A closer look at the reef
Studies of coral reefs show that most of the reefs have a similar structure, where different parts can be distinguished.
The following game will help you identify the different parts of a coral reef.
What do I have to do?
Read each description of the reef parts below. Every icon in the game represents one part. Click on the icon and drag it to the right place in the image.
Most of the reefs have a similar structure, where different parts can be distinguished. The way these reef parts are laid out - or reef geomorphology - can be seen as a signature of the reef; just like the arrangement of your face features (eyes, mouth, cheeks, etc.) defines your proper and unique face.
Reef crest
The reef crest is the highest point of the reef, and is almost always exposed at low tide. The reef crest is exposed to the full fury of incoming waves and is an important coastal defense. Living corals are practically non-existent here. Small crabs, shrimps, and other animals often live in the cavities under the reef crest, protected from waves and predators.
Back reef/reef flat
The back reef is the shallow zone between the reef crest and the lagoon. The reef flat is on the sheltered side of the reef. The substrate is made of coral rock and loose sand, and large parts may be exposed during low tides.
Fore reef
The fore reef is the area from the seaward edge of the reef crest downwards (slope = lower than 45°). The fore reef acts to dissipate the tremendous force of unabating waves and stabilizes the reef structure. It also drains debris and sediment off the reef and into deeper water.
Lagoon
The lagoon is the shallow area between the shoreline and the back reef of a barrier reef, or the shallow area encircled by an atoll. This zone is generally protected from high-energy waves by the reef crest.
Escarpment
Generally, an escarpment is defined as any part of the seafloor where slopes exceed 45°. No light penetrates to this depth, so coral reefs are rare in this deeper, darker water.
Bank/shelf
The bank or shelf zone is defined as the relatively undeep area of the continental shelf which is not in direct relation to the reef structure.
