Biorock
Encyclopedia
Biorock, also known as Seacrete, is a substance formed by electro-accumulation of mineral
s dissolved in seawater
. The building process, popularly called accretion, is not to be confused with Biorock sewage treatment
. The biorock building process grows cement
-like engineering structure
s and marine ecosystems, often for mariculture
of coral
s, oyster
s, clam
s, lobster
s and fish
in salt water. It works by passing a small electrical current through electrode
s in the water
. The structure grows more or less without limit as long as current flows.
Biorock accelerates growth on coral reef
s by as much as fivefold and increases coral survival
. Biorock can enable coral growth
and regrowth even in the presence of environmental stress such as thermal pollution
, i.e. increasing water temperatures. When mixed with construction aggregate
s, it can build components on the sea floor or on land. Biorock represents the only known method that can sustain and grow natural coral species using only basic conducting elements, typically of a common metal
such as steel
.
Biorock samples range in compressive strength
from 3720 to 5350 lbf/in² (26 to 37 MPa
) – for comparison, the concrete
typically used in sidewalk
s has a strength of about 3500 lbf/in² (24 MPa). One of the main component of biorock is magnesium hydroxide
, another is calcium carbonate
. This composition is chiefly the result of the ion
ic composition of seawater. Over three decades of practical experience with biorock have shown that one kilowatt hour of electricity
will result in the accretion of about 0.4 to 1.5 kg (0.9 to 3.3 lb) of biorock, depending on various parameter
s such as depth, electrical current, salinity
and water temperature
.
Biorock is cost-effective, requiring only metal bars or equivalent and a small amount of electricity. While electricity provided from fossil fuel
s generates CO2, biorock projects have often used solar power
, wind power
, tidal power
, and wave power
, which don't produce CO2. The resulting material is cheaper than concrete blocks in many places, depending on local electricity and cement transport costs.
(*1938 †2007) and marine biologist Dr. Thomas J. Goreau
(*1950).
Biorock technology arose from experiments in the 1970s when Hilbertz was studying how seashells and reefs grow, by passing electrical currents through salt water. In 1974, he found that as the salt water electrolyzes, calcium carbonate
(aragonite
) slowly forms around the cathode
, eventually coating the electrode
with a material as strong as concrete. Later experiments showed that the coatings can thicken at the rate of 5 cm per year. As long as current flows, the structure continues to get larger and stronger. It can also heal itself if damaged, making it particularly useful as a replacement for concrete in hard-to-access locations.
Hilbertz originally called his invention, on which he had several patents, underwater mineral accretion or accretion for short. The term biorock wasn't coined until later. Hilbertz’s original plan was to use this technology to grow low-cost structures in the ocean for developing countries. He also envisioned accreting large aquadynamic OTEC ocean thermal energy conversion
plants, both for generating power and for producing hydrogen
, ammonia
, and magnesium hydroxide
. This appeared to result in a building process largely independent of land-based resources.
His focus shifted to coral reef
s after meeting Dr. Thomas Goreau in the 1980s. They formed a long-standing partnership, with Goreau continuing work on biorock technologies and coral reef restoration after Hilbertz' death in 2007. Because the biorock process uses such simple materials, electrode
forms can be constructed in a variety of shapes to mimic natural reefs. Since the calcium carbonate coating that forms is so similar to natural reef substrate
, corals take to biorock reef
s very readily. Countless projects over the years have demonstrated that coral thrive on the electrified reef. One prominent example was in the Maldives
during the 1998 warming, during which fewer than 5% of the natural reef corals survived. On biorock reefs in the area, 80% of corals not only survived, they flourished.
As "Seacrete" the process was substantially publicised in a book of futurology
, The Millennial Project
. The author, Marshall Savage
, reiterated Hilbertz' earlier proposal that the conductive metal magnesium
be extracted from ocean water, and that the process use electricity from ocean thermal energy conversion.
electrical current (completely safe for swimmers and marine
life) to a submerged conductive structure causes dissolved minerals in seawater to precipitate and adhere to that structure. The result is a composite of brucite
and limestone
with mechanical strength similar to concrete. Derived from seawater, this material is similar to the composition of natural coral reefs and tropical sand beaches.
