All corals are uniquely suited to particular environments, but it so happens that most coral reefs are full of microhabitats. This is why we mostly see a wide variety of different coral species from the shallows to the depths at tropical reef locations.
But in very specific habitats and where conditions are a particular combination of temperature, light, flow and nutrients, you can find expansive growth of just one or a couple species. We mostly tend to be in awe at fields of gorgonians or forests of staghorn corals, but the ocean is vast and it holds many more environments than the typical ‘coral reef’.
One such example that was recently documented is a very unique habitat where just a few species of Cycloseris absolutely dominate the seabed. This discovery was made in the Persian Gulf about 50 km from Qatar at a depth of 21 meters, or 69 feet, and was estimated to be around 1km in diameter. The coral cover was found to be between 50% and 100% coverage with coral densities as high as 1,000 per square meter.
So if we do a little back of the envelope math and take a middle of the road density of 500 colonies per square meter, over an area of 785,000 square meters, that roughly equates to nearly FOUR HUNDRED MILLION Cycloseris on this one patch of the ocean alone! Even if we’re off by a decimal point in either direction, there’s still a ridiculous number of disc corals in this tiny patch of seafloor. [ESA]
