Biodiversity of Bangladesh: Extinction, Causes, impact and
conservation.
Biodiversity refers to all species of plants, animals and
micro-organisms existing and interacting within an ecosystem. Natural
biodiversity provides the foundation for all agricultural plants and animals.
The entire range of the domestic crops used in world agriculture is derived
from wild species that have been modified through domestication, selective
breeding and hybridization. Most remaining world centers of diversity contain
populations of variable and adaptable landraces as well as wild and weedy
relatives of crops, all of which provide valuable genetic resources for crop
improvement.
In addition to producing valuable plants and animals,
biodiversity performs many ecological services. In natural ecosystems, the
vegetative cover of a forest or grassland prevents soil erosion, replenishes
ground water and controls flooding by enhancing infiltration and reducing water
runoff. In agricultural systems, biodiversity performs ecosystem services
beyond production of food, fiber, fuel, and income. Examples include recycling
of nutrients, control of local microclimate, regulation of local hydrological
processes, regulation of the abundance of undesirable organisms and
detoxification of noxious chemicals.
These renewal processes and ecosystem services are largely
biological; therefore their persistence depends upon maintenance of biological
diversity. When these natural services are lost due to biological
simplification, the economic and environmental costs can be quite significant.
Economically, in agriculture the burdens include the need to supply crops with
costly external inputs, because agro ecosystems deprived of basic regulating
functional components lack the capacity to sponsor their own soil fertility and
pest regulation. Now we will see the overall conditions of biodiversity of
Bangladesh.
Biodiversity:
Generally, Bio means "life" and diversity
means "variety". Biodiversity means "variety of
life". So biodiversity refers to the variety of life and its biological
diversity on earth. It means the diversity of all life forms on earth. This
includes the various the various races and species of all microbes, plants and
animals that live on earth including their genetic differences.
In other words, biodiversity means the variability among
living organism from all sources including terrestrial, marine and other
aquatic ecosystems. It also includes diversity within species between species
and the number of species of plants, animals, and microorganisms, the enormous
diversity of genes in these species, the different ecosystems on the planet,
such as deserts, rainforests and coral reefs etc.
Biodiversity of Bangladesh:
Bangladesh is a
transitional zone of flora and fauna, because of its geographical settings and
climatic characteristics. There are many rivers and streams existing in the
country covering a length of 22,155 km. In addition to the regular inland
waters, seasonally a large part of the country remains submerged for 3-4 months
during monsoon. This country is rich in fish and aquatic resources, and other
biodiversity. Bangladesh’s inland water bodies are known to be the habitat of
266 species of indigenous fish, 13 exotic fish, 56 prawns, about 26 freshwater
mollusks, and 150 birds. The marine water bodies (200 nautical miles along the
coast) are also remarkable for being habitat of 442 species of fish. There are
at least 36 species of marine shrimps. About 336 species of mollusks, covering
151 genera have been identified from the Bay of Bengal. In addition, several
species of crabs, and 31 species of turtles and tortoises, of which 24 live in
freshwater are found in Bangladesh.
There are numerous
invertebrates in the country that are yet to be identified. Various authors
have recorded about 70 species of bees, and many species of wasps. In
Bangladesh only about 8-10 per cent of the land area is under good canopy
cover. It supports approximately 5000 species of angiosperms, out of which
about 300 species are being cultivated. The list of medicinal plants is
currently being revised at the Bangladesh National Herbarium (BNH), and is
expected to exceed 5000 species. There are 224 species of timber yielding
plants found in Bangladesh. The IUCN
Bangladesh Red Data Book (2000) has described 266 species of inland fishes, 442
marine fishes, 22 amphibians, 109 inland reptiles, 17 marine reptiles, 388
resident birds, 240 migratory birds, 110inland mammals, as well as 3 species of
marine mammals in Bangladesh
According to the Red
List of IUCN, there are 54 species of inland fishes, 8 amphibians, 58 reptiles,
41 resident birds, and 40 mammals, which are threatened throughout the country.
Among the marine and migratory species of animals, 4 fishes, 5 reptiles, 6 birds,
and 3 mammals are threatened. So far, the Red Data Book on plants, which is
under preparation at BNH, lists 96 seed-bearing plant species that are
threatened. The depletion of biodiversity is the result of various kinds of
human development interventions and activities, especially in the areas of
agriculture, forestry, fisheries, urbanization, industries, chemicals,
minerals, transport, tourism, and energy.
