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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Coral reef | 11/13 | https://en.wikipedia.org/wiki/Coral_reef | reference | science, encyclopedia | 2026-05-05T07:34:41.179437+00:00 | kb-cron |
Coral gardens take advantage of a coral's natural ability to fragment and continue to grow if the fragments can anchor themselves onto new substrates. This method was first tested by Baruch Rinkevich in 1995 which found success at the time. By today's standards, coral farming has evolved into various forms, but it still aims to cultivate corals. Consequently, coral farming quickly replaced previously used transplantation methods, which involved physically moving sections or entire coral colonies to a new area. Transplantation has seen success in the past, and decades of experiments have led to a high success and survival rate. However, this method still requires removing corals from existing reefs. Given the current state of reefs, this method should generally be avoided if possible. Saving healthy corals from eroding substrates or reefs doomed to collapse could be a significant advantage of using transplantation. Coral gardens generally take on safe forms, no matter where you go. It begins with the establishment of a nursery where operators can observe and care for coral fragments. It goes without saying that nurseries should be established in areas that are going to maximize growth and minimize mortality. Floating offshore coral trees or even aquariums are possible locations where corals can grow. After a location has been determined, collection and cultivation can occur. The primary benefit of using coral farms is that they reduce polyp and juvenile mortality. By removing predators and recruitment obstacles, corals can mature without much hindrance. However, nurseries cannot stop climate stressors. Warming temperatures or hurricanes can still disrupt or even kill nursery corals. Technology is becoming more popular in the coral farming process. Teams from the Reef Restoration and Adaptation Program (RRAP) have trialled coral-counting technology using a prototype robotic camera. The camera uses computer vision and machine learning algorithms to detect and count individual coral babies, and to track their growth and health in real time. This technology, led by QUT, is intended for use during annual coral spawning events and will provide researchers with control not currently possible when mass-producing corals.
=== Creating substrates ===
Efforts to expand the size and number of coral reefs generally involve supplying substrate to allow more corals to find a home. Substrate materials include discarded vehicle tires, scuttled ships, subway cars, and formed concrete, such as reef balls. Reefs grow unaided on marine structures such as oil rigs. In large restoration projects, propagated hermatypic coral on substrate can be secured with metal pins, superglue, or milliput. Needle and thread can also attach A-hermatype coral to the substrate. Biorock is a substrate produced by a patented process that runs low-voltage electrical currents through seawater to cause dissolved minerals to precipitate onto steel structures. The resultant white carbonate (aragonite) is the same mineral that makes up natural coral reefs. Corals rapidly colonize and grow on these coated structures. The electrical currents also accelerate the formation and growth of both chemical limestone rock and the skeletons of corals and other shell-bearing organisms, such as oysters. The vicinity of the anode and cathode provides a high pH environment, which inhibits the growth of competing filamentous and fleshy algae. The increased growth rates depend entirely on accretion activity. Under the influence of an electric field, corals exhibit increased growth rates, sizes, and densities. Simply having many structures on the ocean floor is not enough to form coral reefs. Restoration projects must consider the complexity of the substrates they are creating for future reefs. Researchers conducted an experiment near Ticao Island in the Philippines in 2013 where several substrates in varying complexities were laid in the nearby degraded reefs. Large complexity consisted of plots with both human-made substrates (smooth and rough rocks) and a surrounding fence; medium consisted of only the human-made substrates; and small had neither the fence nor substrates. After one month, researchers found a positive correlation between structural complexity and larval recruitment rates. The medium complexity performed the best, with larvae favoring rough rocks over smooth rocks. After one year of their study, researchers visited the sites and found that many supported local fisheries. They concluded that reef restoration could be done cost-effectively and would yield long-term benefits if protected and maintained.
=== Relocation ===
One case study with coral reef restoration was conducted on the island of Oahu in Hawaii. The University of Hawaii operates a Coral Reef Assessment and Monitoring Program to help relocate and restore coral reefs in Hawaii. A boat channel from the island of Oahu to the Hawaii Institute of Marine Biology on Coconut Island was overcrowded with coral reefs. Many coral reef patches in the channel had been damaged by past dredging. Dredging covers corals with sand. Coral larvae cannot settle on sand; they can only build on existing reefs or compatible hard surfaces, such as rock or concrete. Because of this, the university decided to relocate some of the coral. They transplanted them with the help of United States Army divers to a site relatively close to the channel. They observed little to no damage to any of the colonies during transport, and no coral reef mortality at the transplant site. While attaching the coral to the transplant site, they found that coral placed on hard rock grew well, including on the wires connecting it to the site. No environmental effects were seen from the transplantation process, recreational activities were not decreased, and no scenic areas were affected. As an alternative to transplanting coral themselves, juvenile fish can also be encouraged to relocate to existing coral reefs by auditory simulation. In damaged sections of the Great Barrier Reef, loudspeakers playing recordings of healthy reef environments were found to attract fish twice as often as equivalent patches where no sound was played, and also increased species biodiversity by 50%.