Gorgonia, the non-living branch like material, and the gravel are surface area in the ecosystem. The gorgonia and gravel are also a hiding place for microorganisms - a place where they can not be eaten by the shrimp. All other areas in the water are accessible by the animals. By having more surface area for the bacteria to grow on the eco-system has the ability to break down more of the waste materials. A closed eco-system is a group of organisms placed in any sealed container along with nutrients to sustain and regenerate life.
Water is the most essential item in the system, for without it nothing lives.
There are numerous microorganisms inside that keep reproducing and dying, each time they give off and take in oxygen and carbon dioxide. The key component is energy in the form of light. With light energy, chemicals are changed into nutrients and are then available to the higher organisms. The nature of all closed ecosystems is to wind down. There is no weather inside the EcoSphere to pull these chemicals apart from each other.