Great Barrier Reef Animals and Marine Life

Coral forms the backbone of the Great Barrier Reef with over 400 species that play a huge part in making up the visual splendour that has contributed to its worldwide fame. The vibrant colours of the Great Barrier Reef coral are striking, with vivid reds and cool blues coexisting side by side to form an underwater rainbow which has to be seen up close to be properly appreciated. The Great Barrier Reef, like most other coral reefs on earth grew from a hard surface on the ocean floor and continually evolved over the course of 500,000 years to take the shape of the vibrant ecosystem that can be found in today.

Types of Coral

Corals are generally divided into two main groups, “soft coral” and “hard coral” which are defined not only by their composition and texture but also by the number of tentacles that can be found on their adjoining polyps. The corals have pigment in their tissue which them give their colourful hues.

Hard corals are found in clear, shallow tropical waters and has contributed to the relatively swift growth of the Great Barrier Reef. Many of the world’s older major reef formations have existed for several million years. The most common type of hard coral found in the Great Barrier Reef is the Staghorn variety, which over time forms limestone casings that become an important building block in the reef’s expansion providing a safe habitat for its many ocean-dwelling creatures to live in.

Soft corals are more visually striking than the hard variety and are differentiated by having eight tentacles as opposed to hard corals’ six. Soft corals generally have a squishy and/or leathery texture. Soft corals are an essential food source in the entire Great Barrier Reef -as marine algae- in which the entire ecosystem is dependent on. The small fish and other members of the Great Barrier Reef’s food chain use the algae as their main form of sustenance, and they themselves serve as food for larger predators.

How are Coral Reefs created?

Corals spread and reproduce via a process known as “spawning”, which occurs when coral releases eggs and sperm into the surrounding ocean. This mass spawning only happens once a year and occurs 1-6 nights after the first full moon in October. Once fertilised the bud settles on the ocean floor and the coral starts to develop and grow at a rate of 30cm per year.

Threats to the Coral of the Great Barrier Reef

Ironically, one of the major threats to the Great Barrier Reef is one of the dwellers of the reef itself – the Crown of Thorns Starfish. As natives of the reef themselves, their mere presence isn’t what causes the damage; it’s the overwhelming numbers that are the leading factor. Visit our section where you can find out more about the Crown of Thorns and other threats to the Great Barrier Reef.