Effects of ultraviolet radiation on corals and other coral reef organisms

“Similarly, the role of mycosporine amino acids (MAA) in protecting both coral host and zooxanthellae from the effects of ultraviolet radiation still requires further clarification (Shick et al. 1995; Shick et al. 1996).”

“…the spectrum, have also been variably implicated in mass coral bleaching (Hoegh-Guldberg and Smith, 1989; Brown et al., 1994; Fitt and Warner, 1995; Shick et al., 1996; Brown, 1997a,b; Lesser, 1997; Brown et al., 1999; Dunne and Brown, 2001; Coles and Brown, 2003; Lesser, 2004; Smith et al.,…”

“Environmental UVB and the short wavelengths of UVA can be detrimental to marine life (2, 3), and enhancement of UVB (via ozone loss) can disrupt trophic interactions (3, 4).”

“…PAR and UV-R independently increase the activities of enzymes responsible for detoxifying active forms of oxygen, and Drollet et al. ( 1994, 1995) provide field evidence that distinguishes the role of UV-R in a bleaching event in Tahiti (for a balanced discussion on UV-R see Shick et al. 1996).”

“Bleaching is most often correlated with elevated seawater temperature, but may be associated with salinity extremes (Coles & Jokiel 1992), light irradiance extremes (Brown et al. 1994, 2000, Brown 1997b, Shick et al. 1996), and pollutants (Peters et al. 1981, Harland & Brown 1989).”

“Algal symbionts are also responsible in some corals for the production of sunscreens (the mycosporine-like amino acids), which are secreted into the mucus layer as a protection against harmful ultraviolet radiation (UVR) (Drollet et al. 1993, Shick et al. 1995, 1996.”

“Corals respond toUVRby synthesizingUV-absorbing compounds (mycosporine-like amino acids [MAAs]) and enzymes involved in the protection of both the host and symbiont from oxidative stress (Lesser and Shick 1989; Lesser 1996; Shick et al. 1996; Lesser 2000).”

“Other UV-B sensitive marine organisms include sea urchins and corals [27,140].”

“Printed in the Netherlands. spheric ozone depletion, the intensity of biologically damaging ultraviolet radiation (UVb) at 20o N latitude between April and August now exceeds the June 1969 (summer solstice) maximum (Shick et al., 1996).”

“Bleaching (via the photodestruction of algal pigments or expulsion of endosymbionts from the host) is a response to various physical environmental stressors, especially elevated seawater temperature, and in some cases, solar UVR (reviewed in Glynn 1996, Shick et al. 1996, Brown 1997).”

“Blue light (400–500 nm) transmits the deepest in the oceans while ultraviolet radiation (UVR, 200– 400 nm) and red light (620–740 nm) attenuate the fastest (Dustan, 1982; Shick et al., 1996; Lesser, 2000; Lesser et al., 2000; Kirk, 2010).”

“…· Acclimatisation · Irradiance stress Resale or republication not permitted without written consent of the publisher Mar Ecol Prog Ser 242: 119–129, 2002 (Shick et al. 1996) and fluorescent pigments (Salih et al. 2000, Dove et al. 2001) which restrict penetration of light into coral tissues,…”

“These include the production of mycosporine-like amino acids for which a UV absorbing function has been inferred, and a range of active oxygen scavenging systems (for a review, see Shick et al. 1996).”

“Ultraviolet radiation is known to have a detrimental effect on photosynthesis and growth in zooxanthellae (Shick et al., 1996) with the harmful effects of UVR involving damage to DNA, proteins, and lipids.”

“…aposymbiotic specimens of Anthopleura elegantissima contain MAAs (Stochaj et al. 1994; Banaszak and Trench 1995a), the zooxanthellae from this anemone do not synthesize MAAs (Banaszak and Trench 1995a), and the nonsymbiotic congener Anthopleura artemisia contains MAAs (Shick et al. 1996a).”

“…depletion to be a problem for tropical marine communities because the most extreme ozone depletion occurs at high latitudes, while intensities of ultraviolet radiation (UV, 280–400 nm wavelength) are naturally higher and more seasonally variable at lower latitudes (e.g., Shick et al., 1996).”

“Coral bleaching Coral bleaching events in recent years have been a consequence of high sea surface temperatures in direct combination with high irradiance (Glynn 1993, 1996; Shick et al. 1996; Hoegh-Guldberg 1999; Marshall and Baird 2000).”

