Aquaculture of coral

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Coral in a culture facility Commercially supplied coral.JPG
Coral in a culture facility

Coral aquaculture, also known as coral farming or coral gardening, is the cultivation of corals for commercial purposes or coral reef restoration. Aquaculture is showing promise as a tool for restoring coral reefs, which are dying off around the world. [1] [2] [3] The process protects young corals while they are most at risk of dying. Small corals are propagated in nurseries and then replanted on the reef. [4]

Contents

Coral is also farmed by scientists for research, by businesses for the live and ornamental coral trade, and by private reef aquarium hobbyists.

Coral reef farming involves extracting a part of a coral colony or free-floating larvae from a reef, and growing them in a nursery until outplanting [5] would be successful. It is commonly referred to as the "gardening method" and has been compared to silviculture as a management practice that mimics natural ecosystems. [3] [6]

Adult corals can be transplanted onto a reef, usually in a damaged area. [3] [7] Coral is farmed for conservation reasons in the Philippines, Israel, Solomon Islands, Palau, Fiji, Marshall Islands, and Japan. Land-based coral farming occurs in public aquariums in North America and Europe. [8]

Benefits of healthy reefs

Orange cup coral housed in the Anuenue coral farm in Honolulu, Hawaii. The light is deep blue to simulate the light of the deep sea. This species can be found up to 130 meters deep. Coral Aquaculture .jpg
Orange cup coral housed in the Ānuenue coral farm in Honolulu, Hawaii. The light is deep blue to simulate the light of the deep sea. This species can be found up to 130 meters deep.

A healthy reef houses a large amount of biodiversity with varying species of corals. It requires herbivores including parrotfish and collector urchins that graze on infesting algae. [7] Most corals require oligotrophic water, that is, water that is clear and nutrient-poor. [9] Corals derive nutrients from zooxanthellae symbionts, as well as from plankton and other free-floating particles. [10] Zooxanthellae require a mixture of white and blue light to thrive within the coral, depending on the coral type. [11] Some corals, like the orange cup coral, do not require light, and rely on the plankton or free-floating nutrients as sustenance. [12]

Coral reefs protect the coastline from erosion and storm damage. They are important foundation species that increase biodiversity in the area by providing nursery ground and habitat for nearly one-third of saltwater fish species. These include ten percent of all fish captured for human consumption, even though reefs only cover less than one percent of the ocean's surface. [8]

Reefs in decline

Reefs are affected by severe weather events, such as cyclones, [13] temperature changes of 1–2 degrees of the average water temperature over a period of weeks, from predation by crown of thorns starfish, and from competition for habitat with other foundation species such as algae. Algae can take over coral habitats when the water contains excess nutrients (nitrogen and phosphorus) or when fishing stocks are too low and herbivorous fish do not keep the algae at bay by eating it. [7]

Corals can minimally protect themselves from algae as well, by removing it with their polyps. When corals are in suboptimal conditions they are less able to protect themselves from algal coverage, diseases, and other stressors. This diversion of energy from growth puts the coral's life at risk. Coral bleaching is the result of the loss of vital zooxanthellae; any of the stressors can cause bleaching. [14] The corals expel their symbionts because they are trying to get rid of any foreign bodies that might be causing them stress. Corals can survive up to a week without the zooxanthellae, but it is difficult. [15] Corals can recover from bleaching and uptake vital zooxanthellae again but this requires a change in environment and the lessening of stressors. [16]  

Natural stressors to the coral reef are further aggravated by the human impact on coral reefs. Anthropogenic stressors such as runoff, coastal development, dynamite fishing, cyanide fishing, overexploitation of resources and marine pollution, put 58% percent of the world's reefs under threat as of 2009. [17] An example is the exploitation of mushroom coral in Indonesia which is harvested for supply of the jewelry and curio trades. [18] [19] Harvesting of living reef organisms, including coral, is increasing around the world. [2] Coral is often overharvested to supply growing demand. Overharvesting weakens the ability of reefs to replenish after other harmful events.

