An artificial reef is a human-created underwater structure, typically built to promote
marine life in areas with a generally featureless bottom, to control
erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is d ...
, block ship passage, block the use of
trawling nets, or improve
surfing.
Many reefs are built using objects that were built for other purposes, such as by sinking oil rigs (through the
Rigs-to-Reefs program),
scuttling ships, or by deploying
rubble or
construction debris. Other artificial reefs are purpose-built (e.g. the
reef balls) from
PVC or concrete. Shipwrecks may become artificial reefs when preserved on the seafloor. Regardless of construction method, artificial reefs generally provide hard surfaces where
algae and invertebrates such as
barnacles,
corals, and
oyster
Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not ...
s attach; the accumulation of attached marine life in turn provides intricate structures and food for
assemblages of fish.
History
The construction of artificial reefs began in ancient times.
Persians blocked the mouth of the
Tigris River to thwart
Arabian pirates by building an artificial reef and during the
First Punic War the
Romans built a reef across the mouth of the
Carthaginian harbor in Sicily to trap enemy ships within and assist in driving the Carthaginians from the island.
Artificial reefs to increase fish yields or for
algaculture began no later than 17th-century Japan, when rubble and rocks were used to grow
kelp. The earliest recorded artificial reef in the United States is from the 1830s, when logs from huts were used off the coast of
South Carolina to improve fishing. In the
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
a traditional native fishing technique known as
fish nests (natively known by various names like ''gango'', ''amatong'', or ''balirong''), is basically an artificial reef. It uses rocks and waterlogged wood to build mounds inside excavated trenches on shallow tidal waters that attract fish and crustaceans. The mounds are then harvested every few weeks during low tide by surrounding them with nets and dismantling them piece by piece. They are rebuilt after every harvest. Fish nests are often used to capture
grouper fingerlings to be used as seeds for
aquaculture. Fish nests were in common use since before 1939.
Beginning before the 1840s, US fishermen used interlaced logs to build artificial reefs. More recently, refuse such as old refrigerators, shopping carts, ditched cars and out-of-service vending machines replaced the logs in ad hoc reefs. Officially sanctioned projects have incorporated
decommissioned ships, subway cars, battle tanks,
armored personnel carriers
An armoured personnel carrier (APC) is a broad type of armoured military vehicle designed to transport personnel and equipment in combat zones. Since World War I, APCs have become a very common piece of military equipment around the world.
Ac ...
, oil drilling rigs and beehive-like reef balls.
[
]
Development
Artificial reef communities tend to develop in more or less predictable stages. First, where an ocean current encounters a vertical structure, it can create a plankton-rich upwelling that provides a reliable feeding spot for small fish such as sardines and minnows, which draw in pelagic predators such as tuna and sharks. Next come creatures seeking protection from the ocean's lethal openness—hole and crevice dwellers such as grouper, snapper, squirrelfish
Holocentrinae is a subfamily of Holocentridae containing 40 recognized species and one proposed species. Its members are typically known as squirrelfish and all are nocturnal. All three genera in the subfamily are found in the Atlantic and ''Hol ...
, eels and triggerfish
Triggerfish are about 40 species of often brightly colored fish of the family Balistidae. Often marked by lines and spots, they inhabit tropical and subtropical oceans throughout the world, with the greatest species richness in the Indo-Pacif ...
. Opportunistic predators such as jack and barracuda
A barracuda, or cuda for short, is a large, predatory, ray-finned fish known for its fearsome appearance and ferocious behaviour. The barracuda is a saltwater fish of the genus ''Sphyraena'', the only genus in the family Sphyraenidae, which ...
also appear. Over months and years the reef structure becomes encrusted with algae, tunicates, hard and soft corals and sponge
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate throu ...
s.[
3D printing technology has been employed both to create moulds for cast ceramic and concrete artificial reefs,][3D printing technology to aid coral growth in Maldives](_blank)
Maldives Independent. and to directly create artificial reefs, also through the use of environmentally friendly materials.
An electrified reef
An electric reef (also electrified reef) is an artificial reef made from biorock, being limestone that forms rapidly in seawater on a metal structure from dissolved minerals in the presence of a small electric current. The first reefs of this typ ...
is an artificial reef where a small low voltage electric charge is applied to a sub-sea metallic structures that causes limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms w ...
to precipitate onto a metal frame onto which coral planulae can then attach and grow; the process also speeds up post-attachment growth.
