As the world marks the International Day for the Conservation of the Mangrove Ecosystem, Mumbai mangroves tell a story of survival, climate resilience, and lessons learned from the devastating 2005 floods. From Thane Creek to the Mithi River, these coastal forests reduce flood risk, store carbon, support marine biodiversity, and sustain millions of livelihoods. Yet despite legal safeguards and restoration efforts, pollution, infrastructure projects, and climate change continue to threaten one of India’s most valuable natural defences.
“This is Avicennia marina,” said Manish Zendeker, pointing to the trees lining the water as he steered his ferry through the narrow channels of the Thane Creek Flamingo Sanctuary. “In total, 17 species are found in Maharashtra. Overall, they are called mangroves, but among them, this is a distinct species. We see this more commonly here in Mumbai. If you go towards Ratnagiri, you will mostly see Sonneratia alba.” He went on, unprompted, into the mechanics of why the species in front of us mattered: “Its presence here is so important because it works to filter the creek water — it purifies it. Its roots go underwater and come back up, which are called pneumatophores, or breathing roots. Those roots have many tiny pores. When the high tide water comes in, their pores open up and absorb whatever pollution or chemicals are in the water. So that is its main benefit — it works to keep the creek water clean.”
What surprised our reporting team wasn’t that a boat driver on Thane Creek knew mangroves mattered — most people who live near them can tell you that much. It was the precision: a species name offered without hesitation, a north-south distinction between what grows here and what grows 300 kilometres south near Ratnagiri, a working theory of how the roots do their job, delivered from memory, between turns of the outboard motor. It was the kind of knowledge that usually lives in a research paper.
Today, 26 July, is the International Day for the Conservation of the Mangrove Ecosystem, a date the United Nations chose deliberately: it marks the anniversary of the 2005 Mumbai deluge, the day 944 millimetres of rain fell on the city in 24 hours and more than a thousand people died. The date is not a coincidence, and neither is the connection to Mumbai. What happened that day, and what has happened in the two decades since, is one of the clearest real-world demonstrations anywhere of what a mangrove forest is actually worth — and what a city pays when it disappears.
Manish Zendeker, a boat driver at the Thane Creek Flamingo Sanctuary, explains the ecological role of Avicennia marina to visitors aboard his ferry. Photo: Dipin Damodharan/EdPublica
How mumbai mangroves protect the city from floods
By the time the 2005 floods hit, Mumbai had already spent roughly a decade quietly getting rid of its mangroves. Between the early 1990s and 2005, the city lost close to 40% of its mangrove cover — something in the range of 9,000 acres — much of it along the Mithi River, where the swampy, root-tangled land was drained and filled to build what is now the Bandra Kurla Complex, one of the city’s premier commercial districts. The Mithi itself, an 18-kilometre stormwater channel that carries overflow from Powai and Vihar lakes out to the Arabian Sea, had been narrowed, built over, and used for decades as an open drain for sewage and industrial waste.
When the rain came, the river had nowhere to put it. A 2018 hydrological case study of the Mithi River modelled what the mangrove loss actually cost the city in physical terms: intact mangrove forest along the riverbanks reduces flood wave height and cuts the inundation area by roughly 21%, by absorbing and slowing the surge before it reaches built-up land. Without that buffer, the 2005 floodwaters had nowhere to go but into the shops, homes, and railway lines of central Mumbai.
The flood changed the law almost immediately. Later that year, the Bombay High Court banned the destruction of mangroves on government land across Maharashtra and prohibited construction within 50 metres of any mangrove area, and by 2012 the state had set up a dedicated Mangrove Cell to enforce it. The reversal that followed is one of the more striking examples of legal protection actually working at scale: according to Forest Survey of India data, Mumbai’s own mangrove cover grew from 42 square kilometres in 2005 to 66 square kilometres by 2017, a 57% recovery. State-wide, Maharashtra’s mangrove cover more than kept pace, expanding from 186 square kilometres in 2013 to 320 square kilometres by 2019, according to the Mangrove Cell’s own figures.
