Explain why the rapid removal of oxygen from sea water leads to the deaths of many plants and animals.

Oxygen in Water: Oxygen is dissolved in seawater and is vital for the survival of many marine organisms. Fish, shellfish, and some types of bacteria need oxygen to survive. They breathe in oxygen dissolved in water, much like humans breathe in oxygen from the air.

Oxygen Depletion: Rapid removal of oxygen from seawater is known as hypoxia or oxygen depletion. This can occur due to several reasons such as excessive nutrient pollution from human activities, which can result in an overgrowth of algae. When these algae die and decompose, they consume a large amount of oxygen in the water.

Impact on Marine Life: When oxygen levels in the water drop rapidly, it can lead to the death of marine life. Fish, shellfish, and other marine animals cannot survive without sufficient oxygen. They either die or move to areas with higher oxygen levels. This can disrupt the food chain and impact the overall ecosystem.

Impact on Plants: Aquatic plants also need oxygen to survive. Without enough oxygen, they can't perform photosynthesis effectively, which can lead to their death. This can further reduce oxygen levels in the water, as plants produce oxygen through photosynthesis.

Long-term Effects: If oxygen depletion continues for a long time, it can lead to the creation of 'dead zones' in the ocean where no life can survive. This can have serious long-term effects on biodiversity and the health of the world's oceans.