Cross-references
Eastern Tropical Pacific Coral Reefs
Pacific Coral Reefs: An Introduction
Sea Level Change and Its Effect on Reef Growth
Sediments, Properties
Temperature Change: Bleaching
Upwelling and Coral Reefs
Waves and Wave-Driven Currents
ELECTRO MINERAL ACCRETION
Andrew C. F. Taylor
James Cook University, QLD, Townsville, Australia
Pacificus Biological Services Ltd., BC, Port Hardy,
Canada
Synonyms
Biorock; Electric artificial reef; Electro mineral accretion
of minerals in seawater
Definition
Electro mineral accretion (EMA) artificial reefs are metal
structures used to secure transplants and promote the
growth of scleractinian corals (Hilbertz and Goreau,
1996) and to provide a nature-like colonization substrate
(Schuhmacher and Schillak, 1994).
EMA artificial reef structures act similar to an electrolytic cell. They consist of a metal frame upon which coral
transplants are attached. An anode (made of a slowly oxidizing metal) is placed in the direct vicinity of the frame
(cathode), with a weak DC electrical current applied to
the set up. Sea water acts as the conductive electrolyte
solution between the cathode and the anode. The applied
electric current causes the deposition of minerals, such
as CaCO 3 , Mg(OH) 2 , CaSO 4 , and NaCl, on the structure
(Meyer and Schumacher, 1993; Hilbertz and Goreau,
1996). This is due to a reduction reaction taking place on
the negatively charged cathode of the electrolytic cell
(EMA artificial reef ). The product of the reduction reaction which is of benefit to the corals is CaCO 3 , as this is
the primary compound that forms the skeletons of
scleractinian corals.
The EMA process has been found to significantly
increase growth rates of scleractinian coral transplants
(Sabater and Yap, 2002, 2004; Eggeling, 2006) Increased
skeletal growth rates have been attributed to an increase in
mineral ion concentration within the vicinity of transplants attached to the cathode causing a diffusional influx
of ions into the coral polyp’s coelenterons, increasing the
availability of ions for calicification (Sabater and Yap,
2004). Corals face a production trade-off between allocating resources into colony growth or production of reproductive cells (Rinkevich, 1996). Debate has developed
regarding the use of habitat forming organisms with
artificially altered physiological traits in environmental
restoration.
EMA artificial reefs have been installed for diving tourism (Van Treek and Schuhmacher, 1998) in many areas
and have suffered from degrading natural coral reefs. They
have also been promoted and implemented for coral reef
restoration projects. Rapidly growing corals may have significant potential to be used in coral reef restoration projects for stabilizing substrate and promoting growth of
key habitat forming species of coral. The technology has
also been utilized for rapidly growing corals for use in
aquaria (Eggeling, 2006).
Bibliography
Eggeling, D., 2006. Electro-mineral accretion assisted coral growth:
An aquarium environment. In Reef HQ Technical Report. Great
Barrier Reef Marine Park Authority, p. 21.
Hilbertz, W., and Goreau, T., 1996. Method of enhancing the growth
of aquatic organisms and structures created thereby. US Patent
no. 5,543,034.
Meyer, D., and Schuhmacher, H., 1993. Ökologisch verträgliche
Bauprozesse im Meerwasser. Geowissenschaften, 11, 408–412.
Rinkevich, B., 1996. Do reproduction and regeneration in damaged
corals compete for energy allocation? Marine Ecology Progress
Series, 143, 297–302.
Sabater, M., and Yap, H., 2002. Growth and survival of coral transplants with and without electrochemical deposition of CaCO3.
Journal of Experimental Marine Biology and Ecology, 272,
131–146.
Sabater, M., and Yap, H., 2004. Long-term effects of induced mineral accretion on growth, survival and corallite properties of
Porites cylindrical Dana. Journal of Experimental Marine Biology and Ecology, 311, 355–374.
Schuhmacher, H., and Schillak, L., 1994. Integrated electrochemical and biogenic deposition of hard material – a nature-like colonization substrate. Bulletin of Marine Science, 55, 672–679.
Van Treek, P., and Schuhmacher, H., 1998. Mass Diving Tourism –
A new dimension calls for new management approaches. Marine
Pollution Bulletin, 37, 499–504.