That recovery is real, but it is not the whole story, and it is not evenly spread. Forest officials themselves have cautioned that a rising area figure can mask falling ecological quality — mangroves can be denser or thinner, healthier or stressed, without that showing up in a simple hectare count. And the growth has come alongside continuing, highly localised battles: mangrove clearance tied to the Navi Mumbai International Airport, the Jawaharlal Nehru Port Trust’s expansion, and the Mumbai Trans-Harbour Link have repeatedly ended up in court, with activists and the state’s own Mangrove Cell frequently on opposite sides of the same case. Nationally, the trend has also turned again: India lost an estimated 7.43 square kilometres of mangrove cover just since 2021, though that recent decline is concentrated in Gujarat and the Andaman and Nicobar Islands rather than in Mumbai itself. The net picture for the city is a genuine recovery, won directly by an emergency response to a specific disaster, that now has to be actively defended patch by patch rather than assumed to hold on its own.
The comparison that made the point hardest to argue with came from a single village. Nandakumar Pawar, a fisherman in Bhandup, a mangrove-fringed suburb in Mumbai’s north-east, has described being startled that his neighbourhood came through the 2005 deluge largely unscathed while the rest of the city drowned. A more than 800-hectare stretch of mangroves near his village had acted as exactly what mangroves are built to be — a sponge, absorbing the surge rather than passing it on to the houses behind it. Pawar went on to found Shree Ekvira Aai Pratishthan, a fishing-community organisation that today serves as caretaker of some 1,042 hectares of mangrove forest between Mulund and Vikhroli along Thane Creek, working with the state Forest Department on protection and restoration. Pawar, now in his sixties, also serves as president of the Maharashtra Small-Scale Traditional Fish Workers Union — one measure of how directly a single flood turned a fisherman into one of the city’s more persistent mangrove advocates.
Thane Creek: a working case study
The waters our reporting team travelled — Thane Creek, Asia’s largest creek at 26 kilometres long — offer a live, ongoing version of this story rather than a historical one. The northern stretch of the creek was declared a flamingo sanctuary in 2015, protecting 1,690 hectares, of which 896 hectares are mangrove forest and the rest open water and mudflats. The creek has drawn over 30,000 migratory flamingos annually since the early 1990s, and by some counts accounts for close to a fifth of the mangrove species diversity found anywhere in India.
Boats registered out of Navi Mumbai sit anchored against a mangrove treeline on Thane Creek Flamingo Sanctuary — the same waters, and the same fishing communities, whose livelihoods are tied directly to the health of the forest behind them. Photo: Dipin Damodharan/EdPublica, Thane Creek
It is also a case study in what happens when mangroves are stressed rather than removed outright. Untreated sewage, industrial effluent, and construction runoff have degraded water quality across large stretches of the creek; one WWF-India assessment found that 58 of 69 marine species once recorded there have disappeared over a 14-year period, largely attributed to rising arsenic levels and falling oxygen content in the water. The sanctuary’s own mangroves have been the subject of repeated pollution complaints, including an industrial pipeline leak flagged by local fishermen in 2022. The lesson embedded in Thane Creek is that mangrove protection on paper — a sanctuary notification, a protected-area boundary — does not by itself guarantee a functioning ecosystem; the water quality and the tree cover have to be defended separately and continuously.
Restoration work has had some success. Community-led projects around Thane Creek and Mahim Bay have restored more than 100 hectares of mangrove cover in recent years, working with local fishing communities to combine habitat recovery with sustainable fishing practices and small-scale eco-tourism — the same boat tours that carried our reporting team through the sanctuary.
What the research says mangroves are worth, everywhere
Mumbai’s experience is a local instance of a pattern researchers have now quantified at a global scale, and the numbers are large enough to change how governments plan coastal defence.
