New research shows Aldabra's mangroves are crucial to Seychelles' climate change mitigation   |04 November 2022

Aldabra’s mangroves are crucial to Seychelles’ climate change mitigation © Martin van Rooyen

A new paper reveals that Aldabra's 1720 hectare (ha) mangroves store over 66,000 tonnes of carbon, the highest mangrove carbon stock contribution in Seychelles.

The study was conducted by researchers from the Seychelles Islands Foundation (SIF) and the University of Zurich and has been published in the journal, Ecological Indicators. Their findings confirm that Aldabra's mangroves are a substantial contributor to climate change mitigation in Seychelles with the equivalent of 243,000 tonnes of carbon dioxide stored in Aldabra’s mangrove forests – nearly half the annual fossil fuel emissions of Seychelles (520,000 tonnes of CO2).

Mangroves are particularly effective at storing atmospheric carbon dioxide as carbon, and can absorb four times more carbon than forests on land.

However, there have been no estimates so far of mangrove carbon stocks in Seychelles and how they can be used to manage island landscapes.

To address this, the researchers aimed to quantify the carbon stored in Aldabra’s mangroves, representing 78% of the total extent of mangroves in Seychelles, and the factors that influenced this.

On Aldabra, they found that the greater the variability in water levels, the greater the soil nutrients and the overall tree carbon pool.

The study's lead author, Annabelle Constance, SIF's science coordinator, stated, “We know that mangroves are essential for coastal protection and biodiversity. Our research shows another critical role of mangroves in buffering against the impact of climate change. To do that, mangroves need an enabling environment. Therefore, it is not enough to only protect mangrove trees; we must protect their environment – the whole ecosystem.”

SIF’s chief executive and co-author of the paper, Dr Frauke Fleischer-Dogley, commented: “From a management perspective, this study highlights the critical role that carbon-dense forests like Aldabra can play when viewed on a national scale, especially for island nations like Seychelles. For many islands, deforestation or degradation of mangroves can significantly influence the regional carbon balance, and SIF fully supports Seychelles’ pledge to protect 100% of its mangroves by 2030.”

The results of this research are already being used to inform Seychelles’ nationally determined contributions to the United Nations Framework Convention on Climate Change, which tracks efforts by member countries to reduce national emissions and adapt to the impacts of climate change.

To encourage the uptake and sharing of information from this research to national and international stakeholders, the authors have made the article and corresponding data publicly available on this link: https://doi.org/10.1016/j.ecolind.2022.109292

Press release from SIF