Chapter 57, Problem 1Q

Summary Introduction

To review:

The position of sea cucumbers in the marine benthic food web and how their position may affect the net primary production through this particular ecosystem.

Given:

Sea cucumbers feed or graze on organic matter (marine sediments).

Introduction:

Food web is an interconnection between various different food chains. In nature, food chains do not occur in isolation and are always in conjunction with other food chains. Net primary production is a measure of the amount of carbon that is uptaken by organisms after accounting for the loss through respiration. Sea cucumbers play a very important role in the marine food web. Their position also contributes greatly to the net primary production in the marine ecosystem.

Explanation of Solution

Sea cucumbers eat the marine sediments that get accumulated in the marine ecosystem. They clear out various organic materials, such as plankton, algae, and bacteria, that would otherwise grow in numbers unchecked and decrease the productivity of the system. They also get preyed on by other species like the leatherback sea turtle and different types of fishes. Thus, it both acts as a recycler of nutrients and as a food source for other species.

Thus, this position of sea cucumber in the food web is essential for the greater productivity in the ecosystem. If sea cucumbers were to get extinct, it would greatly impact the net primary production of that ecosystem. Without sea cucumbers, a food source for the other species would be missing. The algae, plankton, and bacteria would also grow unchecked and eventually cause hypoxia, which would lead to a decrease in the net primary production.

Conclusion

Therefore, it can be concluded that sea cucumbers occupy an important position in the marine food web and their absence would lead to a decrease in the net primary production.