A widely cited 2020 study published in Scientific Reports, led by researchers Pelayo Menéndez and Michael Beck, modelled the flood-protection value of every mangrove forest on Earth at 20-kilometre resolution and found that mangroves currently prevent more than US$65 billion in flood damage every year, and protect over 15 million people from flooding they would otherwise experience. A follow-up analysis, published in the World Bank’s Changing Wealth of Nations 2024 report, priced the total long-term value of that protection — the present value of a century of avoided flood damage — at US$855 billion globally. The countries that benefit most in absolute terms include China, Vietnam, the United States, Australia, and India; in terms of the sheer number of people protected, Vietnam, India, and Bangladesh top the list.
Mangroves do this largely through friction. Their dense, tangled root systems and low canopy break up wave energy and slow storm surge as it moves inland; the State of the World’s Mangroves 2024 assessment estimates that mangrove forests reduce flood depth by 15–20% compared with a coastline that has none.
The carbon case is, if anything, stronger. Mangrove soil is waterlogged and largely oxygen-free, which means the organic matter that collects in it barely decomposes — it simply stays there, sometimes for thousands of years. Researchers estimate mangroves store an average of 394 tonnes of carbon per hectare, split roughly 78% in the soil, 15% in above-ground biomass, and the rest below ground, figures that vary sharply by region: forests in Southeast Asia and the Philippines can exceed 650 tonnes per hectare, while carbon density in parts of the Middle East falls below 100. Even though mangroves cover under 1% of the world’s tropical forest area, one estimate puts their total global carbon stock at around 6.5 billion tonnes — the single largest carbon pool of any blue carbon ecosystem, ahead of seagrass meadows and salt marshes combined in density per hectare, if not in total area.
None of this is guaranteed to last. The global rate of mangrove loss has slowed — from roughly 1% a year in the 1990s to about 0.66% a year between 2010 and 2020, and the FAO’s 2025 Global Forest Resources Assessment even found a net global gain since 2010, reversing decades of decline — but a 2024 assessment by the International Union for Conservation of Nature found that more than half of the world’s mangrove ecosystem types are still at risk of collapse by 2050 if current pressures continue, a category that includes South India’s mangroves specifically, which the IUCN has already classified as critically endangered. Area recovering is not the same as risk disappearing; it mainly means the fight has shifted from outright clearance to slower, harder-to-see pressures — pollution, aquaculture expansion, and the kind of localised infrastructure disputes already playing out around Mumbai.
Traffic crosses the Airoli Bridge over Thane Creek while its mangrove banks sit largely undisturbed below — a rare single frame that captures the tension at the heart of this story: a city and its wetlands sharing the same narrow strip of water. Photo: Dipin Damodharan/EdPublica, Thane Creek, near Airoli.
Governments have started responding at the scale the research implies is necessary. At COP28 in 2023, the Mangrove Breakthrough initiative set a global target of restoring or protecting 15 million hectares of mangrove forest by 2030, backed by a proposed US$4 billion in financing — an explicit bet that the cost of restoration is small next to the avoided cost of flooding, storm damage, and lost carbon storage that follows when mangroves disappear.
What the boat driver already knew
None of this would have surprised the man steering the boat through Thane Creek. Long before any of these studies were published, people who live beside mangrove forests — fishermen in Bhandup, boat operators on the creek, families along the Mithi’s banks — had already worked out, through direct experience, what the data now confirms with figures: that the trees standing between them and the water were doing something that mattered, long before anyone put a price on it.
Mumbai’s flood risk has not gone away since 2005, even though its mangrove cover has, on paper, come back. Sea levels are rising, monsoon rainfall is becoming more erratic and more intense, and the city’s population and built footprint keep expanding into the same low-lying, once-swampy land that used to absorb the water. The mangroves that have grown back — in Thane Creek, along Mahim Bay, in the restored patches near the Mithi — are doing exactly the job the research describes: quietly absorbing surge, filtering pollutants, and storing carbon. Whether they keep doing it depends less on whether the trees are allowed to grow than on whether anyone keeps watching, largely unnoticed, until the next storm makes their condition impossible to ignore.
