CORAL REEFS

• A coral reef is an underwater ecosystem characterized by reef building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.

• Coral reefs begin to form when free swimming coral larvae attach to submerged rocks or other hard surfaces along the edges of islands or continents.

• As the corals grow and expand, reefs take on one of three major characteristic structures; fringing, barrier or atoll.

• Coral reefs are built by coral polyps as they secrete layers of calcium carbonate beneath their bodies. The corals that build reefs are known as hard or reef building corals. Soft corals, such as sea fans and sea whips, do not produce reefs, they are flexible organisms that sometimes resemble plants or trees.

• Corals are animals and unlike plants, corals do not make their own food. The branch or mound that we often call a coral is actually made up of thousands of tiny animals called polyps. 

• There are about 6,000 (species) of corals, though there are some estimates that reach as high as 9,000 species. with about 3,000 species being hard corals that build coral reefs.

• Most corals contain a symbiotic algae called zooxanthellae which helps with photosynthesis and also produces oxygen and helps the coral to remove wastes.  

• Healthy coral reefs require: light, low nutrients and clear water, salinity comprised between 32 and 42 ppm* (parts per million), water temperatures between 18 and 32 degree celcius and water circulation.
  

WHY ARE CORAL REEFS IMPORTANT?

• Coral reefs provide a buffer, protecting 20% of the world's coasts from waves, storms, and floods. Corals form barriers to protect the shoreline from waves and storms. The coral reef structure buffers shorelines against waves, storms, and floods, helping to prevent loss of life, property damage and erosion.

• Coral reefs are nature's water filtration system. Many individual corals and sponges consume particles found in the ocean. In turn, this enhances the clarity and quality of the ocean's waters.

• Corals act as a nursery for more than 25% of all marine species and provide a food source for more than 100 million people worldwide.

• Bring approximately 10 trillion USD into worldwide economies through tourism activities.

WHAT TYPE OF SPECIES DO CORAL REEFS SUPPORT?

• Millions of species live in and around coral reefs. Fish, lobsters, clams, seahorses, sponges, and sea turtles are only a few of the thousands of creatures that rely on reefs for their survival. 

• Coral reefs are some of the most diverse and valuable ecosystems on Earth. Coral reefs support more species per unit area than any other marine environment, including about 4,000 species of fish.

THREATS TO CORAL REEFS

• The whole marine ecosystem is being threatened by the loss of our reefs and coral reefs are dying around the world. Some of the factors which are killing the corals are increasing temperatures of our oceans, ocean acidification, unethical fishing methods, water pollution, sedimentation and human activities. 

• Damaging activities include coral mining, pollution (organic and non organic), overfishing, blast fishing, the digging of canals and access into islands and bays.

• Climate change, such as warming temperatures, causes coral bleaching, which if severe can kill coral.

• When sediment and other pollutants enter the water, they smother coral reefs, speeding up the growth of damaging algae, and lowering water quality. 

• Pollution can also make corals more susceptible to disease, impede coral growth and reproduction, and cause changes in food structures on the reef.

• Plastic can block light and oxygen from reaching the coral; two things which are needed for corals to survive. The presence of plastic is also thought to promote the growth of harmful pathogens and transport these into coral reefs.

• According to one study, air pollution due to vehicular emissions and ash clouds from volcanoes can reduce the amount of sunlight reaching corals, leading to the slow growth of corals.*
  
  * Kwiatkowski, L., Cox, P., Economou, T. et al. Caribbean coral growth influenced by anthropogenic aerosol emissions. Nature Geosci 6, 362–366 (2013). https://doi.org/10.1038/ngeo1780
  
  

CORAL REEFS IN THE UNITED ARAB EMIRATES

Historically, coral reefs of the United Arab Emirates (UAE) were among the most extensive in northeastern Arabia. Records from the 1960s and 1970s describe extensive reefs extending across most of the Arabian Gulf coast, occupying hundreds of hectares of near-shore waters from western Abu Dhabi to Ras Al Khaimah (Kassim, 1969; Kinsman, 1964; Purser and Evans, 1973; Shinn, 1976).