(1) Flora
(a) Habitats
(b)Forests
(c) Hill forest
(d) Sal forest
(e) Reed-land Forest etc.
(2)Fauna:
(a) Turtles
and Tortoises
(b) Monitor Lizards
(c) Aquatic invertebrates
(d) Shrimp
(e) Crab
(f) Fish
(g) Frogs
(h) Birds
(i) Mammals
(3)Mangrove
Forest Biodiversity
(4)Wetland
Biodiversity in the Haor Basin
(5) Coastal Biodiversity
(a) St. Martin’s Island
(b) Nijhum Dweep
(c)Madhupur
Tract
(d)Chalan Beel
(e) the Teknaf
Peninsula and
(f) Sonadia
Island etc.
Extinction of Biodiversity in
Bangladesh:
Biodiversity is said to be extinct
when any species, plant or animal of it is in danger of dying out or suffering
population reductions to such an extent that the species can no longer recover
and faces extinction in the wild.
In other words, a species would be
considered endangered when the best available evidence indicates that the
species is facing a very high risk of extinction in the wild.
Extinction is usually referring to the
species in the wild. Although there may be some specimens in zoos, or
controlled environments, if there is really no reasonable doubt that the last
specimen has died, then after surveys have been conducted, over the lifespan of
the species, in its native or known habitat, then a species should be declared
extinct. Extinction is happening too fast, to too many species of
plants and animals, in too many places. Three species become extinct every hour of every day. More than 30 species become extinct while
you sleep at night. More than 20,000
species become extinct every
year.
Causes of Extinction of
Biodiversity in Bangladesh:
(1) Invasive Alien Species
(2) Climate Change
(3) Nutrient Loading
(4) Habitat Change
(5) Over-hunting and Over-exploitation:
(6) Wildlife Trade
(7) Carbon Trade
(8)
Fragmentation and Loss of Habitat
(9)
Change in Hydrological Regime:
(10)
Uncontrolled Tourism
(11)
Unsustainable Agricultural Practices
(12)
The Military and the Environment
(13)
Lack of Knowledge and Awareness
Impacts of extinction of biodiversity:
Humans play a tremendous role in
wildlife extinction. Habitat loss, degradation, and fragmentation are the
leading factors that cause wildlife extinction to occur. The second largest
threat is from introducing nonnative species into ecosystems. Many species are
accidentally introduced. Many are introduced because of their value as a food
source and as pest control. The problem with these nonnative species is that
they have no “natural predators, competitors, parasites, or pathogens” that
control their population. Poaching and hunting is another cause of wildlife
extinction, but it is a very lucrative business so it is popular.
The impact of deforestation on
wildlife extinction is severe. Deforestation is the greatest eliminator of
terrestrial species. As shown in the last slide habitat loss is the greatest
factor in wildlife extinction and habitat loss is caused by deforestation. When
deforestation occurs many species lose their natural homes and food supplies.
It happens so rapidly that they do not have time to adapt and species are lost.
These areas are industrialized, commercialized, urbanized, and used for
agriculture. Deforestation not only causes many plants and animals to become
extinct it also causes soil degradation which causes more habitat loss and extinction.
Wildlife extinction has a large
impact on our world that most people are not aware of. It will take at least 5
million years for speciation to rebuild the biodiversity we are likely to
destroy during this century. The instrumental value of some species should be
taken into consideration. “Species provide economic value in the form of food
crops, fuel wood and lumber, paper, and medicine. The genetic information in
species is also very important to mankind. The information is used to create
new crop types, as well as food, medicines, and vaccines. The plants and
animals of the earth are also important because of the recreational pleasure
they provide us with. More people in America spend time watching wildlife than
they do watching movies or sports. Eco-tourism generates at least $500 billion
per year worldwide. There are many ways wildlife extinction has an influence on
the world.
Conservation of Biodiversity:
In order to ensure a better life some effective measures
should have been taken. By this time our govt. has already taken some steps but
those are the least steps. The Government
of Bangladesh has recently initiated a number of programs to manage avifauna,
both in wilderness and in situ. Worth mentioning are programs for the
protection of migratory birds through promulgation of the Bangladesh Wildlife
Preservation (Amendment) Act, 1974, and the publication of awareness-building
materials. A number of training programs at both local and national levels have
been organized for developing human resources, and building institutional
capacity. Bangladesh is also a member of Global Tiger Forum, a group that is
involved in the conservation of tiger populations. In order to protect wildlife
biodiversity the Bangladesh Wildlife Preservation (Amendment) Act, 1974 is
available, where names of protected animals are also enlisted.