Reef restoration

Coral transplantation in South Sulawesi, Indonesia Coral transplant.jpg
Coral transplantation in South Sulawesi, Indonesia
Coral restoration site at the Florida Keys National Marine Sanctuary FKNMS - coral nursery (27367671414).jpg
Coral restoration site at the Florida Keys National Marine Sanctuary

Coral propagation can improve coral cover, biodiversity, and structural heterogeneity of a degraded reef. Success has been achieved with fire coral, Pocillopora verrucosa , and Acropora hemprichii . [20] A restored reef hosts organisms associated with the reef, such as reef fishes. [4]

Reefs are delicate and complex ecosystems. It is difficult to replicate what a damaged reef looked like before the damage occurred. Most coral farms that are utilized for mitigation of damage are only able to propagate the fast growing corals that are easy to grow. Slow growing corals are expensive to propagate and are not a fast growing foundation species which is needed when damage occurs. Most coral reefs will take decades to return to their previous state. [21]  Nursery-grown coral promote reef resilience by making contributions to the larval pool. This could have a positive effect on new growth if transplanting of the new coral is made just before a larval release season. [1]

Oceanographer Baruch Rinkevich [22] coined the term active restoration to describe coral reef farming, in contrast with what he described as passive restoration efforts focused on mitigation of stressors by means such as the designation of marine protected areas (MPAs). [3] Coral reefs are often placed in MPAs in the hope that reducing human activity will allow the coral to recover. [7]

Aquarium trade

Coral fragments recovered from bomb fishing sites ready for replanting Coral planting and reef restoration may 11 -2.jpg
Coral fragments recovered from bomb fishing sites ready for replanting

Many people enjoy the creating their own coral display in a home aquarium. In response to this, businesses farm coral to supply them. Some companies farm in sunlit greenhouses instead of artificially lighted aquariums. [23] The 1999 Hawaii Marine Ornamentals Conference concluded with a recommendation to "give highest priority to projects involving the advancement of marine ornamental aquaculture and reef preservation." Conferees pressed the importance of encouraging hobbyists to supply only from coral reef farms to help deter over-harvesting. Conferees recommended initiatives to encourage consumer understanding that cultured ornamentals are a more sustainable and 'higher value' alternative to wild-caught live reef organisms. [24]

Methods

For conservation

The stages to farming for reef restoration are: collecting polyps or larvae; growing the specimens in tanks; further growth in sea nurseries and re-transplantation onto the reef.

Collection

Coral fragments replanted in nontoxic cement Coral planting and reef restoration may 11.jpg
Coral fragments replanted in nontoxic cement

Coral can reproduce asexually by budding or sexually by spawning.

Collecting coral polyps from existing reef colonies or fragments can be done any time. Branches, fragments, or tips of branches are common targets. This is the most widely practiced method. [8]

Collecting coral spawn is generally an annual activity, conducted immediately following a spawning event. Coral colonies on a reef usually spawn together in a synchronized event on a specific day. This allows for hundreds of thousands of coral embryos to be collected at one time. This method is known as spat stocking.

At the Great Barrier Reef Aquarium in Townsville, Australia, large colonies of Acropora formosa have collection devices placed above them during spawning. [25] Small mature colonies are transplanted from the reef into a tank for spawning. They can then be reattached to the reef.

Using this method, the mother colonies are unaffected. [8] This method has also been proved effective on Red Sea soft coral species, Alcyonarians : Clavularia hamra, Nephthea sp. and Litophyton arboreum . [20]

Tank cultivation

Linden describes an apparatus made of Petri dishes lined with preconditioned Mailer's paper disks on which the planula of Stylophora pistillata are grown. One-month-old survivors were transferred onto plastic pins in a mid-water coral nursery, where the trays were covered with fitted plastic nets to prevent predation and detachment. After four months, more than 89% of the corals had survived. [26]

Ocean cultivation

Next the corals are transported into floating nurseries in the sea. The corals float in the water column, attached on a submerged structure. Some authors recommend 6 metres depth to ensure the corals get the right amount of sunlight. They are affixed to an artificial substrate. This is usually made from string, wire, mesh, monofilament line or epoxy. The colonies remain there from 8 to 24 months to reach a size for transplantation back to the reef. [3]

