Listening to the Tide

15 Jul, 2025

Traditional knowledge of Mangroves along India’s coasts

We often talk about mangroves for the protection they offer against storms or the carbon they store. Less often do we talk about the knowledge they have shaped.

Along India's coastline, generations of fishers, farmers and honey gatherers have watched mangroves closely. They noticed which trees flowered before the shrimp arrived, which leaves hinted at rising salinity, and which roots told them the tide was turning. Some of these observations became customs. Others became sayings that continue to be passed from one generation to the next.

Here are a few examples from different parts of India.

1. Reading salinity through the grey mangrove (Andhra Pradesh and Gujarat)
   The grey mangrove (Avicennia marina), known locally as Cheriya, grows along both the east and west coasts. In the Godavari Delta, farmers pay attention to its leaves. Yellowing leaves are often associated with increasing salinity in the soil, signalling that it may be time to move cattle. In Kutch, fishers associate the tree's budding season with the arrival of shrimp in shallow creeks and begin preparing their nets.
2. Fishing with the fruiting season (Andaman and Nicobar Islands)
   Nicobarese fishers track the fruiting of Mada Kandal (Bruguiera gymnorrhiza). When the fruit falls into the creeks during the monsoon, fish follow. It is time to set the nets. But it also carries a warning that stronger currents are near. They plan their trips with care.
3. Where Khalisha grows, rice won’t survive (West Bengal)
   In the low-lying chars of coastal Bengal, the sudden spread of Khalisha (Aegiceras corniculatum) signals change. It grows where the soil turns saline. Its spread marks increasing salinity, often signalling that paddy can no longer be grown. People shift to millet, which tolerates salt, or turn to prawn farming in waterlogged fields that once grew rice.
4. Dyeing fishing nets with mangrove bark (Goa)
   On Chorao Island, elders collect bark from Kandal (Ceriops tagal) to dye their nets. “Nave jale disana,” they say in Konkani—“the net disappears in water.” When boiled, the bark releases a rust red dye that makes the nets stronger and less visible to fish.
5. New mothers bathe in the ‘living tree’ (Maharashtra)
   Along the Konkan coast, the stilt-rooted Chir or jeevant zhad (meaning living tree) is boiled in bathwater. Women use it after childbirth to treat skin infections and cool inflammation. The bark is bitter but believed to be cleansing. Firewood is taken too, but carefully. Each year, they shift to different groves, a quiet rule that ensures the trees are not overused. The practice is passed down through generations, with different groves used each year to avoid overharvesting.
6. Remembering the 1999 super cyclone (Bhitarkanika, Odisha)
   After the 1999 super cyclone, this became a saying in Bhitarkanika. Villages protected by Bani (Avicennia officinalis) saw less damage. The trees slowed the wind. Their roots held the soil. Many residents remember that villages protected by mangroves experienced less damage during later storms as well.
7. Fishing by the lunar cycle (Bhitarkanika, Odisha)
   “Don’t go on full moon, the crabs will hide.” Locals report fewer crabs near full moon, so nighttime fishing with pots is more successful when crabs are more active.
8. Soil health seen in crab burrows (Bhitarkanika, Odisha)
   Fishers count crab burrows near the roots of Rhizophora trees. These small holes, dug by crabs, show how healthy the soil is. Many burrows mean the ground has enough oxygen and life below the surface. Few burrows mean the soil is weak or damaged. This helps them decide where to fish or plant.
9. When birds nest, boats rest (Odisha)
   When openbill storks (goriya pakhi) begin nesting, engines are turned off. While they roost, the boat stays still. Many fishers avoid disturbing nesting sites until the breeding season has passed.
10. Keora trees stand as storm walls (Sundarbans, West Bengal)
    Keora/ Kewda (Pandanus tectorius), or mangrove apple, grows at the water’s edge. It stands strong in wind and wave, planted by many to break storms before they reach the village.
11. Sundari roots help boatmen track time (Sundarbans, West Bengal)
    Boatmen read the Sundari (Heritiera fomes) by its roots. More roots above water mean the tide is going out. That’s when they steer fast before the river runs shallow.
12. Do you know Dakshin Rai? (Sundarban, West Bengal)
    In the Sundarbans, people believe Dakshin Rai watches over the forest. He is known as the Tiger God, protector of the land and ruler of the wild. Before entering the forest to collect honey or crabs, some wear masks of his face tied to the back of their heads. This confuses tigers and helps keep people safe.
13. Planting mangroves after the tsunami (Tamil Nadu)
    After the 2004 tsunami, this became a quiet truth. In Nagapattinam, some fishers began planting a mangrove sapling after every trip. A gesture of memory and of protection.
14. Mangrove flowers guide women’s work (Pichavaram, Tamil Nadu)
    In Pichavaram, women track the flowering of the grey mangrove. When the yellow-white flowers begin to fall, it means dry winds are coming. That's when they dry fish, make salt and mend their nets.

These examples offer only a glimpse of the many ways coastal communities understand and work with mangrove ecosystems. Much of this knowledge continues to be shared through everyday practice and local experience, alongside scientific research.

If you know of similar stories from your own community, we'd love to hear them.

Learn more about our projects working on Mangroves:

1. Wetland Management for Biodiversity and Climate Protection
2. Strengthening Regional Cooperation and Financing for Sustainable Management of the Sundarbans and Restoration of Coastal Ecosystems in the Bay of Bengal (SUNDARBAY)

References: 

• Chakraborty, M., Chowdhury, D., & Basu, P. (2023). Indigenous and Local Knowledge Systems in Mangrove Biodiversity: A Cross-Regional Synthesis. Journal of Ethnobiology and Ethnomedicine
• Ghosh, S. (2008). Naming the Land: Toponymy and Ecological Memory in the Sundarbans. South Asia Research
• Journal of Marine Biology. (2014). Studies on Kutch fisheries, documenting seasonal salinity changes and shrimp aggregation in mangrove creeks
• Kathiresan, K., & Rajendran, N. (2005). Coastal Mangrove Forests Mitigated Tsunami. Estuarine, Coastal and Shelf Science
• Ravishankar, T., Anbarasu, M., & Arul, J. (2021). Ethnobotanical Practices in Tamil Nadu’s Mangrove Regions. Indian Journal of Traditional Knowledge
• Sahoo, B., Das, M., & Pattnaik, A.K. (2022). Community-based Mangrove Management in Bhitarkanika, Odisha: Insights from Local Knowledge. Wetlands Ecology and Management, 30(1)
• Upadhyay, V.P. (2002). Ethnobotany of Mangroves in India: A Review. Trees for Life Journal, 12(1)
• Yenneti, K., Dayal, M., & Sikka, G. (2023). Cultural Dimensions of Climate Knowledge in Coastal India. Frontiers in Climate