Where can I be found?
As humans, we usually find rocky reefs near the shoreline.
In geology, however, any elevation above the sea floor is called a reef. Rocky reefs are a subcategory.
Why am I important?
The solid surface of rocky reefs provides a great habitat for a wide variety of marine life.
Whether an animal is looking for safety - in case a bigger and hungrier one comes along - or food, they'll find both on a rocky reef.
Not only does this structure provide natural protection from currents, but it also provides the opportunity to settle there for decades.
To all the divers out there, a look under a ledge or two can often be rewarding.
Who am I giving home to?
There are different zones along each vertical rock face, depending on the amount of daylight.
The upper, light-flooded areas are mainly populated by algae.
Further down, the algae are replaced by a variety of solid animals such as sponges, anemones, corals and hydropolyps that filter plankton from the water.
What do I consist of?
They consist of either dead rock, such as granite, shale, and sandstone, or biogenic rock, such as limestone. Biogenic means that the rock is made up of dead organisms.
In the case of limestone, these are all the animals, algae and protozoa that have stored calcium in their skeletons. Over millions of years, this has created impressive reef structures.
And for the avid divers among you: No, freshly sunken wrecks are not (yet) reefs from a geological point of view - but they quickly become an amusement park for fish.
Text: Carolina Leiter
