Ecosphere (aquarium) - Comparable Objects and Systems

Comparable Objects and Systems

Commercially packaged aquarium kits, including algae, anchialine shrimp, and a container that can be left open or closed, are available in Hawaii. The customer can combine these to create an aquarium comparable to the EcoSphere.

It is possible to purchase Halocaridina shrimp from Hawaiian aquarium dealers and create home-made sealed aquaria with no other special supplies. Sand, gravel, crushed shell, and very well cycled filtered water from a successful saltwater aquarium, with the lowest attainable ammonia content, should be used. A small inoculation of live Spirulina algae may be introduced. Certain ubiquitous algae and bacteria are likely to be carried by the shrimp themselves and will soon colonize the walls of the container. There is a risk that pathogens also may be introduced.

Every manmade closed system inevitably degrades. The EcoSphere and comparable closed systems are actually "self-sustaining" only in comparison to systems which degrade much more quickly. In any closed, unfiltered, unaereated aquarium, it must be expected that the larger organisms will reach the end of their lifespans, die, and pollute the water with a sharp influx of decay products; or the nutrients in the food cycle will gradually get "locked up" in unusable forms; or the pH of the water will fall outside the survival range of the organisms. The EcoSphere is remarkable in that its degradation is so slow, supporting relatively large, complex organisms (the shrimp) for years, cycling nutrients many times.

The advantage of an aquarium closed with a lid (rather than a permanently sealed plug, which is found in the base of an EcoSphere) is that if the system goes out of equilibrium, the owner can remedy conditions and prevent a complete die-off. Intervention to maintain good water quality allows a larger number of shrimp to live in the open system than can survive in the relatively poor quality closed environment.

Freshwater closed systems are often attempted by nature hobbyists and as experimental projects or demonstrations for biology classes. These require nothing more than a large glass jar with an airtight lid, a few cups of lake or river water, and mud or other substrate from the same body of water. Kept indoors at room temperatures, with exposure to sunlight from a window, such systems have been found to contain living organisms even after several years. The original level of diversity always falls drastically, sometimes exhibiting interesting patterns of population flux and extinction. Multicellular organisms fare poorly. Eventually an equilibrium of micro-organisms is established.

Make Magazine Volume 10 contained instructions for creating a self-contained fresh-water "biosphere", which contained a freshwater amano shrimp, snails, amphipods, ostracods, copepods, rigid hornwort, duckweed, pond scum (for microorganisms), and small rocks or shells (as a pH buffer).