Artificial surfing reefs
Artificial surfing reefs have been created in several locations. Supporters cite benefits such as coastal protection, habitat enhancement and coastal research. The world's first attempt was made in El Segundo, near Los Angeles
Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the world ...
, in California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
. The next attempt was at Mosman Beach, Perth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth is ...
. This reef was constructed of large granite rocks placed in a pyramidal shape to form an appropriate breaking wave form that would suit surfers. An artificial reef constructed of over 400 massive, geotextile
Geotextiles are permeable fabrics which, when used in association with soil, have the ability to separate, filter, reinforce, protect, or drain. Typically made from polypropylene or polyester, geotextile fabrics come in two basic forms: woven (r ...
bags (each larger than a bus) filled with sand was constructed in 2000 at Narrowneck on the Gold Coast of Queensland, Australia. This artificial reef had two objectives: stabilizing beach nourishment and improving surfing conditions.
Europe's first artificial reef was approved in 2008. Construction began August 30, 2008, in Boscombe, Bournemouth, UK (5 months after 3 local councillors spent 18 days in New Zealand on a fact-finding mission), and opened in November 2009. The £3 million (2.5% of the Council's annual budget that year) reef was expected to create waves up to 30% larger and double the number of surfing days annually. Construction on this reef continued from June 2008 through August 2009. Boscombe Reef was built from large sand-filled geotextile
Geotextiles are permeable fabrics which, when used in association with soil, have the ability to separate, filter, reinforce, protect, or drain. Typically made from polypropylene or polyester, geotextile fabrics come in two basic forms: woven (r ...
containers, totaling . It failed entirely and attempts were made to convert it into a multi purpose reef, which also failed. Bournemouth Council attempted to get a refund from the New Zealand-based reef construction company but it went into administration before paying any compensation.
In the United States coastal permitting requirements present major obstacles to building surfing reefs. The only reef built in the U.S. for surfing is southern California's " Pratte's Reef", which was constructed in 2000 and removed in 2008 as planned.
Environmental concerns
According to environmental group The Ocean Conservancy
Ocean Conservancy (founded as The Delta Corporation) is a nonprofit environmental advocacy group based in Washington, D.C., United States. The organization formulates ocean policy at the federal and state government levels based on peer reviewe ...
, the Osborne Reef may be an indication that the benefits of artificial reefs need to be re-examined. Jack Sobel, a senior scientist at the group, stated "There's little evidence that artificial reefs have a net benefit," citing concerns such as toxicity from paint, plastics parts, etc., damage to ecosystems and concentrating fish into one place (worsening overfishing).
Fish-attracting device
Artificial reefs can show quick increases in local fish population rehabilitation, coral reef
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of Colony (biology), colonies of coral polyp (zoology), polyps held together by calcium carbonate. Most coral reefs are built from stony corals, wh ...
and algae growth. However, far more than half the amount of biomass found on artificial reefs is attracted from other areas rather than developing there. James Bohnsack, a biologist with the National Marine Fisheries Service
The National Marine Fisheries Service (NMFS), informally known as NOAA Fisheries, is a United States federal agency within the U.S. Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) that is responsible for the stew ...
(NMFS) concluded artificial reefs do not increase fish populations. Instead they operate as fish aggregating devices (FADs) bringing in fish from other reefs. Concentrating fish on a reef also makes for easier fishing.[Perkol Finkel, S., Shashar, N., & Benayahu, Y. (2006). Can artificial reefs mimic natural reef communities? The roles of structural features and age. Marine Environmental Research, 61( 2), 121135. ]
The fish attracted to artificial reef zones vary from reef to reef depending on its age, size and structure. Large reef structures such as large sunken ships attract larger fish.
The use of shipwrecks in rocky zones creates a new trophic structure for the local ecosystem
An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...
. They become the home for certain species and many nearby animals migrate to the shipwreck. This unbalances the natural ecosystem and has the potential to alter many other habitats.[Thiony Simon, JeanChristophe Joyeux, Hudson T. Pinheiro, Fish assemblages on shipwrecks and natural rocky reefs strongly differ in trophic structure, Marine Environmental Research, Volume 90, September 2013, Pages 5565, .]
