Back to previous page
     Click on areas  
Background   Links   People
Ashtamudi wetland is an estuary, which lies in the Kollam district. This is the second largest wetland in Kerala with a palm shaped extensive water body and eight prominent arms, adjoining the Kollam town. All the arms converge into a single outlet at Neendakara near Kollam, to enter the Lakshadweep sea. This estuary is the deepest among all the estuaries of Kerala with a maximum depth of 6.4 m at the confluence zone. The Kallada river which originates from the western ghats, traverses through virgin forests and finally falls into the Ashtamudi wetland, after traveling a distance of about 120 km. It carries an average runoff of 76,000 million cu m of freshwater into the estuary every year. The wetland supports 57 species of birds (6 migratory and 51 resident species) and 97 species of fish (42 typically marine, 3 estuarine, 9 estuarine-riverine and 15 marine-estuarine). About 40 species of wetland dependant birds are noted in Ashtamudi Lake, out of which 45% are long distant migrants. The lake is the source of livelihood for the people living close to it in fishing, coconut husk retting for coir production and inland navigation services.

The two most important factors causing deterioration of the wetland are pollution and encroachment. More and more industries including tourism coming up adjacent to the shores and basin are without effluent and waste treatment facilities. Coconut husk retting and related operations, though of small scale, are intensive, contributing heavily to the organic pollution load of the open water bodies. Wastes from the houseboats and resorts are also ultimately released into the wetland. The fishing boats fitted with outboard engines releases large quality of hydrocarbons into the system. The agricultural practices which involve the use of chemical/organic fertilizers and insecticides/pesticides, and the residues on entering the system cause pollution and eutrophication. The modern aquaculture also induces change in the ecosystem.

The area of the lake decreased from original 54 sq m to 34 sq m in 2007. Land use changes and deforestation in the watershed as well as the increase in withdrawal of surface and ground water from the basin for irrigation, domestic, industrial and other uses have also put forth pressure on the system through stream flow changes. Hydrological interventions, like the Kallada Dam also exert pressure on the system. Many fish species may have become extinct due to lack of spawning facilities on the banks of the lake due to canalization of the lake’s banks by walls built of laterite and granite stones.

In 2000, a portion of the lake, the Kanjiracode creek on the southeast end of the lake has been completely destroyed due to dumping of clay into the lake by the State government-owned PSU, the Kerala Ceramics Limited (KCL), Kundara. Alarmed at the danger posed by the dumping of clay, the local residents formed a Pollution Control and Prevention Joint Action Committee. The action committee largely comprised those from the fishing community and coir workers of the area. They protested strongly against KCL. To stop the deterioration of the estuary, Ashtamudi Management Plan was proposed in 2001. In 2002, the lake was designated as a Ramsar site. Later on in 2004, the Union Ministry of Environment and Forests has sanctioned a Management Action Plan (MAP) with an aim to conserve and mange the biodiversity of the wetland. The District Rural Development Agency (DRDA) and the Brakishwater Fish Farmers Development Agency (BFFDA) were jointly given the responsibility to implement the 22.83 lakh plan. In spite of the constitution of a Special Task Force (STF) for the conservation of Ashtamudi lake, the STF could not achieve much. Kerala Sasthra Sahithya Parishad (KSSP) is also working on the conservation of the lake since 2006.

In the year 2007, the district administration conducted a revenue survey of the lake as part of a move to save it. Massive encroachments were detected during this survey. The survey also detected that traditional mangrove forest areas of the lake had been destroyed to facilitate encroachments. As a result of these encroachments, almost 80 per cent of the lake's banks comprised vertical walls built with laterite stones and granite. These walls prevent spawning of fish. STF was allocated a sum of 30 lakh by the Union Ministry of Environment and Forests to revive mangrove forests on the banks of the lake. Under this programme, 2,40,000 mangrove saplings were planted along the banks of the lake in phases that began two years ago. Only few are surviving now. In 2007, the Kollam Corporation commissioned a biogas plant at the mouth of the lake with the help of State Pollution Control Board. The plant operated only for once and twice and raw sewage was pumped into the lake. By 2008, the situation worsened and Pollution Control Board directed the Corporation authorities to close down the plant and reopen it only after ensuring proper waste treatment management. The fisheries department also tried to put forward their help to conserve the lake. In the same year, the department launched a major operation to bust the destructive methods of fishing employed in Ashtamudi Lake.

Ashtamudi Management Plan


Bhadran Geetha (Dept Zoo, St Gregorios Coll, Kottarakara, Kollam, Kerala 691 506). The plankton population of Asramam creek of Ashtamudi lake in Kerala South India. J Ecobio, 13(2) (2001), 123-129 [14 Ref].

Arunachalam, M & Nair, N. B.,1988. Harpaetioid copepods associated with the sea grass Halophila ovalis in the Ashtamudi estuary, South-West coast of India, Hydrobiologia, 167-168: 515-522.

Divakaran, O., Arunachalam, M., Nair, N. B., & Balasubramanian, N.K., 1981. Seasonal variation of the Zooplankton of the Ashtamudi lake, South west coast of India. Mahasagar , Bull. Natn. Inst. Oceanogar. 15:53.

Dharmaraj, K & Nair, N.B., 1981. The nature of distribution of major inorganic nutrients in the Ashtamudi backwaters in relation to environmental factors. Proc. Seminar on Status of Environmental studies in India. March 1981, Trivendrum, Kerala, pp. 232-242.

