Which zone spans depths from 200 to 1000 meters, often called the Twilight Zone due to partial sunlight?

• A. Euphotic Zone
• B. Disphotic Zone
• C. Aphotic Zone
• D. Splash Zone

Answer: (B)

Light decreases rapidly with depth, creating distinct ocean zones based on how much sunlight remains. The layer where enough light for photosynthesis no longer exists is the disphotic zone, the twilight region where some light is still present but too weak to support photosynthesis. This zone typically spans roughly 200 to 1000 meters, matching the description of partial sunlight at those depths. Many animals in this zone rely on the little light that penetrates and on bioluminescence to find prey or mates. Below this, the aphotic zone has essentially no light. The splash zone is a coastal surface area, not a depth-based zone, so it doesn’t fit the description.