Biorock structures can be built in any size or shape depending only on the physical makeup of the sea bottom, wave, current energies and construction materials. They are well suited for remote, third world
sites where exotic building materials, construction equipment and highly skilled labor are non-existent.
, a welded, electrically conductive frame, often made from construction grade rebar
or wire mesh, is submerged and anchored to the sea bottom. A low voltage direct current is applied using an anode
. This initiates an electrolytic reaction causing mineral crystals naturally found in seawater, mainly calcium carbonate
and magnesium hydroxide
, to grow on the structure.
Within days, the structure takes on a whitish hue as it becomes encrusted with precipitated minerals adding rigidity and strength. Electrical fields, plus the shade and protection offered by the metal/limestone frame, attract a wide range of colonizing marine life including fish, crabs, clams, octopus, lobster, and sea urchins.
Once the reef structure is in place and minerals begin to coat the surface, the next phase of reef construction begins. Divers
transplant coral fragments from other reefs, attaching them to the ark’s frame. Immediately, these coral pieces begin to bond to the accreted mineral substrate and start to grow—typically three to five times faster than normal. Soon the reef takes on the appearance and utility of a natural reef
ecosystem
rather than a man-made one.
Electrolysis
of biorock reefs enhances coral growth, reproduction and ability to resist environmental stress. Coral species typically found on healthy reefs gain a major advantage over the weedy organisms that often overgrow them on reefs stressed by eutrophication
. In tests where the electrical current is interrupted, mineral accretion stops and weeds begin to cover the corals. But, if the current is maintained, coral reef habitats can often be restored even in areas where water quality would prevent their recovery by any other method.
Biorock reefs grow rapidly and strengthen as they age. They thus have great potential for many applications, such as making breakwaters. If waves or colliding ships cause damage, renewed accretion makes them, to an extent, self-repairing. Unlike some other types of artificial reefs made from cars or tires, biorock reefs don't leach harmful pollutants into the sea.
, Indian Ocean
, Pacific, and Southeast Asia
. One project is located on one of the most remote and unexplored reef areas of the world, the Saya de Malha Bank
in the Indian Ocean. Other biorock projects are located in Indonesia
, Maldives
, Mexico
, Panama
, Papua New Guinea
, Seychelles
, and Thailand
. The most biorock projects are currently located in Indonesia, with sites in over half a dozen islands, including the two largest reef restoration projects in the world: Pemuteran with the Karang Lestari and the Gili islands with the Gili Eco Trust
. Non-coral biorock projects have been conducted in other places such as Barataria Bay
, Galveston, seagrass
es in the Mediterranean, oyster reefs and salt marsh
es in New York City
, in Port Aransas
, and in St. Croix.
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
s dissolved in seawater
Seawater
Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% . This means that every kilogram of seawater has approximately of dissolved salts . The average density of seawater at the ocean surface is 1.025 g/ml...
. The building process, popularly called accretion, is not to be confused with Biorock sewage treatment
Sewage treatment
Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants from wastewater and household sewage, both runoff and domestic. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants...
. The biorock building process grows cement
Cement
In the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed...
-like engineering structure
Structure
Structure is a fundamental, tangible or intangible notion referring to the recognition, observation, nature, and permanence of patterns and relationships of entities. This notion may itself be an object, such as a built structure, or an attribute, such as the structure of society...
s and marine ecosystems, often for mariculture
Mariculture
Mariculture is a specialized branch of aquaculture involving the cultivation of marine organisms for food and other products in the open ocean, an enclosed section of the ocean, or in tanks, ponds or raceways which are filled with seawater. An example of the latter is the farming of marine fish,...
of coral
Coral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
s, oyster
Oyster
The word oyster is used as a common name for a number of distinct groups of bivalve molluscs which live in marine or brackish habitats. The valves are highly calcified....
s, clam
Clam
The word "clam" can be applied to freshwater mussels, and other freshwater bivalves, as well as marine bivalves.In the United States, "clam" can be used in several different ways: one, as a general term covering all bivalve molluscs...
s, lobster
Lobster
Clawed lobsters comprise a family of large marine crustaceans. Highly prized as seafood, lobsters are economically important, and are often one of the most profitable commodities in coastal areas they populate.Though several groups of crustaceans are known as lobsters, the clawed lobsters are most...
s and fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
in salt water. It works by passing a small electrical current through electrode
Electrode
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit...
s in the water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
. The structure grows more or less without limit as long as current flows.
