Coastal features found on tidal mud flats in tropical and sub-tropical areas.
Features: stilt roots — anchor plant in soft mud, slows wave movement and
encourages more mud deposition; extending coastal area into sea and reducing
erosion risk. conical breathing tubes — stick up out of mud from root system
Need gently sloping, muddy coastline and warm tropical climate.
They’re halophytic and well adapted to salt water.
Help to protect coastline from flooding.
e.g. Indian Ocean tsunami December 2004, 6000 deaths in one Sri Lankan village
where they cut mangroves down. 2 deaths in village that didn’t cut.
They grow up to 15m tall so offer protection against high winds of tropical storms
Case study: The importance of mangroves in protecting tropical coastlines.
Development on Grand Cayman
36% of Grand Cayman occupied by mangroves, centre of island was largest area.
Located in hurricane zone so the low-lying island has always needed protection
that mangroves provide. Risk from tsunamis from Caribbean plate boundary.
1997-2009: development on island, building on new hotels and condominiums.
10% of mangroves had been lost due to developments.
2010: 66% of mangroves on western peninsula had been removed. (83 hectares)
for development at Dragon Bay, stretches from 7 Mile Beach to North Sound. The
development with have houses with private beaches, gold course, tennis court and
other facilities. Project caused controversy. Said that mangroves that were
removed had been damaged in 2004 although they had said to have recovered.
Developer planning to plant more mangroves.
Tourism started in 1960’s and provides 75% of GDP to country. Result of 1977
development plan; many areas of mangrove swamp were reclaimed for road
building, golf courses, tourist accommodation, marinas and housing.
Locals have mixed opinions about issue. Western side of island said to be concrete
jungle. Anger as mangroves were seen as protection. 75% of building damaged in
2004 Hurricane Ivan but much worse without mangroves.
Mangrove uses: roots help to stabilise coast against erosion. source of fuelwood.
absorb inorganic nutrients that drain into them in water from farmland and urban
areas. prevents them from going into sea and harm marine life. mangrove leaves
decay and odd organic nutrients to water, provides food for small fish that hatch
and shelter in mangroves area. swamps provide nursery for fish and shellfish.
important wildlife habitats as well as temporary homes for migrating birds.
breeding and feeding grounds. important for recreation — fishing, bird watching,
photography and boating.
