The Effects Of Coral Bleaching On Coral Reefs

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Coral reefs are unique and diverse underwater marine ecosystems that are found in many parts of the world. Today these tropical reefs suffer a great deal of environmental stresses and are projected to decline over the next century due to global warming. In Grottoli’s article: The cumulative impact of annual coral bleaching can turn some coral species winners into losers, she elaborates on the effects of annual bleaching on three species of coral. Grottoli took three species of coral such as O. Faveolata, P.asreoides P.divaricata and exposed the treatment groups to high temperatures of 31.5 °C for 15 days while control groups remained at a normal temperature of 30.6 °C for the same amount of days. After treatment species were then weighed and…show more content…
Such high level of energy reserve is a good indication of over all health and ability to acclimate to harsh environments. An endosymbiont level is a measurement of other beneficial cells that lives on the coral and forms a symbiotic relationship. Researchers recorded their results and then repeated the experiment on the same corals a year later to see the effects of repeated high temperatures as a model for annual coral bleaching as a result of global warming. Upon completion of the experiment Grottoli and her team of researchers noted, “yearly bleaching can dramatically alter the thermal tolerance of corals” (Grottoli’s, 2014). Interestingly enough, while the majority of the species decreased in all variables compared to controls, P.divaricata increased in energy reserves at about 20-45% higher than controls after the second treatment. This increase in total energy reserve lead to a reduction in the susceptibility to coral bleaching for that species. Thus, suggests that this species of coral can adapt to high temperatures after the first event of bleaching occurs. Conversely, due to its low energy reserves and its low potential to increase endosymbiont levels, P.asreoides is not likely acclimatize to higher temperatures thus resulting in low abundance of the species in future
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