Coral bleaching is the loss of intracellular endosymbionts (Symbiodinium, also known as zooxanthellae) from coral either through expulsion or loss of algal pigmentation. The corals that form the structure of the great reef ecosystems of tropical seas depend upon a symbiotic relationship with algae-like unicellular flagellate protozoa that are photosynthetic and live within their tissues. Zooxanthellae give coral its coloration, with the specific color depending on the particular clade. Some scientists consider bleaching a poorly-understood type of "stress" related to high irradiance; environmental factors like sediments, harmful chemicals and freshwater; and high or low water temperatures. This "stress" causes corals to expel their zooxanthellae, which leads to a lighter or completely white appearance, hence the term "bleached". Bleaching has been attributed to a defense mechanism in corals; this is called the "adaptive bleaching hypothesis", from a 1993 paper by Robert Buddemeier and Daphne Fautin. Bleached corals continue to live, but growth is limited until the protozoa return.
- 1 Causes
- 2 Triggers
- 3 Effects
- 4 Mass bleaching events
- 5 Impact
- 6 Coral adaptation
- 7 Recovery and macroalgal regime shifts
- 8 Coral damage by sunscreens
- 9 See also
- 10 Notes
- 11 References
- 12 External links
Bleaching occurs when the conditions necessary to sustain the coral's zooxanthellae cannot be maintained. Any environmental trigger that affects the coral's ability to supply the zooxanthellae with nutrients for photosynthesis (carbon dioxide, ammonium) will lead to expulsion. This process is a "downward spiral", whereby the coral's failure to prevent the division of zooxanthellae leads to ever-greater amounts of the photosynthesis-derived carbon to be diverted into the algae rather than the coral. This makes the energy balance required for the coral to continue sustaining its algae more fragile, and hence the coral loses the ability to maintain its parasitic control on its zooxanthellae.
Physiologically the lipid composition of the symbiont thylakoid membrane affects their structural integrity when there is a change in temperature, which combined with increased nitric acid results in damage to photosystem II. As a result of accumulated oxidative stress and the damage to the thylakoid of chloroplasts there is an increase in degradation of the symbiosis and the symbionts will eventually abandon their host. Not only does the change in temperature in the water increase the chances of bleaching, but there are other factors that play a role. Other factors include an increase in solar radiation (UV and visible light), regional weather conditions, and for intertidal corals, exposure to cold winds.
Coral bleaching is theorized to be a generalized stress response of corals that may be caused by a number of biotic and abiotic factors, including:
- increased (most commonly due to global warming), or reduced water temperatures
- oxygen starvation caused by an increase in zooplankton levels as a result of overfishing
- increased solar irradiance (photosynthetically active radiation and ultraviolet light)
- increased sedimentation (due to silt runoff)
- bacterial infections
- changes in salinity
- low tide and exposure
- cyanide fishing
- elevated sea levels due to global warming (Watson)
- mineral dust from African dust storms caused by drought
- four common sunscreen ingredients, that are nonbiodegradable, and can wash off of skin
While most of these triggers may result in localized bleaching events (tens to hundreds of kilometers), mass coral bleaching events occur at a regional or global scale and are triggered by periods of elevated thermal stress resulting from increased sea surface temperatures. The coral reefs that are more subject to continued bleaching threats are the ones located in warm and shallow water with low water flow. Physical factors that can prevent or reduce the severity of bleaching are available for the reefs located under conditions that include low light, cloud cover, high water flow and higher nutrient availability.
The color of a coral depends largely on the species of symbiont. A reduction in concentration of zooxanthellae causes paling and an increase results in deepening of color. Stony corals have calcium carbonate skeletons and most have transparent tissues, so expulsion of the zooxanthellae causes them to lose their color and become white. The coral protects the algae from the surrounding environment, in return the algae provides the coral with oxygen and gets rid of waste. Although the coral polyps feed on zooplankton and other food particles, the majority of reef-forming corals rely for a large proportion of their nutritional requirements on their zooxanthellae. This means that without them they are liable to starve. Coral growth and reproduction are reduced and the coral becomes increasingly susceptible to disease. If stress factors reduce and the zooxanthellae return, the coral can recover, but prolonged bleaching causes death of the coral.
Ejection increases the polyp's chance of surviving short-term stress[why?][clarification needed]. It can regain symbionts, possibly of a different species, at a later time. If the stressful conditions persist, the polyp eventually dies.
