MM

Prepared By: Raheem pkDepartment of ocean studies and Marine biology

Mangrove ecosystem

Introduction

They are (Angiosperms) trees or shrubs growing in shallow and muddy salt water or brackish waters

Found mainly in tropical and sub-tropical inter-tidal regions of the world. Exhibit remarkable capacity for salt water tolerance Do not appear on sandy beaches and rocky shores. A muddy substratum of varying depth and consistency is necessary for

growth.

Mangrove cover in various parts of world (Source: Spalding et al.)

Region Mangrove area(ha)

% to Globalarea

South and Southeast Asia

75,17,300 41.0

Australia 18,78,900 10.4

Americas 49,09,600 27.1

West Africa 27,99,500 15.5

Africa and the Middle East

10,02,400 5.5

Total 1,81,07,700

100

Found throughout the world between Latitudes 32°N and 38°S. Around 80 species found throughout the World (Saenger et al., 1983).

State wise mangrove cover (in sq.km.)

Sr. No.

States/ union territory

Estimated by Forest Survey of India

1991

1993 1995 1997 1999 2001

1. Andaman &Nicobar Islands

971 966 966 966 966 789

2. Andhra Pradesh 399 378 383 383 397 3333. Goa 3 3 3 5 5 54. Gujarat 397 419 689 901 1031 9115. Karnataka 0 0 2 3 3 26. Maharashtra 113 155 155 124 108 1187. Orissa 195 195 195 211 215 2198. Tamil Nadu 47 21 21 21 21 239. West Bengal 211

9 2119 2119 2123 2125 2081

Total 4244

4256 4533 4737 4871 4481

Species of Andaman and nicobar

Acanthus ebracteatusA. ilicifoliusA.volubilisAegialitis rotundifoliaAegiceras corniculatumAvicennia marina White/Grey MangroveA. officinalisBruguiera cylindricaB. gymnorrhiza B. parviflora B. exangula Ceriops decandra C. Tagal (Yellow mangrove) Cynometra ramiflora C. iripaExcoecaria agallocha

Heritiera littoralis Kandelia candelLumnitzera littorea (Black mangrove)L .racimosaNypa fruiticans (Mangrove palm)Phoenix paludosa(Mangrove date palm)Rhizophora apiculata (Red mangrove)R. lamarckiiR.mucronataR. stylosaScyphiphora hydrophyllaceaSonneratia alba (Mangrove apple)S. apetalaS.caseolaris S.griffithiiXylocarpus granatumX.mekongensis A very rare (Baratang and New Wandoor only)X.moluccensis

Sundarban Delta

The total landarea today is

4,143 km² .The Indian part ofthe forest isestimated to

be about 19%, while The

Bangladesh part is 81%.

Mangroves of Sundarban

Sundari (Heritiera fomes), Gewa (Excoecaria agallocha), Goran (Ceriops decandra) and Keora (Sonneratia apetala) The characteristic tree of the forest is the sundari (Heritiera

littoralis), Dhundul or passur (Xylocarpus granatum) Kankra (Bruguiera gymnorrhiza) Among palms, Poresia coaractata, Myriostachya

wightiana ,golpata (Nypa fruticans)

Ecological succession

Ecological succession is generally defined as the successive occupation of a site by different plant communities.

Succession began in the newly accreted land created by fresh deposits of eroded soil.

The pioneer vegetation is Sonneratia, followed by Avicennia and Nypa.

The late species to appear, is Excoecaria. As the level of land rises, the land is only occasionally

flooded by tides. Heritiera fomes begins to appear.

Zonation

Rocky & Sandy

Sandy clay Silty clay Silt

Mangroves absent

Sonneratia albaRhizophora mucronataAvicennia marinaA. officinalisBruguiera gymnorrhizaB. parvifloraAcanthus ilicifolius

Kandelia candelAcanthus officinalisRhizophora mucronataAegiceras corniculatus

Sonneratia caseolarisCyperus sp

EUHALINE POLYHALINE MESOHALINE OLIGOHALINE LIMNETIC

40-30% O 30-18% O 18-5% O 5-0.5% O <0.5% O

On the basis of salinity, five zones of mangrove distribution are considered-

Adaptation

LenticelsBruguiera gymnorhiza

PneumatophoresAvicennia officinalis

Salt glandsAvicennia corniculata

Stilt root Prop root Hanging root

Knee root & buttress root

Heritiera littoralis Bruguiera spp.

Reproductive strategy

Dispersal by means of water and vivipary.

Vivipary means that the embryo develops continuously while attached to the parent tree.

Cryptovivipary (Greek kryptos, hidden) refers to the condition whereby the embryo grows to break through the seed coat but not the fruit wall before it splits open. This condition is exhibited by Aegiceras,Avicennia and Nypa species.

Ecological Values

The most productive natural systems found throughout the world.

Used by a vast array of organisms as breeding , nursery and feeding areas.

Foreshore protection, reducing erosion by cyclones and lessening the impact of storm surge.

Primary Productivity

Function of a vegetation community.