Krishnakumar, K., Nair, N.B. & Balasubranian, N.K., 1986. On the fecundity of grey mullets Valamugil cunnesius (Val.) and Valamugil speigleri (Bleeker) from the Ashtamudi
waters. Aquatic Biol., 6: 157-163.

Mohandas, A., Ramanujan, N & Sreedevi, P., 1994. The effect of man-made changes in the mangrove ecosystem at Asramom, Kollam. Proc. VI th Kerala Science Congress, 28- 30 January 1994, Tiruvanantapuram, Kerala, pp 55-57.

Nair, N.B. Abdul Aziz, P.K. Arunachalam, M., Krishna Kumar, K & Balasubranian, N.K., 1983.Ecology of Indian estuaries Part I. Physicochemical features of water and sediment
nutrients of Ashtamudi estuary: Indian J. Mar. Sci., 12: 143-150.

Nair, N.B., Arunachalam, M., Abdul Aziz, P.K., Dharmaraj, K & Krishnakumar, K., 1983. Ecology of Indian estuaries Part II. Ecology of seagrass bed of Halophila Ovalis (Hook) in the Astamudi estuary, South West Coast of India. Proc. Indian Acad. Sci. (Anim. Sci.)., 93: 19-23.

Nair N.B., Krishnakumar, K., Abdul Aziz, P.K., Rajashekaran nair, R., Dharmaraj, K & Arunachalam, M., 1983. Ecology of Indian Estuaries XI. A preliminary survey of the fishery resources of the Ashtamudi estuarine system. Fishery Technol., 20: 75-83

Nair, N.B., Dharmaraj, K & Balasubramanian, N.K., 1984. Ecology of Indian estuaries VIII. Inorganic nutrients in the Ashtamudi estuary. Mahasagar, Bull, Natn. Inst. Oceanogr., 17

Nair, N.B., Abdul Aziz, P.K. Arunachalam, M., Dharmaraj, K & Krishnakumar, K., 1984. Ecology of Indian estuaries: Ecology and distribution of benthic macrofauna in the Ashtamudi estuary Kerala: Mahasagar, Bull. Natn. Inst. Oceanogr, 17: 89-101

Nair, N.B., Abdul Aziz, P.K., Arunachalam, M., Krishnakumar, K & Dharmaraj, K., 1984. Ecology of Indian estuaries X: Distribution of total phosphorus, total nitrogen and total potassium in the sediments of the Ashtamudi estuary. Mahasagar, Bull. Nam. Inst. Oceanogr., 17: 33-39

Nair, N.B., Arunachalam, M., Abdul Aziz, P.K., Krishnakumar, K & Dharmaraj, K., 1985. Ecology of Indian Estuaries: Seasonal variation of organic carbon, total phosphorus, total nitrogen and total potassium in the sediments of the Ashtamudi estuary. Proc. Natn. Acad. Sci., India. 57. B: 17-18

Nair, N.B. & Abdul Aziz, P.K., Suryanarayanan, H., Arunachalam, M., Krishnakumar, K & Tresa V. Ferndez, 1987. Distribution of heavy metals in the sediments of the Ashtamudi estuary, South-West coast of India. Contribution in Marine Sciences. Dr. S.A. Quasium Sasthyabdapurthy Felicitation Volume, pp. 260-289

Nair, N.B., Abdul Aziz, P.K., 1988. Ecology of the Ashtamudi estuary – a tropical backwater system in Kerala. J. Mar. Biol. Assoc. India, 29: 177-194

Ramachandaran, K.K., Mohan, C.N., Balasubramanian, G., Johnson Kurian & Jessy Thomas, 1986. The mangrove ecosystem of Kerala. Centre for Earth Science Studies Trivandrum, 38 pp

Thresiamma Mathew & Nair, N.B., 1980. Phytoplankton of the Ashtamudi estuary, Kerala. Indian J. Mar. Sci., 9: 253-257


Geetha Bhadran
Dept of Zoology
St. Gregorios College,
Kottarakara, Kollam Dist, Kerala
Phone +91-474-2650133

Dr K.K. Ramachandran
Centre for Earth Science Studies
Post Box No.7250, Akkulam,
Thiruvananthapuram - 695 031
Phone: +91-471-2442451-54
Fax: +91-471-2442280

Kerala Sastra Sahitya Parishad
Add: Parishat Bhawan, Guruvayoor Road
Thrissur, Thiruvananthapuram - 680004
Tel: 91-487-381084, 487-380281

Government Department

Centre For Water Resources Development And Management
Kunnamangalam, Kozhikode-673 571 , Kerala, India
Tel: +91 495 2357151, 2351803, 2351804
Fax: 2351808
Url :

Prof. K. V. Jayakumar, Executive Director

Mobile: +919446531806/9895095237

Brackish Water Fish Farmers Development Agency
No.28/3004,Nedungelli House, Ponneth Temple Rd, 
Kadavanthara, Ernakulam – 682020
Tel: +(91)-(484)-2317760

District Rural Development Agency, Kollam
KSFE Buildings, Chinnakkada
Kollam-691 001
Tel: +91-474- 2743738
Fax: 2747801

E mail:

Now buy viagra online from different online pharmacies and sort out all sexual performance related issues. You can get comprehensive and up to date source of drug information online. Not only Viagra, but you can buy cialis online also at some discounted price. From the site casino online also you can buy these.