For the better conservation of the biodiversity of
Bangladesh the following measures should be taken-
(1)
Measures to ensure Coastal and Wetland Biodiversity Management.
(2) Taking National Biodiversity Strategy and
Action Plan.
(3) Taking steps for the Conservation
and Management of Medicinal Plants.
(4) Taking Sustainable Environment
Management Program.
(5) Taking measures for the Management
of Aquatic Ecosystem through Community Husbandry.
(6) Taking Sundarbans’ Biodiversity
Conservation Program.
(7) Taking Forest Resources Management
Project
(8) Running Biodiversity Survey in 13
Protect Areas annually.
(9) Taking steps for the Maintenance of the ecological
balance, and overall progress and development of the country through protection
and improvement of the environment.
(10) Identification and control of all types of activities
related to pollution and degradation of environment.
(11) Ensuring environmentally sound development
in all Sectors.
(12)
Ensuring sustainable long-term and environmentally congenial utilization of all
natural resources.
(13)
The national policy planning authorities should recognize the necessity for
conservation of biodiversity, and ensure multi-sectored coordination for it.
(14)
Government agencies involved in biodiversity conservation should be
strengthened, and new agencies should be created wherever necessary.
(15)
Agencies for the survey of fauna and microorganisms need to be created.
(16)
The Wildlife Conservation Circle should be activated and strengthened.
(17)
As per the declaration made by the Environment Conservation Act, 1995, an ECA
wing should be created in the DoE. The Department of Environment should be
strengthened for ECA management.
(18)
Establishment of a National Institute of Biodiversity.
(19)
Preparing a digitized national database on biodiversity.
(20)
Raising Awareness about the need for conservation of biodiversity among all
sections of society should be encouraged.
(21) Conservation regulations should be updated, and enforced
strictly.
(22) Revision and reallocation of resources should be made to
make development sustainable, if necessary.
(23) Running Studies and development of
environmentally sound biotechnology and evaluation of the positive and negative
effects of biotechnology on biodiversity.
Legal and Regulatory Framework of Bangladesh regarding
Biodiversity:
1. The Protection and
Conservation of Fish Act, 1950.
2. The Protection and
Conservation of Fish Rules, 1985.
3. The Private
Fisheries Protection Act, 1889.
4. Bangladesh
Fisheries Development Corporation Act, 1973.
5. The Marine
Fisheries Ordinance, 1983.
6. The Fisheries
Research Institute Ordinance, 1984.
7. Wildlife
Preservation Act, 1974 (Amendment Act, 1994).
8. Forest (Amendment)
Act, 1990.
9. Forest Act, 2000
(Amending Act, 1927).
10. The Environment
Conservation Act, 1995.
11. The Environment
Conservation Rules, 1997.
But these laws are not enough for the conservation of our
biodiversity. By amending the faults of these laws and enacting new laws we can
conserve the most needed biodiversity.
In fine, Bangladesh is
a signatory to about 28 environmental treaties, conventions and protocols.
Bangladesh signed the Biodiversity Convention at Rio in 1992, and ratified it
in 1994. A focus on biodiversity has been emphasized in the Forest Policy and Environment
Policy. However, a separate policy on biodiversity is yet to be formulated, and
until then various departments of the government are responsible for
conservation of biodiversity. The Bangladesh National Biodiversity Strategy and
Action Plan are under preparation as a national obligation to the Convention on
Biological Diversity. In order to live a healthy and planned life we need a
fresh environment. To ensure a fresh environment we need profuse biodiversity.
For the maintenance of healthy life we need to conserve our biodiversity with
extra care. Along with the govt. initiatives we should come forward to keep our
biodiversity safe and free of all dangers. The search for self-sustaining,
low-input, diversified, and energy-efficient agricultural systems is now a
major concern of many researchers, farmers, and policymakers worldwide. A key
strategy in sustainable agriculture is to restore functional biodiversity of
the agricultural landscape. Biodiversity performs key ecological services and
if correctly assembled in time and space can lead to agro-ecosystems capable of
sponsoring their own soil fertility, crop protection and productivity.
In
fine, biodiversity is very much important for maintaining intergenerational
equity and ecological balance.
