosystems can help to rapidly restore mangroves without the need for plantation. IMRO hope that their study can help to increase scientific knowledge and allow for the implementation of similar projects in Indonesia and around the world – and help to optimise blue carbon sequestration from mangrove restoration.