“Nevertheless, this claim has not been verified yet, because MAAs exhibit a low fluorescence, if at all [112,114].”

“may be considered ecologically relevant to corals living in somewhat more shaded areas or in deeper water [29].”

“These stresses can induce increased production of reactive oxygen species (ROS) leading to significant oxidative damage to the coral–algal complex (Lesser et al., 1990; Shick et al., 1996; Downs et al., 2000, 2002).”

“Shick et al. (1996), reported some of the negative effects of UVR on coral reefs, showing the sensitivity of corals to excessive UVR exposure.”

“2% increase in UV-B (308 nm) at 1 m depth per 10 years (Shick et al. 1996).”

“The formation of oxygen radicals disrupts protein synthesis and damages cell membranes, resulting in decreased photosynthetic rates (Lesser, 1996; Shick et al., 1996).”

“…is evident that light stress does play a prominent role when combined with heat stress in such events (Bhagooli & Hidaka, 2004; Downs et al ., 2013; Glynn, 1993; Jokiel & Brown, 2004; Lesser, 1996; Lesser & Farrell, 2004; Mumby et al ., 2001; Robison & Warner, 2006; Shick, Lesser & Jokiel, 1996).”

“…al. 1996), sedimentation (Philipp & Fabricius 2003), and UV radiation (Brown et al. 1994, Shick et al. 1996), most recent bleaching events have been a consequence of high sea surface temperature in direct combination with high irradiance (Glynn 1993, 1996, Shick et al. 1996, Hoegh-Guldberg 1999).”

“In corals, both the host and the Symbiodinium need protection under extreme environments, and certain coral hosts are able to produce photo- or thermal-protective pigments and proteins to facilitate this (Shick et al., 1996; Dunlap and Shick, 1998; Brown et al., 2002b; Baird et al., 2009).”

“distribution of coral reef communities (Jokiel, 1980; Shick et al., 1996; Dunlap and Shick, 1998; Gleason, 2001).”

“…active radiation (PAR) is essential for coral reef growth (Kleypas, 1997) even though an excess (often associated with subaerial exposure and high temperatures) can lead to bleaching (Glynn, 1997), while ultraviolet radiation (UVR) may be deleterious (Shick et al., 1997).”

“Therefore, future research needs to give more attention to the consequences of UVR on benthic reef diazotrophs, particularly because even small anthropogenic increases in UVB levels will have sublethal physiological manifestations in coral reef macroorganisms (Shick et al. 1996).”

“…irradiance levels near the sea surface supports higher photosynthesis rates, which promote hypercalcification, but also increase the risk of widespread photo-oxidative stress, which can induce mass bleaching during periods of calm and hot weather (Shick et al., 1996; Kleypas et al., 1999, 2001).”

“, 2004), although corals growing in shallow waters may be negatively affected by enhanced UVB radiation (Shick et al., 1996; Banaszak & Lesser, 2009).”

“The intertidal zone is also an area of high solar irradiance and potential UV stress; both of these factors may have deleterious eVects on photosynthetic organisms such as corals (Brown et al. 1994a; Shick et al. 1996 ).”

“Besides the coral host, the coral algal symbiont Symbiodinium has been shown to synthesize mycosporine-like amino acids, which are then transported to the host (Banaszak and Trench, 1995; Shick et al., 1996; Banaszak et al., 2000).”

“It has been suggested that fluorescence by UV-absorbing compounds might be used for photosynthesis (Sivalingham et al. 1976) as the excitation of mycosporinelike amino acids at 340 nm causes the emission of fluorescent light that could potentially be absorbed by Chl a (Sivalingham et al. 1976).”

“…observed for the UVB portion of the spectrum on Conch Reef (0.18 to 0.28 at 320 nm) during the experimental period fall between those measured for Kaneohe Bay, a tropical estuary (& [m-']) of 1.0 at 320 nm), and Moku Manu, an offshore Hawaiian reef (& [m-']) of 0.20 at 320) (Shick et al. 1996).”

“These results support previous suggestions that increased UV exposure of corals may result from clarification of the seawater during the doldrums that accompany El Niño events (Gleason and Wellington 1993; Shick et al. 1996; Gleason 2001).”