Dipin Damodharan is an award-winning journalist, editor and media entrepreneur, and Co-founder and Editor-in-Chief of EdPublica, an independent global media platform covering education, science, research, innovation, climate and public policy. With more than a decade of experience in journalism, he has worked across print, digital and multimedia media. His reporting explores science, climate, sustainability and the social impact of research and innovation. His work has been recognised by the Solutions Journalism Network and other journalism organisations.
Earth is Heating Up: The Economic Cost of a Rising Sea
Rising seas are turning coastal exposure into an economic challenge. Cities must weigh the cost of protecting infrastructure, livelihoods and communities against the growing risks of inaction.
Homes and waterfront structures sit at the edge of the sea, illustrating the growing exposure of coastal communities to sea-level rise and flooding. Representational image. Image credit: Jude Mitchell-Hedges/Pexels
For Mumbai, the sea has always been an economic asset. Its position along the Arabian Sea helped turn the city into a centre of trade, finance, industry and transport. But the same coastline that sustains its economy also exposes homes, roads, businesses and critical infrastructure to flooding and rising sea-level. The United Nations identifies Mumbai and Kolkata, along with Dhaka, as low-lying South Asian cities where more than 14 million people face the immediate risk of losing their homes to permanent inundation.
What rising seas cost, however, depends on what a coastline holds. In Bangladesh, a one-metre rise could inundate around 4,000 sq km of land, nearly 3% of the country and climate impacts including rising seas could force more than 13 million people to move within the country by 2050. In Saint Kitts and Nevis, saltwater intrusion threatens the freshwater aquifers on which communities depend. In New York City, sea levels could rise by up to 1.3 metres by the end of the century, putting a vast concentration of infrastructure and economic activity at greater risk.
Around 770 million people, roughly one in every 10 people on Earth, live in coastal areas less than five metres above the high-tide line. Nearly 900 million people live in low-lying coastal zones, and more than one billion could be exposed to coastal hazards by 2050. These are not empty margins of the map. They contain ports, roads, industries, homes, tourism facilities and freshwater systems that support economies and everyday life.
That makes sea-level rise more than a question of where the water will reach. It is a question of what sits in its path, who depends on it, and how much it will cost to protect, rebuild or relocate what cannot be saved.
The Baseline is Already Moving
Global mean sea level remained near the record high observed in 2024, according to the World Meteorological Organization’s State of the Global Climate 2025. Between 2012 and 2025, sea level rose at an average rate of 4.75 millimetres a year, compared with 2.65 mm a year between 1993 and 2011. In 2024 alone, global mean sea level rose 5.9 mm, the highest annual increase in the satellite record, with exceptional ocean warming a major factor.
The economic significance lies in what that extra water does to the baseline. A higher sea means tides can reach critical infrastructure more often. Storm surges can travel farther inland. Drainage systems can become less effective. Flooding that was once rare can become recurrent, bringing repeated repair costs and disruption.
The UN estimates that an extreme sea-level event that historically occurred once every 100 years could occur at least annually at more than half of the world’s tide-gauge locations by 2100 under all the scenarios examined. For businesses and governments, that changes the economics of risk.
When the Sea Threatens More Than Land
Mexico’s coastline is more than a boundary between land and sea. With more than 11,000 kilometres of coastline and nearly half its population living in coastal states, the country is already confronting the wider consequences of a rising sea.
In its contribution to the UN negotiations, Mexico said sea-level rise is putting pressure on ecosystems, infrastructure, livelihoods and water security. Its message was that the response cannot stop at protecting land from encroaching water. It must address the systems and communities that depend on vulnerable coasts. Mexico also called for the international response to move from broad commitments towards a smaller set of clear, actionable priorities, grounded in international law.
