THE OCEAN DEEP

A Fringing reef is a kind of coral reef, that is located in the tropics generally immediately near the shoreline. This type of coral reef is the most common type of reef that is found. This type of reef grows the best on some kind of hard surface, so it preferentially grows on areas with rocky bottoms. They may also grow on softer bottoms as well if there are some hard areas. Fringing reefs grow as a thin strip along the shore at a rate of about 2 to 7mm per year. It is Darwin’s belief that fringing reefs are the first kind of reefs to form around a landmass in a long-term reef growth process. Sometimes it is hard to tell the difference between fringing reefs and another type of reef called a barrier reef. One of the ways that these two types of reefs are separated is based on the depth of the lagoon in the back reef which is the area near to shore. If the water in the lagoon is less than 10m deep it is a fringing reef. Another major difference is that barrier reefs tend to be farther away from shore than fringing reefs and have a larger lagoon. There are two main components that make up a fringing reef, the reef flat and the reef slope. Reef Flat : The reef flat is the flat, broadest area of the reef. This area is found in fairly shallow water, and is at some points in time uncovered during low tide. This area of the reef is only slightly sloped towards the open ocean. Due to this part of the reef being found adjacent or nearly adjacent to land it maintains the most damage from freshwater runoff and sediments. Based on this there is few living corals found here, though there are some. Located on this flat area are often such things as seagrasses, seaweeds soft corals.Reef Slope (Fore reef) : The reef slope is found at the outer edge of the fringing reef, closest to the open ocean. This area of the reef is often quite steep and may even be a straight vertical drop to the bottom of the ocean. There is much more abundant coral growth found on this slope as well as a greater number of different species than are found on the reef flat. This is mostly because there is not much affect felt in this part of the reef from freshwater runoff and sediments, unlike the flat which is nearer to the shore. This area of the reef also benefits and has much more growth due to waves which carry nutrients to this area and take away sediments that could harm the corals. The upper portion of this slope is called the reef crest. In this area the corals grow the best since it is closest to the surface and gets the most sunlight. The base of the slope which receives the least sunlight has the least growth out of the whole slope.