Coral forms the backbone of the structure of the Great Barrier Reef, and with over 400 species that comprise the various sections of reef, they 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
can be striking, with vivid reds and cool blues coexisting side by side to form a veritable underwater rainbow which has to be seen up close to be properly appreciated. The Great Barrier Reef, like most other coral reefs on earth, initially 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, simply labeled “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.
(also known as stony corals) can typically be found in clear, shallow tropical waters and are the closest thing to a “construction force’ that the reef has, contributing largely to the relatively swift growth of the Great Barrier Reef as opposed to many of the world’s older major reef formations (many of which have existed for several million years.) The most common type of hard coral which can be found in the Great Barrier Reef is of the Staghorn variety, which over time form limestone casings that become an important building block in the reef’s expansion and providing more viable habitats for its many ocean-dwelling creatures to live in.
, on the other hand, are often more visually striking than the hard variety and are differentiated by having eight tentacles as opposed to hard corals’ six, along with their lack of a solid exoskeleton. Soft corals generally have a squishy and/or leathery texture. Soft corals are especially important as they serve as home to one of the most essential food sources in the entire Great Barrier Reef – marine algae – on which the entire ecosystem is dependent on. The smallest of 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, and so on – none of which would be possible without the many kinds of soft corals that populate the reef.
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 approximately 10 to 12 days after a full moon, encouraging maximum fertilisation rates due to various tidal factors.
Threats to the Coral of the Great Barrier Reef
Ironically, the major threat to the coral of 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 disproportionate numbers of them 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