Mangroves

What caused this?• Picture of Thai coast after Tsunami• Mangrove Protection Would

Have Lessened Tsunami’s Impact

• Many of the affected countries admitted the damage caused was partially self inflicted

• For reasons of tourism much of the mangrove that would have partially protected the region has been removed

• Since 1961 50% of Thai mangroves have been removed

• These tourist areas where mangrove had been removed was area where 5000 people died during the tsunami

• In Sri Lanka a tale of contrasts Wanduruppa an area where Mangroves are degraded 5-6000 died, in nearby Kapuhenwala surrounded by 200 hectares of dense mangroves only 2 deaths occurred!

On first appearances- these places do not look inviting.

Full of sticky mud and biting insects, they’re smelly and look like wastelands.

But to an educated intelligent eye, they are an important habitat for a diverse range of marine flora and fauna- manatees, crab eating monkeys, fishing cats, monitor lizards, mud skipper fish and Bengal tigers

They are essential to marine biodiversity- they stabilise coastlines against erosion, collect sediment and provide a nursery for coastal fish

Where do we find them?

• Grow in inner tidal areas and estuary mouths• Found along tropical and sub-tropical coasts of Africa, Australia,

Asia and the Americas • Greatest diversity of mangrove species is in South East Asia

Areas above 20 degrees

Where shorelines are protected from full force of waves

On shores where deposition occurs

Found in areas with• Permanently waterlogged soil• With high salinity• Areas which are frequently flooded or

inundated• Areas with intense sunlight and hot

weather• Areas with a sometimes limited

supply of fresh water

Sundra Shelf Mangroves (Sundaland wetlands hotspot)

• The spectacular flora and fauna of the Sundaland Hotspot are succumbing to the explosive growth of industrial forestry in these islands and to the international animal trade that claims tigers, monkeys, and turtle species for food and medicine in other countries. Populations of the orangutan, found only in this hotspot, are in dramatic decline. Some of the last refuges of two Southeast Asia rhino species are also found on the islands of Java and Sumatra. Like many tropical areas, the forests are being cleared for commercial uses. Rubber, oil palm, and pulp production are three of the most detrimental forces facing biodiversity in the Sundaland Hotspot.

Covers area 2x Wales

Found on the Island of Borneo and Sumatra

proboscis monkey

Vegetation

Mangroves vary in height from shrubs to 40 metres tall

Prop roots- essential for support in waterlogged ground

Pneumataphores- erect roots that protrude from the stem above water and hang down

They breathe in both water and air using pores known as lenticels which allow oxygen to diffuse into the plant

Vegetation description

They have a Zonation pattern-• Red mangroves- closest to coast, taking

brunt of wave action, protect inland areas, can survive permanent waterlogging

• Black Mangroves- found further inland, protected behind red mangroves. Have pneumatophores to obtain oxygen, die if permanently waterlogged

• White Mangroves- furthest from coast least able to survive waterlogging

How productive? Service provision?• Highly productive, nearly as so as Tropical Rainforests• Flora and Fauna important but perhaps more so is their role as

nursery for fish, shrimp larvae• A teaspoon of mangrove mud holds 10 million bacteria• Indication of high productivityMangrove service provision- • High level of fish, algae and invertebrate production• High production of timber and fuel wood, charcoal, fibre and dyes

also construction materials• Medium levels of climate regulation- of carbon and greenhouse

gas emissions• High level of resistance to species invasions• High level of removal of phosphates and nitrates from soil,

regulating soil pollution• High level of prevention of shoreline erosion• Mangroves have high levels of protection of storm surges, floods,

hurricanes and reduce resultant loss of life• Provide high levels of habitat for tropical fish- 75% rely on

mangroves in some part of life• Medium influence in storing and accumulating organic matter• Also medium aid in nutrient recycling

Can we put a value on Mangroves?

• Economic- areas where the mangroves were intact suffered less economic damage during Indian Ocean Tsunami

• Intact mangroves can provide locals with timber, charcoal, education, protection from storms, fisheries off shore- about $1000 a hectare, in some places $36,000

• Cleared mangrove ie ones cleared to make a quick fisheries buck reduced worth of $200

Mangrove loss

• Over 50% of Mangrove forests have been lost• Only around 15 million hectares remain• Thailand has lost 50% of mangrves since 1961• Phillipines- 40% lost between 1918 and 1988.

By 1993 only 123,000 hectares left- lost 70% in 70 years

• In Ecuador thought between 20- 50% has been lost

What is leading the changes?

• Asian loss- 50% due to Aquaculture (38% shrimp farming 14% fish farming)

• 25% lost to deforestation and another 11% to upstream freshwater diversion

• In Latin America- due to agriculture and cattle farming, cutting for fuel wood and building material, and beginnings of shrimp agriculture

Aquaculture- production of aquatic organisms under controlled conditions

Case Study- impact of shrimp farms on Thai Mangroves

• Shrimp farming has been practised in Thailand for 60 yrs, originally shrimp were trapped in natural environments, but during 70s and 80s farms sprung up

• Thailand exports nearly all the shrimp it farms, it provides ½ million tonnes pr year to USA ¼ million to France, UK and Italy

• More is now being consumed actually in Thailand since 90s where tourism has increased dramatically

Dulah Kwankwa used to be a rice farmer earning $400 a year, now earns 6 times more

He turned his rice farm into a shrimp farm- producing 3 crops a year. Dulah has money for first time in life. But he still has to pay off his initial loan and has to borrow more money every year, but he worries a lot more about the debt.

