Aquatic Ecosystems - River or Stream

RIVER OR STREAM ECOSYSTEM
Running water in a river or stream is usually well oxygenated as it absorbs oxygen from the air. River or stream is full of life with aquatic life.

CHARACTERISTICS

1. It is fresh and freely flowing water system
2. Due to constant mixing of water during the flow of water in a river, the dissolved oxygen content is high
3. Rivers deposit large amount of nutrients.

STRUCTURE AND FUNCTION

STREAMS & RIVERS

• Streams and rivers originate from mountains and come from melting of ice.
• Streams and rivers are fresh water bodies that move continuously in one direction
• Rivers are larger than streams
• Characteristics of a river or stream may change during the journey from source to mouth
• At source, river water is clear with minimum turbidity
• Dissolved Oxygen (D.O) is very high at the source
• At the source, temperature is cool and freshwater fish is found here
• Width of the river increases towards the middle part where green plants and algae are found
• Towards the mouth, the water becomes very murky due to all the sediments picked up upstream. This causes high turbidity and decreased penetration of sunlight through the water
• At the mouth, water contains very less percentage of oxygen than the source or the middle portion. Due to this, there is very low species diversity
• Fishes requiring less oxygen such as catfish and carp are found at the mouth of the river or stream

1. Abiotic components Temperature, light, pH, nutrients, organic and inorganic compounds
2. Biotic components
1. Producers: Phytoplankton, algae, water grass, aquatic mass and other amphibious plants
2. Consumers: Primary consumers feed on phytoplankton. Ex: Water      insects, Snails, Fish. Secondary consumers feed on primary consumers. Ex: Birds and mammals. 
3. Decomposers: They decompose the dead plants and animals. Ex: Bacteria and Fungi.