Athankarai estuary
Athankarai estuary
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Name of the River
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Vaigai
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Place
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Athankarai
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District
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Ramanathapuram
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State
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Tamil Nadu
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Latitude
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9°12’N
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Longitude
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79°8’E
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Important Landmarks
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Average depth
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4 m
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Type of the Estuary
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|
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Nature of the Substratum
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Sandy-Muddy
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Predominat benthic fauna
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|
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Commercially important shellfishes
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Sewage discharges
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Image
Map
River Basin Map
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Water temperature, salinity and dissolved oxygen in the period July, 1975 to September, 1976 at three stations where the three oyster beds are situated in Athankarai estuary
Concentration of Po-210 in water, sediment, seaweeds and plants of Athangarai and Punnalkayal estuary
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Sl. No.
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Sample
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Po-210 Activity (Bq/Kg)
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Athangarai estuary
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Punnaikayal estuary
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1
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Water (m Bq/l)
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1.2 ± 0.5
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1.8 ± 0.3
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2
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Sediment
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6.3 ± 0.6
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8.9 ± 0.8
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3
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Seaweeds
Brown Algae
Padina parvulla
Sargassum wightii
Green Algae
Ulva reticulata
Enteromorpha intestinalis
Byropsis
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12.3 ± 0.3
–
18.0 ± 1.5
15.1 ± 1.6
14.1 ± 0.6
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–
19.6 ± 2.2
–
–
–
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4
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Seagrass
Cymadocea serrulata
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15.4 ± 0.5
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–
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5
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Muddy Shore Plant
Salicornia brachiata
Stem
Root
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–
–
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6.6 ± 0.9
10.7 ± 1.7
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6
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Mangrove Plant
Avicennia officinalis
Leaf
Stem
Arial Root
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–
–
–
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5.6 ± 0.9
11.1 ± 1.7
15.6 ± 1.2
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Concentration of Po-210 in Crustaceans and Molluscs of Gulf of Mannar
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Sl. NO.
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Sample
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Po-210 Activity (Bq/Kg)
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Athangarai estuary
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Punnaikayal estuary
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1
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Crustaceans
Prawn
Muscle
Exoskeleton
Crab
Scylla serrata
Muscle
Exoskeleton
Portunus pelagicus
Muscle
Exoskeleton
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112.5 ± 3.2
90.7 ± 4.5
40.5 ± 2.12
18.7 ± 1.5
72.6 ± 2.8
10.4 ± 1.1
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113.8 ± 11.8
76.5 ± 3.2
236.1 ± 7.2
92.8 ± 3.2
209.1 ± 4.8
6.7 ± 0.9
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2
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Molluscs
Gastropods
Potamides palustris
Whole
Strombus canarium
Soft tissue
Shell
Bivalves
Meretrix casta
Soft tissue
Shell
Modiolus metcalfei
Soft tissue
Shell
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279.6 ± 6.4
51.0 ± 2.4
13.7 ± 1.3
345.8 ± 5.2
41.2 ± 2.7
–
–
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385.2 ± 6.5
–
–
1334.1 ± 38.3
43.6 ± 2.2
893.6 ± 30.9
74.3 ± 10.0
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Concentration of Po-210 in the Fishes of Gulf of Mannar
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Sl. No.
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Sample
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Po-210 Activity (Bq/Kg)
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Athangarai estuary
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Punnaikayal estuary
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1
2
3
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PLANKTON FEEDER
Sardinella longicephs
Muscle
Bone
Chanda lala
Muscle
Bone
Thryssa malabarica
Muscle
Bone
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181.3 ± 4.2
102.2 ± 2.4
108.2 ± 4.1
29.1 ± 1.5
88.9 ± 4.4
51.7 ± 2.6
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173.0 ± 4.4
72.6 ± 2.8
168.1 ± 5.1
68.2 ± 4.0
242.2 ± 5.6
106.9 ± 6.7
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4
5
6
7
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CARNIOVOROUS FEEDER
Sphyraena barracuda
Muscle
Bone
Tachysurus jella
Muscle
Bone
Muraenesox bagio
Muscle
Bone
Scombiromorus lineolatus
Muscle
Bone
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83.9 ± 4.3
37.0 ± 2.9
20.8 ± 1.1
12.6 ± 0.8
76.5 ± 3.2
32.0 ± 2.3
–
–
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116.5 ± 5.4
72.4 ± 7.2
125.9 ± 4.9
71.0 ± 4.0
202.0 ± 6.6
156.5 ± 5.2
147.4 ± 7.1
98.3 ± 2.8
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|
8
9
10
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OMNIVOROUS FEEDER
Sardinella longicephs
Muscle
Bone
Chanda lala
Muscle
Bone
Thryssa malabarica
Muscle
Bone
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44.5 ± 3.2
33.6 ± 2.8
30.7 ± 2.5
22.9 ± 2.4
30.5 ± 2.7
27.8 ± 2.5
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148.1 ± 5.7
34.0 ± 2.7
131.1± 5.4
70.9 ± 4.0
–
–
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11
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DETRITUS FEEDER
Mugil cephalus
Muscle
Bone
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–
–
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88.1 ± 4.4
21.1 ± 2.2
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Ø The distribution of Po-210 in Athangarai estuary (Palk Strait) of river Vaigai was compared with Punnaikayal estuary (Gulf of Mannar) River Tamiraparani.
Ø Measurements were made on the Po-210 levels of water, sediment and selected biota collected from the two different estuaries.
Ø Analyses of the results indicate that Punnaikayal estuary tends to accumulate Po-210 in the environmental matrices tested at relatively higher level as compared to Athangarai estuary.
Ø In water, dissolved concentration of Po-210 ranged from 1.2 mBq/l (Athangarai estuary) to 1.8 mBq/1 (Punnaikayal estuary).
Ø Polonium-210 concentration in sediment was also significantly higher in Punnaikayal estuary (8.9 Bq/Kg) than in Athangarai estuary (6.3 Bq/Kg).
Ø The Po-210 activity in the biota fell within the range of 5.6 to 1334.1 Bq/Kg.
Ø The bivalve mollusc Meretrix casta was identified to concentrate higher level of Po-210 in their soft tissues, suggesting that it could be used as a sentinel organism for Po-210 in an estuarine system.
Ø The functional role of estuary in the sediment transport into sea and consequently the transport of radioactive materials make this kind of study imperative.
Blennidae
Blennius semifasciatus
Clinidae
Tripterygion fasciatum
Sources
Satyanarayana Rao, K., D. Sivalingam, P.N. Radhakrishnan Nair and K.A. Unnithan, 1987. Oyster resources of Athankarai estuary, southeast coast of India. CMFRI Bulletin, 38: 17–29.
Lal Mohan, R.S., 1968. On the occurrence of the blennioid fishes Blennius semifasciatus Ruppell (Family : Blenniidae) and Tripterygion fasciatum (Weber) (Family: Clinidae) along the Indian coast. J. Mar. Biol. Ass. India, 10(1): 114–117.
Ravikumar, S., V. Masilamani, R. Krishnamoorthy, M.K. Palaniappan and P. Shahul Hameed, 2001. A comparative study on the distribution of Polonium–210 in the ecosystem of Athangarai estuary (Palk Strait) and Punnaikayal estuary (Gulf of Mannar). In: P. Shahul Hameed, M.M. Shahul Hameed, S. Ravikumar and V. Masilamani (eds.), Proc. Nat. Sem. Atom. Energ. Ecol. Environ., Jamal Mohamed College, Trichy, 135–142.