That shifts the question from how much land could be lost to the sea to what happens to the people and systems that depend on that land. For coastal countries, that distinction could determine how the cost of rising seas is ultimately distributed.
Trillions of Dollars are Exposed
The physical assets at risk are already enormous. Infrastructure worth at least 1.8 trillion dollars is exposed to sea-level risks globally. More than 80% of global goods trade is carried by sea, making ports and the networks connected to them particularly important to the world economy.
The potential losses rise sharply as sea levels climb. The UN report cites estimates of $1.7 trillion to 5.5 dollars trillion in residual damage costs from sea-level rise over the coming century. A global mean sea-level rise of 20 centimetres by 2050 could contribute to more than $1 trillion in annual flood losses across the world’s 136 largest coastal cities. Without adaptation, global annual losses have been estimated at 1.2 trillion dollars to 4 trillion dollars.
These figures capture more than the cost of repairing flooded buildings. A damaged port can interrupt manufacturing hundreds of kilometres inland. Flooded roads can prevent workers from reaching businesses. Power and sanitation failures can halt economic activity. Repeated disruption can make coastal locations more expensive to insure and less attractive for investment. The economic damage can therefore travel well beyond the flood line.
Cities Face a Compounding Bill
Coastal cities concentrate both people and capital. Their economic advantage has historically come partly from proximity to the sea. Ports connect them to global trade. Waterfronts support tourism and real estate. Rivers and estuaries provide transport, fisheries and access to freshwater.
The same geography now creates concentrated exposure. Nearly 500 million people live in low-lying river-ocean zones. In South Asia, more than 14 million people in low-lying cities, including Mumbai and Kolkata, are identified as being at immediate risk of losing their homes to permanent inundation. In some areas, land subsidence compounds sea-level rise, increasing the rate at which relative water levels rise.
For households, the consequences can include damaged homes, lost income and rising costs of recovery. For cities, the bill can include repeated repairs to roads, drainage, public buildings and utilities. And there is a less visible cost: the money that must be spent simply to keep existing systems functioning as the baseline changes.
India: Exposure Meets Rapid Development
India’s coastline makes the challenge clearer. Coastal cities and industrial regions are expanding alongside a coastline exposed to cyclones, storm surges, flooding and erosion. As development continues, more assets are being placed in areas where future climate risks need to be considered.
INCOIS has assessed future changes in average and extreme sea levels at 11 locations of India’s coast and islands. Under the high-emissions SSP5-8.5 scenario, relative mean sea level by 2100 is projected to rise between 0.62 metres at Visakhapatnam and 0.87 metres at Bhavnagar, relative to the 1995–2014 baseline.
Projected extreme sea-level increases are higher, ranging from 0.68 metres at Chennai to 1.12 metres at Bhavnagar. These numbers matter economically because cities do not experience mean sea level in isolation. A higher baseline interacts with tides, cyclones, storm surges and waves, increasing the potential for damaging events.
Wading birds fly along a rocky shoreline of Mumbai beneath a coastal bridge, highlighting the ecosystems and infrastructure that share increasingly exposed waterfronts. Image credit: Illuseenator/Pexels
INCOIS found that coastal regions north of 13°N are particularly vulnerable to changes in extreme sea levels, with the Gulf of Gujarat and northern Bay of Bengal showing some of the largest changes in tidal maxima and climate extremes. The challenge for India is therefore not simply protecting today’s coastline. It is deciding where tomorrow’s infrastructure, housing and economic activity should be concentrated.
The Cost of Adaptation
Avoiding losses will itself require substantial investment. The UN estimates that developing countries need 310 billion dollars to 365 billion dollars every year for adaptation, while adaptation finance stood at about 26 billion dollars in 2023. Adaptation costs in developing countries are estimated to be 10–18 times current public adaptation finance.
