Abiotic & Biotic Characteristics of Reefs

Reefs are among the most well-known and sought out underwater features in the world. Though the definition of a reef in nautical terms can encompass a wide range of aquatic structures lying below the surface, there are several biotic and abiotic factors that give each one a unique aura.

  1. Basics

    • Though there is no universally accepted definition of a reef, most can agree that they are often far-reaching underwater landscapes that vary in shape, size and composition. There are several different kinds of reefs, from barrier reefs which surround landmasses to small fringing reefs that can be found but a few yards from shorelines. All reefs are composed of biotic and abiotic factors, which are essentially the building blocks of any biome, or ecological community.

    Biotic and Abiotic Factors

    • Biotic factors, as their name implies, are organic or biological factors. They are the living organisms or biological processes that make up a given community. Abiotic factors are typically geological structures that contribute to the environment, but can be any non-organic component like a burrow or cave.

    Biotic Factors of Reefs

    • There are two well-known types of reefs that rely almost solely on biotic factors to make up their composition. Tropical coral reefs, which are often enormous and very widely distributed, are made up of large communities of ever-growing coral. These corals, which make up the bulk of the reef, host many other types of organisms, aiding in creating a sizeable and diverse aquatic community. Oyster reefs are also not uncommon, and are made up of layers upon layers of oysters.

    Abiotic Factors of Reefs

    • The foundation for nearly all reefs lies in rocks. Rocks that lay in succession can provide the proper anchorage for coral, the primary biotic factor of many reefs, to grow and spread. Light, salinity, and water temperature are also vital abiotic factors of reefs. Salinity will determine the type of fish that can inhabit the community, while water temperature and exposure to light are significant in reef formation. One of the most well known and beautiful reefs in the world, Australia's Great Barrier Reef, owes its majesty to its warm waters, perfect amount of light exposure, and salt waters allowing for a great abundance of life.

    Artificial Reefs

    • There are several artificial reefs riddled throughout the world. These are created by submerging retired structures like old subway trains or cars. These provide an abiotic surface for corals and coralline algae to grow.