Return to the reef

When the corals are big enough to be transplanted into the reef, the transplantation stage involves securing to the corals by plastic pegs or masonry anchors or with epoxy. [1]

For commercial or exhibition supply

For commercial markets, the process is the same except that the ocean cultivation is extended until the colonies reach marketable size (about fist-sized) and the final step is replaced by extraction and packaging for sale. [2]

Economy

Coral aquaculture offers alternative livelihoods to people living near the reefs. This is especially important for communities where fishing or harvesting marine organisms have become unsustainable, such as in Indonesia. [27] It is possible to use coral resources in a way that is environmentally friendly. Many coral reefs are in impoverished locations. Coral reef aquaculture requires only basic, cheap materials, making it possible for communities with limited resources. [28] Some new methods, such as seeding of concrete tetrapods containing coral larvae, make it possible to reduce costs and outplanting time compared to previous approaches. [29]

History

Broodstock coral on display at Mote Marine Laboratory Coral on display at Mote Marine Laboratory 2.jpg
Broodstock coral on display at Mote Marine Laboratory

One of the first serious attempts at propagating coral ex situ occurred at Nouméa Aquarium in 1956. At the time it was common for aquarium hobbyists in Germany to create home "mini-reefs". Commercial coral propagation began in America in the 1960s, and hobby industry took off in the early 1980s. The trend was attributed to hobby magazines. [8]

In 2009 the US government awarded $3.3 million for a project to cultivate 5,000 colonies of Acropora . Researchers claimed that transplanting 35 colonies per year would restore coral populations to 1970s levels in 10 years. [30]

Research and development

Coral aquaculture provides insights into coral life histories. [20] Petersen showed that early sexual recruits grow larger when fed the nauplii of brine shrimp. This discovery could shorten the fragile post settlement time in the hatchery. [31]

The Mote Marine Laboratory keeps many broodstock colonies at its Tropical Research Laboratory. The laboratory website reports that its colonies are grown from fragments rescued from boat groundings and environmental disturbances. The corals in the broodstock reserve provide fragments for restoration research. Studies are done to determine optimal size, shape and season for restoration. [32]

Market

Indonesia and the Philippines supply ~85% of coral reef products. Indonesia requires 10% of coral production to be transplanted into the ocean. As of 2012, a majority of coral imports to the US were wild-caught, although an increasing proportion were cultured. From 1990 to 2010, imports increased by some 8% annually. Imports declined thereafter the wake of the Great Recession and from increasing domestic production. Commercial trade in stony and reef-building corals is regulated by the Convention on International Trade in Endangered Species (CITES). In Indonesia, most production is located around airports to speed the shipping process. [30]

See also

Related Research Articles

<span class="mw-page-title-main">Coral</span> Marine invertebrates of the class Anthozoa

Corals are colonial marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.

<span class="mw-page-title-main">Coral reef</span> Outcrop of rock in the sea formed by the growth and deposit of stony coral skeletons

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.

<span class="mw-page-title-main">Scleractinia</span> Order of Hexacorallia which produce a massive stony skeleton

Scleractinia, also called stony corals or hard corals, are marine animals in the phylum Cnidaria that build themselves a hard skeleton. The individual animals are known as polyps and have a cylindrical body crowned by an oral disc in which a mouth is fringed with tentacles. Although some species are solitary, most are colonial. The founding polyp settles and starts to secrete calcium carbonate to protect its soft body. Solitary corals can be as much as 25 cm (10 in) across but in colonial species the polyps are usually only a few millimetres in diameter. These polyps reproduce asexually by budding, but remain attached to each other, forming a multi-polyp colony of clones with a common skeleton, which may be up to several metres in diameter or height according to species.

<i>Acropora</i> Genus of stony coral

Acropora is a genus of small polyp stony coral in the phylum Cnidaria. Some of its species are known as table coral, elkhorn coral, and staghorn coral. Over 149 species are described. Acropora species are some of the major reef corals responsible for building the immense calcium carbonate substructure that supports the thin living skin of a reef.

