Mangrove restoration failures (Sri Lanka, Philippines, Indonesia, Sundarbans)
- Government and regulators Indian authorities (regional official): Announced the 50 million-seedling target as met and said survival is normally 70%; at 5,000 seedlings per hectare the target would require 10,000 hectares.
- Government and regulators West Bengal chief minister Mamata Banerjee: Asked a year later where the 50 million mangroves had gone. Mongabay-India
- Communities and civil society Villagers at Pakhiraloy: Estimated that no more than 30,000 of about 200,000 seedlings remained. Mongabay-India
- Government and regulators State of Forests in India report (via India CSR): Dense mangrove cover fell from 1,038 km² to 994 km² between 2007 and 2021. India CSR
- Government and regulators Peatland and Mangrove Restoration Agency (BRGM): Announced it had exceeded its 2021 target with 34,911 hectares against 30,000.
- Government and regulators Peatland and Mangrove Restoration Agency (BRGM): Did not answer a question about verification.
- Researchers Indonesian peer-reviewed journals (2022-2025): Report mangrove survival of 10% to 44%. Universitas Trunojoyo journals
Mangrove planting programmes in four regions announced targets in hectares or seedlings. Field studies and press reports record low survival at many sites, and in two cases the implementing body's announcement could not be matched with survival data.
Survey of 23 sites by Kodikara and colleagues (Restoration Ecology, 2017).
Status As of 2022 for the latest case-specific report (Mongabay-India, September 2022): survival data remain disputed or unavailable in Indonesia and the Sundarbans.
- Implementing agencies — Announced targets as met or exceeded on planted-area or seedling counts (BRGM in Indonesia; authorities in the Sundarbans). Mongabay-India
- Local workers in the Sundarbans region — 3.2 lakh paid workdays costing 6.52 crore rupees. Mongabay-India
- Villagers at Pakhiraloy — Waiting for the embankment-protecting planting to establish; villagers estimate no more than 30,000 of about 200,000 seedlings remain. Mongabay-India
- Mangrove ecosystems — Sri Lanka: no plants survived at 9 of 23 surveyed sites; Sundarbans: dense cover fell from 1,038 km² to 994 km² between 2007 and 2021. Restoration Ecology
What happened
A 2015 review of 54 studies found a median survival of 44.7% for planted mangroves in developing countries (Bayraktarov and colleagues, cited by Mongabay).
In Sri Lanka after the 2004 tsunami, Kodikara and colleagues surveyed 23 planting sites covering about 1,000 to 1,200 hectares. Only about 200 to 220 hectares carried mangrove. At 9 sites, covering 36 of 67 plantings, no plants survived; survival ranged from 0% to 78%, and three sites had survival above 50%. About USD 13 million had been spent on the work. A separate summary records that at 75% of sites fewer than 10% of seedlings survived.
In the Philippines, long-term survival of planted mangroves was generally 10% to 20%, according to Primavera and Esteban (Mongabay, 2008); a World Bank-supported project reached 35% and a small local project 97%. The authors attributed low survival to planting the wrong species on seagrass beds and open sand where mangroves never grew. Trellis reported that fewer than 2% of record-setting numbers of seedlings survived.
In Indonesia, a target of 600,000 hectares by 2024 was set. The Peatland and Mangrove Restoration Agency (BRGM) announced it had exceeded its 2021 target with 34,911 hectares (target 30,000). It did not answer a question about verification, and the survival rate is not known. Only 30% of the target area was suitable for restoration. Indonesian peer-reviewed journals (2022 to 2025) report mangrove survival of 10% to 44%.
In the Indian Sundarbans, authorities announced in 2020 that a target of 50 million seedlings had been met; a regional official said survival is normally 70%. A year later West Bengal's chief minister, Mamata Banerjee, asked where the 50 million mangroves had gone. At Pakhiraloy on Gosaba island, part of a 10-hectare planting was washed away by the river and the rest damaged by cattle grazing; villagers estimated that no more than 30,000 of about 200,000 seedlings remained (Mongabay-India, 2022). In the region, 3.2 lakh (320,000) paid workdays cost 6.52 crore rupees. Dense mangrove cover in the Sundarbans fell from 1,038 km² to 994 km² between 2007 and 2021 (State of Forests in India report, via India CSR).
