"mangrove" refers to a tidally influenced wetland ecosystem
within the intertidal zone of tropical and subtropical latitudes.
Mangrove also designates the marine tidal forest that includes
trees, shrubs, palms, epiphytes and ferns (Tomlinson, 1986). The
distinctive community of plants and animals associated with
mangroves is sometimes referred to as the 'mangal' (Macnae,
1968). The origins of the terms for mangrove are well researched by
Vanucci (1989). She concludes that the word mangue is from West
Africa, Senegal, Gambia and Guinea. The English word mangrove is a
derivation of the Portuguese or Spanish meaning grove made of
mangue. Mangrove ecosystems are heterogeneous habitats with an
unusual variety of animals and plants adapted to the environmental
conditions of highly saline, frequently inundated, soft-bottomed
anaerobic mud. (Khairnar
all mangroves are obligated to live in saline intertidal areas
(Clough, 1992). Plants that are confined to the mangrove are called
true mangroves; plants that can also occur elsewhere are called
mangrove associates (Tomlinson, 1986). Mangrove
associates never grow in true mangrove communities and may occur in
terrestrial vegetation. The mangrove fauna includes terrestrial,
marine, temporary and permanent animal species, all of which have
different adaptations to cope with the mangrove environment. The
diversity of mangroves is high, but the variety of mangrove
ecosystems also makes it difficult to produce general guidelines for
conservation and management of mangroves because each system is
are found in depositional
coastal environments where fine sediments, often with high organic
content, collect in areas protected from high energy wave action.
are salt-tolerant plants of tropical and subtropical intertidal
regions of the world. The specific regions where these plants occur
are termed as 'mangrove ecosystem'. These are highly productive but
extremely sensitive and fragile. Besides mangroves, the ecosystem
also harbours other plant and animal species.
It has been proved that the
presence of mangrove ecosystems on coastline save lives and property
during natural hazards such as cyclones, storm surges and erosion.
These ecosystems are also well known for their economic importance.
They are breeding, feeding and nursery grounds for many estuarine
and marine organisms. Hence, these areas are used for captive and
culture fisheries. The ecosystem has a very large unexplored
potential for natural products useful for medicinal purposes and
also for salt production, apiculture, fuel and fodder, etc.
warming is expected to result in the global sea level rise affecting
various marine habitats in the low-lying regions. Mangrove
ecosystems would be more vulnerable to the climatic changes, as
directly influenced by tides. Mangroves are believed to keep pace
with rising sea level by continuous sedimentation enriching the
ambient environment with organic matter. Due to sea level rise the
intertidal and supralittoral zones are likely to be extended farther
inland causing destruction of existing mangroves and associated
biota. The changes in the salinity concentration may cause genetic
erosion as well as change in the species composition. There may be a
total new assemblage of species in response to the changing salinity
regime. Climate changes coupled with anthropogenic pressures and
poor management practices may reduce productivity and loss of
mangrove dependent biodiversity, adversely impacting ecological and
socioeconomic benefits (Jagtap & Komarpant, 2003).
of the environmental, social and economic impacts associated with
the decline and degradation of mangroves are now being addressed
through legislative, management, conservation and rehabilitation
efforts aimed at mitigating the negative impacts of development on
Tidal action is a
primary factor that determines mangrove ecology, i.e. ecosystem
established, roots of mangrove plants provide a habitat for oysters
and help to impede water flow, thereby enhancing the deposition of
sediment in areas where it is already occurring. Usually, the fine,
anoxic sediments under mangroves act as sinks for a variety of heavy
which are scavenged from the overlying seawater by colloidal
in the sediments. In areas of the world where mangroves have been
removed for development purposes, the disturbance of these
underlying sediments often creates problems of trace metal
contamination of seawater and biota.
Mangroves protect the coast from erosion, surge storms (especially
and tsunamis. Their massive root system is efficient at dissipating
wave energy. Likewise, they slow down tidal water enough that its
sediment is deposited as the tide comes in and are not re-suspended
when the tide leaves, except for fine particles. As a result,
mangroves build their own environment. Because of the uniqueness of
the mangrove ecosystems and their protection against erosion, they
are often the object of conservation programs including national
their benefits, the protective value of mangroves is sometimes
overstated. Wave energy is typically low in areas where mangroves
grow, so their effect on erosion can only be measured in the
long-term. Their capacity to limit high-energy wave erosion is
limited to events like storm surges and tsunamis. Erosion often
still occurs on the outer sides of bends in river channels that wind
through mangroves, just as new stands of mangroves are appearing on
the inner sides where sediment is accreting.
support unique ecosystems, especially on their intricate root
systems. The mesh of mangrove roots
produces a quiet marine region for many young organisms. In areas
where roots are permanently submerged, they may host a wide variety
of organisms, including algae,
which all require a hard substratum for anchoring while they filter
use the muddy bottom as their home. Mangrove
improve the nutritional quality of the mangal muds for other bottom
feeders by mulching the mangrove leaves. In at least some cases,
export of carbon fixed in mangroves is important in coastal food
webs. The habitats also host several commercially important species
of fish and crustaceans.
major factors, governing the mangrove ecosystem
Climate plays major role in inter-tidal
region for natural growth, development and succession of the
mangroves. Among these climatic factors
Sedimentation play very major role for
the mangrove viability in a holistic manner.
The soil structure
and soil salinity are the main agents, controlling the distribution
of mangroves. The soil salinity of the supralittoral zone, where
water reaches once or twice in a month during highest high-water
tide, is comparatively high because of the rate of evaporation.
tidal fluctuation has the major role for mangrove habitats, as most
mangroves grow well in between the Mean High Water Spring Tide
(MHWST) and Mean Sea Level (MSL).
The threats to the mangrove ecosystem
could be broadly grouped into two: Natural and Anthropogenic
of the Mangrove ecosystem:
(including laws and policies);
Surveys (land and aerial, etc.);
Protection (including conservation,
parks and reserves development, etc.)
use of Mangrove ecosystem:
(Agriculture, Aquaculture -capture fisheries, culture fish),
Natural products useful for medicinal
purposes, drugs, etc.);
(timber, salt production, honey, etc.);
Clough, B.F., 1992. Primary productivity
and growth of mangrove forests. In: A.I. Robertson and D.M. Alongi
(Eds.) Tropical Mangrove Ecosystems. American Geophysical Union,
Washington, D.C. pp.225-249.
& Komarpant, 2003. Evaluation of mangrove ecosystem of India for
assessing its vulnerability to projected climatic changes.
Assessment of climate change in India and mitigation policies, World
Wide Fund for Nature-India eds. Dash, S.K.; Rao P. 39-51p.
S. O., Sathe, A.R., Mhatre V.D., Jadhav S. S and Desai K.B., 2009. Mangroove Biodiversity of India.
E., 1968. A general account of the fauna and flora of mangrove
swamps and forests in the Indo-West Pacific Region. Advances
in Marine Biology 6:
P.B., 1986. The botany of
mangroves. University Press,
Cambridge, 419 pp.
M., 1989. The mangroves and
us: a synthesis of insights.
Indian Association for the advancement of Science, New Delhi, India.