Mass bleaching events
Most evidence indicates that elevated temperature is the cause of mass bleaching events. Sixty major episodes of coral bleaching have occurred between 1979 and 1990, with the associated coral mortality affecting reefs in every part of the world. In 2016, the longest coral bleaching event was recorded.
Correlative field studies have pointed to warmer-than normal conditions as being responsible for triggering mass bleaching events. These studies show a tight association between warmer-than-normal conditions (at least 1 °C higher than the summer maximum) and the incidence of coral bleaching.
Factors that influence the outcome of a bleaching event include stress-resistance which reduces bleaching, tolerance to the absence of zooxanthellae, and how quickly new coral grows to replace the dead. Due to the patchy nature of bleaching, local climatic conditions such as shade or a stream of cooler water can reduce bleaching incidence. Coral and zooxanthellae health and genetics also influence bleaching.
Large coral colonies such as Porites are able to withstand extreme temperature shocks, while fragile branching corals such Acropora are far more susceptible to stress following a temperature change. Corals consistently exposed to low stress levels may be more resistant to bleaching.
Monitoring reef sea surface temperature
The US National Oceanic and Atmospheric Administration (NOAA) monitors for bleaching "hot spots", areas where sea surface temperature rises 1 °C or more above the long-term monthly average. This system detected the worldwide 1998 bleaching event, that corresponded to the 1997–98 El Niño event. NOAA also uses a nighttime-only satellite; these observations are taken at night to avoid the increase in temperature due to daily warming caused by solar heating at the sea surface during the day. This is also a precaution to avoid glare from the sun.
Changes in ocean chemistry
Increasing ocean acidification due to rises in carbon dioxide levels exacerbates the bleaching effects of thermal stress. Acidification affects the corals' ability to create calcareous skeletons, essential to their survival. A recent study from the Atkinson Center for a Sustainable Future found that with the combination of acidification and temperature rises, the levels of CO2 could become too high for coral to survive in as little as 50 years.
Infectious bacteria of the species Vibrio shiloi are the bleaching agent of Oculina patagonica in the Mediterranean Sea, causing this effect by attacking the zooxanthellae. V. shiloi is infectious only during warm periods. Elevated temperature increases the virulence of V. shiloi, which then become able to adhere to a beta-galactoside-containing receptor in the surface mucus of the host coral. V. shiloi then penetrates the coral's epidermis, multiplies, and produces both heat-stable and heat-sensitive toxins, which affect zooxanthellae by inhibiting photosynthesis and causing lysis.
During the summer of 2003, coral reefs in the Mediterranean Sea appeared to gain resistance to the pathogen, and further infection was not observed. The main hypothesis for the emerged resistance is the presence of symbiotic communities of protective bacteria living in the corals. The bacterial species capable of lysing V. shiloi had not been identified as of 2011.
In the 2012–2040 period, coral reefs are expected to experience more frequent bleaching events. The Intergovernmental Panel on Climate Change (IPCC) sees this as the greatest threat to the world's reef systems.
Great Barrier Reef
The Great Barrier Reef along the coast of Australia experienced bleaching events in 1980, 1982, 1992, 1994, 1998, 2002, 2006, and 2016. Some locations suffered severe damage, with up to 90% mortality. The most widespread and intense events occurred in the summers of 1998 and 2002, with 42% and 54% respectively of reefs bleached to some extent, and 18% strongly bleached. However coral losses on the reef between 1995 and 2009 were largely offset by growth of new corals. An overall analysis of coral loss found that coral populations on the Great Barrier Reef had declined by 50.7% from 1985 to 2012, but with only about 10% of that decline attributable to bleaching, and the remaining 90% caused about equally by tropical cyclones and by predation by crown-of-thorns starfishes.
The IPCC's moderate warming scenarios (B1 to A1T, 2 °C by 2100, IPCC, 2007, Table SPM.3, p. 13) forecast that corals on the Great Barrier Reef are very likely to regularly experience summer temperatures high enough to induce bleaching.
Other coral reef provinces have been permanently damaged by warm sea temperatures, most severely in the Indian Ocean. Up to 90% of coral cover has been lost in the Maldives, Sri Lanka, Kenya and Tanzania and in the Seychelles.
Evidence of thermal tolerance in Hawaiian corals and of oceanic warming from research in the 1970s led researchers in 1990 to predict mass occurrences of coral bleaching throughout Hawaii. Major bleaching occurred in 1996 and in 2002. Biologists from the University of Queensland observed the first mass bleaching event for Hawaiian coral reefs in 2014, and attributed it to The Blob.