Biorock accelerates growth on coral reef
Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
s by as much as fivefold and increases coral survival
Survival
Survival is the struggle to remain alive and living. The term may refer to:- Companies and organisations :* Survival International, a non-governmental human rights organization working for tribal peoples- Literature :...
. Biorock can enable coral growth
Growth
Growth refers to an increase in some quantity over time.The quantity can be:*Physical *Abstract ....
and regrowth even in the presence of environmental stress such as thermal pollution
Thermal pollution
Thermal pollution is the degradation of water quality by any process that changes ambient water temperature.A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers...
, i.e. increasing water temperatures. When mixed with construction aggregate
Construction Aggregate
Construction aggregate, or simply "aggregate", is a broad category of coarse particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates. Aggregates are the most mined material in the world...
s, it can build components on the sea floor or on land. Biorock represents the only known method that can sustain and grow natural coral species using only basic conducting elements, typically of a common metal
Metal
A metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...
such as steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
.
Biorock samples range in compressive strength
Compressive strength
Compressive strength is the capacity of a material or structure to withstand axially directed pushing forces. When the limit of compressive strength is reached, materials are crushed. Concrete can be made to have high compressive strength, e.g...
from 3720 to 5350 lbf/in² (26 to 37 MPa
MPA
-Academic degrees:* Master of Professional Accountancy* Master of Public Administration* Master of Public Affairs* Master of Physician's Assistant-Chemicals:* Medroxyprogesterone acetate, also known by the brand name Depo-Provera* Morpholide of pelargonic acid...
) – for comparison, the concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
typically used in sidewalk
Sidewalk
A sidewalk, or pavement, footpath, footway, and sometimes platform, is a path along the side of a road. A sidewalk may accommodate moderate changes in grade and is normally separated from the vehicular section by a curb...
s has a strength of about 3500 lbf/in² (24 MPa). One of the main component of biorock is magnesium hydroxide
Magnesium hydroxide
Magnesium hydroxide is an inorganic compound with the chemical formula Mg2. As a suspension in water, it is often called milk of magnesia because of its milk-like appearance. The solid mineral form of magnesium hydroxide is known as brucite....
, another is calcium carbonate
Calcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
. This composition is chiefly the result of the ion
Ion
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...
ic composition of seawater. Over three decades of practical experience with biorock have shown that one kilowatt hour of electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
will result in the accretion of about 0.4 to 1.5 kg (0.9 to 3.3 lb) of biorock, depending on various parameter
Parameter
Parameter from Ancient Greek παρά also “para” meaning “beside, subsidiary” and μέτρον also “metron” meaning “measure”, can be interpreted in mathematics, logic, linguistics, environmental science and other disciplines....
s such as depth, electrical current, salinity
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
and water temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
.
Biorock is cost-effective, requiring only metal bars or equivalent and a small amount of electricity. While electricity provided from fossil fuel
Fossil fuel
Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years...
s generates CO2, biorock projects have often used solar power
Solar power
Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available...
, wind power
Wind power
Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships....
, tidal power
Tidal power
Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into useful forms of power - mainly electricity....
, and wave power
Wave power
Wave power is the transport of energy by ocean surface waves, and the capture of that energy to do useful work — for example, electricity generation, water desalination, or the pumping of water...
, which don't produce CO2. The resulting material is cheaper than concrete blocks in many places, depending on local electricity and cement transport costs.
History
In an attempt to slow the damage done to the world’s coral, artificial reefs have been built since the 1950s out of materials ranging from concrete blocks to discarded tires. However, most of these plans have failed to provide a new coral habitat, most notoriously the attempt using tires off the shore of Fort Lauderdale has become a complete environmental disaster. There have been some successes with artificial reefs, but most remain relatively barren compared with natural reefs. The one notable exception is the work of architect/marine scientist Prof. Wolf HilbertzWolf Hilbertz
Prof. Wolf Hartmut Hilbertz was a German-born futurist architect, inventor, and marine scientist.-Youth and schooling:...
