Abiotic Factors
Temperature and sunlight are found in nearly every ecosystem. Buoyancy, viscosity, light penetration, salts, gases and water density are some of the other abiotic factors found in the Great Barrier Reef ecosystem. The force that supports the weight of an organism is known are buoyancy and the resistance to the movement of sea water is viscosity. These two abiotic factors both contribute to the movement of fish and other sea animals in the ecosystem. Light penetrates the ocean surface only about 20 meters. The Great Barrier Reef has much more salt than a freshwater ecosystem, because of this some biotic components that live near estuaries, which is where salt water and fresh water mixes and have to deal with changing amounts of salt in their water. There is less oxygen in water than air. Also, the density of water in the Great Barrier Reef changes with depth, which changes the biotic components that can live in a given depth.
Biotic Factors
Coral is the basis for the diverse animal and plant life in the Great Barrier Reef. These colonies of coral make up the reefs in this ecosystem. Coral takes the form of brain, antler, fan or plate shapes, groups of coral can sometimes form a forest-like appearance. This biotic component creates a habitat for other living things. Animals such as crabs, sea turtles, sea urchins and fish act as consumers in the ecosystem of the Great Barrier Reef. The primary consumers are Zooplankton and herbivorous fish, while other fish that eat coral polyps or barnacles make up the secondary consumers. Large reef fish, sharks, eels and barracudas make up the tertiary consumers which are at the top of the food chain. Marine mammals such as dolphins and seals, also as sea birds, also act as tertiary consumers. Plants and bacteria are two other major biotic components of the Great Barrier Reef. Bacteria act as decomposers for this ecosystem. Detrivores consume dead or decaying plant and animal matter. Autotrophs eg phytoplankton, algae and seaweed are primary producers and major plant life in the reef. These plants convert the sun’s light into energy for food.