Economic and political impact
According to Brian Skoloff of The Christian Science Monitor, "If the reefs vanished, experts say, hunger, poverty and political instability could ensue." Since countless sea life depends on the reefs for shelter and protection from predators, the extinction of the reefs would ultimately create a domino effect that would trickle down to the many human societies that depend on those fish for food and livelihood. There has been a 44% decline over the last 20 years in the Florida Keys, and up to 80% in the Caribbean alone.
In 2010, researchers at Penn State discovered corals that were thriving while utilizing an unusual species of symbiotic algae in the warm waters of the Andaman Sea located in the Indian Ocean. Normal zooxanthellae cannot withstand temperatures as high as in that location, so this finding was unexpected. This gives researchers hope that with rising temperatures due to global warming, coral reefs will develop tolerance for different species of symbiotic algae that are resistant to high temperature, and can live within the reefs.
Recovery and macroalgal regime shifts
After corals experience a bleaching event to increased temperature stress some reefs are able to return to their original, pre-bleaching state. Reefs either recover from bleaching, where they are recolonized by zooxanthellae, or they experience a regime shift, where previously flourishing coral reefs are taken over by thick layers of macroalgae. Discovering what causes reefs to be resilient or recover from bleaching events is of primary importance because it helps inform conservation efforts and protect coral more effectively.
Corals have shown to be resilient to short-term disturbances. Recovery has been shown in after storm disturbance and crown of thorns starfish invasions. Fish species tend to fare better following reef disturbance than coral species as corals show limited recovery and reef fish assemblages have shown little change as a result of short term disturbances. In contrast, fish assemblages in reefs that experience bleaching exhibit potentially damaging changes. One study by Bellwood et al. notes that while species richness, diversity, and abundance did not change, fish assemblages contained more generalist species and less coral dependent species. Studies note that better methods are needed to measure the effects of disturbance on the resilience of corals.
Until recently, the factors mediating the recovery of coral reefs from bleaching were not well studied. Research by Graham et al. (2005) studied 21 reefs around Seychelles in the Indo-Pacific in order to document the long-term effects of coral bleaching. After the loss of more than 90% of corals due to bleaching in 1998 around 50% of the reefs recovered and roughly 40% of the reefs experienced regime shifts to macroalgae dominated compositions. After an assessment of factors influencing the probability of recovery, the study identified five major factors: density of juvenile corals, initial structural complexity, water depth, biomass of herbivorous fishes, and nutrient conditions on the reef. Overall, resilience was seen most in coral reef systems that were structurally complex and in deeper water.
The ecological roles and functional groups of species also play a role in the recovery of regime shifting potential in reef systems. Coral reefs are affected by bioeroding, scraping, and grazing fish species. Bioeroding species remove dead corals, scraping species remove algae and sediment to further future growth, grazing species remove algae. The presence of each type of species can influence the ability for normal levels of coral recruitment which is an important part of coral recovery. Lowered numbers of grazing species after coral bleaching in the Caribbean has been liked to sea urchin dominated systems which do not undergo regime shifts to fleshy macroalgae dominated conditions.
There is always the possibility of unobservable changes, or cryptic losses or resilience, in a coral community's ability to perform ecological processes. These cryptic losses can result in unforeseen regime changes or ecological flips. More detailed methods for determining the health of coral reefs that take into account long term changes to the coral ecosystems and better informed conservation policies are necessary to protect coral reefs in the years to come.
Coral damage by sunscreens
Marine and coastal tourism is the fastest growing sector of the global tourism industry. Between 1992 and 2004, the amount of tourists grew from 463 to 763 million. In 2020 the expected number of tourists is estimated to increase to 1.56 billion. As a result, more and more sunscreen is being released into marine environments and contributing to coral bleaching. The amount of sunscreen estimated to be released into coral reefs each year is between 6,000 and 14,000 tons. 10% of the world's coral reefs are said to be threatened by coral bleaching induced by sunscreen alone.
The main components in sunscreens are known as UV filters. UV filters are chemicals that have been developed to absorb the sun's UV radiation to decrease the negative effect the sun has on the skin. However, it has been seen that some UV filters break down in aquatic environments and produce by-products that contribute to coral bleaching. Many UV filters break down by photo-degradation and produce reactive oxygen species (ROS) as their by-products. ROS are known to cause stress to coral reef systems that results in coral bleaching.
This occurs when nano TiO2 particles absorb UV light (hv) from the sun. Conduction band electrons (e-) and valence band holes (h+) form in the compounds' structure. The electrons then reduce oxygen in seawater to a superoxide (O2-) ROS and the h+ will react with water to produce a hydroxyl radical (OH•).
