ENVIS Centre, Ministry of Environment & Forest, Govt. of India

Printed Date: Saturday, January 25, 2020

Athankarai estuary

Athankarai estuary
 
 
Name of the River
Vaigai
Place
Athankarai
District
Ramanathapuram
State
Tamil Nadu
Latitude
 9°12’N
Longitude
 79°8’E
Important Landmarks
 
Average depth
4 m
Type of the Estuary
 
Nature of the Substratum
Sandy-Muddy
Predominat benthic fauna
 
Commercially important shellfishes
 
Sewage discharges
 
 
 
 Image

Map

River Basin Map

 

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

 
Sl. No.
Sample
Po-210 Activity (Bq/Kg)
Athangarai estuary
Punnaikayal estuary
1
Water (m Bq/l)
1.2 ± 0.5
1.8 ± 0.3
2
Sediment
6.3 ± 0.6
8.9 ± 0.8
3
Seaweeds
  Brown Algae
     Padina parvulla
     Sargassum wightii
 
  Green Algae
     Ulva reticulata
     Enteromorpha intestinalis
     Byropsis
 
 
12.3 ± 0.3
 
 
18.0 ± 1.5
15.1 ± 1.6
14.1 ± 0.6
 
 
19.6 ± 2.2
 
 
4
Seagrass
     Cymadocea serrulata
 
15.4 ± 0.5
 
5
Muddy Shore Plant
     Salicornia brachiata
        Stem
        Root
 
 
 
 
6.6 ± 0.9
10.7 ± 1.7
6
Mangrove Plant
     Avicennia officinalis
        Leaf
        Stem
        Arial Root
 
 
 
 
5.6 ± 0.9
11.1 ± 1.7
15.6 ± 1.2

 

Concentration of Po-210 in Crustaceans and Molluscs of Gulf of Mannar

 

Sl. NO.
Sample
Po-210 Activity (Bq/Kg)
Athangarai estuary
Punnaikayal estuary
1
Crustaceans
  Prawn
          Muscle
          Exoskeleton
 
  Crab
     Scylla serrata
          Muscle
          Exoskeleton
 
     Portunus pelagicus
          Muscle
          Exoskeleton
 
 
112.5 ± 3.2
90.7 ± 4.5
 
 
 
40.5 ± 2.12
18.7 ± 1.5
 
 
72.6 ± 2.8
10.4 ± 1.1
 
 
113.8 ± 11.8
76.5 ± 3.2
 
 
 
236.1 ± 7.2
92.8 ± 3.2
 
 
209.1 ± 4.8
6.7 ± 0.9
2
Molluscs
  Gastropods
      Potamides palustris
          Whole
        
       Strombus canarium
          Soft tissue
          Shell
 
  Bivalves
     Meretrix casta
          Soft tissue
          Shell
 
     Modiolus metcalfei
          Soft tissue
          Shell
 
 
 
279.6 ± 6.4
 
 
51.0 ± 2.4
13.7 ± 1.3
 
 
 
345.8 ± 5.2
41.2 ± 2.7
 
 
 
 
 
385.2 ± 6.5
 
 
 
 
 
1334.1 ± 38.3
43.6 ± 2.2
 
 
893.6 ± 30.9
74.3 ± 10.0

 

Concentration of Po-210 in the Fishes of Gulf of Mannar

 

Sl. No.
Sample
Po-210 Activity (Bq/Kg)
Athangarai estuary
Punnaikayal estuary
 
 
1
 
 
2
 
 
3
PLANKTON FEEDER
 
Sardinella longicephs
       Muscle
       Bone
Chanda lala
       Muscle
       Bone
Thryssa malabarica
       Muscle
       Bone
 
 
 
181.3 ± 4.2
102.2 ± 2.4
 
108.2 ± 4.1
29.1 ± 1.5
 
88.9 ± 4.4
51.7 ± 2.6
 
 
 
173.0 ± 4.4
72.6 ± 2.8
 
168.1 ± 5.1
68.2 ± 4.0
 
242.2 ± 5.6
106.9 ± 6.7
 
 
4
 
 
5
 
 
6
 
 
7
CARNIOVOROUS FEEDER
 
Sphyraena barracuda
       Muscle
       Bone
Tachysurus jella
       Muscle
       Bone
Muraenesox bagio
       Muscle
       Bone
Scombiromorus lineolatus
       Muscle
       Bone
 
 
 
83.9 ± 4.3
37.0 ± 2.9
 
20.8 ± 1.1
12.6 ± 0.8
 
76.5 ± 3.2
32.0 ± 2.3
 
 
 
 
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
 
 
8
 
 
9
 
 
10
OMNIVOROUS FEEDER
 
Sardinella longicephs
       Muscle
       Bone
Chanda lala
       Muscle
       Bone
Thryssa malabarica
       Muscle
       Bone
 
 
 
44.5 ± 3.2
33.6 ± 2.8
 
30.7 ± 2.5
22.9 ± 2.4
 
30.5 ± 2.7
27.8 ± 2.5
 
 
 
148.1 ± 5.7
34.0 ± 2.7
 
131.1± 5.4
70.9 ± 4.0
 
11
DETRITUS FEEDER
 
Mugil cephalus
       Muscle
       Bone
 
 
 
 
 
 
88.1 ± 4.4
21.1 ± 2.2
 
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.