Mangroves in Asia are threatened by loss of habitat, which negatively impacts fish breeding grounds. Over 25% of mangroves in Asia were lost from 1980-2005, mainly in Indonesia, Pakistan, Vietnam, Malaysia, and India. Mangroves are important ecosystems that protect coastlines from erosion, serve as fish breeding grounds, and support local livelihoods. Their loss contributes to environmental degradation and economic and social problems for coastal communities. Responsibility for addressing the issue lies with local communities, governments, and authorities who must develop and apply policies to restore mangroves and manage them sustainably through community involvement and protected area designation.

1. Threats of loss of fish breeding
grounds due to loss of mangroves in
Asia
Dhiman Gain
Svetlana Vasic

2. Outline
• Introduction
• Who is affected and what the effects are
• What values are at stake, and how the ethical
theories discussed would apply in considering
the issue
• Who bears responsibility for addressing the
situation
• What policies should be applied

3. Introduction
• Locality: River mouths, river banks, coasts, small islands
• Wave action: Preference to grow at areas with low wave action -
Why mangroves do not grow on most shores, e.g. sandy beaches?
• Dynamic environment: periodically submerged by tidal flows (recall
definition!)
• Elevation: relatively low elevation (compared to other forest)
• Sediment: prefers to grow on muddy-silty terrain
• Temperature and weather: sunny and tropical all-year long

4. Introduction…
• Mangroves are various large and extensive types of trees up to medium
height and shrubs that grow in saline coastal sediment habitats in
the tropics and subtropics—mainly between latitudes 25° N and 25° S.
• Mangroves are salt tolerant trees (halophytes) adapted to live in harsh
coastal conditions.
• Some of the largest mangrove forests in the world are found in Asia, the
most well known being the Sundarbans, a transboundary forest covering
approximately 1 million hectares in Bangladesh and India.
• Other Asian countries with a significant extent of mangroves are (in order
of mangrove area) Malaysia, Myanmar, Bangladesh and India, which,
together with Indonesia, account for more than 80 percent of total Asian
mangrove area.

6. Introduction…
• Human pressure on coastal areas and
increasing demand for land for agriculture
represent increasing threats to mangroves in
these countries
• In this region some 1 900 million hectares of
mangroves – or about 25 % of the 1980 area –
have been lost during the last 25 years. More
than 90 % of this loss has been caused by the
major mangrove area changes in Indonesia,
Pakistan, Viet Nam, Malaysia and India, which
experienced a cumulative loss of more than
1700 million hectares.

8. -Buffer Zone between the land and sea.
-Protect the land from erosion.
-Play an invaluable role as nature's shield against cyclones, ecological disasters
and as protector of shorelines.
-Breeding and nursery grounds for a variety of marine animals.
-Harbor a variety of life forms like invertebrates, fish, amphibians, reptiles, birds
and even mammals like tigers.
-Good source of timber, fuel and fodder.
-Main source of income generation for shoreline communities like fisherfolk.
-Save the marine diversity, which is fast diminishing.
-Purify the water by absorbing impurities and harmful heavy metals and help us
to breathe a clean air by absorbing pollutants in the air.
-Potential source for recreation and tourism.
Importance of Mangrove

10. Figure from Yee et. al (2000) The present extent of mangroves in Singapore, NIS,
Provides coastal protection: attenuates wave energy
Prevents erosion

11. Ongoing threats to mangroves
1. Clearing(Major factor of mangrove loss!)
-seen as unproductive and smelly
- cleared to make room for agricultural land, human settlements and infrastructure (such
as harbours), tourist developments, shrimpaquaculture, and salt farms
2. Overharvesting
-non-sustainable harvest of timber
3. River changes
- Dams and irrigation: reduce water and sediment reaching mangrove forests, increases
salinity level in mangroves
-freshwater diversions can also lead to mangroves drying out.
4. Overfishing:
- ecological balance of food chains and mangrove fish communities can also be altered.
5. Destruction of coral reefs
-when they are destroyed, the stronger-than-normal waves and currents reach coasts
6. Pollution
-Fertilizers, pesticides and chemicals kill animals living in mangrove forests
- Oil pollution can smother mangrove roots and suffocate the trees.
Ongoing threats to mangroves
Ongoing threats to mangroves