- TiO2 + hv → h+ + e-
- h+ + H2O → OH•
- e- + O2 → O2-
The superoxides (O2-) can further protonate to form hydrogen peroxide (H2O2).
- O2- + H+ → HO2•
- HO2• + H+ → H2O2
- OH• + OH• → H2O2
Superoxides, hydroxyl radicals, and hydrogen peroxide are all types of ROS that contribute to coral bleaching. They do this by disrupting the coral zooxanthallae's photosynthesis, which then causes stress to the coral system. Nano-Titanium dioxide isn't the only UV filter that contributes to coral bleaching. However, the chemical break down of other harmful UV filters needs to be studied further. Some steps have already been made to try to reverse coral bleaching. In many marine-managed areas in Mexico, certain sunscreens are banned that are known to contain harmful UV filters.
Nano and non-nano study
- Dove SG, Hoegh-Guldberg O (2006). "Coral bleaching can be caused by stress. The cell physiology of coral bleaching". In Ove Hoegh-Guldberg, Jonathan T. Phinney, William Skirving, Joanie Kleypas. Coral Reefs and Climate Change: Science and Management. [Washington]: American Geophysical Union. pp. 1–18. ISBN 0-87590-359-2.
- Hoegh-Guldberg, Ove (1999). "Climate change, coral bleaching and the future of the world's coral reefs". Marine and Freshwater Research. 50 (8): 839–66. doi:10.1071/MF99078.
- Bowen, James (2015). The coral reef era: from discovery to decline: a history of scientific investigation from 1600 to the Anthropocene epoch. Springer International Publishing. doi:10.1007/978-3-319-07479-5. ISBN 978-3-319-07478-8.
- Wooldridge, S. A. (2010). "Is the coral-algae symbiosis really 'mutually beneficial' for the partners?". BioEssays. 32 (7): 615–625. doi:10.1002/bies.200900182. PMID 20517874.
- Baker, Andrew. Glynn, Peter. Riegl, Bernhard. 2008 "Climate change and coral reef bleaching: An ecological assessment of long-term impacts, recovery trends and future outlook". Estuarine, Coastal and Shelf Science. 80: 435–471
- "Reef 'at risk in climate change'" (Press release). The University of Queensland. April 6, 2007. Retrieved August 2, 2016.
- Anthony, K. 2007; Berkelmans
- Saxby, T.; Dennison, W. C.; Hoegh-Guldberg, O. (2003). "Photosynthetic responses of the coral Montipora digitata to cold temperature stress". Marine Ecology Progress Series. 248: 85. doi:10.3354/meps248085.
- Marimuthu, N.; Wilson, J. Jerald; Vinithkumar, N. V.; Kirubagaran, R. (2012). "Coral reef recovery status in south Andaman Islands after the bleaching event 2010". Journal of Ocean University of China. 12 (1): 91–96. Bibcode:2013JOUC...12...91M. doi:10.1007/s11802-013-2014-2.
- "Mass Coral Bleaching". fisherycrisis.com.
- Fitts 2001[full citation needed]
- Rogers, CS (1990). "Responses of coral reefs and reef organisms to sedimentation". Marine Ecology Progress Series. 62: 185–202. doi:10.3354/meps062185.
- Kushmaro, A; Rosenberg, E; Fine, M; Loya, Y (1997). "Bleaching of the coral Oculina patagonica by Vibrio AK-1". Marine Ecology Progress Series. 147: 159–65. doi:10.3354/meps147159.
- Hoegh-Guldberg, Ove; Smith, G.Jason (1989). "The effect of sudden changes in temperature, light and salinity on the population density and export of zooxanthellae from the reef corals Stylophora pistillata Esper and Seriatopora hystrix Dana". Journal of Experimental Marine Biology and Ecology. 129 (3): 279–303. doi:10.1016/0022-0981(89)90109-3.
- Jones, RJ; Muller, J; Haynes, D; Schreiber, U (2003). "Effects of herbicides diuron and atrazine on corals of the Great Barrier Reef, Australia". Marine Ecology Progress Series. 251: 153–167. doi:10.3354/meps251153.
- Anthony, K. R. N.; Kerswell, A. P. (2007). "Coral mortality following extreme low tides and high solar radiation". Marine Biology. 151 (5): 1623–31. doi:10.1007/s00227-006-0573-0.
