Journal ArticleDOI
Coral reef bleaching: ecological perspectives
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TLDR
An effort must be made to understand the impact of bleaching on the remainder of the reef community and the long-term effects on competition, predation, symbioses, bioerosion and substrate condition, all factors that can influence coral recruitment and reef recovery.Abstract:
Coral reef bleaching, the whitening of diverse invertebrate taxa, results from the loss of symbiotic zooxanthellae and/or a reduction in photosynthetic pigment concentrations in zooxanthellae residing within the gastrodermal tissues of host animals. Of particular concern are the consequences of bleaching of large numbers of reef-building scleractinian corals and hydrocorals. Published records of coral reef bleaching events from 1870 to the present suggest that the frequency (60 major events from 1979 to 1990), scale (co-occurrence in many coral reef regions and often over the bathymetric depth range of corals) and severity (>95% mortality in some areas) of recent bleaching disturbances are unprecedented in the scientific literature. The causes of small scale, isolated bleaching events can often be explained by particular stressors (e.g., temperature, salinity, light, sedimentation, aerial exposure and pollutants), but attempts to explain large scale bleaching events in terms of possible global change (e.g., greenhouse warming, increased UV radiation flux, deteriorating ecosystem health, or some combination of the above) have not been convincing. Attempts to relate the severity and extent of large scale coral reef bleaching events to particular causes have been hampered by a lack of (a) standardized methods to assess bleaching and (b) continuous, long-term data bases of environmental conditions over the periods of interest. An effort must be made to understand the impact of bleaching on the remainder of the reef community and the long-term effects on competition, predation, symbioses, bioerosion and substrate condition, all factors that can influence coral recruitment and reef recovery. If projected rates of sea warming are realized by mid to late AD 2000, i.e. a 2°C increase in high latitude coral seas, the upper thermal tolerance limits of many reef-building corals could be exceeded. Present evidence suggests that many corals would be unable to adapt physiologically or genetically to such marked and rapid temperature increases.read more
Citations
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Journal ArticleDOI
Zooxanthellae Densities are Highest in Summer Months in Equatorial Corals in Kenya
TL;DR: Direct tracking of mapped corals provided evidence that zooxanthellae densities were highest during the North-East Monsoon (NEM) season and displayed highest mitotic indices during transition periods directly preceding this season.
Posted ContentDOI
Coral Symbiodinium community composition across the Belize Mesoamerican Barrier Reef System is influenced by host species and thermal variability
TL;DR: Overall, thermal parameters alone were likely not the only primary drivers of Symbiodinium community composition, suggesting that environmental variables unrelated to temperature may play key roles in structuring coral-algal communities in Belize and that the relative importance of these environmental variables may vary by coral host species.
Journal ArticleDOI
Stony corals in Dominica during the 2005 bleaching episode and one year later
Sascha C. C. Steiner,J. M. Kerr +1 more
TL;DR: Deep sites (6-18m) were more affected by recent coral mortality than shallow sites, undermining the extent to which they may serve as refugia, and highlights the urgency of immediate action in reducing local disturbances if the island?s coral reef resources are to have a chance of being conserved.
Dissertation
Exploring the cellular mechanisms of Cnidarian bleaching in the sea anemone Aiptasia pallida
TL;DR: It is shown that exposure to elevated temperatures induces symbiotic anemones to produce high levels of NO leading to the collapse of the symbiosis, shedding light on the poorly understood cellular mechanism through which elevated sea water temperature causes the release of symbiotic algae from symbiotic cnidarians, a detrimental process known as coral bleaching.
Journal ArticleDOI
Isolated and combined effects of thermal stress and copper exposure on the trophic behavior and oxidative status of the reef-building coral Mussismilia harttii
Juliana da Silva Fonseca,Miguel Mies,Alana Paranhos,Satie Taniguchi,Arthur Z. Güth,Márcia Caruso Bícego,Joseane Aparecida Marques,Laura Fernandes de Barros Marangoni,Adalto Bianchini +8 more
TL;DR: The findings show that trophic behavior was predominantly autotrophic and remained unchanged under individual and combined stressors for both 4- and 12-day experiments; for the latter, however, there was an increase in the heterotrophy marker.
References
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Journal ArticleDOI
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Journal ArticleDOI
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Journal ArticleDOI
Responses of coral reefs and reef organisms to sedimentation
TL;DR: Data is needed on the threshold levels for reef orgarusms and for the reef ecosystem as a whole the levels above which sedimentation has lethal effects for particular species and above which normal functioning of the reef ceases.
Book
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TL;DR: The Southern Oscillation (Variability of the Tropical Atmosphere). Oceanic Variability in the Tropics as mentioned in this paper is a well-known phenomenon in meteorological models of tropical weather.
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