“The potentially negative effects of ultraviolet radiation (UVR) on tropical marine organisms have been welldocumented and thoroughly reviewed ( Shick et al. 1996; Gleason 2001).”

“Although corals and zooxanthellae have mechanisms to mitigate the effects of such stress (Ayoub et al., 2012; Shick & Dunlap, 2002; Shick et al., 1996), it can nevertheless deteriorate the symbiotic relationship between corals and algae, especially in conjunction with elevated sea temperatures.”

“Under normal physiological conditions, the efficiency of the antioxidant system reflects the basal prooxidant pressure on the organism which is influenced in different species by several biological and environmental factors including oxygen pressure, regime of light exposure, temperature, food availability, metabolic…”

“It has long been hypothesized that UV-absorbing compounds, especially mycosporine-like aminoacids (MAAs) might act as sunscreens thus conferring protection against damaging levels of UVR (15).”

“Corals live in shallow, warm waters and house intra-cellular photosymbionts resulting in exposure to high levels of UV radiation and oxidative stress [8].”

“Short wavelengths (290–400·nm) and elevated temperature may act synergistically with intense radiation, causing destructive effects in both partners (host and symbiotic algae; Jokiel, 1980; Shick et al., 1996).”

“…onset of bleaching in Florida Keys populations of A. gibbosa coincided with global stratospheric ozone depletion following the eruption of Mount Pinatubo (Randel et al. 1995), an event that Shick et al. (1996) described as a ‘natural experiment’ on the effects of ozone depletion on reef organisms.”

“Solar radiation is attenuated as it passes through seawater, and a reduction of UV-B radiation from 1.5 m to depth was reported in a coral reef study (Shick et al. 1996).”

“Although bleaching has been correlated with increased temperatures, many studies have concluded that solar irradiance might also be implicated as a stressor producing additive or synergistic effects (Shick et al. 1996; Brown 1997 for reviews; Brown et al. 2000).”

“…global changes and synergism between several factors (Lesser et al., 1990; Gleason and Wellington, 1993; Glynn, 1993; Brown et al., 1995; Le Tissier and Brown, 1996; Shick et al., 1996; Brown, 1997; HoeghGuldberg, 1999) that can jointly result in massive bleaching of coral reefs worldwide.”

“In coral ecosystems, symbioses are also greatly affected by temperature variations, and increased sea surface temparature has been associated with mass coral bleaching events (Lesser 1996, 1997, Stone et al. 1999, Wilkinson 1999, Douglas 2003).”

“Most of our knowledge on the interaction between UVR and mutualistic associations is based on studies on invertebrate—algal symbiosis, particularly on scleractinian corals and their ‘zooxanthellae’ of the genus Symbiodinium (Gleason 2001; Shick et al. 1996; Shick and Dunlap 2002).”

“…the direct photoprotective role of MAAs in marine organisms has been recently obtained for primary producers as well as for non-symbiotic invertebrates (reviewed by Banaszak 2003) which, although unable to synthesize MAAs can obtain them through the diet (Carroll and Shick 1996; Shick et al. 2002).”

“…radiation environment by an evolutionary history to high UVR fluxes, various degrees of UVR sensitivity have been observed, with different physiological and biochemical processes being affected ( Jokiel, 1980; Shick et al., 1996; Kinzie et al., 1998; Villafañe et al., 1999; Helbling et al., 2001).”

“Many aquatic organisms are sensitive to ultravioletB radiation (UV-B; 280–320 nm) exposure, including species of phytoplankton, zooplankton, aquatic invertebrates, fish, and amphibians (e.g., Shick et al. 1996, Blaustein et al. 1998, Hader et al. 1998, Beland et al. 1999).”

“Experimental manipulations of coral reef organisms in the field have confirmed that UVR could be an environmentally relevant stressor able to cause death, inhibition of growth, and bleaching (Shick et al. 1996).”

“Corals pay a metabolic cost for the large-scale production of MAAs needed to protect them against constant UV radiation, and it is likely that zoanthids would incur similar costs; thus, this physiological defence is untenable for extended periods of time (Shick et al. 1996; Ow and Todd 2010).”

“The detrimental effects of increasing solar UV radiation on corals have been recognized for a long time (Jokiel 1980; Shick et al. 1996 ).”