- Jones, Ross J.; Hoegh-Guldberg, Ove (1999). "Effects of cyanide on coral photosynthesis:implications for identifying the cause of coral bleaching and for assessing the environmental effects of cyanide fishing". Marine Ecology Progress Series. 177: 83–91. doi:10.3354/meps177083.
- U. S. Geological Survey. Coral Mortality and African Dust. Retrieved on 2007-06-10.
- "Protect Yourself, Protect The Reef! The impacts of sunscreens on our coral reefs" (PDF). U.S. National Park Service. Retrieved 1 July 2013.
- Than, Ker. "Swimmers' Sunscreen Killing Off Coral". National Geographic News. National Geographic News. Retrieved 29 January 2008.
- "Coral Reef Safe Sunscreen". badgerbalm.com.
- Danovaro, Roberto; Bongiorni, Lucia; Corinaldesi, Cinzia; Giovannelli, Donato; Damiani, Elisabetta; Astolfi, Paola; Greci, Lucedio; Pusceddu, Antonio (2008). "Sunscreens Cause Coral Bleaching by Promoting Viral Infections". Environmental Health Perspectives. 116 (4): 441–447. doi:10.1289/ehp.10966. PMC . PMID 18414624.
- Downs, C. A.; Kramarsky-Winter, Esti; Fauth, John E.; Segal, Roee; Bronstein, Omri; Jeger, Rina; Lichtenfeld, Yona; Woodley, Cheryl M.; Pennington, Paul; Kushmaro, Ariel; Loya, Yossi (2014). "Toxicological effects of the sunscreen UV filter, benzophenone-2, on planulae and in vitro cells of the coral, Stylophora pistillata". Ecotoxicology. 23 (2): 175–91. doi:10.1007/s10646-013-1161-y. PMID 24352829.
- Hoegh-Guldberg, O.; Mumby, P. J.; Hooten, A. J.; Steneck, R. S.; Greenfield, P.; Gomez, E.; Harvell, C. D.; Sale, P. F.; Edwards, A. J.; Caldeira, K.; Knowlton, N.; Eakin, C. M.; Iglesias-Prieto, R.; Muthiga, N.; Bradbury, R. H.; Dubi, A.; Hatziolos, M. E. (2007). "Coral Reefs Under Rapid Climate Change and Ocean Acidification". Science. 318 (5857): 1737–42. Bibcode:2007Sci...318.1737H. doi:10.1126/science.1152509. PMID 18079392.
- "Symbiotic algae". NOAA coral reef conservation program. NOAA. Retrieved 2015-01-29.
- Toller, W. W.; Rowan, R.; Knowlton, N. (2001). "Repopulation of Zooxanthellae in the Caribbean Corals Montastraea annularis and M. faveolata following Experimental and Disease-Associated Bleaching". Biological Bulletin. 201 (3): 360–73. doi:10.2307/1543614. JSTOR 1543614. PMID 11751248.
- Chumkiew, Sirilak; Jaroensutasinee, Mullica; Jaroensutasinee, Krisanadej (2011). "Impact of Global Warming on Coral Reefs". Walailak Journal of Science and Technology. 8 (2): 111–29.
- Huppert, Amit; Lewis Stone (September 1998). "Chaos in the Pacific's Coral Reef Bleaching Cycle". The American Naturalist. 152 (3): 447–459. doi:10.1086/286181. PMID 18811451.
- McDermott, Amy (June 22, 2016). "Coral bleaching event is longest on record". Science News. Retrieved July 25, 2016.
- Baker, Andrew C.; Glynn, Peter W.; Riegl, Bernhard (2008). "Climate change and coral reef bleaching: An ecological assessment of long-term impacts, recovery trends and future outlook". Estuarine, Coastal and Shelf Science. 80 (4): 435–71. Bibcode:2008ECSS...80..435B. doi:10.1016/j.ecss.2008.09.003.
- Marshall, Paul; Schuttenberg, Heidi (2006). A Reef Manager's Guide to Coral Bleaching (PDF). Townsville, Australia: Great Barrier Reef Marine Park Authority. pp. 78–79. ISBN 1-876945-40-0.
- Baird and Marshall 2002
- Gabriel D. Grinmsditch and Rodney V. Salm, Coral Reef Resilience and Resistance to Bleaching, "IUCN: The World Conservation Union", 2006[page needed]
- Iguchi, Akira; Ozaki, Saori; Nakamura, Takashi; Inoue, Mayuri; Tanaka, Yasuaki; Suzuki, Atsushi; Kawahata, Hodaka; Sakai, Kazuhiko (2012). "Effects of acidicied seawater on coral calcification and symbiotic algae on the massive coral Porites australiensis". Marine Environmental Research. 73: 32–36. doi:10.1016/j.marenvres.2011.10.008. PMID 22115919.
