The effects of prolonged ?bleaching? on the tissue biomass and reproduction of the reef coral Montastrea annularis

Szmant, Alina M.; Gassman, Nancy J.

doi:10.1007/bf00265014

Cited by 416 publications

(277 citation statements)

References 20 publications

Supporting

Mentioning

260

Contrasting

Unclassified

Order By: Relevance

“…The mean densities of Symbiodinium in P. rus, as well as calcification and F v /F m for both species, suggest that these variables might also have changed under fluctuating conditions in trial 1. Declines in Symbiodinium density can be expected to affect the capacity for autotrophy, nutrient recycling, and light-dependent calcification (Muller-Parker and D'Elia, 1997), with the implications accentuated with greater declines in Symbiodinium density, eventually resulting in death (Jokiel and Coles, 1990;Szmant and Gassman, 1990;Fitt et al, 2001;Rodrigues and Grottoli, 2007). Contrasts of the present results with comparable studies employing steady thermal stress for similar durations indicate that the losses of Symbiodinium reported here are large.…”

Section: Discussioncontrasting

confidence: 84%

The physiological response of reef corals to diel fluctuations in seawater temperature

Putnam

Edmunds

2011

Journal of Experimental Marine Biology and Ecology

View full text Add to dashboard Cite

An opportunity to explore the effects of fluctuating temperatures on tropical scleractinian corals arose when diurnal warming (as large as 4.7°C) was detected over the rich coral communities found within the back reef of Moorea, French Polynesia. In April and May 2007, experiments were completed to determine the effects of fluctuating temperature on Pocillopora meandrina and Porites rus, and consecutive trials were used to expose them for 13 days to 26°C, 28°C (ambient conditions), 30°C, or a fluctuating treatment ranging from 26 to 30°C over 24 h. The multivariate response was assessed using maximum dark-adapted quantum yield of PSII (F V /F M ), Symbiodinium density, chlorophyll-a content, and calcification. In trial 1, multivariate physiology of both species was significantly affected by treatments, with the fluctuating temperature resulting in a 17-45% decline in Symbiodinium density (relative to the ambient) matching that occurring at a constant 30°C; F V /F M , chlorophyll-a content, and calcification, did not differ between the fluctuating and the steady treatments. In contrast, in trial 2 that utilized corals collected two weeks after those used in trial 1, the corals were unaffected by the treatments, likely due to an environment × trial interaction caused by seasonal declines in Symbiodinium density. Together, these results demonstrate that short transgressions to ecologically relevant high and low temperatures can elicit a potentially detrimental response equivalent to that occurring upon exposure to a constant high temperature. The dissimilar responses among dependent variables and consecutive trials underscore the importance of temporal replication and multivariate approaches in coral ecophysiology. It is likely that recent history has a stronger effect on the response of corals to treatments than is currently recognized.

show abstract

Section: Discussioncontrasting

confidence: 84%

The physiological response of reef corals to diel fluctuations in seawater temperature

Putnam

Edmunds

2011

Journal of Experimental Marine Biology and Ecology

View full text Add to dashboard Cite

show abstract

“…2a and 2e). Some studies have not endorsed losses in chlorophyll a and c and have even suggested an increase of these pigments in stressed and bleached corals (Szmant and Gassman 1990;Le Tissier and Brown 1996). This has been ascribed to increased nutrient availability to the remnant algae in the host or the greater loss of apical algae leaving the subsurface algae with higher chlorophyll concentrations below (Brown et al 1999).…”

Section: Discussionmentioning

confidence: 99%

“…Bleaching in corals is either due to loss of zooxanthellae that bear the pigments, or loss of pigments in zooxanthellae without the zooxanthellae themselves being expelled (Hoegh-Guldberg and Smith 1989;Szmant and Gassman 1990;Fitt and Warner 1995). In the latter case, chlorophyll a and chl c may decrease in stressed and diseased corals because they are degraded to form phaeopigments (Brown 1997).…”

Section: Discussionmentioning

confidence: 99%

Stress response of two coral species in the Kavaratti atoll of the Lakshadweep Archipelago, India