Recreational dive sites
Thousands of popular wreck diving sites throughout the world are shipwrecks sunk as artificial reefs. Some of these wrecks were sunk deliberately to attract divers. The and in Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and ...
, and in North Carolina, and in Grenada draw thousands of divers annually.
Potential sources of pollution
Waste tires
Tire recycling, or rubber recycling, is the process of recycling waste tires that are no longer suitable for use on vehicles due to wear or irreparable damage. These tires are a challenging source of waste, due to the large volume produced, t ...
have been used to create some artificial reefs. Tropical storm
A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depend ...
s may demolish the tire containment system, washing tires onto beaches, destroying nearby coral reefs and inhibiting new coral growth. On the Osborne Reef off the coast of Fort Lauderdale, Florida, storms broke the nylon straps holding the original tire bundles together. As of November 2019, 250,000 of an estimated 700,000 tires have been removed. France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
has begun removing its tire reefs. The Ocean Conservancy now includes tire removal during the International Coastal Cleanup in September of each year.
Erosion prevention
Some artificial reefs are used to prevent coastal erosion. They can be designed to act in multiple ways. Some are designed to force waves
Waves most often refers to:
* Waves, oscillations accompanied by a transfer of energy that travel through space or mass.
* Wind waves, surface waves that occur on the free surface of bodies of water.
Waves may also refer to:
Music
*Waves (ban ...
to deposit their energy offshore rather than directly on the coastline. Other reefs are designed to hold sediment
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand ...
on beaches. These reefs trap the sediment. These reefs are custom-designed for each unique zone.[Morang, A., Waters, J. P., & Stauble, D. K. (2014). Performance of Submerged Prefabricated Structures to Improve Sand Retention at Beach Nourishment Projects. Journal of Coastal Research, 3 0( 6), 11401156. ]
Examples
Florida
Florida is the site of many artificial reefs, many created from deliberately sunken ships, including Coast Guard cutters Duane and Bibb and the U.S. Navy landing ship Spiegel Grove.
Osborne Reef
In the early 1970s, more than 2,000,000 used vehicle tires were dumped off the coast of Fort Lauderdale, Florida to form an artificial reef. However, the tires were not properly secured to the reef structures, and ocean currents broke them loose, sending them crashing into the developing reef and its natural neighbors. As of 2009, fewer than 100,000 of the tires had been removed after more than 10 years of efforts.
Neptune Reef
Neptune Memorial Reef
The Neptune Memorial Reef is an underwater columbarium in what was conceived by the creator as the world's largest man-made reef (covering over of ocean floor) at a depth of ). It was originally conceived by Gary Levine and designed by artis ...
was originally conceived as an art project called The Atlantis Reef Project and was envisioned and created by Gary Levine and Kim Brandell. Burial at sea became a way of financing the project. As of 2011, about 200 "placements" had occurred. Cremated remains are mixed with concrete and either encased in columns or molded into sea-star, brain-coral, castings of lions or other shapes before entering the water.[
]
Ex-USS ''Massachusetts''
In 1921 the US battleship was scuttled in shallow water off the coast of Pensacola, Florida and then used as a target for experimental artillery. In 1956 the ship was declared the property of the state of Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and ...
by the Florida Supreme Court. Since 1993 the wreck has been a Florida Underwater Archaeological Preserve
The Florida Underwater Archaeological Preserves are a system of underwater parks in the state of Florida, USA. They consist of shipwrecks of historic interest, both off the coast and inland, and are open all year round, free of charge. Similar prog ...
and is included in the National Register of Historic Places
The National Register of Historic Places (NRHP) is the United States federal government's official list of districts, sites, buildings, structures and objects deemed worthy of preservation for their historical significance or "great artistic ...
. She serves as an artificial reef and recreational dive site.
Ex-USS ''Oriskany''
The world's largest artificial reef was created by sinking of the 44,000 ton aircraft carrier off the coast of Pensacola, Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and ...
, in 2006.
Ex-USNS ''Hoyt S. Vandenberg''
The second-largest artificial reef is USNS ''Hoyt S. Vandenberg'', a former World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...
era troop transport that served as a spacecraft-tracking ship after the war. The Vandenberg was scuttled seven miles off Key West on May 27, 2009, in of clear water. Supporters expected the ship to draw recreational divers away from natural reefs, allowing those reefs to recover from damage from overuse.