Cities may need to strengthen drainage, raise roads, protect ports, upgrade water systems and reinforce critical infrastructure. Coastal ecosystems may need restoration and space to migrate inland. Some communities may eventually require planned relocation. A seawall may make sense around a densely developed port. A wetland may offer better protection in another location. In places facing persistent inundation, continuing to rebuild may cost more than planned relocation.
The UN report points to a combination of measures, including risk-informed planning, early-warning systems, resilient infrastructure, nature-based approaches and, where necessary, relocation.
Paying Later Could Cost More
One of the central economic questions is timing. Sea-level rise is a slow-onset hazard. Its costs accumulate gradually, while much disaster financing is designed around sudden events. Waiting until repeated flooding becomes a crisis can leave governments paying for emergency repairs instead of planned adaptation.
Money spent before infrastructure is repeatedly damaged can reduce future losses. Coastal planning can prevent new assets from being locked into high-risk locations. Early-warning systems can limit casualties and economic disruption. Protecting wetlands can preserve a natural buffer while supporting fisheries and other livelihoods. Adaptation is therefore not simply an expenditure. It can also be a way of limiting future losses.
Changing Coastline, an Economic Choice
The ocean will continue to rise for centuries because of heat already stored in the climate system and the slow response of glaciers and ice sheets. The economic question is how societies respond to that trajectory.
The sea will not wait for cities to settle their priorities. For Mumbai, rising seas will shape decisions about what to protect, where to build and how much risk communities can bear. The water may rise gradually. The cost of being unprepared will not.
How India’s River Dolphins Navigate a Changing River System
India’s river dolphins are being counted again in 2026, as researchers assess populations and habitats after a 2021–23 survey estimated 6,327 dolphins across eight states. The findings could reveal how changing river conditions are affecting the species.
A bottlenose dolphin surfaces in the water, illustrating the species’ sophisticated communication, learning and sensory abilities discussed in the context of dolphin cognition. Representational image. Image credit: Pixabay
Dolphins recognise individuals, learn behaviours, remember information and communicate through a sophisticated repertoire of sounds. In some populations, they even use tools. These abilities have made dolphins one of the most closely studied animals in research on animal cognition. But “intelligent” is a broad description. Scientists studying dolphin cognition are asking more specific questions: How does a dolphin learn? What does it remember? How does it recognise another individual? How does it use information from its surroundings to make decisions?
Some of the clearest answers have come from bottlenose dolphins. They can develop individually distinctive signature whistles, learn behaviours socially and retain information about other dolphins. In Shark Bay, Australia, bottlenose dolphins have been observed using marine sponges while foraging, a behaviour that can be passed from mothers to calves.
The research tells us that dolphins are capable of sophisticated learning and social behaviour. It also raises a less familiar question for India: what happens to a species with such a complex relationship with its surroundings when those surroundings are changing?
India’s River Dolphins Live by Listening
The Ganges river dolphin has an unusual way of experiencing its habitat. It has extremely limited vision and depends heavily on echolocation. In the turbid waters of the Ganga and its tributaries, it sends out high-frequency clicks and interprets the returning echoes to locate prey and navigate. Its survival therefore depends on more than whether there is water in the river.
It needs suitable depth and flow, enough prey and stretches of habitat through which it can move. Dams and barrages can alter these conditions. Water extraction can reduce flows. Fishing can lead to accidental entanglement, while pollution can affect the aquatic food chain.
The river is also a working landscape for people. It supplies water, supports agriculture and fisheries, and is increasingly shaped by infrastructure. For the dolphin, those same interventions change the conditions under which it lives.
How Many Dolphins does India Have?
For the first time, India has a national baseline. A survey conducted between 2021 and 2023 covered more than 8,500 km of rivers across eight states and estimated 6,327 riverine dolphins. The overwhelming majority were Ganges river dolphins—6,324. Only three Indus river dolphins were recorded in the Beas River.
