Management of Mangrove Swamps (DP IB Geography)

Mangrove Swamps Characteristics

Characteristics of mangrove swamps

• Mangrove swamps are wetlands located in coastal areas

• They thrive in tropical or subtropical areas with a good sediment supply

• Mangrove swamps are located in the intertidal zone

• This means that mangrove swamps deal with regular environmental disruption, as sea levels change

• Vegetation found in mangrove swamps is halophytic and thrives in brackish environments

• Mangroves produce dense thickets of mangrove trees with tangled roots above the ground

• Mangrove trees have breathing roots to absorb oxygen 

• Some trees have buttress roots, which help to support the tree in the softer sediment 

• These roots trap sediment, building up the land and reducing erosion

• Due to the high saline and low oxygen environment, germination is difficult:

  • To deal with this, seeds germinate while they are still attached to the mangrove plant.

  • They float around in the water before eventually taking root

• Mangrove forests are home to all sorts of species. They are incredibly productive environments

Diagram of mangrove swamps

Mangrove Swamps Uses & Value

Uses and value of mangrove swamps

• Mangrove swamps are extremely valuable

• Stakeholders value and use mangrove swamps differently e.g. environmentalists, locals, fishermen etc.

• Mangrove swamps are also under threat

• Over half of the mangrove forests of the world no longer exist

• Stakeholders from all perspectives must work together to reduce threats to mangrove environments

• Coastline protection

  • Mangrove roots stabilise the sediment, slowing down wave erosion

  • Mangrove trees protect coastal areas from storm waves and tsunamis by absorbing wave energy 

  • Swamps absorb water from storm surges or rainfall, reducing coastline flooding

• Habitats and ecosystems 

  • Mangrove swamps are rich habitats for mammals, insects and marine life

  • They are vital nesting areas, particularly for migrating birds

• Pollution

  • Mangrove forests can trap pollutants in run-off stormwater

  • This protects coral reefs and other habitats from dangerous water pollution 

  • This also protects waterways used by locals living nearby

• Resources

  • Mangrove swamps are rich fisheries, used in the seafood industry

  • They are vital for people’s livelihoods and access to food

  • They are ideal for medicine, charcoal and wood resources 

• Carbon sink

  • As the sediment and soil in mangrove swamps are so nutrient-rich, they can store carbon 

  • Mangrove forests can store billions of tonnes of carbon. If this was released, it could be catastrophic for the environment 

Threats to mangrove swamps

• Clearing

  • Swamps are cleared for agriculture, aquaculture, farming, tourism, settlements and harbours

• Overuse

  • Overharvesting is unsustainable and can threaten the future of mangrove swamps

  • Overfishing in the ocean can impact marine life and marine food chains in mangrove environments 

• Water changes

  • Irrigation and damming can affect the salinity of mangrove swamps

  • With an increase in salinity, mangrove vegetation can’t survive 

  • Increased sediment from erosion caused by deforestation can choke mangrove swamps

  • Climate change is causing sea levels to rise. Mangrove swamps require stable sea levels to thrive

• Pollution

  • Rivers can bring fertilisers or pesticides into mangrove environments, killing species 

  • Oil pollution also chokes mangrove roots, meaning the trees cannot get enough oxygen

• Coral reef destruction 

  • Coral reefs absorb powerful wave energy

  • As coral reefs degrade, powerful waves can reach the coastline. This affects the sediment in mangrove environments

  • Nutrients and seedlings can wash away 

Case Study: Sundarbans

Bangladesh, Sundarbans

Map showing the location of the Sundarbans

• This mangrove forest lies in the delta of the Bay of Bengal

• It is roughly 10,000 square kilometres

• It became a UNESCO World Heritage Site in 1997

• It is home to all kinds of species, such as the Bengal tiger, deer, crocodiles and snakes

• The mangroves are vital for storm protection

• They are useful for resources e.g. fish, timber and fuel wood

• This mangrove swamp is a great example of mangrove management

Threats

• Increased settlement and agricultural growth

• Deforestation for food, shelter and fuel

• Barrages or dams for irrigation 

• Ownership difficulties with poor management plans

• Construction of coastal embankments, affecting sediment

• A general misunderstanding of mangrove importance 

Management strategies 

• World Heritage Status – international law protects this mangrove environment

• Wildlife refuge areas – this stops people from entering the area, as well as from using or damaging the land for other purposes 

• Eco-engineering e.g. mangrove afforestation – a project beginning in 2011 saw the planting of 16 million mangrove plants. This increased protection from flooding for local settlements and brought rich biodiversity

• Co-management – many different stakeholders can work together to support mangrove swamps. This will help to balance conservation strategies and sustainable use of mangrove environments 

• Education – educating all stakeholders on the rules and management of mangroves is vital. Education has contributed to a new version of the Integrated Resource Management Plan (IRMP), which focuses on sustainable management of the Sundarbans

• Spatial monitoring – spatial tools provide data on any illegal activities, patrolling and biodiversity change

• Ecological monitoring – helping to predict threats that require responses 

• Each year, smaller fishing camps ensure locals still have access to fish supplies