- "NOAA Hotspots".
- "Pro-opinion of NOAA Hotspots".
- NOAA Coral Reef Watch. "Methodology, Product Description, and Data Availability of Coral Reef Watch Operational and Experimental Satellite Coral Bleaching Monitoring Products". NOAA. Retrieved 27 February 2014.
- Lang, Susan (13 December 2007). "Major international study warns global warming is destroying coral reefs and calls for 'drastic actions'". Cornell Chronicle. Retrieved 8 August 2011.
- Kushmaro, A.; Loya, Y.; Fine, M.; Rosenberg, E. (1996). "Bacterial infection and coral bleaching". Nature. 380 (6573): 396. Bibcode:1996Natur.380..396K. doi:10.1038/380396a0.
- Rosenberg E, Ben Haim Y; Ben-Haim (2002). "Microbial Diseases of Corals and Global Warming". Environ. Microbiol. 4 (6): 318–26. doi:10.1046/j.1462-2920.2002.00302.x. PMID 12071977.
- Sheridan, Christopher; Kramarsky-Winter, Esti; Sweet, Michael; Kushmaro, Ariel; Leal, Miguel Costa (2013). "Diseases in coral aquaculture: causes, implications and preventions". Aquaculture. 396: 124–135. doi:10.1016/j.aquaculture.2013.02.037.
- Sutherland KP, Porter J, Torres C; Porter; Torres (2004). "Disease and Immunity in Caribbean and Indo-pacific Zooxanthellate Corals". Marine Ecology Progress Series. 266: 273–302. doi:10.3354/meps266273.
- Reshef, Leah; Koren, Omry; Loya, Yossi; Zilber-Rosenberg, Ilana; Rosenberg, Eugene (2006). "The Coral Probiotic Hypothesis". Environmental Microbiology. 8 (12): 2068–73. doi:10.1111/j.1462-2920.2006.01148.x. PMID 17107548.
- IPCC (2007). "Summary for policymakers" (PDF). In Parry ML, Canziani OF, Palutikof JP, van der Linden PJ, Hanson CE. Climate Change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge, UK: Cambridge University Press. pp. 7–22. ISBN 0-521-70597-5.
- Fischlin A, Midgley GF, Price JT, Leemans R, Gopal B, Turley C, Rounsevell MD, Dube OP, Tarazona J, Velichko AA (2007). "Ch 4. Ecosystems, their properties, goods and services" (PDF). In Parry ML, Canziani OF, Palutikof JP, van der Linden PJ, Hanson CE. Climate Change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge, UK: Cambridge University Press. pp. 211–72. ISBN 0-521-70597-5.
- Nicholls RJ, Wong PP, Burkett V, Codignotto J, Hay J, McLean R, Ragoonaden S, Woodroffe CD (2007). "Ch 6. Coastal systems and low-lying areas" (PDF). In Parry ML, Canziani OF, Palutikof JP, van der Linden PJ, Hanson CE. Climate Change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge, UK: Cambridge University Press. pp. 315–57. ISBN 0-521-70597-5.
- Hennessy K, Fitzharris B, Bates BC, Harvey N, Howden M, Hughes L, Salinger J, Warrick R (2007). "Ch 11. Australia and New Zealand" (PDF). In Parry ML, Canziani OF, Palutikof JP, van der Linden PJ, Hanson CE. Climate Change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge, UK: Cambridge University Press. pp. 507–40. ISBN 0-521-70597-5.
- Plumer, Brad. "The unprecedented coral bleaching disaster at the Great Barrier Reef, explained". Vox Energy & Environment. Retrieved 31 March 2016.
- Johnson, Johanna E; Marshall, Paul A (2007). Climate change and the Great Barrier Reef: a vulnerability assessment. Townsville, Qld.: Great Barrier Reef Marine Park Authority. ISBN 978-1-876945-61-9. Archived from the original on 25 January 2014.
- Done T, Whetton P, Jones R, Berkelmans R, Lough J, Skirving W, Wooldridge S (2003). Global Climate Change and Coral Bleaching on the Great Barrier Reef (PDF). Queensland Government Department of Natural Resources and Mines. ISBN 0-642-32220-1. Archived from the original (PDF) on 27 September 2011.