Ex-USS ''Spiegel Grove''
The ex-USS is located on Dixie Shoal, off the Florida Keys in the Florida Keys National Marine Sanctuary. Her exact location is .
North Carolina
Ex-USS ''Yancey''
was sunk as an artificial reef off Morehead City, North Carolina, 1990. She is lying on her starboard side at a depth of
Ex-USCGC ''Spar''
was scuttled in June 2004 by Captain Tim Mullane in of water, off Morehead City, North Carolina, where she serves as an artificial reef.
Ex-USS ''Indra''
was sunk as an artificial reef, 4 August 1992 in of water.
Its coordinates are .
Ex-USS ''Aeolus''
was sunk to form an artificial reef in August 1988. The ex-''Aeolus'', located about 22 miles from Beaufort Inlet in of water, is regularly visited by divers.
Delaware
Redbird Reef
In the late 2000s, the New York City Transit Authority decided to retire an outdated fleet of subway cars to make room for new R142 and R142A trains. The obsolete subway cars, (nicknamed " Redbirds"), had run on the A Division (former Interborough Rapid Transit Company routes) of the New York City Subway system for 40 years. Each car was stripped, decontaminated, loaded on a barge, and sunk in the Atlantic Ocean off the coast of Delaware, Virginia, South Carolina, Georgia, and Florida. Some cars had number plates removed because of rust, which were then auctioned off on eBay. A total of 1,200 subway cars were sunk for this project.
In September 2007, the NYCTA approved a further contract with Weeks Marine
Weeks Marine is a marine construction and dredging contractor based in Cranford, NJ. It was founded by Francis Weeks and his son Richard B. Weeks in 1919 as the Weeks Stevedoring Company.
Company
Weeks has three key divisions—Construction, D ...
worth $6 million, to send 1,600 of its retired subway cars to be used as artificial reefs. The old models were sheathed in stainless steel, except for the fiberglass reinforced plastic front ends, which were removed before sinking. The retired fleet included old work trains and cars that were badly damaged beyond repair.
Mexico
Cancun Underwater Museum
Since November 2009, artist Jason deCaires Taylor
Jason deCaires Taylor (born 12 August 1974 in Dover) is a British sculptor and creator of the world's first underwater sculpture park – the Molinere Underwater Sculpture Park – and underwater museum – Cancún Underwater Museum. He is best k ...
has created more than 400 life size sculptures off the coast of Cancun, Mexico at the Cancun Underwater Museum. The coral reefs in this region suffered heavy degradation due to repetitive hurricane abuse. This project was funded by The National Marine Park and the Cancun Nautical Association. It was designed to emulate coral reefs using a neutral ph clay. Taylor constructed unique settings depicting daily activities ranging from a man watching TV to a 1970s replica of a Volkswagen Beetle. This artificial reef relieved pressure from the nearby Manchones Reef.
Australia
Since the late 1990s, the Australian government has been providing decommissioned warships for use as artificial reefs for recreational scuba diving. So far, seven ships have been sunk:
* at Dunsborough in Western Australia during December 1997.
* at Albany in Western Australia during November 2001.
* in Yankalilla Bay in South Australia during November 2002.
* off the Sunshine Coast in Queensland during July 2005.
* at a site west of the entrance to Port Phillip Bay in Victoria during October 2009.
* off Terrigal on the New South Wales Central Coast during April 2011
* off Hervey Bay on the Queensland Coast on 29 June 2018
Spain
Ex-SS ''American Star''
The former ocean liner SS ''American Star'' was wrecked on 18 January 1994 on the west coast of the island of Fuerteventura, on Playa de Garcey. By 2008, the wreck of the ship had completely collapsed and sunk, and is now lying about 10 metres underwater near the coast. Its coordinates are 28° 20′ 45.88″ N, 14° 10′ 49.59″ W.
Costa Rica
At Playa Hermosa, the Playa Hermosa Artificial Reef Project has created an artificial reef using discarded porcelain insulators.
Curacao
On Curaçao, Secore International has created 12 artificial reefs using the cost-effective technique with small tetrapod-shaped concrete structures, seeded with coral larvae.
