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| Last Updated:: 02/02/2017

Palk bay

 Palk Bay


Palk Bay
Name of the area
Palk Bay
Place :
Near Rameswaram
State :
Latitude :
9°55’ – 10°45’N
Longitude :
78°58’ – 79°55’E
Key Physical Characters
Estimated reef area
Reef starts from Munakad (1-2m Broad) and runs east up to
Tonithurai.(5.5km) width of the reefs attains 300m
East to the Pamban pass , the reef again starts near
Thangachimadam and end near Angitheertham(Rameswaram)
9 meter (Never Exclude 15 mts)
Tidal amplitude (in meter) :
1m (generally calm) except in North-East Monsoon
Water temperature:
24.60c and 29.10c
Chemical Characters
pH :
7.5 to 8.4
Salinity :
22.5 to 35 ppt
Dissolved Oxygen :
3.29 to 5.44 mg/l
Biodiversity status
Foraminifera 51
Tintinnids 12
Flora 143
Sponges 275
Coelentrates (other than corals) 123
Stony corals 128
Polyzoa 100
Polychaeta 75
Insecta 1
Crustacea 651
Mollusca 733
Echinodermata 274
Prochordata 66
Fishes 580
Turtles 5
Birds 61
Mammals 11
Major flora Fauna
List of phytoplankton species recorded from Kattumavadi, Palk Bay.
(Sridhar et al 2006)
Bacillariophyceae (Diatoms)
Achnanthes brevipes - Not available
Asterionella glacialis - Not available 
Bacteriastrum delicatulum - Threatened
Cerataulina bergonii - Not evaluated
C. indicus sp. - Not  available
C. orientalis -  Not  available
Climacosphenia elongata - Not available
Coscinodiscus jonesianus (Greville) -  Not available
C. lineatus Ehrenberg - Not available
C. marginatus - Not available 
C. sub-lineatus - Not available
Fragilaria brevistriata - Not available
G. sphaerophorum - Least concern
Grammatophora undulata - Not available
Gyrosigma balticum - Not available
G. disortum - Not available
Navicula cincta - Not available
N. cuspidata Kutz. - Not available
Nitzschia closterium - Not evaluated
N. longissima - Not evaluated
N. sigma - Not evaluated
Odontella heteroceros - Not available
O. mobiliensis - Not evaluated
O. pulchella - Not available
Pinnularia acrosphaeria - Not available
Planktoniella sol - Least concern
P. aestuarii - Not available
P. angulatum - Not available
P. elongatum. - Not evaluated
P. normanii - Not available
Pyxidicula minuta - Not available
Rhizosolenia alata - Not available
R. crassispina - Not available
R. cylindrus Cleve - Not available
Synedra ulna - Not available
Tabellaria fenestrate - Not available
Thallassionema nitzschioides - Not available
T. lineatum - Not available
Thallassiothrix frauenfeldii - Not available
T. longissima - Not available
T. favus - Not available
T. reticulatum - Not available
T. robertsianum - Not available
Cyanophyceae (Blue-green)
Aphanocapsa conferta - Not avaiable 
Chroococcus indicus - Not available
Phytoplankton bloom : Generally 2 to 3 blooms occur in a year particularly
Commercially Important Shell Fishes
Lobster, crabs, cephalopods (foreign exchange earner), cuttle fish, pearl oyster etc.,
Fin Fishes
Fishes 580
61 species of marine macroalgae
Green algae (14 genera and 28 species)
Ulva lactuca - Not evaluated
U. reticulate - Endangered
Cladophora sp. - Near threatened
Chaetomorpha sp. - Not available
Neomeris annulata - Not evaluated
Acetabularia moebii - Not available
Halicystis boergesenii - Not available
Valonia aegagropila - Not evaluated
Boergesenia forbesii - Not evaluated
Microdictyon agardianum - Not evaluated
Struvea delicatula - Not available
Caulerpa cupressoides - Not evaluated
C. fergusonii - Not threatened
C. Mexicana - Not evaluated
C. micropysa - Not available
C. peltata - Not evaluated
C. racemosa. V. clavifera - Least concern
C. racemosa V. coryneflora - Least concern
C. scalpelliformis - Not available
C. serrulata v. typical, formalata - Not evaluated
C. sertularioides forma brevipes - Not evaluated
C. sertularioides forma longiseta- Not evaluated
C. taxifolia - Not evaluated
C. verticillata -  Not evaluated
Udotea javensis - Not available
Halimeda opunita - Not avialable
H. tuna - Not available
Codium sp. - Not evaluated
Brown algae (8 genera and 13 species)
Dictyota spp. - Not evaluated
Padina commersonii - Not available
P. gymnospora - Not available
P. pavonia - Not available
P. tetrastromatica - Not available
Pocockiella variegate - Not available
Pocockiella sp. - Not available
Hydroclathrus clathratus - Not available
Chnoospora implexa - Not available
Hormophysa triquetra - Not available
Sargassum sp. - Endangered
Turbinaria conoides - Not evaluated
T. ornate - Not available
Red algae (17 genera and 20 species)
Gelidiella acerosa - Not evaluated
Gelidium pusillum - Not evaluated
Amphiroa fragilissima - Not evaluated
Chondrococcus harnemanni - Not available
Gracilaria crassa - Not available
G. foliifera - Not evaluated
Glichenoides - Not available
Hypnea spp. - Not evaluated
Champia globulifera - Not available
Wranglia argus - Not available
Ceramium spp. - Data deficient
Centroceras clavulatum - Not evaluated
Spyridia filamentosa - Not evaluated
Martensia fragilis - Not evaluated
Roschera glomerulata - Not available
Leveillea jungermannioides - Not evaluated
Cohondrai dasyphylla - Not evaluated
Acanthophora spicifera - Not threatened
Laurencia obtuse - Not available
L. papillosa - Not available
Cumodocea sp. - Least concern
Diplanthera wrightii - Not available
Syringodium filiforme - Least concern
Halophila ovalis - Least concern
Endangered species
Turtules, seahorses, dolphins, dugongs etc.,
Archeologically/Ecologically Important Places
Palk Bay
The reefs has been classified into 5 Zones Shore
Shoreward slope
Reef crest
Seaward slope
The Scleractinian fauna of Palk Bay (82 species and 27 genera)
Environmental status
Associated ecosystem
Mangroves, seaweeds, seagrass etc.,
Gross average productivity in benthic floor
142 to 472 mg C.m3d-1
Major threats
Cyclonic winds, strong monsoon winds (cause mechanical damage), dumping untreated domestic and industrial waste into the oceans, unscrupulous fishing, using trawl nets in shallow depths 2 to 3 fathoms (or) by use of shore seine fishing nets around coral reef areas, coral minning, coral bleaching etc.,