<span class="mw-page-title-main">Leaf plate montipora</span> Species of coral

Leaf plate montipora, also known as vase coral, cap coral, or plating montipora, is a type of small polyp stony (SPS) coral in the family Acroporidae.

<span class="mw-page-title-main">Fire coral</span> Genus of hydrozoans

Fire corals (Millepora) are a genus of colonial marine organisms that exhibit physical characteristics similar to that of coral. The name coral is somewhat misleading, as fire corals are not true corals but are instead more closely related to Hydra and other hydrozoans, making them hydrocorals. They make up the only genus in the monotypic family Milleporidae.

<span class="mw-page-title-main">Elkhorn coral</span> Species of coral

Elkhorn coral is an important reef-building coral in the Caribbean. The species has a complex structure with many branches which resemble that of elk antlers; hence, the common name. The branching structure creates habitat and shelter for many other reef species. Elkhorn coral is known to grow quickly with an average growth rate of 5 to 10 cm per year. They can reproduce both sexually and asexually, though asexual reproduction is much more common and occurs through a process called fragmentation.

<span class="mw-page-title-main">Coral reef protection</span> Modifying human activities to reduce impact on coral reefs.

Coral reef protection is the process of modifying human activities to avoid damage to healthy coral reefs and to help damaged reefs recover. The key strategies used in reef protection include defining measurable goals and introducing active management and community involvement to reduce stressors that damage reef health. One management technique is to create Marine Protected Areas (MPAs) that directly limit human activities such as fishing.

The resilience of coral reefs is the biological ability of coral reefs to recover from natural and anthropogenic disturbances such as storms and bleaching episodes. Resilience refers to the ability of biological or social systems to overcome pressures and stresses by maintaining key functions through resisting or adapting to change. Reef resistance measures how well coral reefs tolerate changes in ocean chemistry, sea level, and sea surface temperature. Reef resistance and resilience are important factors in coral reef recovery from the effects of ocean acidification. Natural reef resilience can be used as a recovery model for coral reefs and an opportunity for management in marine protected areas (MPAs).

<i>Galaxea fascicularis</i> Species of coral

Galaxea fascicularis is a species of colonial stony coral in the family Euphylliidae, commonly known as octopus coral, fluorescence grass coral, galaxy coral among various vernacular names.

<i>Porites lobata</i> Species of coral

Porites lobata, known by the common name lobe coral, is a species of stony coral in the family Poritidae. It is found growing on coral reefs in tropical parts of the Indian and Pacific Oceans.

<i>Millepora platyphylla</i> Species of hydrozoan

Millepora platyphylla is a species of fire coral, a type of hydrocoral, in the family Milleporidae. It is also known by the common names blade fire coral and plate fire coral. It forms a calcium carbonate skeleton and has toxic, defensive polyps that sting. It obtains nutrients by consuming plankton and via symbiosis with photosynthetic algae. The species is found from the Red Sea and East Africa to northern Australia and French Polynesia. It plays an important role in reef-building in the Indo-Pacific region. Depending on its environment, it can have a variety of different forms and structures.

<i>Acropora pulchra</i> Species of coral

Acropora pulchra is a species of colonial staghorn coral in the family Acroporidae. It is found on the back fringes of reefs in shallow water in the western Indo-Pacific Ocean. The oldest fossils of this species date back to the Pleistocene.

<i>Micromussa lordhowensis</i> Species of coral

Micromussa lordhowensis, previously known as the 'Acan Lord', is a species of stony coral in the family Lobophylliidae. It is a widespread and common coral with large polyps occurring on shallow reefs in the Indo-Pacific Ocean. It was originally classified under the genus Acanthastrea, and reclassified under the genus Micromussa in 2016.

<i>Acropora grandis</i> Species of coral

Acropora grandis is a species of colonial stony coral. It is a large species with multiple branches forming a bush-like structure and is found on reefs and in lagoons. It is native to the tropical western Indo-Pacific and has a range extending from East Africa to the east coast of Australia.

