THE STORY OF A RIVER

Most of the rivers begins in the central hills and radiate out, ending up in the ocean.

An Upper region of a river

Fast flowing of water.

Fast flowing. Highly oxygenated

Water is pure. Clear.

In the upper region , it makes water falls.

Low bio diversity. These organisms survive only in unpolluted water. They are adapted to high speed water.

“Trout” fish - they live in clear,pure water

The river flows down to the plains.

The river flows down to the plains.

In plains, its water flow is reduced.

Silt and clay get collected.

Water is less clear. Bio -diversity is high High amount of plankton..

They are very small organisms. High in polluted water. Planktons

These organisms can live in polluted water. Eg: “Lula”, “Thilapia”, Eel.

In coast line, The water flow is slow. Sediment and silt load is high

Estuaries Estuaries are places where the rivers fall in to the sea.

Estuaries show grater biodiversity than rivers . Some of the species are fresh water migrants , marine species , and permanent inhabitants adapted to the low salinity.

Salmon fish They can live in both brackish and fresh water.

Lagoons

Lagoons are; Brackish water bodies with out permanent connection to the sea. They are rich in bio- diversity and are good fishery lands.

Marshy lands around the estuaries and lagoons.

Mangroves

Indian ocean