Uttar Pradesh and Bihar accounted for the largest populations. It is a count of riverine dolphins, not all dolphins found in Indian waters. India’s coast and estuaries support several marine and estuarine species, for which population information is less comprehensive.
Ganges river dolphins swimming in the river, a species that relies heavily on echolocation to navigate and find prey in the turbid waters of the Ganga and its tributaries. Representational image. Image credit: Pexels
More importantly, a national total cannot show everything happening inside individual rivers. Two stretches of the same river can offer very different conditions for dolphins. A national population may therefore hide local changes in habitat, distribution or abundance. That is why India is counting them again.
The Second National Assessment is Underway
In January 2026, India began its second range-wide estimation of riverine and estuarine dolphins under Project Dolphin. The Wildlife Institute of India is coordinating the assessment with state forest departments and conservation organisations. The exercise includes Irrawaddy dolphins in the Sundarbans and Odisha, while researchers are also using underwater acoustic monitoring to detect dolphins through their sounds.
The value of a second survey is not simply that it will produce another number. It will allow researchers to compare populations and distribution with the earlier baseline and begin identifying where changes are occurring.
What Protects Dolphins Under Indian law?
The Wild Life (Protection) Act, 1972 provides the principal legal protection. The Ganges and Indus river dolphins are listed under Schedule I, which provides the highest level of protection under the Act. Hunting is prohibited except in circumstances specifically permitted by law.
The Ganges river dolphin was declared India’s National Aquatic Animal in 2009. In 2020, the government launched Project Dolphin, bringing riverine and marine dolphins under a dedicated conservation programme focused on population assessment, habitat protection, research and reducing threats.
Yet there is a gap between protecting a species and protecting the conditions it needs. A protected-species law can prohibit hunting. It cannot, by itself, determine how much water is diverted from a river, how a barrage affects connectivity or how fishing pressure is managed. Those decisions are made through several parts of India’s environmental and development policy.
What does the Number Reveal?
For a Ganges river dolphin, a healthy river is defined by measurable conditions: enough flow and depth to move through its habitat, sufficient prey to feed on, connected stretches of water and fewer risks from fishing gear and pollution.
That makes the 6,327-dolphin estimate more than a conservation headline. It is a baseline against which India can track whether those conditions are supporting or limiting dolphin populations. The second national assessment should show where populations are increasing, declining or shifting. The harder task will be linking those changes to what is happening in the rivers—changes in flow, habitat connectivity, prey availability, fishing pressure and pollution.
That is where dolphin conservation moves beyond counting. Protecting the species also means managing the river conditions on which its survival depends.
Kerala’s Biodiversity Records Are Going Digital. What Could That Change?
Kerala has prepared 1,034 People’s Biodiversity Registers to document local species, habitats and traditional ecological knowledge. As these records move into digital systems, the state is exploring how they can better support biodiversity planning.
A squirrel among flowering plants, reflecting the plants and wildlife that form part of the local biodiversity documented through a People’s Biodiversity Register. Representational image. Image credit: Mohit Khare/Pexels
A farmer may remember a rice variety that disappeared from neighbouring fields. An older resident may know which fish once filled a local pond. A traditional practitioner may still know how a plant was used long before it appeared in a scientific database. Much of this knowledge remains with the people who live around these landscapes.
People’s Biodiversity Registers, or PBRs, were created to document it. Prepared with community participation through Biodiversity Management Committees, the registers record local plants, animals, crops, habitats and other biological resources, along with traditional knowledge about their uses and changes observed over time.
Kerala has spent years building this record. It has prepared 1,034 PBRs covering 941 grama panchayats, 87 municipalities and six corporations. Its network of Biodiversity Management Committees is larger, covering 1,200 local bodies. The state is now moving much of this information into digital systems.
From Paper Records to e-PBRs
Kerala was among the states involved in India’s early effort to develop electronic PBRs. In 2020, the National Biodiversity Authority and the National Informatics Centre worked on an e-PBR pilot involving Kerala, Goa, Tripura and Tamil Nadu.