- Berkelmans, Ray; De'ath, Glenn; Kininmonth, Stuart; Skirving, William J. (2004). "A comparison of the 1998 and 2002 coral bleaching events on the Great Barrier Reef: spatial correlation, patterns, and predictions". Coral Reefs. 23 (1): 74–83. doi:10.1007/s00338-003-0353-y.
- Gratwicke, Brian; Osborne, Kate; Dolman, Andrew M.; Burgess, Scott C.; Johns, Kerryn A. (2011). "Disturbance and the Dynamics of Coral Cover on the Great Barrier Reef (1995–2009)". PLoS ONE. 6 (3): e17516. Bibcode:2011PLoSO...617516O. doi:10.1371/journal.pone.0017516. PMC . PMID 21423742.
- De'ath, G.; Fabricius, K. E.; Sweatman, H.; Puotinen, M. (2012). "The 27-year decline of coral cover on the Great Barrier Reef and its causes". Proceedings of the National Academy of Sciences. 109 (44): 17995–9. Bibcode:2012PNAS..10917995D. doi:10.1073/pnas.1208909109. PMC . PMID 23027961.
- IPCC (2007). "Summary for policymakers" (PDF). In Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL. Climate change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK: Cambridge University Press. pp. 1–18.
- N. Middleton, Managing the Great Barrier Reef (Geography Review, January 2004)
- Alevizon, William. "Red Sea Coral Reefs". Coral Reef Facts. Retrieved 27 February 2014.
- Hokiel, Paul J. "Climate Change and Hawaii's Coral Reefs" (PDF). Hawaii Coral Reef Monitoring and Assessment Program. US Fish and Wildlife Service.
- "Rapidly warming ocean a threat to Hawaiian coral reefs". The University of Queensland. 2015.
- Brian Skoloff, , "The Christian Science Monitor", 26 March 2010
- PBS Newshour, "Endangered Coral Reefs Die as Ocean Temperatures Rise and Water Turns Acidic", "PBS Newshour", 5 December 2012
- LaJeunesse, Todd. "Diversity of Corals, Algae in Warm Indian Ocean Suggests Resilience to Future Global Warming". Penn State Science. Retrieved 27 February 2014.
- LaJeunesse, Todd; Smith, Robin (2010). "Host–symbiont recombination versus natural selection in the response of coral–dinoflagellate symbioses to environmental disturbance". Proceedings: Biological Sciences. 277 (1696): 2925–2934. doi:10.1098/rspb.2010.0385. PMC . PMID 20444713.
- Ateweberhan, Mebrahtu; Feary, David A.; Keshavmurthy, Shashank; Chen, Allen; Schleyer, Michael H.; Sheppard, Charles R.C. (2013). "Climate change impacts on coral reefs: Synergies with local effects, possibilities for acclimation, and management implications". Marine Pollution Bulletin. 74 (2): 526–39. doi:10.1016/j.marpolbul.2013.06.011. PMID 23816307.
- Graham, Nicholas A. J.; Jennings, Simon; MacNeil, M. Aaron; Mouillot, David; Wilson, Shaun K. (2015). "Predicting climate-driven regime shifts versus rebound potential in coral reefs". Nature. 518 (7537): 94–7. Bibcode:2015Natur.518...94G. doi:10.1038/nature14140. PMID 25607371.
- Folke, Carl; Carpenter, Steve; Walker, Brian; Scheffer, Marten; Elmqvist, Thomas; Gunderson, Lance; Holling, C.S. (2004). "Regime Shifts, Resilience, and Biodiversity in Ecosystem Management". Annual Review of Ecology, Evolution, and Systematics. 35 (1): 557–81. doi:10.1146/annurev.ecolsys.35.021103.105711. JSTOR 30034127.
- Hughes, Terry P.; Graham, Nicholas A.J.; Jackson, Jeremy B.C.; Mumby, Peter J.; Steneck, Robert S. (2010). "Rising to the challenge of sustaining coral reef resilience". Trends in Ecology & Evolution. 25 (11): 633–42. doi:10.1016/j.tree.2010.07.011. PMID 20800316.
- Bellwood, David R.; Hoey, Andrew S.; Ackerman, John L.; Depczynski, Martial (2006). "Coral bleaching, reef fish community phase shifts and the resilience of coral reefs". Global Change Biology. 12 (9): 1587–94. doi:10.1111/j.1365-2486.2006.01204.x.
- Bellwood, D. R.; Hughes, T. P.; Folke, C.; Nyström, M. (2004). "Confronting the coral reef crisis". Nature. 429 (6994): 827–33. Bibcode:2004Natur.429..827B. doi:10.1038/nature02691. PMID 15215854.