- 2004Tsunami; planting programmes follow in Sri Lanka
- 2008Primavera and Esteban report 10% to 20% long-term survival in the Philippines (Mongabay, 23 July 2008)
- 2012Kodikara and colleagues' field visits to Sri Lankan planting sites begin (visits ran 2012 to 2014)
- 2017Kodikara and colleagues publish in Restoration Ecology
- 2020Sundarbans: 50 million seedling target announced as met; Pakhiraloy planting
- 2021BRGM announces 34,911 ha, above its 30,000 ha target; West Bengal chief minister asks where the 50 million mangroves went
- 2022Mongabay-India reports on survival at Pakhiraloy (6 September)
What was said
Where accounts differ
Each party's account, side by side, with its source. The record does not settle these points; it shows them.
Announced the 50 million-seedling target as met and said survival is normally 70%; at 5,000 seedlings per hectare the target would require 10,000 hectares.
Asked a year later where the 50 million mangroves had gone.
Mongabay-IndiaEstimated that no more than 30,000 of about 200,000 seedlings remained.
Mongabay-IndiaDense mangrove cover fell from 1,038 km² to 994 km² between 2007 and 2021.
India CSRAnnounced it had exceeded its 2021 target with 34,911 hectares against 30,000.
Did not answer a question about verification.
Report mangrove survival of 10% to 44%.
Universitas Trunojoyo journalsHow it looked
Shown
- A target of 50 million seedlings in the Sundarbans announced in 2020 as metIndian authorities, as reported by Mongabay-India (2022) · Mongabay-India
- 34,911 hectares restored in 2021 against a 30,000-hectare targetIndonesia's Peatland and Mangrove Restoration Agency (BRGM)
Recorded
- Sri Lanka: about 200 to 220 of 1,000 to 1,200 planted hectares carried mangrove; no plants survived at 9 of 23 sites
- Philippines: long-term survival generally 10% to 20%; 35% in a World Bank-supported project; 97% in a small local project
- Indonesia: survival 10% to 44% in peer-reviewed journals; the agency's survival rate is not known
- Sundarbans: villagers estimate no more than 30,000 of about 200,000 seedlings remain at Pakhiraloy; dense mangrove cover fell from 1,038 km² to 994 km² between 2007 and 2021
Who gained
Reached nature or the ground
Gained elsewhere
Responses on record
- brgm (2021-2022): Announced it had exceeded its 2021 target with 34,911 hectares; did not answer a question about verification.
- west-bengal-gov (2020-2021): A regional official said mangrove survival is normally 70%; a year after the 50 million-seedling announcement the chief minister, Mamata Banerjee, asked where the 50 million mangroves had gone. · Mongabay-India
In court and with insurers
Lawsuits and rulings
Insurers
What nature saw
Nature's report opens this page. Below: further outcomes measured on the ground.
What we don't know
Nature
- Not measured Harm to nature: The record holds no measurement of harm to nature.
- Disputed How many of the mangroves planted in the Sundarbans survived?
- Disputed Did the planted area in Indonesia survive to count as restored mangrove?
Figures
- Insufficient Restoration spending: Sri Lanka: spent on mangrove work at more than 20 sites (2012 to 2014 visits).
Accounts
- None on record Peatland and Mangrove Restoration Agency (BRGM): Did not answer a question about verification.
Record
- None on record Indonesia: survival rate of the mangroves counted by the agency is not known; the agency did not answer a question about verification.
- Insufficient Reported but not independently verified: that the Philippines' National Greening Programme missed 88.17% of its 2011 to 2019 targets, according to the Commission on Audit.
- Insufficient Reported but not independently verified: the site-level survival figures for Sri Lanka (9 of 23 sites with no surviving plants; about USD 13 million spent) are taken from summaries of the Kodikara and colleagues study rather than from the paper itself.
Did the harm stop?
Not applicable as a single event; the sources reviewed describe planting programmes, not a halt.
Who paid?
Spending on record: about USD 13 million on the Sri Lanka work, and 3.2 lakh paid workdays costing 6.52 crore rupees in the Sundarbans region. The sources reviewed do not say who bore the costs of the losses.
Sources
Press and investigations
- The reality of saving young mangroves in the SundarbansMongabay-India · 2022-09-06
Researchers
- Indonesian peer-reviewed journal article on mangrove survival (Juvenil)Universitas Trunojoyo journals · 2022-2025