<i>Pocillopora damicornis</i> Species of coral

Pocillopora damicornis, commonly known as the cauliflower coral or lace coral, is a species of stony coral in the family Pocilloporidae. It is native to tropical and subtropical parts of the Indian and Pacific Oceans.

<i>Dipsastraea speciosa</i> Species of coral

Dipsastraea speciosa is a species of colonial stony coral in the family Merulinidae. It is found in tropical waters of the Indian and Pacific oceans.

<i>Heliofungia actiniformis</i> Species of coral

Heliofungia actiniformis is a solitary species of mushroom coral, a large polyp stony coral in the family Fungiidae. This coral is found in shallow water in the Indo-Pacific region. It is a zooxanthellate species. It is a popular coral in the reef aquarium trade; wild populations are threatened by disease, climate change, and over-collecting, and the species is considered vulnerable by the IUCN.

<i>Porites cylindrica</i> Species of coral

Porites cylindrica, commonly known as hump coral, is a stony coral belonging to the subclass Hexacorallia in the class Anthozoa. Hexacorallia differ from other subclasses in that they have 6 or fewer axes of symmetry. Members of this class possess colonial polyps which can be reef-building, secreting a calcium carbonate skeleton. They are dominant in both inshore reefs and midshelf reefs.

<span class="mw-page-title-main">Coral reef restoration</span> Restoration of coral reefs

Coral reef restoration strategies use natural and anthropogenic processes to restore damaged coral reefs. Reefs suffer damage from a number of natural and man-made causes, and efforts are being made to rectify the damage and restore the reefs. This involves the fragmentation of mature corals, the placing of the living fragments on lines or frames, the nurturing of the fragments as they recover and grow, and the transplantation of the pieces into their final positions on the reef when they are large enough.

