1. Artificial & Natural Ecosystems By Anne Gillis & Emily Silliker

2. Artificial ecosystem are created and maintained artificially by human beings where, by addition of energy and deliberate management, balance of the nature is disturbed regularly, e.g. croplands like maize, sugarcane, rice-fields, wheat, orchards, villages, gardens, dams, aquarium, cities, and manned spaceship. The basic components biotic and abiotic components are defined by man in artificial ecosystem. Natural ecosystem is a natural unit consisting of all plants, animals and microorganism in an area functioning together with all the non-living physical of the environment. That or, a place where plants and animals are dependent upon one another- and their particular surroundings-for survival. Natural vs. Artificial

3. Natural Coral Reefs The sun is the initial source of energy for this ecosystem. Through photosynthesis, phytoplankton, algae, and other plants convert light energy into chemical energy. As animals eat plants or other animals, a portion of this energy is passed on. Coral reefs are among the oldest ecosystems on Earth. Coral reefs are the largest living structure on the planet. Without the existence of coral reefs, parts of Florida would be under water. Coral reefs are underwater structures made from calcium carbonate secreted by corals.

5. Artificial Coral Reefs An artificial reef is a human-made underwater structure. Artificial reefs can be built in a number of different methods. Many reefs are built by deploying existing materials in order to create a reef.

6. Natural Arctic Ocean Due to the severe water temperatures, ice packs and lack of year round sunlight, many species that live in the Arctic Ocean environment are unique and can't be found anywhere else in the world. The arctic is high in oxygen which leads to larger organisms

7. Artificial Arctic New research is being done today to create more sustainable environment in the Arctic. Drifting ice and water currents are effecting the natural ocean environment caused by global warming. "We have to think about using some... constructions, instead of blocks of drifting ice as platforms," Alexander Frolov said.

8. Upper trophic levels Plankton Arctic Food Web

9. http://www.solcomhouse.com/coralreef.htm