Detritus is organic matter produced by the decomposition of dead organisms. Considering that detritus tends to sink in water over time, in which ocean zone does detritus make up the base of the food chain?

• A. Photic zone because many organisms can photosynthesize and live here, producing organic matter.
• B. Intertidal zone because detritus is frequently washed up on shore by waves & tides.
• C. Aphotic/Benthic zones because photosynthesis cannot occur, but detritus falls to the ocean floor.
• D. All of the above.

Answer: (C)

Verified step by step guidance

1. Understand the concept of detritus: Detritus is organic matter resulting from the decomposition of dead organisms. It plays a crucial role in aquatic ecosystems as a source of nutrients.
2. Identify the characteristics of the ocean zones: The ocean is divided into different zones based on light penetration and depth, such as the photic zone (where sunlight penetrates and photosynthesis occurs) and the aphotic zone (where sunlight does not reach, and photosynthesis cannot occur).
3. Consider the role of detritus in the food chain: In zones where photosynthesis is not possible, such as the aphotic zone, detritus becomes a primary source of energy and nutrients for organisms, forming the base of the food chain.
4. Evaluate the options: The photic zone supports photosynthesis, so detritus is not the primary energy source. The intertidal zone experiences wave action that can deposit detritus, but it is not the primary base of the food chain. The aphotic/benthic zones rely on detritus as a primary energy source due to the lack of sunlight.
5. Conclude that the aphotic/benthic zones are where detritus makes up the base of the food chain, as photosynthesis cannot occur, and detritus provides essential nutrients and energy.