(*1938 †2007) and marine biologist Dr. Thomas J. Goreau
Thomas J. Goreau
Thomas J. Goreau is a biogeochemist and marine biologist; son of Thomas F. Goreau and Nora I. Goreau.After studying in Jamaican primary and secondary schools, he earned degrees in planetary physics at the Massachusetts Institute of Technology, in planetary astronomy at the California Institute of...
(*1950).
Biorock technology arose from experiments in the 1970s when Hilbertz was studying how seashells and reefs grow, by passing electrical currents through salt water. In 1974, he found that as the salt water electrolyzes, calcium carbonate
Calcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
(aragonite
Aragonite
Aragonite is a carbonate mineral, one of the two common, naturally occurring, crystal forms of calcium carbonate, CaCO3...
) slowly forms around the cathode
Cathode
A cathode is an electrode through which electric current flows out of a polarized electrical device. Mnemonic: CCD .Cathode polarity is not always negative...
, eventually coating the electrode
Electrode
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit...
with a material as strong as concrete. Later experiments showed that the coatings can thicken at the rate of 5 cm per year. As long as current flows, the structure continues to get larger and stronger. It can also heal itself if damaged, making it particularly useful as a replacement for concrete in hard-to-access locations.
Hilbertz originally called his invention, on which he had several patents, underwater mineral accretion or accretion for short. The term biorock wasn't coined until later. Hilbertz’s original plan was to use this technology to grow low-cost structures in the ocean for developing countries. He also envisioned accreting large aquadynamic OTEC ocean thermal energy conversion
Ocean thermal energy conversion
Ocean Thermal Energy Conversion uses the difference between cooler deep and warmer shallow or surface ocean waters to run a heat engine and produce useful work, usually in the form of electricity....
plants, both for generating power and for producing hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
, ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
, and magnesium hydroxide
Magnesium hydroxide
Magnesium hydroxide is an inorganic compound with the chemical formula Mg2. As a suspension in water, it is often called milk of magnesia because of its milk-like appearance. The solid mineral form of magnesium hydroxide is known as brucite....
. This appeared to result in a building process largely independent of land-based resources.
His focus shifted to coral reef
Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
s after meeting Dr. Thomas Goreau in the 1980s. They formed a long-standing partnership, with Goreau continuing work on biorock technologies and coral reef restoration after Hilbertz' death in 2007. Because the biorock process uses such simple materials, electrode
Electrode
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit...
forms can be constructed in a variety of shapes to mimic natural reefs. Since the calcium carbonate coating that forms is so similar to natural reef substrate
Substrate (marine biology)
Stream substrate is the material that rests at the bottom of a stream. There are several classification guides. One is:*Mud – silt and clay.*Sand – Particles between 0.06 and 2 mm in diameter.*Granule – Between 2 and 4 mm in diameter....
, corals take to biorock reef
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
s very readily. Countless projects over the years have demonstrated that coral thrive on the electrified reef. One prominent example was in the Maldives
Maldives
The Maldives , , officially Republic of Maldives , also referred to as the Maldive Islands, is an island nation in the Indian Ocean formed by a double chain of twenty-six atolls oriented north-south off India's Lakshadweep islands, between Minicoy Island and...
during the 1998 warming, during which fewer than 5% of the natural reef corals survived. On biorock reefs in the area, 80% of corals not only survived, they flourished.
As "Seacrete" the process was substantially publicised in a book of futurology
Futurology
Futures studies is the study of postulating possible, probable, and preferable futures and the worldviews and myths that underlie them. There is a debate as to whether this discipline is an art or science. In general, it can be considered as a branch under the more general scope of the field of...
, The Millennial Project
The Millennial Project: Colonizing the Galaxy in Eight Easy Steps
The Millennial Project: Colonizing the Galaxy in Eight Easy Steps by Marshall T. Savage is a book in the field of Exploratory engineering that gives a series of concrete stages the author believes will lead to interstellar colonization...
. The author, Marshall Savage
Marshall Savage
Marshall Thomas Savage is an advocate of space travel who wrote The Millennial Project: Colonizing the Galaxy in Eight Easy Steps and founded the Living Universe Foundation, which was designed to make plans for stellar exploration over the next 1,000 years....
