The Marine Diaries

View Original

Mangrove Mania - The Ecosystem that Keeps on Giving

Josh Pysanczyn

Mangrove Action Project (MAP) utilises a bottom-up tactic to mangrove conservation and restoration. Through their photographs from the Mangrove Photography Awards 2020, I hope to introduce the ways in which healthy mangrove forests provide a diverse array of benefits to both humans and wildlife. We will look at the sustainable use of its resources, how it can promote alternative livelihoods, and highlight how important and interconnected each ecosystem service and the entire ecosystem really is. If you’re not already, you’ll be feeling the mangrove mania by the time we finish! 

Mangrove Crab Fisherman ©Enrico Marone/MAP Mangrove Photography Awards.

The MAP uses the Community-Based Ecological Mangrove Restoration’ (CBEMR) technique. Through this holistic approach, their aims are to empower local stakeholders and communities, teaching them how to use mangrove ecology and biology to facilitate the forests natural regeneration.

Ecosystem Services 

In her 1997 article Gretchen Daily summarised ecosystem services (ES) as “the conditions and processes by which natural ecosystems and the species they comprise, sustain and fulfil human life”. 

The various conditions and processes provided by ecosystems were once categorised under two headings: ‘ecosystem goods’, which were generally regarded as tangible, material products which resulted from ecological processes, such as timber, fish or vegetables, and ‘ecosystem services’, which encompassed the larger, natural cycles of earth which tended to improve the quality, condition or location of things of value, such as pollination, soil formation and the hydrogen and carbon cycles. 

Now, the Millennium Ecosystem Assessment (MA), a UN-sponsored analysis of the impact of anthropogenic actions on ecosystems and human well-being, has identified four major categories comprising both ecosystems goods and services, which fall under the umbrella term ecosystem services, these are:

Provisioning services

The usable products obtained from the ecosystem. 

Regulating services

Benefits obtained from the regulation of ecosystem processes. 

Cultural services 

Non-material benefits obtained from the ecosystem. 

Supporting/Habitat services 

Services necessary to produce all other ecosystem services. 

Mangroves and Anglers ©Srikanth Mannepuri/MAP Mangrove Photography Awards.

Mangrove Forest Ecosystem Services  

Mangrove forests are an exceptionally important ecosystem for humans and wildlife, playing a crucial role in the functioning of the natural environment. 

“Mangroves produce a tonne of ecosystem services, each of which provide different benefits depending on who you are”, says Dr Dominic Wodehouse, Executive Director of Mangrove Action Project.  

Their services range from the provision of safe-zones for young fish nursing themselves to adulthood, act as bio-filters for nutrient runoff, sediment and heavy metals, reduce and slow soil erosion, act as a buffer against storm damage to coastal infrastructure, and provide a vital food source and income for local communities. Many of the mangroves ecosystem services can be organised according to the MA’s four categories, however several services tend to overlap, encompassing large processes at the ecosystem scale, whilst providing tangible products to be used by its inhabitants. 

It is for this reason that I have chosen to discuss several ecosystem provisions and processes supplied by the mangrove forest which overlap in their service and highlight the interconnectedness between the ecosystem and its inhabitants. 

Coastal Community ©Morgan Bennet-Smith/MAP Mangrove Photography Awards.

Mangrove Honey 

The primary productivity of mangrove forests is similar to that of the average for tropical terrestrial forests, and for millennia local communities have been sustainably harvesting a range of products from mangrove forests, including food (fish, shrimp and honey), charcoal and firewood, timber for construction, fibres and dyes, and medicines. 

Of these products, one of the most interesting, important and fruitful resources provided by the mangroves is honey. In the small village of Nai Nang, in Krabi Province, Thailand, some 800 colonies of wild bees (Apis cerana) and 60 hives of stingless bees gather nectar from the seasonal flower blossoms of fruit orchards and mangrove tree which are known to be particularly attractive to bees and produce some of the best honey.

Wild bees provide several ecosystem services to the people of Nai Nang, in the Krabi province of Thailand. ©Leo Thom.

In 2014, Mangrove Action Project set up a CBEMR project in Nai Nang to help revive their lost mangrove forests. 

“Parallel to the development of our reforestation project in Nai Nang, the community that we were working with ended up observing bees pollinating certain mangrove species”, says Wodehouse. 

The declining marine fish stocks and other environmental stressors have had devastating effects on small scale coastal fishing communities. As such, the local villagers and Mangrove Action Project have developed the production and sale of honey as an alternative livelihood and now have more than 300 beehives. 

Several species of wild bees are kept including the Asian honey bee (Apis cerana). ©Leo Thom.