Saba and Statia
The AROSSTA project is located at Saba and Statia. They are using MOREEFs, which are said to be more efficient then reefballs.
Gibraltar
The Gibraltar Reef was first proposed by Eric Shaw in 1973. Initial experiments with tires proved unsuccessful as the tires were swept away by currents or buried underneath sand. In 1974, boats from local marinas and the Gibraltar Port Authority were donated. The first two were barges
Barge nowadays generally refers to a flat-bottomed inland waterway vessel which does not have its own means of mechanical propulsion. The first modern barges were pulled by tugs, but nowadays most are pushed by pusher boats, or other vessels. ...
that were sunk in Camp Bay. In 2006, a 65-ton wooden boat, ''True Joy'' (also referred to as ''Noah's Ark'') was sunk there as well, followed by , a mid-sized bulk carrier, in 2007.
In 2013, more than 70 concrete blocks were sunk, each one square meter in size with protruding metal bars. This led to heated debate between the United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and ...
and Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, ...
, with Gibraltar accusing Spain of over forty incursions into their waters per month and Spain accusing Gibraltar of including metal bars in the reef to stop Spanish fishermen trawling the seabed for fish. The dropping led to a diplomatic conflict between the two countries because Gibraltar is a British Overseas Territory.
India
Temple Reef
The surfing reef Temple reef
Temple Reef is an artificial reef off the coast of Pondicherry, India. It was constructed of fully recycled materials such as concrete blocks, rocks, trees, palm leaves, and iron bars by thTemple Adventuresteam starting from October 2013Temple ...
is off the coast of Pondicherry, India constructed of fully recycled materials such as concrete, rocks, trees, palms, and iron bars. It is located at a depth of .
Dubai
Pearl of Dubai is an art-inspired Lost City off the coast of Dubai
Dubai (, ; ar, wikt:دبي, دبي, translit=Dubayy, , ) is the List of cities in the United Arab Emirates#Major cities, most populous city in the United Arab Emirates (UAE) and the capital of the Emirate of Dubai, the most populated of the 7 ...
. The site encompasses five acres and is located at the World Islands. At a depth of , the site is designed as an ancient lost city, complete with temples and statues using regional design cues from 800 BC.
Aqaba, Jordan
Jordan made an under-water military vehicles museum, which is intended to form an artificial reef over time.
Philippines
Underwater Chocolate Hills is an artificial reef project undertaken by Spindrift Reefs Dive Center off the coast of Panglao Island in the Philippines. It consists of broken coral harvested by local divers, who attach it to wire structures. The structures are built in the same shape as the Chocolate Hills, which can be found in the Bohol
Bohol (), officially the Province of Bohol ( ceb, Lalawigan sa Bohol; tl, Lalawigan ng Bohol), is an island province of the Philippines located in the Central Visayas region, consisting of the island itself and 75 minor surrounding islands. ...
Region. The intent is to create a new dive site and new marine habitat.
Lebanon
In 2018, the Lebanese Army donated 10 stripped tanks to an NGO and sunk them 3 km away from the coast of Sidon, South Lebanon.
Australia
Cooper Reef is a purpose-built artificial reef off the coast of Esperance, Western Australia. It is at a depth of 30m and consists of 128 dome-like concrete modules designed to attract fish and enhance fish stocks, thereby creating new fishing and recreation opportunities for tourists, anglers and local families.
Malta
Following a gas explosion that occurred on 3 February 1995, the Libyan-owned motor tanker Um El Faroud was scuttled off the coast of Malta
Malta ( , , ), officially the Republic of Malta ( mt, Repubblika ta' Malta ), is an island country in the Mediterranean Sea. It consists of an archipelago, between Italy and Libya, and is often considered a part of Southern Europe. It lies ...
as an artificial reef.
Diver perception of artificial reefs
A study in Barbados showed a marked variation in diver satisfaction with artificial reef diving experiences. Novice divers tended to be more satisfied than more experienced divers, who had a strong preference for natural reefs and large shipwrecks.
See also
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References
External links
Eastern Carolina Artificial Reef Association
Organization for Artificial Reefs
Florida Artificial Reef Program
*
{{DEFAULTSORT:Reef (artificial)
Ship disposal
Recreational diving