Offshore reefs can be broken down into two subcategories: abiotic and biotic. Abiotic reefs result from sand deposition or wave erosion of outcropping rocks, whereas biotic reefs (notably coral reefs) are developed by the secretions of tiny aquatic organisms. Additionally, artificial reefs can be made by humans in order to enhance the biodiversity of a given area and add features to an otherwise flat seabed.
Ecologically, offshore reefs (particularly tropical coral reefs) are integral to oceanic biomes. Coral reefs are the aquatic equivalent of rainforests. Tropical waters are naturally low in nutrients and the photosynthesis carried out by coral acts as a vital base for these ecosystems. Offshore reefs of all kinds provide home and shelter to approximately 25 per cent of fish in the ocean, and are home to approximately 2 million species. Furthermore, they act as nurseries for juvenile marine life.
Pro: Economic value
It is estimated that coral reefs alone provide goods and services equivalent to approximately £243 billion per anum. Offshore reefs protect shorelines from waves and storms and are significant tourist attractions. Tropical reefs are often located in developing countries, where they provide a strong economic base. Moreover, offshore reefs account for about one-quarter of total fish catches worldwide, and provide food and jobs for approximately one billion people in Asia alone.
Offshore reefs are obstacles to nearby boats, both of whom may be damaged by a collision. There are significant fines associated with damaging coral reefs in many countries. Usually such fines do not exist when a collision occurs between a boat and an abiotic reef, though such an impact may significantly damage the hull or propeller of the boat.
Offshore reefs act as congregation points for large populations of fish, making large catches relatively easy for fisherman. Consequently, if proper regulation is not put into place and enforced, the demand for fish can lead to overfishing and depletion of fish stocks.