Through a series of workshops, the village not only produces raw honey - which is said to have a very distinctive taste, with a hint of sea salt – but they have also learned to produce honey-based products such as hand soap, shampoo and conditioner. In addition, a village Conservation Fund was established with 10% of all honey and honey product sales.  

It is generally believed that mangroves are primarily pollinated by insects. This extremely important regulating service provided by the insects, maintains biodiversity in the ecosystem and ensures the regeneration of the forest. Without this crucial service, the ecosystem and those which inhabit and benefit from it, wildlife and human, would cease to exist.  

The development of an apiculture group has allowed the Nai Nang community to benefit from an alternative livelihood and share their knowledge with surrounding villages. ©Leo Thom.

Since its development, the Nai Nang community has obtained financial support from the ocean advocates at Only One, an ocean conservation NGO, which has allowed for the successful development of mangrove apiculture as an alternative livelihood, offering an income to local people, whilst avoiding the unsustainable harvesting of resources such as timber and fish from the mangrove. 

Furthermore, the Nai Nang Apiculture Group has shared its knowledge through a series of community led educational programmes. A visit to a local mangrove conservation women’s group on nearby Koh Klang, encouraged members to become involved in mangrove restoration, inspired developing supplementary livelihoods such as the production of tie-dyed products from mangrove bark, and further developed stingless bee apiaries to encourage biodiversity on the island. 

As such the development of apiaries in the Nai Nang community has not only acted as a provisioning service for the local villagers, but has also contributed to the cultural and regulating services provided by the mangrove forest, allowing all its inhabitants to reap the benefits of a healthy ecosystem.  

Mangrove Fisheries

Another of the tangible, provisional services provided by mangrove forests is the nursery function for fish, crabs, oysters and shrimp which inhabit its waters. With roughly 210 million people living within 10km of mangrove forests, mangrove-associated fisheries are a crucially important resource, providing significant economic value, job opportunities and food security.  

Moment of Hope ©Luis Felipe Rivera Lezama/MAP Mangrove Photography Awards.

The fisheries directly benefiting from the mangroves’ provisional services are those operate inshore. The nursery function of mangroves for small marine creatures directly benefits the inshore fisheries. To catch these creatures, a variety of techniques are used to catch species found at all levels of the food chain, which will then be consumed locally or sold at local markets. These ‘mixed species fisheries’ tend to include economically important planktivorous fish such as herring and sardines, as well as mangrove snappers, mullet and detritivores such as mud crabs and prawns. 

Environmental Balance in the Bijagos ©Ricci Shryock /MAP Mangrove Photography Awards.

Several species of mollusc and crustaceans found in the inshore mangrove ecosystem have high market values, producing a good income at local markets. Of these important ecosystem detritivores, the most prized species include mangrove oysters (Crassostrea spp. and Saccostrea spp.) and mud crab (Scylla spp.), which, in Micronesia, are thought to have an economic value of around US$423/ha of mangrove per year. 

An artisanal fisherman on the Isle de Pajaros, Honduras, holds up a handful of mangrove cockles (Anadara tuberculosa), an important commercial species along the pacific coast of South America. ©Dominic Wodehouse/MAP.

When we think of fisheries, it’s primarily the provisional services that first come to mind (fish, shrimp and crustaceans). However, other supporting services such as the provision of habitat and nursery grounds for juvenile fish, and the mangrove tree’s heterogeneous root structure which accommodate young bivalves and crustaceans, play a crucial role in the success of fisheries and sustenance of local populations, as well as maintaining high levels of biodiversity within the ecosystem.

Juvenile lemon sharks (Negaprion brevirostris) use the mangrove forest as a sanctuary and nursery before their voyage to the open ocean ©Anita Kainrath/MAP Mangrove Photography Awards.

The thicket of roots and bountiful detritus, algae and small fish make mangrove forests the perfect nursery grounds for young, vulnerable fish, crustaceans and molluscs from neighbouring coral reefs. 

This supporting service is essential for ecologically important fish species such as the rainbow parrotfish (Scarus guacamaia). The rainbow parrotfish is largest herbivorous fish in the Atlantic Ocean and Caribbean Sea, and has an obligate dependence on both mangrove and coral reef habitats to complete its lifecycle. This fish plays an important role in the maintenance of healthy coral reefs by grazing on macroalgae and promoting coral recruitment. 

Similarly, mangroves provide sanctuary for economically valuable fish such as the endangered goliath grouper (Epinephelus itajara). One study has shown how dependent on the mangroves this fish really is, suggesting that the offshore abundance (or lack) of the adult fish is directly linked to the abundance (or lack) of mangrove forests in Florida, USA. 