Cross-references
Conservation and Marine Protection Areas
Reef Restoration
ELECTRON SPIN RESONANCE DATING (ESR)
Gerhard Schellmann
1
, Ulrich Radtke
2
,
Helmut Brückner
3
1
University of Bamberg, Bamberg, Germany
2
University of Duisburg-Essen, Essen, Germany
3
Institute of Geography, University of Marburg, Marburg,
Germany
Definition
The electron spin resonance (ESR) dating method is one
of several radiation exposure methods based on radiation
368
ELECTRO MINERAL ACCRETION
Eastern Tropical Pacific Coral Reefs
Pacific Coral Reefs: An Introduction
Sea Level Change and Its Effect on Reef Growth
Sediments, Properties
Temperature Change: Bleaching
Upwelling and Coral Reefs
Waves and Wave-Driven Currents
ELECTRO MINERAL ACCRETION
Andrew C. F. Taylor
James Cook University, QLD, Townsville, Australia
Pacificus Biological Services Ltd., BC, Port Hardy,
Canada
Synonyms
Biorock; Electric artificial reef; Electro mineral accretion
of minerals in seawater
Definition
Electro mineral accretion (EMA) artificial reefs are metal
structures used to secure transplants and promote the
growth of scleractinian corals (Hilbertz and Goreau,
1996) and to provide a nature-like colonization substrate
(Schuhmacher and Schillak, 1994).
EMA artificial reef structures act similar to an electrolytic cell. They consist of a metal frame upon which coral
transplants are attached. An anode (made of a slowly oxidizing metal) is placed in the direct vicinity of the frame
(cathode), with a weak DC electrical current applied to
the set up. Sea water acts as the conductive electrolyte
solution between the cathode and the anode. The applied
electric current causes the deposition of minerals, such
as CaCO 3 , Mg(OH) 2 , CaSO 4 , and NaCl, on the structure
(Meyer and Schumacher, 1993; Hilbertz and Goreau,
1996). This is due to a reduction reaction taking place on
the negatively charged cathode of the electrolytic cell
(EMA artificial reef ). The product of the reduction reaction which is of benefit to the corals is CaCO 3 , as this is
the primary compound that forms the skeletons of
scleractinian corals.
The EMA process has been found to significantly
increase growth rates of scleractinian coral transplants
(Sabater and Yap, 2002, 2004; Eggeling, 2006) Increased
skeletal growth rates have been attributed to an increase in
mineral ion concentration within the vicinity of transplants attached to the cathode causing a diffusional influx
of ions into the coral polyp’s coelenterons, increasing the
availability of ions for calicification (Sabater and Yap,
2004). Corals face a production trade-off between allocating resources into colony growth or production of reproductive cells (Rinkevich, 1996). Debate has developed
regarding the use of habitat forming organisms with
artificially altered physiological traits in environmental
restoration.
EMA artificial reefs have been installed for diving tourism (Van Treek and Schuhmacher, 1998) in many areas
and have suffered from degrading natural coral reefs. They
have also been promoted and implemented for coral reef
restoration projects. Rapidly growing corals may have significant potential to be used in coral reef restoration projects for stabilizing substrate and promoting growth of
key habitat forming species of coral. The technology has
also been utilized for rapidly growing corals for use in
aquaria (Eggeling, 2006).
Bibliography
Eggeling, D., 2006. Electro-mineral accretion assisted coral growth:
An aquarium environment. In Reef HQ Technical Report. Great
Barrier Reef Marine Park Authority, p. 21.
Hilbertz, W., and Goreau, T., 1996. Method of enhancing the growth
of aquatic organisms and structures created thereby. US Patent
no. 5,543,034.
Meyer, D., and Schuhmacher, H., 1993. Ökologisch verträgliche
Bauprozesse im Meerwasser. Geowissenschaften, 11, 408–412.
Rinkevich, B., 1996. Do reproduction and regeneration in damaged
corals compete for energy allocation? Marine Ecology Progress
Series, 143, 297–302.
Sabater, M., and Yap, H., 2002. Growth and survival of coral transplants with and without electrochemical deposition of CaCO3.
Journal of Experimental Marine Biology and Ecology, 272,
131–146.
Sabater, M., and Yap, H., 2004. Long-term effects of induced mineral accretion on growth, survival and corallite properties of
Porites cylindrical Dana. Journal of Experimental Marine Biology and Ecology, 311, 355–374.
Schuhmacher, H., and Schillak, L., 1994. Integrated electrochemical and biogenic deposition of hard material – a nature-like colonization substrate. Bulletin of Marine Science, 55, 672–679.
Van Treek, P., and Schuhmacher, H., 1998. Mass Diving Tourism –
A new dimension calls for new management approaches. Marine
Pollution Bulletin, 37, 499–504.
Cross-references
Conservation and Marine Protection Areas
Reef Restoration
ELECTRON SPIN RESONANCE DATING (ESR)
Gerhard Schellmann
1
, Ulrich Radtke
2
,
Helmut Brückner
3
1
University of Bamberg, Bamberg, Germany
2
University of Duisburg-Essen, Essen, Germany
3
Institute of Geography, University of Marburg, Marburg,
Germany
Definition
The electron spin resonance (ESR) dating method is one
of several radiation exposure methods based on radiation
368
ELECTRO MINERAL ACCRETION