Management of Mangrove Swamps (SL IB Geography)

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

Diagram of mangrove swamps

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 

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