For Kerala, the move builds on an extensive collection of paper registers. The state has worked with NIC to digitise its existing PBRs, while the national BIOMIS platform provides tools for creating and managing electronic registers.
An electronic register can do more than preserve the contents of a paper volume. Species records can be linked to locations, maps and observations. Information can be updated without creating an entirely new physical register. The system can also bring together information collected by different communities and local bodies.
BIOMIS includes features such as geotagging, maps, species information, knowledge holders and citizen observations. That could make the information considerably more useful for biodiversity planning, provided the records are kept current and properly verified.
National Database with Different Levels of Progress
India’s People’s Biodiversity Register programme has reached a substantial scale. The National Biodiversity Authority’s latest database lists 2,72,648 PBRs across the country. Uttar Pradesh accounts for 59,407, followed by Maharashtra with 28,649 and Madhya Pradesh with 23,557. Tamil Nadu has 13,604, Karnataka 6,554 and Kerala 1,034.
These numbers need some context. States differ considerably in the number and type of local bodies covered by their biodiversity programmes, so the number of PBRs alone does not provide a meaningful measure of progress.
Digitisation provides another view, but the figures come from a different database. BIOMIS, the electronic biodiversity-management system, records 13,600 of Tamil Nadu’s 13,600 entries as digitised, along with 14,080 of 14,083 for Andhra Pradesh, 3,376 of 3,416 for Odisha and 6,239 of 6,763 for Karnataka. For Kerala, BIOMIS lists 1,203 of 1,373 entries as digitised, or 87.62%.
The Kerala figures illustrate why the two databases should not be treated as interchangeable. The NBA database lists 1,034 PBRs for the state, while BIOMIS uses 1,373 as the base for its digitisation figures. The difference suggests that the systems are working with different datasets or categories of records. The BIOMIS percentage therefore indicates the status of records within that system; it cannot be used to say that 87.62% of Kerala’s 1,034 PBRs have been digitised.
For the same reason, the BIOMIS figures are better understood as indicators of digitisation within the electronic system, rather than as a ranking of states. The more important question is what happens to these records once they enter the system: whether they are updated, verified, linked to locations and observations, and eventually used in local biodiversity planning.
Why is PBR Important?
The value of a PBR lies in what it can capture that a conventional biodiversity survey may miss. A community may notice that a crop variety is disappearing long before the change appears in a wider agricultural database. Fishers can observe changes in a water body. Residents may know how a wetland, forest patch or stream has changed over decades. Traditional knowledge can also point to the food, medicinal or cultural uses of species that might otherwise remain poorly documented.
A PBR gives this knowledge a formal record. Repeated over time, the registers could also help track local ecological change. A species recorded in an earlier PBR but absent from a later one, for instance, could prompt questions about habitat loss, pollution, invasive species or changes in land use. That is particularly relevant in Kerala, where agricultural land, wetlands, forests and densely settled areas often exist within a short distance of one another. But the usefulness of the data depends on what happens after the register is prepared.
Sections listed in the People’s Biodiversity Register of Kalliyoor Grama Panchayat in Thiruvananthapuram, Kerala.
Keeping the Record Alive
The state has begun updating its existing PBRs and preparing Local Biodiversity Strategy and Action Plans. According to the Kerala Economic Review, 40 PBRs were updated in 2024–25. Twenty-eight BMCs were selected to prepare LBSAPs, of which 23 had completed them during the period. These efforts point towards a shift from simply recording biodiversity to using the information in local planning.
Whether that is happening widely is less clear. A PBR can document a disappearing crop, a declining species or a threatened habitat, but the information has little practical value if it is not updated, verified and considered when local decisions are made. India has already created a vast body of grassroots biodiversity records. Now, the test is whether those records become working data for the people and institutions responsible for managing the landscapes they describe?