Coral reefs were also widely distributed across the northern emirates and along the UAE's east in the Sea of Oman (Purser and Evans, 1973). Over the past several decades there has been rapid degradation of coral reefs across the UAE. Channelization, reclamation, and port development associated with the oil boom impacted reefs, particularly in Abu Dhabi, in the 1970s and 1980s (Burt, 2014; Evans et al., 1973; Murray, 1970; Neuman, 1979), but reefs in most of the country remained relatively intact through this period (George and John, 2000b; John and George, 1999; Purser and Evans, 1973).

This changed in the late-1990s when two major thermal bleaching events (1996 and 1998) impacted reefs throughout the southern Arabian Gulf and resulted in the loss of N90% of coral in many areas (Riegl, 2002; Sheppard and Loughland, 2002). Formerly dominant reef structures were decimated throughout the entire country during these events, surviving only around offshore islands and in isolated pockets in Dubai and Sharjah. (George and John, 2000a; Riegl, 2002; Sheppard and Loughland, 2002).

Although there have been isolated signs of recovery in some areas (Burt et al., 2008), recurrent bleaching events in subsequent years and increasing pressure from coastal development have meant that the reefs continue to be in a degraded state (Burt, 2014; Burt et al., 2011a, 2016; Riegl and Purkis, 2012a).

The coasts and islands that flank Abu Dhabi, the United Arab Emirates (UAE)’s largest emirate, host the country’s most significant coastal and marine habitats including coral reefs. These reefs, although subject to a variety of pressures from urban and industrial encroachment and climate change, exhibit the highest thresholds for coral bleaching and mortality in the world. The UAE has coastlines along the Gulf of Oman and the Arabian Gulf and ranks 38th in the world in terms of coral reef size. It hosts large areas of coral reef assemblages of approximately 1,190 km2, the majority of which are located within Abu Dhabi waters.

The UAE’s local coral species diversity is among the richest in the Arabian Gulf, counting around 34 hard coral species. These UAE reefs are subject to pressures from urban and industrial encroachment such as dredging and oil exploration activities, as well as climate change.

What About Artificial Reefs?

Artificial reefs are underwater manmade structures that mimic the characteristics of natural reefs. Far from a new fad, manmade reefs have been around for hundreds of years. Artificial reefs have been around for hundreds of years and have many applications including controlling erosion, blocking shipping passages, improving surfing, and provide a home for marine organisms. In the Middle Ages, Japanese fishermen built artificial reefs from bamboo to improve fish stocks. More recently, people have tried to create reefs from all sorts of materials from ships to concrete blocks to tires, used to provide shelter for marine organisms. Such materials have had varying success in actually promoting coral growth and in the past couple of decades people have realized that reefs must be built with care.

How do Artificial Reefs Benefit the Environment?

Given the decline of natural reefs due to factors like pollution and climate change, many resource managers have tried to boost coral growth and provide a home for many organisms, by building artificial reefs. Baby corals (polyps) need a hard substrate on which to attach themselves and grow. Sinking materials into the ocean can encourage recruitment and coral growth by giving them more opportunities to settle. Over the course of months and years, the corals grow, attract fish, and create a new and healthy marine environment. These artificial reefs benefit people by providing protection from erosion as well as providing dive sites for people, which can be educational. They are used to build surfing structures, which promote health in people. People benefit a lot from artificial reefs and so do many organisms. Studies done on artificial reefs compared to natural reefs have shown vast amount of diversity and abundance of several species from both benthic and pelagic fish. A study done comparing artificial reef biodiversity to natural reef biodiversity showed that objects facing the same way as natural reef structures have the same sort of organismal growth. So a natural reef that is parallel to the ocean floor will have the same organismic growth as a artificial reef that is parallel to the ocean floor.

Artificial reefs can also take the pressure off of natural environments as fishermen and divers move their efforts elsewhere.

Why Would Artificial Reefs Be Bad?

Sometimes the materials people sink into the ocean are not only ineffective, they’re downright bad. Old ships, planes, and other materials may be carrying pollutants such as fuels, asbestos, PCBs, or floating debris. Such pollutants could be harmful to the marine environment if not dealt with appropriately. Sometimes the materials themselves are just a bad idea – in the 1970’s roughly 2 million old tires were sunk off of Florida in the hopes of building a reef. The tire dumping has since been called a ‘disaster’ as little sea life has formed on the tires, and the tires themselves are breaking away to float off into the ocean.