Impacts of shrimp Farming

• Reduced rural to urban migration from rural Thailand to the Capital Bangkok

• Increased wealth in local areas• Money has led to improved infrastructure• The decaying remains after a cycle of shrimp

farming are toxic and have to be removed• This residue affects mangrove fauna and flora

negatively• It can also lead to disease and infections among

those who are paid to remove it• Biodiversity is lost

Summarise the IMPACTS of shrimp farming on the economy, environment and the local Thai people, list BOTH positive and negative impacts

Impact of Climate Change

• Climate change is likely to lead to an increase in sea levels of between 15 and 95 cm by the end of this century

• If the rise is 95cm many of the mangroves will be lost, and these are very important in protecting areas from coastal erosion

• The loss of mangroves impacts negatively on the level of greenhouse gases in our air, because mangroves take in carbon

• Alos the changing mangrove to shrimp farms releases carbon that is contained in the mangroves soils

Over harvesting, exploiting marine life

Over harvesting• Mangrove trees are used for many purposes like for fuel wood,

construction, wood chip and pulp production, charcoal and for animals feed

• Although this has been happening for centuries, in some areas it has reached the point where it is becoming unsustainable

Over exploitation of marine life• This is depleting fish, prawns and other marine species• As one species becomes uneconomic, they focus on others• Results in decline in biodiversity• This can lead to loss of jobs• Over fishing alters the balance of the food chain/ web and

mangrove fish communities can be altered as a result• Tourism is spreading along mangrove coasts- previously they have

been viewed as mosquito infested mud swamps and have often been destroyed for golf courses, cruise shi p ports, apartments and restaurants.

Tasks

1) Draw a diagram to show links between mangrove destruction and economic activity

2) Explain the impacts of mangrove destruction

3) Which is more important- conserving mangroves or the benefits of exploiting and removing them?

Who are the key players involved in the mangrove debate?

Local organisations- Community Mangrove forests Thailand• Yadfon, small organisation in Thailand, formed in 1985-

working in Chao Mai, it faced 2 main problems-• Mangroves were being destroyed to produce charcoal,

which affected the supply of seafood- Yadfon created an 80 hectare community managed mangrove forest- which did not allow shrimp farms in its borders

• Destruction of sea grass- by large drag nets and large fishing boats. Sea grass is am important nursery for species of fish. To protect the sea grass a publicity campaign was launched which led to reduced destruction.

• The project also adopted a dugong - an animal that lives in and feeds from sea grass- it was adopted as a symbol of their conservation commitment.

EU funded initiative-Biodiversity along coast in Ranong Thailand• Collaborative project between Natural History

museum London, Wildlife Fund Thailand, Kampaun Fisheries cooperative

• Main objective is to assess biodiversity and enable long term environment monitoring. To make info available to locals

• Developed a number of activities- meeting with locals

• Open days • Newsletters• A education officer who liases with local schools • Youth camps to raise awareness

Wetlands international

• A non profit global NGO dedicated to the conservation and wise use of all wetlands. It has 4 long term goals-

• Global goal 1- all those who use and impact on wetlands should be well informed about their importance

• Global Goal 2- functions and value of wetlands are recognised and integrated into sustainable development

• Global Goal 3- conservation and sustainable yield of wetlands is achieved through effective uses of water resources and coasts

• Global Goal 4- large scale strategic initiatives result in improved conservation status of species, habitats and ecological networksSustainable Yield- ways in which ecosystems can be productive, but at levels which can be maintained and are sustainable, without causing damage

Some wetland international initiatives

• Green coast- for nature and people after the tsunami- provides capital grants and technical support and advice to support local communities in restoring and managing mangroves, coral reefs and sand dunes

• Community based mangrove restoration- to reduce poverty and vulnerability and increase sustainability in Aceh, Indonesia- enabling communities to restore and replicate a mangrove aquaculture ecosystem

• Mangrove replanting in Kuala Gula Perak, to rehabilitate degraded mangrove areas, involving private companies in funding community projects

Asia’s coastal ecosystems- Greenbelts

• TVE Asia- a not for profit media organisation- make programs about issues, made series about the mangroves to inform people of their whereabouts and importance.

• The programs made to encourage protection and restoration projects

Had Chao National Park, Thailand- A Ramsar Site-

• Thailand has 10 designated Ramsar sites- including the above

• Located in Trang province and consists of 3 distinct wetland areas, with a range of habitats including mangroves, mudflats, sandy beaches and coral reefs.

• It is important in terms of biodiversity• At least 212 bird species have been recorded in the

area, including vulnerable and endangered species• Home to at least 22 mammal species including the

endangered Dugong• At least 75 fish species are found here- critical to

livelihoods• http://www.seagrasswatch.org/Thailand.html

Reliance on wetlands

• Chao Mai is home to 10,000 people many of whom make a living from fisheries either in canals the trang river or coast areas

• Locals rely on wetlands as water source for agriculture

• 250,000 tourists visit each year and locals earn from them

Despite Chao Mai being a Ramsar site Threats

• Habitat change still threatens

• Over fishing• Lack of pollution control

Ramsar Sites- Ramsar Convention on Wetlands –intergovernmental treaty established 1971 in Iranian city- Ramsar

It’s mission is ‘conservation and wise use of all wetlands through local, regional and national actions and international cooperation as a contribution towards achieving sustainable development’

The convention has 158 member states and 1720 wetland sites totalling 159 million hectares

Tasks

• Assess the projects in terms of each one’s costs and benefits

• How effective do you think each will be?

End of sub unit tasksAnnotate an A3 world map, choose an ecosystem (Daintree

rainforest or mangroves)1) Identify the locations where your ecosystem is found and

annotate all the goods and services it provides2) Annotate the threats to your chosen ecosystem on the

map3) Show how the different areas are being managed

Exam Question-

Assess the role played by different players in managing areas where biodiversity is under threat (15 marks)