A partially restored site at Ramganga in Indian Sundarbans. Credit: Sahana Ghosh
Densely planted multiple species of mangroves and salt-tolerant grasses have partially restored mangrove patches around Ramganga village in Indian Sundarbans1.
This has increased near-shore native fish and edible crabs, which local people depend on for their livelihoods.
The restored mangrove belt and a landward dyke at the Ramganga site formed a hybrid barrier that thwarted the negative effects of two cyclones, ‘Amphan’ and ‘Yaas’, says a team of researchers at West Bengal State University in Kolkata.
The scientists, led by Krishna Ray, planted native true mangrove species, locally threatened mangrove species and salt-tolerant grasses in 31 small, degraded mangrove patches on the banks of the Saptamukhi-Gobadia-Barchara-Mridangabhanga rivers in the Indian Sundarbans.
They also applied growth-promoting bacteria isolated from the roots of a specific mangrove species.
The team, which included researchers at the Indian Institute of Science Education and Research Kolkata, monitored the mangroves between 2014 and 2023.
Post-planting, naturally regenerated mangrove seedlings steadily increased at the Ramganga site from 2014 to 2022. This suggests that once begun, the restoration process can become self-sustaining without human intervention.
In addition, the diversity and abundance of surface mobile organisms rose across the Ramganga site, which attracted horseshoe crabs. Such organisms hinder the conversion of sulfate to sulfide. Sulfide toxicity prevents seedling colonisation in mangrove sediments.
