Seagrass conservation key to global biodiversity and climate targets, studies show

A recent review published on February 28, 2025 in Nature Reviews Earth & Environment by Carlos M Duarte, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia and team shows that seagrass is declining worldwide due to human activities. 

According to this review, seagrass has been declining at a rate of 1-2 per cent per year for the past century and nearly 5 per cent of species are now endangered.

They say that safeguarding 30 per cent of seagrass by 2030 could protect over 750 fish species, store millions of tons of carbon and sustain coastal communities.

Seagrass meadows are one of the most important but least appreciated ecosystems on Earth. They are better than trees for capturing carbon and providing food for millions of people.

These underwater plants can store carbon up to 35 times faster than tropical rainforests, locking it away for thousands of years. Yet, their importance is not recognised by more popular conservation narratives like blue carbon initiatives.

Additionally, they protect marine life and coastlines. Seagrasses grow in shallow coastal waters and serve as nurseries for fish, turtles and dugongs. They provide shelter for 121 threatened marine species and nearly 750 fish species, contributing to over 20 per cent of global fishery landings. 

Beyond supporting marine life, seagrass also acts as a natural barrier, protecting coastal communities from storms and erosion. 

India possesses a coastline that has been recalculated to span approximately 11,098 kilometers as of 2023-24, reflecting a 48 per cent increase from previous measurements.  Despite this extensive coastline, it accounts for less than 0.25 per cent the world's total coastline.

However, about 10 per cent of the world's coastal population resides along India's shores, underscoring the critical importance of these areas.

India too has vast seagrass meadows, home to 16 species of seagrass with major concentrations in the Gulf of Mannar, Palk Bay, Andaman and Nicobar Islands, Lakshadweep Islands and the Gulf of Kutch. 

A 2022 study estimated that India’s seagrass covers 516.59 square kilometres, with the ability to absorb 434.9 tonnes of carbon dioxide per sq km per year. This makes seagrass a powerful but underappreciated tool in climate action.

Though there is no comprehensive study on the seagrass associated floral and faunal composition in the country, about 1,250 species of flora and fauna including endangered dugong and green turtles are reported from this fragile ecosystem. 

We are losing biodiversity fast. A 2024 study by Balaji Vedharajan, published in the Journal of Indian Society of Remote Sensing, mapped seagrass along Tamil Nadu’s Manora coast using advanced acoustic technology and ground-truthing techniques. 

The findings were alarming, while 46 per cent of the surveyed area had seagrass and seaweed cover, 54 per cent was just open seafloor. This means there’s a huge opportunity for restoration, but more importantly, we need to stop the destruction in the first place.

Despite laws to protect coastal ecosystems, enforcement remains weak. Pollution from cities, industries, and agriculture continues to degrade these meadows, while coastal development and tourism put additional pressure on fragile habitats. 

However, there is hope. Some countries have successfully restored seagrass by improving water quality, establishing marine protected areas, and launching conservation projects.

Currently, 23.9 per cent of known seagrass areas are in marine protected zones, and nearly 2,000 restoration projects have been initiated worldwide, according to Duarte's review. 

For example, in Virginia in the United States, a large-scale project has successfully restored approximately 1,700 hectares of Zostera marina, leading to the recovery of associated invertebrate populations.

In India, notable restoration initiatives have been undertaken. Between 2011 and 2020, researchers restored 14 acres of degraded seagrass areas in the Gulf of Mannar and Palk Bay, achieving a success rate of 85-90 per cent.

Additionally, the Organization for Marine Conservation, Awareness and Research has been actively involved in community-based seagrass restoration projects in Palk Bay, employing eco-friendly methods such as bamboo frames and coconut rope to transplant seagrass sprigs.   

Studies like the one in Manora provide crucial data for conservation planning. But work is needed on ground.

Seagrass protection must become a national priority. It should be integrated into broader marine conservation policies with strict enforcement. Scientists, conservationists, policymakers and local communities must work together to safeguard these ecosystems for the future.