What is a "dead zone" typically characterized by?

• A. High oxygen levels
• B. Little to no oxygen
• C. A breeding ground for wildlife
• D. A vibrant ecosystem

Answer: (B)

A "dead zone" is typically characterized by little to no oxygen, which is a critical condition that harms marine life. These areas primarily occur in oceans or large lakes where nutrient pollution, often from agricultural runoff, leads to excessive algal blooms. When these algae die and decompose, they consume oxygen from the water, creating hypoxic conditions—meaning there is not enough oxygen to support most marine organisms. As a result, fish and other aquatic animals either abandon these areas or perish due to lack of oxygen, leading to a significant decline in biodiversity. Thus, the term "dead zone" aptly describes these environments as they become inhospitable for the majority of marine life.