- Sánchez-Quiles, David; Tovar-Sánchez, Antonio (2015). "Are sunscreens a new environmental risk associated with coastal tourism?". Environment International. 83: 158–70. doi:10.1016/j.envint.2015.06.007. PMID 26142925.
- Giokas, Dimosthenis L.; Salvador, Amparo; Chisvert, Alberto (2007). "UV filters: From sunscreens to human body and the environment". TrAC Trends in Analytical Chemistry. 26 (5): 360–74. doi:10.1016/j.trac.2007.02.012.
- Lewicka, Zuzanna A.; Yu, William W.; Oliva, Brittany L.; Contreras, Elizabeth Quevedo; Colvin, Vicki L. (2013). "Photochemical behavior of nanoscale TiO2 and ZnO sunscreen ingredients". Journal of Photochemistry and Photobiology A: Chemistry. 263: 24–33. doi:10.1016/j.jphotochem.2013.04.019.
- Baird, Andrew H.; Bhagooli, Ranjeet; Ralph, Peter J.; Takahashi, Shunichi (2009). "Coral bleaching: the role of the host". Trends in Ecology & Evolution. 24 (1): 16–20. doi:10.1016/j.tree.2008.09.005.
- Brezová, Vlasta; Gabčová, Soňa; Dvoranová, Dana; Staško, Andrej (2005). "Reactive oxygen species produced upon photoexcitation of sunscreens containing titanium dioxide (an EPR study)". Journal of Photochemistry and Photobiology B: Biology. 79 (2): 121–34. doi:10.1016/j.jphotobiol.2004.12.006.
- Fujishima, Akira; Rao, Tata N.; Tryk, Donald A. (2000). "Titanium dioxide photocatalysis". Journal of Photochemistry and Photobiology C: Photochemistry Reviews. 1 (1): 1–21. doi:10.1016/S1389-5567(00)00002-2.
- Buchalska, Marta; Kras, Gabriela; Oszajca, Marcin; Łasocha, Wiesław; Macyk, Wojciech (2010). "Singlet oxygen generation in the presence of titanium dioxide materials used as sunscreens in suntan lotions". Journal of Photochemistry and Photobiology A: Chemistry. 213 (2–3): 158–63. doi:10.1016/j.jphotochem.2010.05.019.
- Tashiro, Yutaka; Kameda, Yutaka (2013). "Concentration of organic sun-blocking agents in seawater of beaches and coral reefs of Okinawa Island, Japan". Marine Pollution Bulletin. 77 (1–2): 333–40. doi:10.1016/j.marpolbul.2013.09.013. PMID 24139648.
- Downs, C. A.; Kramarsky-Winter, Esti; Segal, Roee; Fauth, John; Knutson, Sean; Bronstein, Omri; Ciner, Frederic R.; Jeger, Rina; Lichtenfeld, Yona; Woodley, Cheryl M.; Pennington, Paul; Cadenas, Kelli; Kushmaro, Ariel; Loya, Yossi (2016). "Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone (Benzophenone-3), on Coral Planulae and Cultured Primary Cells and Its Environmental Contamination in Hawaii and the U.S. Virgin Islands". Archives of Environmental Contamination and Toxicology. 70 (2): 265–88. doi:10.1007/s00244-015-0227-7. PMID 26487337.
- Wiench, Karin; Wohlleben, Wendel; Hisgen, Volker; Radke, Kristin; Salinas, Edward; Zok, Sabine; Landsiedel, Robert (2009). "Acute and chronic effects of nano- and non-nano-scale TiO2 and ZnO particles on mobility and reproduction of the freshwater invertebrate Daphnia magna". Chemosphere. 76 (10): 1356–65. doi:10.1016/j.chemosphere.2009.06.025. PMID 19580988.
Watson, Megan E. "Coral Reefs." Encyclopedia of Environmental Issues. Rev. ed. Vol. 1. Pasadena: Salem Press, 2011. pp. 317–318. ISBN 978-1-58765-736-8
|Wikimedia Commons has media related to Coral bleaching.|
- Great Barrier Reef Marine Park Authority information on bleaching.
- ReefBase: a global information system on coral reefs.
- More details on coral bleaching, causes and effects.
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- The Link between Overfishing and Mass Coral Bleaching
- Discussion on Overfishing and Coral Bleaching
- Social & Economic Costs of Coral Bleaching[dead link] from "NOAA Socioeconomics" website initiative
- Microdocs: Coral bleaching
- Coral Bleaching at Maro Reef, September 2004