Principle Estuaries of Brackishwater

Principle Estuaries of Brackishwater: An estuaries are highly productive ecosystems and support a variety of fish and shellfish species. Brackishwater estuaries are home to a variety of plants and animals, including fish, shellfish, birds, and mammals. Many of these species are found only in estuaries.

Principle Estuaries of Brackishwater

An estuary is the meeting place of river water and seawater they are categories into two types viz, open estuary and the embanked estuary.

1.    Open estuary

An open estuary is created at the bank of river mouth and connected with the sea. Open estuary in the form of a lake containing brackish water. The lake may be perennial because the constantly flow the river water during rainy and winter season all the year round and it may be a seasonal because the flow of river water are very less during the summer. The popular example of open estuary in India is Chilka Lake.

2.     Embanked estuary

It is a made with the earthen soil and occupied limited area of brackish water. It is exposed to sea only at low tides or else it may remain surrounded by continuous chain of barrier islands. The famous examples of embanked estuaries are Cauvery estuary and Adyar estuary in India. 

Principal estuaries

All the estuaries are created along the coastal area of the country close to where the rivers enter the sea. There are two principle estuaries in India viz- Principle estuaries of east coast river system and Principle estuaries of west coast river system The details of some principle estuaries are as follows in table-

1. Principle estuaries of east coast river system

Sr.
no.

Estuaries

Location

Source
of river water

Source
of marine water

Area

1.

Adyar estuary (Embanked)

Tamilnadu, South of Cauvery estuary

River Adyar

Coromandal Coast, Bay of Bengal

6.4 km from mouth of river

2.

Chilka estuary

Puri & Ganjag of Orissa

Branches of Mahanadi

Bay of Bengal

906 sq. km

& 1165 sq. km

3.

Cauvery embanked estuary

Near Tiruchirapalli- Tamilnadu

Two branches of Cauvery river

Coromandal Coast, Bay of Bengal

Embanked

4.

Godavari east coast estuary

Andhra Pradesh

Branches of Godavari, Gautami

Kakinada, Bay of Bengal

45 km from the river mouth

5.

Hooghly Matlah estuary of east coast

Sunderban

Branches of Tanga & Hooghly river

Tidy Sea water & Bay of Bengal

2340 sq. km

6.

Krishna estuary  of East coast

Machilipattanm Andhra Pradesh

Krishnas three tributaries

Nizamapatnam, Bay of Bengal

6.28 km from mouth of river

7.

Mahanadi estuary

Cuttack & Puri  district of Orissa

River Mahanadi

Tidal water from Bay of Bengal

42 sq. km

From river of mouth

8.

Plicate Lake

A.P. & Tamilnadu

Raayala, Vagu & Kalangi river

Bay of Bengal

44400 sq. km

9.

Vellar estuary

Tamilnadu

Vellar river

Movo port, Bay of Bengal

262 hectare
from the river mouth

10.

Vaigai & others (about 7- estuaries)

Ramnad district Tamilnadu

Vellar River

Palk Bay & Gulf of Mannar in Bay of
Bengal

93.77 ha by all 7 estuaries.

2. Principle estuaries of west coast river system

 

Sr. No.

Estuaries

Location

Source of
river water

Source of
marine water

Area

1.

Choodapur estuary

South Karnataka

Rivers & south west monsoon

Tidal water of Arabian Sea

2 km from the river mouth

2.

Kalinadi

North Karnataka

south west monsoon

Tidal water of Arabian Sea

3.

Nethravathi Gurupur estuary

South Karnataka

Rivers & south west monsoon

Tidal water of Arabian Sea

2 km from the river mouth

4.

Narmada estuary

A Gulf of Cambay near Baroch, Gujarat

Narmada river

Arabian Sea Gulf of Cambay

5.

Tapi estuary

A Gulf of Cambay near Tapi, Surut , Gujarat

Tapi river

Arabian Sea , Khambat

Tidal water from Arabian Sea to several kms

Principle Estuaries of Brackishwater
Open Estuary