Litter produced is measured in kg dry weight ha-1 year-1

Leaf litter : the collection and measurement of leaf litter fallen from a mangrove area over a particular period of time

Food chain

Energy Pyramid

Bacteria:

The tree is the foundation in a complex marine food chain and the detrital food cycle.

The detrital food cycle was discovered by two biologists from the University of Miami, Eric Heald & William Odum, in 1969.

As mangrove leaves drop into tidal waters within a few hours marine bacteria that convert difficult to digest carbon compounds into nitrogen rich detritus material.

These same bacteria give mangroves their "rotten egg" smell - as the sediment is oxygenpoor, only bacteria that use sulphur for energy can survive.

E.g – Bacillus sp. Lactobacillus brevis , L. fermentum , L.buchneri and L. lactis , Pichia salicaria , Geotrichum sp., Pichia fermentans , Cryptococcus dimennae. Trichoderma asperellum , T. Aaggerssivum , T. Spirale , T. polysporum

N-fixation

Atmosphere

Aerobic zone NH4+ NO2- NO3-

Anaerobic zone NH4+ NO3- N2 + N2O

Crustaceans as ecosystem engineers

They modify, maintain and create habitats The topography of mangrove swamps often modified by mud

lobsters(Thalassina spp) Thalassina spp throw up waste material from beneath the mud

surface ,accumulates as mound of 1 or 2 m. in height, which provide suitable habitats for others.

Fiddler crabs are known to influence the productivity of mangrove vegetation.

Fiddler crab

Uca sp.

Habitat

Aquatic fauna Benthic Community Major groups represented by the benthic organisms are

molluscs, crustaceans, echinoderms, hydroids, actinarians,planarians, nematodes, polychaetes and larval forms of several other organisms.

Crabs -Scylla serrata Mud lobster –Thalassina sp. Pistol shrimps –Alpheus sp. The molluscans - Crassostrea spp., Mytilus and Clams.

Pelagic ommunity The major aquatic mammals - dugongs, dolphins (Plantanista

gangetica), porpoises, otters. Detritivorous species of fishes, crustaceans. Fishes- Liza, Mugil, Lates, Polynemus, Sciaena,Setipinna,

Pangasium, Hilsa, Ilisha , Atroplus etc. Prawns- Penaeus sp., Metapenaeus sp., In the upstream regions, giant prawns like Microbrachium

rosenbergii are also found in large quantities.

Plankton community

Representative phytoplankton taxa identified :a) Bacteriastrum spb) Coscinodiscus sp c) Chaetoceros curvesetus d) Bacteriastrum hyalinum e) Closteriumf) Asteronella g) Grammatophora marina h) Nitzschia spi) Navicula penataj) Gyrosigma baticumk) Anabaena l) Asterionellopsis gracilis m) Dinophysis norvegican) Polykrikos schwartzil.

Habitat Terrestrial fauna Rhesus Macaque (Macaca mulatta)

Sonneratia apetala is an important species for wildlife, especially Chital deer (Axis axis)

Endemic shrews , rats of Andaman & Nicobar

Palm civet (Paguma larvata tyleri).

Nicobar crab eating macaque (Macaca fascicularis umbrasa)

Royal Bengal tiger (Panthera tigris tigris)

The reptile and amphibian fauna comprises over 125 species .Reptiles include several species of lizards,geckos, snakes and four species of marine turtles.

The mega species in the Andamans include the king cobra (Ophiophagus Hannah), the Andaman cobra (Naja sagittifera),

Mugger crocodile (Crocodylus palustris), as well as the Gharial (Gavialis gangeticus) and the Water monitor lizards (Varanus salvator)

The saltwater crocodile (Crocodylus porosus),

Water monitor lizard (Varanus salvator)

The king cobra (Ophiophagus hannah),

Andaman cobra (Naja sagittifera)

Mangrove snake-Boiga dendrophila

Yellow -crowned Night-Heron

Nyctanassa violacea

Oriental White eye

Zosterops palpebrosus

Boleophthalmus boddarti (blue-spotted mudskipper)

Adaptation of animal Designed to survive Sessile organisms (like mussels and barnacles) survive the fast tidal

movements in mangrove forests by anchoring themselves to the roots. Mobile fauna avoid the tide by burrowing in the mud (crabs) or climbing up

and down tree trunks (monkeys).

Lizards in mangrove habitat have a nasal gland that secretes salt into the nasal cavity from which it is sneezed out.

The keratinized skin of Crocodiles is relatively impermeable to salt and water , they also use a number of salt glands located on the tongue.

While sea turtles have salt glands modified into tear glands in their eyes.

Uses Used as a resource for food (commonly referred to

as bush tucker), medicine and timber.

Mud crabs, long bums, periwinkles, mangrove worms, mangrove jack, barramundi and many other marine species are collected as bush tucker.

Certain mangrove plants are used as food. Avicennia marina fruit is eaten but only after treatment to remove the bitter taste.

Provide medicines-The ashes from burnt Ceriops tagal wood is used to heal sores and infections,

The bark of Avicennia marina can be used to treat stingray stings (Wightman,1989).

Mangrove timber has also been used to construct canoes,paddles, boomerangs and spears.

Foreshore protection, reducing erosion by cyclones and lessening the impact of storm surge.