Which two gases are the most important for aquatic organisms

Solution

The two most important gases for aquatic organisms are oxygen and carbon dioxide. These two gases are vital for marine organism to survive. Oxygen does not dissolve in water very easily. The green plants living in aquatic ecosystems release oxygen during photosynthesis. This oxygen is used by aquatic organisms for respiration. The amount of oxygen present in an aquatic ecosystem is very important and indicative of the health of the aquatic ecosystem. When the oxygen level falls below a critical point, most of the aquatic organisms die due to lack of oxygen.

Carbon dioxide is the other important gas. It dissolves in water. It can react with water to form carbonic acid or react with carbonates already present in water to form bicarbonates. The bicarbonate is used by plants and animals to for calcium carbonate shells. When the organisms die, most of the bicarbonate is locked up in the shells for a long period of time.

Currently, due to increase in the carbon dioxide content in the atmosphere, more and more carbon dioxide is being absorbed by the ocean leading to a process called ocean acidification – a process that can be hugely detrimental to life in the oceans.