, reiterated Hilbertz' earlier proposal that the conductive metal magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
be extracted from ocean water, and that the process use electricity from ocean thermal energy conversion.
Process
Applying a low voltageLow voltage
Low voltage when used as an electrical engineering term concerning an electricity supply grid or industrial use, broadly identifies safety considerations of the system based on the voltage used. The meaning of the term "low voltage" is somewhat different when used with regard to a more typical end...
electrical current (completely safe for swimmers and marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
life) to a submerged conductive structure causes dissolved minerals in seawater to precipitate and adhere to that structure. The result is a composite of brucite
Brucite
Brucite is the mineral form of magnesium hydroxide, with the chemical formula Mg2. It is a common alteration product of periclase in marble; a low-temperature hydrothermal vein mineral in metamorphosed limestones and chlorite schists; and formed during serpentinization of dunites...
and limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
with mechanical strength similar to concrete. Derived from seawater, this material is similar to the composition of natural coral reefs and tropical sand beaches.
Biorock structures can be built in any size or shape depending only on the physical makeup of the sea bottom, wave, current energies and construction materials. They are well suited for remote, third world
Third World
The term Third World arose during the Cold War to define countries that remained non-aligned with either capitalism and NATO , or communism and the Soviet Union...
sites where exotic building materials, construction equipment and highly skilled labor are non-existent.
Constructing a new reef
To build a biorock reefReef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
, a welded, electrically conductive frame, often made from construction grade rebar
Rebar
A rebar , also known as reinforcing steel, reinforcement steel, rerod, or a deformed bar, is a common steel bar, and is commonly used as a tensioning device in reinforced concrete and reinforced masonry structures holding the concrete in compression...
or wire mesh, is submerged and anchored to the sea bottom. A low voltage direct current is applied using an anode
Anode
An anode is an electrode through which electric current flows into a polarized electrical device. Mnemonic: ACID ....
. This initiates an electrolytic reaction causing mineral crystals naturally found in seawater, mainly calcium carbonate
Calcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
and magnesium hydroxide
Magnesium hydroxide
Magnesium hydroxide is an inorganic compound with the chemical formula Mg2. As a suspension in water, it is often called milk of magnesia because of its milk-like appearance. The solid mineral form of magnesium hydroxide is known as brucite....
, to grow on the structure.
Within days, the structure takes on a whitish hue as it becomes encrusted with precipitated minerals adding rigidity and strength. Electrical fields, plus the shade and protection offered by the metal/limestone frame, attract a wide range of colonizing marine life including fish, crabs, clams, octopus, lobster, and sea urchins.
Once the reef structure is in place and minerals begin to coat the surface, the next phase of reef construction begins. Divers
Scuba diving
Scuba diving is a form of underwater diving in which a diver uses a scuba set to breathe underwater....
transplant coral fragments from other reefs, attaching them to the ark’s frame. Immediately, these coral pieces begin to bond to the accreted mineral substrate and start to grow—typically three to five times faster than normal. Soon the reef takes on the appearance and utility of a natural reef
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
rather than a man-made one.
Electrolysis
Electrolysis
In chemistry and manufacturing, electrolysis is a method of using a direct electric current to drive an otherwise non-spontaneous chemical reaction...
of biorock reefs enhances coral growth, reproduction and ability to resist environmental stress. Coral species typically found on healthy reefs gain a major advantage over the weedy organisms that often overgrow them on reefs stressed by eutrophication
Eutrophication
Eutrophication or more precisely hypertrophication, is the movement of a body of water′s trophic status in the direction of increasing plant biomass, by the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage, to an aquatic system...
. In tests where the electrical current is interrupted, mineral accretion stops and weeds begin to cover the corals. But, if the current is maintained, coral reef habitats can often be restored even in areas where water quality would prevent their recovery by any other method.
Biorock reefs grow rapidly and strengthen as they age. They thus have great potential for many applications, such as making breakwaters. If waves or colliding ships cause damage, renewed accretion makes them, to an extent, self-repairing. Unlike some other types of artificial reefs made from cars or tires, biorock reefs don't leach harmful pollutants into the sea.