2005

View full text Add to dashboard Cite

Frequent occurrences of coral bleaching and the ensuing damage to coral reefs have generated interest in documenting stress responses that precede bleaching.. The objective of this study was to assess and compare physiological changes in healthy, semi-bleached and totally bleached colonies of two coral species, Porites lutea and Acropora formosa during a natural bleaching event in the Lakshadweep Archipelago in the Arabian Sea to determine the traits that will be useful in diagnosis of coral health. In April, 2002, three "health conditions" were observed as "appearing healthy", "semi-bleached" and "bleached" specimens for two dominant and co-occurring coral species in these islands. Changes in the pigment composition, zooxanthellae density, mitotic index of zooxanthellae, RNA/DNA ratios and protein profile in the two coral species showing different levels of bleaching in the field were compared to address the hypothesis of no difference in health condition between species and bleaching status. The loss in chlorophyll a and chlorophyll c and zooxanthellae density in the transitional stage of semi-bleaching in the branched coral A. formosa was 80, 75 and 80% respectively. The losses were much less in the massive coral P. lutea, being 20, 50 and 25% respectively. The decrease in zooxanthellar density and chlorophyll a was accompanied by an increased mitotic index of zooxanthellae and RNA/DNA ratios in both the species. There was an increase in accumulation of lipofuscin granules in partially bleached P. lutea tissue, which is an indication of cellular senescence. Multivariate statistical analyses showed that colonies of P. lutea ranked in different health conditions differed significantly in chl a, chl c, zooxanthellae density, RNA/DNA ratios and protein concentrations whereas in A. formosa chl a, chl c, chl a/c, phaeopigments and mitotic index contributed to the variance between health conditions.

show abstract

“…If symbiont populations are not restored within weeks or months of a bleaching event, then whole or partial coral mortality is likely (Hoegh-Guldberg, 2004a). The reproductive capacity of corals may also be reduced for extended periods following bleaching, further negatively influencing coral populations (Szmant and Gassman, 1990). Bleaching is tightly linked to sea surface temperatures with higher than average sea surface temperatures in a given area combined with high solar radiation widely regarded as the primary cause of large-scale bleaching (Hoegh-Guldberg, 1999, 2004aJokiel and Brown, 2005).…”

Section: Introductionmentioning

confidence: 99%

Changes in coral-associated microbial communities during a bleaching event

et al. 2007

View full text Add to dashboard Cite

Environmental stressors such as increased sea surface temperatures are well-known for contributing to coral bleaching; however, the effect of increased temperatures and subsequent bleaching on coral-associated microbial communities is poorly understood. Colonies of the hard coral Acropora millepora were tagged on a reef flat off Magnetic Island (Great Barrier Reef) and surveyed over 2.5 years, which included a severe bleaching event in January/February 2002. Daily average water temperatures exceeded the previous 10-year average by more than 1 1C for extended periods with field-based visual surveys recording all tagged colonies displaying signs of bleaching. During the bleaching period, direct counts of coral zooxanthellae densities decreased by B64%, before recovery to pre-bleaching levels after the thermal stress event. A subset of three tagged coral colonies were sampled through the bleaching event and changes in the microbial community elucidated. Denaturing gradient gel electrophoresis (DGGE) analysis demonstrated conserved bacterial banding profiles between the three coral colonies, confirming previous studies highlighting specific microbial associations. As coral colonies bleached, the microbial community shifted and redundancy analysis (RDA) of DGGE banding patterns revealed a correlation of increasing temperature with the appearance of Vibrio-affiliated sequences. Interestingly, this shift to a Vibrio-dominated community commenced prior to visual signs of bleaching. Clone libraries hybridized with Vibrio-specific oligonucleotide probes confirmed an increase in the fraction of Vibrio-affiliated clones during the bleaching period. Post bleaching, the coral microbial associations again shifted, returning to a profile similar to the fingerprints prior to bleaching. This provided further evidence for corals selecting and shaping their microbial partners. For non-bleached samples, a close association with Spongiobacter-related sequences were revealed by both clone libraries and DGGE profiling. Despite Vibrio species being previously implicated in bleaching of specific coral species, it is unsure if the relative increase in retrieved Vibrio sequences is due to bacterial infection or an opportunistic response to compromised health and changing environmental parameters of the coral host. This study provides the first molecular-based study demonstrating changes in coral-associated bacterial assemblages during a bleaching event on a natural reef system.

show abstract

The effects of prolonged ?bleaching? on the tissue biomass and reproduction of the reef coral Montastrea annularis

Cited by 416 publications

References 20 publications

The physiological response of reef corals to diel fluctuations in seawater temperature

The physiological response of reef corals to diel fluctuations in seawater temperature

Stress response of two coral species in the Kavaratti atoll of the Lakshadweep Archipelago, India

Changes in coral-associated microbial communities during a bleaching event

Contact Info

Product

Resources

About