- Definition: Thermal pollution means a change in the water temperature.
- Causes:
+ Power station are one factor. They use water in the nearby lake or rivers to cool their equipment, which heats up the water. Then they dump the hot water back into its source.
+ Thermal pollution may also happen due to the discharge of cold water from reservoirs into warm rivers.
- Effects: Most aquatic creatures need a certain temperature to survive. Warmer water has less oxygen in it, and this can harm fish populations. Besides warmer water can cause harmful algal blooms. This can change the colour of the water like in the first picture and, more seriously, the algea poisons the fish.
- Solution: In many places, they build cooling towers like in the second picture to cool down the water from power station