Distribution
As of 2011, biorock coral reef projects exist in over 20 countries in the CaribbeanCaribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
, Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
, Pacific, and Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
. One project is located on one of the most remote and unexplored reef areas of the world, the Saya de Malha Bank
Saya de Malha Bank
The Saya de Malha Bank is the largest submerged bank in the World, part of the vast undersea Mascarene Plateau...
in the Indian Ocean. Other biorock projects are located in Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
, Maldives
Maldives
The Maldives , , officially Republic of Maldives , also referred to as the Maldive Islands, is an island nation in the Indian Ocean formed by a double chain of twenty-six atolls oriented north-south off India's Lakshadweep islands, between Minicoy Island and...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
, Papua New Guinea
Papua New Guinea
Papua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...
, Seychelles
Seychelles
Seychelles , officially the Republic of Seychelles , is an island country spanning an archipelago of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....
, and Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
. The most biorock projects are currently located in Indonesia, with sites in over half a dozen islands, including the two largest reef restoration projects in the world: Pemuteran with the Karang Lestari and the Gili islands with the Gili Eco Trust
Gili Eco Trust
Gili Eco Trust is a local non governmental organization created in 2000 to protect coral reefs from destructive fishing around the three Gili islands, off Lombok, Indonesia....
. Non-coral biorock projects have been conducted in other places such as Barataria Bay
Barataria Bay
Barataria Bay, also Barrataria Bay, is a bay of the Gulf of Mexico that is located in southeastern Louisiana, in Jefferson Parish and Plaquemines Parish, United States....
, Galveston, seagrass
Seagrass
Seagrasses are flowering plants from one of four plant families , all in the order Alismatales , which grow in marine, fully saline environments.-Ecology:...
es in the Mediterranean, oyster reefs and salt marsh
Salt marsh
A salt marsh is an environment in the upper coastal intertidal zone between land and salt water or brackish water, it is dominated by dense stands of halophytic plants such as herbs, grasses, or low shrubs. These plants are terrestrial in origin and are essential to the stability of the salt marsh...
es in New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
, in Port Aransas
Port Aransas, Texas
Port Aransas is a city in Nueces County, Texas. The population was 3,370 at the 2000 census.-Early history:Karankawa Indians played a key role in the early development of the Texas Gulf Coast. The Karankawa Indians inhabited the Gulf Coast of Texas from Galveston Bay all the way to Corpus Christi Bay...
, and in St. Croix.
Published works
- Hilbertz, W. H., Marine architecture: an alternative, in: Arch. Sci. Rev., 1976
- Hilbertz, W. H., Mineral accretion technology: applications for architecture and aquaculture with D. Fletcher und C. Krausse, Industrial Forum, 1977
- Hilbertz, W. H., Building Environments That Grow, in: The Futurist (June 1977): 148-49
- Hilbertz, W. H. et al., Electrodeposition of Minerals in Sea Water: Experiments and Applications, in: IEEE Journal on Oceanic Engineering, Vol. OE-4, No. 3, pp. 94–113, 1979
- Ortega, Alvaro, Basic Technology: Mineral Accretion for Shelter. Seawater as a Source for Building, MIMAR 32: Architecture in Development, No. 32, pp. 60–63, 1989
- Hilbertz, W. H., Solar-generated construction material from sea water to mitigate global warming, in: Building Research & Information, Volume 19, Issue 4 July 1991 , pages 242 - 255
- Hilbertz, W. H., Solar-generated building material from seawater as a sink for carbon, Ambio 1992
- Balbosa, Enrique Amat, Revista Arquitectura y Urbanismo, Vol. 15, no. 243, 1994