12. 7. Overexploitation of abiotic resources
e.g. Timber, honey etc
8. Shrimp aquaculture
9. Natural calamities e.g coastal cyclones, Tsunamies
etc

13. • The main causes of mangrove loss in Indonesia are conversion
of land for shrimp farms (East Java, Sulawesi and Sumatra),
excessive logging and, to a lesser extent, conversion of land to
agriculture or salt pans (Java and Sulawesi).
• Malaysia lost about 110 000 ha of mangroves from 1980 to
2005.

14. Why Mangrove loss is a threat to fisheries
• Mangroves trap debris and silt, stabilizing the near shore environment
and clarifying adjacent open water, which facilitates photosynthesis in
marine plants. The fringing network on Mangroves buffers natural forces
such as hurricanes, wave action, tidal change and run-off, preventing soil
loss with its firm, flexible barrier.
• MANGROVES ARE NUTRIENT PRODUCERS that shed and drop about
seven and a half tons of leaf litter per acre per year. The constantly-shed
leaves are quickly broken down by bacteria and fungi and released into
the water, providing food for sea-life.

15. Mangrove species Food use Medical use Tool use
Avicennia marina, white
mangrove
fruit eaten after treatment,
(Mornington Is; Tiwi;
Boorroloola, Roper R;
Belyuen; Bardi; Dampierland);
flavour in cooking mussels
(Groote Eylandt); nectar
sting-ray and stonefish ‘stings’
(Milingimbi);ringworms, sores
and boils (Yirrkala); scabies
(general); 'cheeky' mangrove
worm medicine for coughs
(Tiwi)
shields
Bruguiera gymnorrhiza mangrove worm
(Tiwi);hypocotyls eaten after
treatment (Cape York)
spear tips (Belyuen); throwing
sticks for hunting magpie
geese (Tiwi);boomerangs
Ceriops australis spear shafts (Tiwi)
Excoecaria ovalis nectar (Groote Eylandt) toxic plant, latex causes skin
to swell (Milingimbi);leprosy
sores, marine stings, body
pain
floats for turtle hunting,
firewood (Groote
Eylandt);cordage
Lumnitzera littorea nectar-rich flowers as sweets
(Yirrkala)
digging sticks, throwing sticks
(Belyuen)
Rhizophora stylosa mangrove worm (Tiwi); mud
crabs found at roots (Belyuen;
Tiwi)
skin sores (Tiwi); ulcers and
yaws (NT)
ceremonial armbands
(Tiwi);boomerangs, spears,
firewood (Bardi); clubs
(Arhnem Land)
Sonneratia alba nectar skin disorders (Tiwi) tops (Tiwi); carving wood

17. The major effects of mangrove loss
• Economic loss
• Environmental alterations
• Social impacts

18. Responsibility for addressing the this
adverse situation
• Community who use this resource and directly
dependent on it for their livelihood:
- Fisher
- Honey collector
- Wood collector
• People who are indirectly dependent on it
- General people
• Local authority e.g. Forest department
• Government

19. Policies that should be applied to mitigate
the problem
• Bottom-up approach can be applied rather top-down
• Giving ownership to the community
• Community based management by giving ownership
to the community
• Mangrove restoration by plantation through paid
work e.g. Nypa frutican

20. • Ecosystem based management
• Declared as a protected area e.g. MPA

21. Who is responsible to develop and apply
the policies
• The Government and the local authorities are
responsible to make the right policies and
management approach
• Community as well as general people need to
respect, follow, apply and act according to that
policies

22. Thanks To All