Some pollutants do not dissolve in water as their molecules are too big to mix between the water molecules. This material is called particulate matter and can often be a cause of water pollution.
The suspended particles eventually settle and cause a thick silt at the bottom. This is harmful to marine life that lives on the floor of rivers or lakes.
Biodegradable substances are often suspended in water and can cause problems by increasing the amount of anaerobic microorganisms present.
Toxic chemicals suspended in water can be harmful to the development and survival of aquatic life.

Causes of water pollution in Marine Dumping.

Dumping of litter in the sea can cause huge problems. Litter items such as 6-pack ring packaging can get caught in marine animals and may result in death. Different items take different lengths of time to degrade in water:

• Cardboard – Takes 2 weeks to degrade.
• Newspaper – Takes 6 weeks to degrade.
• Photodegradable packaging – Takes 6 weeks to degrade.
• Foam – Takes 50 years to degrade.
• Styrofoam – Takes 80 years to degrade.
• Aluminium – Takes 200 years to degrade.
• Plastic packaging – Takes 400 years to degrade.
• Glass – It takes so long to degrade that we don’t know the exact time.