Tricoloured Heron Fishing ©Rishi Goordial/MAP Mangrove Photography Awards.

Fishing Cat ©Dhritiman Mukherjee/MAP Mangrove Photography Awards.

This wealth of biodiversity attracts a whole order of predatory species, such as the tricoloured heron (Egretta tricolor) and the endangered fishing cat (Prionailurus viverrinus) of South and Southeast Asia and even the elusive phantom of the mangroves, the Royal Bengal Tiger (Panthera tigris tigris), keeping fish and herbivore populations in check and enabling the ecosystem to continue its provision of valuable services. 

The Phantom of the Mangroves ©Soham Bhattacharyya/MAP Mangrove Photography Awards.

Carbon Storage in Mangroves

An exceptionally important regulatory service provided by mangrove forests, is their ability to sequester and store carbon from the atmosphere and ocean. These ‘blue carbon ecosystems’ can be characterised by their ability to store a relatively large amount of organic carbon per unit area, at all developmental stages, in particular, in their sediments, helping to mitigate anthropogenic CO2 emissions. It has now been suggested that around 40-90% of the carbon stock is stored in their soil. 

The Dancing Mangroves ©Harry Pieters/MAP Mangrove Photography Awards.

Mangroves account for roughly 1% of carbon sequestration by forests across the world. Nonetheless, as coastal habitats, they account for almost 14% of carbon sequestration by the global ocean; storing large amounts as carbon pools in the soil and in dead roots. A new study has even found that much more carbon is locked up in mangrove forest soils than previously thought, estimating the amount to be around 6.4 billion metric tonnes.

This sequestration of atmospheric CO2 alleviates the effects of greenhouse gases on our planet, and is essential for the survival of many species worldwide, including the mangrove trees themselves. 

Mangroves from the Air ©Chris Scarffe/MAP Mangrove Photography Awards 

As one of the most carbon-rich forests in the tropics, deforestation and destruction of this habitat has globally devastating effects. It has been estimated that the destruction of mangrove forests globally contributes to as much as 10% of CO2 emissions per year, despite accounting for only 0.7% of tropical forest area. 

Mangrove wood is a valuable resource, used by many local communities for a variety of purposes © Dominic Wodehouse/MAP.

In addition to the regulating services provided by mangrove forests through carbon sequestration, the storage of carbon in mangrove ecosystems lends a hand to an exceptionally important provisional service utilised by the many local mangrove communities: timber and fuelwood.

In fact, it’s been suggested that informal, small-scale timber harvesting is likely to be one of the most widespread forms of resource use in mangrove forests. 

Rangers and Fishermen on Pate Island ©Roshni Lodhia/MAP Mangrove Photography Awards. 

The wood harvested from mangrove trees is exceptionally versatile and is utilised for various purposes. The most frequent of which is house and fencing construction, providing homes and residential boundaries for local communities. 

More recently, mangrove timber has been used in the development of seaweed aquaculture in the Bay of Assassins, Southwest Madagascar. Here, young trees and saplings are cut down to stakes and used as anchor points for ropes on which the seaweed is grown and harvested for food consumption.

Similarly, in the Bay of Assassins, mangrove wood is used for the construction of lime kilns. To construct a kiln, sea shells are pressed between stacks of mangrove wood and burned. Water is then added to the powder to create a lime render known as ‘sokay’, which is then applied to house walls to improve their durability and resistance to cyclone damage. 

Timber extracted from mangrove forests is hard and durable, ideal for constructing housing, shelters and fencing. Credit: Dominic Wodehouse.  

The Mangrove Action Project 

The conditions, resources and environmental processes provided by mangrove forests, comprising all provisional, regulating, supporting and community services, will continue to sustain and fulfil human life if the mangrove forests themselves are conserved and remain healthy.

The empowerment of local communities and stakeholders through Mangrove Action Project’s CBEMR programmes not only enables the continual utilisation of mangrove ecosystem services to those most vulnerable to their demise, but also to those unknowingly benefiting from the conservation and restoration of an ecosystem whose services are crucially important on a global scale. 

This year’s Mangrove Photography Awards is open for entries! Check out and get involved in the international photography competition aimed at shining a light on one of our most undervalued ecosystems on the planet; mangrove forests.  


If you’ve enjoyed reading this article look out for more Marine Ecosystem Diaries and Seas the Day blogs from Josh Pysanczyn, check out his website and follow him here @wild_____life

Want to write for us? Check out our ‘Get Involved’ section