References

  1. 1 2 3 Horoszowski-Fridman, YB, Izhaki, I & Rinkevich, B (2011) "Engineering of coral reef larval supply through transplantation of nursery-farmed gravid colonies" Journal of Experimental Marine Biology and Ecology, 399(2): 162–166.
  2. 1 2 3 Pomeroy, RS, Parks, JE and Balboa, CM (2006) "Farming the reef: is aquaculture a solution for reducing fishing pressure on coral reefs?" Marine Policy,30(2): 111–130.
  3. 1 2 3 4 5 Rinkevich, B (2008) "Management of coral reefs: We have gone wrong when neglecting active reef restoration" Archived 2013-05-23 at the Wayback Machine Marine pollution bulletin,56(11): 1821–1824.
  4. 1 2 Ferse, SCA 2010, "Poor Performance of Corals Transplanted onto Substrates of Short Durability" Restoration Ecology, vol. 18, no. 4, pp. 399–407.
  5. ↑ "Outplanting | Reef Resilience".
  6. ↑ Levy, G, Shaish, L, Haim, A & Rinkevich, B (2010) "Mid-water rope nursery--Testing design and performance of a novel reef restoration instrument" Ecological Engineering,36(4): 560–569.
  7. 1 2 3 4 Bellwood DR et al. (2004) Confronting the coral reef crisis Nature, Review, 429(6994): 827–833
  8. 1 2 3 4 5 Delbeek, JC (2001) Coral farming: past, present and future trends" Aquarium Sciences and Conservation, 3(1): 171–81.
  9. ↑ Stambler, Noga (1999). "Coral Reefs and Eutrophications" (PDF). No. IAEA-TECDOC. 1094.
  10. ↑ "The Corals in Your Aquarium Need Food as Well as a Lot of Light". The Spruce Pets. Retrieved 2019-12-22.
  11. ↑ "Factors that Influence Coral Coloration". Live Aquaria.
  12. ↑ "Tubastraea coccinea (Orange Cup Coral) - The Online Guide to the Animals of Trinidad and Tobago" (PDF). March 2016. Retrieved 2023-09-28.
  13. ↑ Shaish, L, Levy, G, Katzir, G and Rinkevich, B (2010) "Coral Reef Restoration (Bolinao, Philippines) in the Face of Frequent Natural Catastrophes" Restoration Ecology,18(3): 285–299.
  14. ↑ "What are mechanisms of zooxanthella expulsion from coral?". ScienceDaily. Retrieved 2019-12-22.
  15. ↑ Iwasaki, Shinya; Inoue, Mayuri; Suzuki, Atsushi; Sasaki, Osamu; Kano, Harumasa; Iguchi, Akira; Sakai, Kazuhiko; Kawahata, Hodaka (2016). "The role of symbiotic algae in the formation of the coral polyp skeleton: 3-D morphological study based on X-ray microcomputed tomography". Geochemistry, Geophysics, Geosystems. 17 (9): 3629–3637. Bibcode:2016GGG....17.3629I. doi:10.1002/2016GC006536. ISSN   1525-2027. S2CID   133565257.
  16. ↑ "Coral Bleaching - CoralWatch". coralwatch-old.org. Retrieved 2019-12-22.
  17. ↑ Coral statistics FAO, Rome. Retrieved 30 September 2011.
  18. ↑ Glaser, M, Baitoningsih, W, Ferse, SCA, Neil, M & Deswandi, R (2010) "Whose sustainability? Top-down participation and emergent rules in marine protected area management in Indonesia" Marine Policy,34: 1215–1225.
  19. ↑ Knittweis, L & Wolff, M (2010) "Live coral trade impacts on the mushroom coral Heliofungia actiniformis in Indonesia: Potential future management approaches" Biological Conservation,143: 2722–2729.
  20. 1 2 3 Gateno, D, Barki, Y & Rinkevich, B (2000) "Aquarium maintenance of reef octocorals raised from field collected larvae" Aquarium Sciences and Conservation, 2(4): 227–236.
  21. ↑ U.S. Coral Reef Task Force, Coral injury and mitigation working group (December 2016). "Handbook on Coral Reef Impacts" (PDF). United States Coral Reef Task Force.
  22. ↑ Baruch Rinkevich Israel Oceanographic and Limnological Research. Retrieved 30 September 2011.
  23. ↑ Oceans, Reefs & Aquariums (ORA). Retrieved 30 September 2011.
  24. ↑ Corbin JS (2001) Marine Ornamentals '99: Conference highlights and priority recommendations Aquarium Sciences and Conservation,3(1–3): 3–11.
  25. ↑ Hough, PD (1996) "The captive breeding of Great Barrier Reef Corals: a new wave of Aussie culture" American Zoo and Aquarium Association, Annual Conference, Hawaii, pp. 151–156.
  26. ↑ Linden, B & Rinkevich, B (2011) "Creating stocks of young colonies from brooding coral larvae, amenable to active reef restoration" Journal of Experimental Marine Biology and Ecology,398(1-2): 40–46.
  27. ↑ Bentley, N (1998) "An overview of the exploitation, trade and management of corals in Indonesia" Traffic Bulletin, Cambridge, 17: 67–78.
  28. ↑ Ellis S (1999) Farming soft corals for the marine aquarium trade Center for Tropical and Subtropical Aquaculture, Publication 140.
  29. ↑ Chamberland, Valérie F.; Petersen, Dirk; Guest, James R.; Petersen, Udo; Brittsan, Mike; Vermeij, Mark J. A. (December 22, 2017). "New Seeding Approach Reduces Costs and Time to Outplant Sexually Propagated Corals for Reef Restoration". Scientific Reports. 7 (1): 18076. Bibcode:2017NatSR...718076C. doi:10.1038/s41598-017-17555-z. PMC   5741773 . PMID   29273761.
  30. 1 2 Garthwaite, Josie (December 17, 2012). "Reimagining the Coral Market". New York Times. Retrieved 2018-08-27.
  31. ↑ Petersen, D, Wietheger, A & Laterveer, M (2008) "Influence of different food sources on the initial development of sexual recruits of reefbuilding corals in aquaculture" Aquaculture,277(3–4): 174–8.
  32. ↑ Coral aquacultural research Archived 2011-12-02 at the Wayback Machine Mote Marine Laboratory. Retrieved 9 September 2011.
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