So are there “good” Artificial Reefs?

In general a successful manmade reef would encourage coral recruitment and growth, in turn attracting fish and encouraging the growth of all creatures dependent on coral habitat. Various organizations now exist that focus entirely on creating healthy manmade reefs. The ReefBall Foundation produces a special concrete structure designed to encourage coral growth. EcoReefs has a spiky ceramic version designed to do the same. Our knowledge of reef systems and how to artificially create them has come a long way over the past few decades. Artificial reefs now provide an excellent way to promote coral growth.

Today, several main goals for artificial reefs are recognized:

·       Replace structure and habitat diversity in places where it has been lost (due to dredging, development, storms, bleaching, etc.)

·       Increase the size of reefs or available structure to enhance local marine resources and improve biodiversity

·       Create artificial dive/snorkeling sites to relieve tourism pressure on natural reefs

·       Create attractive or art inspired reefs to increase awareness and communicate reef issues to the general public

Azraq’s position statement on Artificial Reefs

Azraq believes that given the decline of natural reefs due to factors like pollution and climate change, that artificial reefs, if done carefully and properly, utilising environmentally sensitive materials, have a role in the preservation of the marine environment. As a marine conservation organisation, Azraq however does not endorse the use of artificial reefs as fishing aggregation devices (FADs) nor does it condone the practice of breaking healthy corals to have materials to plant in order to restore coral reefs. This can be better managed by collecting broken off fragments from already established reef systems. Additionally, it is important that consideration is given to the variety of corals planted, so as to enhance the biodiversity that the artificial reef can attract. History has shown that if done properly, artificial reefs can assist to provide a safe haven for marine life, and can be used as a conservation tool to showcase how corals grow, the importance of protecting coral reef structures and engaging the community to learn about the challenges coral reefs face.

WHAT CAN I DO?

You can help protect coral reefs by:

• ensure foods purchased (particularly seafood) is sustainable

• avoid touching corals

• use coral friendly sunscreen and/or wear rashguards. shop our collection of coral safe sunscreens

• limit your consumption of electricity and gas

• join local citizen science coral reef studies

• promote our statistics and information about coral reefs on social media

• book a presentation on coral reefs for your friends, school, peers and colleagues

PROTECTING YOURSELF AND THE CORALS

There are two types of sunscreen - mineral and chemical. Mineral sunscreens mainly use zinc oxide to reflect harmful ultaviolet rays, while chemical suncscreens usually contain avobenzone, benzophenone-3 (also known as oxybenzone or simple BP-3), ecamsule and/or octocrylene. These chemicals are not only bad for the marine environment, but a recent study found that the six active chemicals generally found in sunscreen can be absorbed through the skin into the bloodstream. While studies are being undertaken to determine the clinical significance of these findings, scientists do know that oxybenzone lingers in the body and has been found in amniotic fluid, urine and ever n in the breast milk of both humans and dolphin mothers.

The ingredients in chemical sunscreens have been shown to cause coral bleaching, harm coral DNA, interfere with coral production and and threatens the resiliency of coral reefs to climate change. As a result places such as Aruba, Bonaire, California, Hawai’i, KeyWest - Florida, Mexico, Palau, the U.S. Virgin Islands and various recreational cruise ships and liveaboard boats are banning sunscreens containing oxybenzone and/or octinoxate, with more following suit.

WHAT ELSE CAN I DO TO PROTECT MYSELF FROM ULTRAVIOLET (UV) RAYS?

• Wear rashguards, wetsuits to protect from the elements when enjoying the oceans

• Wear broad-brimmed hats

• Seek shelter wherever possible

Azraq has partnered with SurfHouse Dubai, Al Mahara Dive Center, Abu Dhabi and Freestyle Divers, Fujeriah to have reef safe sunscreen available within the United Arab Emirates. Find out more here

To get involved with coral reef checks either as an individual or as a team building activity, head to our Get Involved page. 

MiSsion Partners