Mapping India’s Mangroves:Quality Matters Too

First published in Sanctuary Asia, Vol. 42 No. 2, February 2022

Laxmikant Deshpande, a mangrove conservationist recognised as a Darwin Scholar, and a member of IUCN’s Commissions on Western Ghat Plants and Conservation Education, outlines the importance of mangrove habitats. Sanctuary asks readers to write to authorities, asking not only to protect mangrove habitats, but also that any conservation and reforestation work places onus on the quality of this ecosystem...

As I floated between water and space, my snorkel helping me breathe, I was struck by the similarity between each breath I took and the pneumatophores that acted like snorkels for the mangrove in front of me. Sandwiched between sea and land, mangroves are found along seashores, creeks, estuaries, islands, bays and lagoons. Although restricted to coastal areas, mangroves sequester carbon four to five times more than any other terrestrial ecosystem. Mangroves are nurseries for various marine species, an estimated 80 per cent of global fish catch depends directly or indirectly on them. They are our first line of coastal defence, stabilising shorelines by slowing erosion with their extensive root system, thus protecting coastal communities inland from storms
and cyclones.

Some of the most biodiverse mangroves are located in Bhitarkanika, Odisha. This Ramsar site is spread across the Brahmani and Baitarani river deltas. About 62 mangrove species have been recorded from Bhitarkanika, including Avicennia, Bruguiera, Heritiera and Rhizophora. Reptiles such as the saltwater crocodile, king cobra, Indian python and water monitor lizard are listed from here. A wide diversity of avians is found in mangrove habitats, with one of the most well-known being the Mangrove Pitta, a unique species restricted to mangrove habitats.

Under the aegis of Dr. K. Kathiresan – India’s pioneer mangrove researcher – I learnt about the Pichavaram mangroves during an ecosystem management training course conducted by Annamalai University and United Nations University. Pichavaram has a well-developed mangrove forest dominated by Rhizophora, Avicennia, Excoecaria, Bruguiera, Lumnitzera, Ceriops and Aegiceras species. Pichavaram and Muthupet mangroves are known international case studies for their protection to the coastal community during tsunamis.

Goa also has excellent mangrove diversity with 16 different species in Mandovi, Chorao, Zuari, Chapora, Terakholi, Sal, Talpona, Galgibag and Kumbharjua river areas. Goa seems to be ahead of the curve in mangrove protection, with a ban on felling any of these species.

Meanwhile, in Aliya Bet, Gujarat, I have seen a large Kharai camel herd grazing amidst grey mangroves. Named for ‘Aal’, a local grass species, this remote corner situated near Gulf of Khambhat is sparsely populated, by people and mangroves alike. Among the maritime states of India, Gujarat has the longest coastline. Two out of the three major gulfs of the country are in this state and it provides a suitable habitat for mangroves, coral reefs, and sea grass. Mangrove cover here is the second largest after the Sundarbans in West Bengal. But low rainfall, high temperature, soil type, less freshwater availability and strong winds make mangrove growth difficult compared to other patches in India.

Dr. Kathiresan’s research has recorded more than 5,700 plant and animal species in Indian mangroves. According to the latest survey by the Forest Survey of India, India’s mangrove cover is around 4,992 sq. km. It hosts three per cent of Asia’s mangrove cover with a 1.10 per cent increase over previous assessments. Despite this, mangroves are under threat everywhere. Mangrove species diversity, tree height and girth, canopy cover, width of the mangrove patch, its biomass and biodiversity are important factors in determining the health of the ecosystem. Any ecosystem service it offers is a result of a combination of the factors mentioned above. While the Central and State Governments are mapping mangrove cover of the country, there is urgent need to assess the quality of this ecosystem. Such deeper assessment will help India improvise its mangrove management plans and help harvest its true potential, for the benefit of biodiversity and people alike.

Sanctuary appeals to its readers to write to the National
Wetland Committee Chairperson at stating these points:
* A nationwide mapping of mangrove areas should be undertaken, with the help of remote sensing techniques coupled with land surveys.
* Suitable sites for mangrove reserve forests should be assessed and then notified.
* Afforestation programmes should be conducted at degraded mangrove areas.
* Assessment of mangrove ecosystem quality based on mangrove species diversity, tree height and girth, canopy cover, width of the mangrove patch, its biomass and biodiversity is vital.
* Build mangrove cells across all states.


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