Which dissolved gases are found in seawater?

Seawater contains nearly every element found in Earth's crust and atmosphere, including various dissolved gases. The principal components of the atmosphere—nitrogen, oxygen, argon, and carbon dioxide—are all present in seawater, though their concentrations vary based on their solubilities and oceanic chemical reactions.1

• Nitrogen and Argon: These are considered unreactive gases. Their concentrations in seawater are primarily established through exchange with the atmosphere.1
• Oxygen: As a reactive gas essential to life, oxygen concentrations are highly variable. They are influenced by exchange with the atmosphere, biological production by photosynthetic organisms in shallow waters, and biological utilization at greater depths.1
• Carbon Dioxide: This gas is highly reactive in seawater. It combines with water to form carbonic acid, which then dissociates into bicarbonate and carbonate ions. These reactions are crucial for buffering the pH of the ocean.1

The solubility of these gases in seawater generally decreases as temperature increases.1