- Goreau, T. J. + Hilbertz, W. H. + Evans, S. + Goreau, P. + Gutzeit, F. + Despaigne, C. + Henderson, C. + Mekie, C. + Obrist, R. + Kubitza, H., Saya de Malha Expedition, March 2002, 101 p., Sun&Sea e.V. Hamburg, Germany, August 2002
- Cervino, J.M. + Hayes, R.L. + Honovich, M. + Goreau, T.J. + Jones, S. + Rubec, P.J., Changes in zooxanthellae density, morphology, and mitotic index in hermatypic corals and anemones exposed to cyanide, In: Marine Pollution Bulletin 46, 573–586, May 2003
- Goreau, T. J. + Hilbertz, W. H., Marine Ecosystem Restoration: Costs and benefits for coral reefs, in: World Resource Review Vol. 17, No. 3, pp. 375–409, 2005
- R. Vaccarella + T. J. Goreau, Applicazione della elettrodeposizione nel recupero die mattes di Posidonia oceanica, in: Posidonia Oceanica, pp. 93–105, Protezione ripopolazione di praterie ed utilazzione dei residui in agricoltora, Editoriale a Cura della Provincia di Bari, Servizio Politiche Comunitarie, Assessorato Risorse del Mare, Bari, Italy, 2008
- Goreau, T. J. + Hilbertz, W. H., Bottom-Up Community-Based Coral Reef and Fisheries Restoration in Indonesia, Panama, and Palau, August 2008
- Goreau, T. J. + Hilbertz, W. H., Reef Restoration as a Fisheries Management Tool, In: Thomas J. Goreau, Raymond L. Hayes ,(2008), Fisheries and Aquaculture, [Ed. Patrick Safran], in Encyclopedia of Life Support Systems (EOLSS), Developed under the Auspices of the UNESCO, Eolss Publishers, Oxford , United Kingdom, 2008
- Strömberg, Susanna M. + Lundälv, Tomas + Goreau, T. J., Suitability of Mineral Accretion as a Rehabilitation Method for Cold-Water Coral Reefs, Journal of Experimental Marine Biology and Ecology, no. 395, pp. 153–161, 2010
- Wells, Lucy + Perez, Fernando + Hibbert, Marlon + Clerveaux, Luc + Johnson, Jodi + Goreau, T. J., Effect of severe hurricanes on Biorock Coral Reef Restoration Projects in Grand Turk, Turks and Caicos Islands, Department of Environment and Coastal Resources (DECR), Grand Turk, Turks and Caicos Islands, 12-VII-2010
- Goreau, T. J., Coral Reef and Fisheries Habitat Restoration in the Coral Triangle : The Key to Sustainable Reef Management, Proceeding of Coral Reef Management Symposium on Coral Triangle Area, pp. 244–253, Coral Reef Rehabilitation and Management Program Phase II, Jakarta Selatan, Indonesia, 2010
External links
- GlobalCoral.org: website of Dr. Thomas Goreau and the Global Coral Reef Alliance
- GCRA biorock overviews
- GCRA White Papers
- WolfHilbertz.com: website of Prof. Wolf Hilbertz with various articles
- WolfHilbertz.com: Wolf Hilbertz' seminal 1979 IEEE paper as PDF download
- WolfHilbertz.com: Saya de Malha second expedition report 2002 as PDF download
- Youtube video of "Coral reef restoration methods that don't work - 3"
- Youtube video of biorock coral reef restoration
- Biorock.net: website about Biorock and accretion as developed by Wolf Hilbertz and Thomas Goreau
- Biorock-Workshop.org: information on Biorock workshops
- Biorock-Thailand.com: coral reef restoration in South East Asia
- Biorock.com: company website for waste water treatment
- "Changes in zooxanthellae density, morphology, and mitotic index in hermatypic corals and anemones exposed to cyanide", 2003, as PDF download
- Goreau + Hilbertz: "Marine Ecosystem Restoration: Costs and benefits for coral reefs", World Resource Review, 2005, as PDF download
- Vaccarella, R. + Goreau: "Applicazione della elettrodeposizione nel recupero die mattes di Posidonia oceanica", 2008, as PDF download
- Goreau + Hilbertz, "Bottom-Up Community-Based Coral Reef and Fisheries Restoration in Indonesia, Panama, and Palau", 2008, as PDF download
- Goreau + Hilbertz, "Reef Restoration as a Fisheries Management Tool", UK 2008, on GCRA website
- Strömberg + Lundälv + Goreau: "Suitability of Mineral Accretion as a Rehabilitation Method for Cold-Water Coral Reefs", 2010, as PDF download
- "Effect of severe hurricanes on Biorock Coral Reef Restoration Projects in Grand Turk, Turks and Caicos Islands", 2010, as PDF download
- Goreau, T. J.: "Coral Reef and Fisheries Habitat Restoration in the Coral Triangle", Indonesia 2010, as PDF download