Wildlife & Biodiversity

Over half of world’s mangroves face collapse due to human actions and climate change

Mangrove ecosystems play crucial role in sequestering carbon, providing livelihoods and protecting populations from hurricanes, cyclones and typhoons

 
By Himanshu Nitnaware
Published: Thursday 23 May 2024
The mangrove ecosystems of south India were identified as critically endangered. Photo: iStock

A recent global assessment by the International Union for Conservation of Nature (IUCN) has painted a grim picture for the world’s mangrove forests. The analysis revealed that more than 50 per cent of these vital ecosystems are on the verge of collapse due to a combination of human activities and climate change.

Activities such as deforestation, development, pollution, and dam construction pose direct threats to mangrove ecosystems, the report said. Furthermore, climate change factors such as increased frequency of severe storms and sea-level rise place them at risk of extinction. 

It is the first time that mangroves along the road have been assessed using the IUCN Red List of Ecosystems as a measurement tool. The IUCN Red List of Ecosystems serves as a global standard for assessing ecosystem health.

The assessment was carried out in 36 regions across 44 countries, with over 250 experts from various institutions including IUCN Commission on Ecosystem Management, IUCN Species Survival Commission and Global Mangrove Alliance. 

The mangrove ecosystems of south India, Sri Lanka, the Maldives and North West Atlantic were identified as critically endangered, while the Agulhas, Central Pacific, East Coral Triangle, east central and south east Australian shelf, Red Sea, Gulf of Aden and South China Sea were classified as endangered.

Mangrove ecosystems cover an area of 150,000 square kilometres, primarily on tropical, subtropical, and warm temperate coasts around the world. Approximately 15 per cent of the world’s coastlines have a mangrove presence.

These unique ecosystems are crucial for biodiversity conservation, offer livelihoods to local communities and reduce the impact of climate change. 

According to the assessment, 50 per cent of the ecosystems examined were classified as vulnerable, endangered, or critically endangered, with a risk of collapse by 2050. 

It showed that nearly 20 per cent (19.6 per cent) of the assessed mangroves are at high risk and have been marked as endangered or critically endangered, indicating a severe risk of collapse. 

Nearly 33 per cent of the mangrove systems on the plant are threatened by the impacts of climate change. 

Mangrove ecosystems sequester approximately 11 billion tonnes of carbon, which is roughly three times the amount of carbon stored by tropical forests of comparable size. It also protects 15.4 million people and supports 126 million fishing days per year, providing a vital source of income for local communities. 

According to the assessment, if business as usual continues and no additional conservation efforts are implemented, approximately 5 per cent, or over 7,000 square kilometres, of mangroves will be lost, while nearly 23,672 square kilometres, or 16 per cent, of these ecosystems will become submerged.

If this becomes a reality, the world faces the risk of losing about 1.8 billion tonnes of carbon sink, which is about 16 per cent of the current carbon stored in mangroves. These numbers amount to $13 billion if compared with voluntary carbon market prices.

It would directly endanger 2.1 million people by exposing them to coastal flooding, as well as impact 17 million days of fishing effort per year, accounting for approximately 14 per cent of current mangrove-assisted fishing. 

The study concludes that maintaining mangrove ecosystems around the world will play an important role in mitigating the effects of climate change because healthy mangroves can combat sea level rise while also providing inland protection from extreme weather events such as hurricanes, typhoons and cyclones. 

According to the assessment, maintaining ecosystem integrity will be critical in helping mangroves combat the effects of climate change. Mangrove protection and restoration can contribute to increased resilience. 

“It is recommended that countries should always use national, sub-national or other lower scale assessment results whenever these are available,” the assessment noted.

In a press statement issued by IUCN, Angela Andrade, chair of IUCN Commission on Ecosystem Management, said, “Mangrove ecosystems are exceptional in their ability to provide essential services to people, including coastal disaster risk reduction, carbon storage and sequestration, and support for fisheries.”

She added that the loss of the mangrove ecosystem could have disastrous consequences for people and nature around the world. 

Grethel Aguilar, director general of the IUCN, stated that the Red List of Ecosystems is critical for tracking progress towards the goal of halting and reversing biodiversity loss, as outlined in the Kunming-Montreal Global Biodiversity Framework. 

“The assessment’s findings will help us work together to restore the mangrove forests that we have lost and protect the ones we still have,” she said.

Subscribe to Daily Newsletter :

Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.