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University of Canberra Proudly Presents a study on

__**OUR CHANGING WORLD - Coral Bleaching and Ocean Acidifcation**__

The following podcasts provide information about the different factors that are changing our world, particularly with the impacts that Coral Bleaching and Ocean Acidification will have on the marine ecosystems that drive a large portion of economies around the world. We hope you find the educational videos enjoyable and insightful.

Etiological agents of coral bleaching: Bacteria Lucy Tunks This vodcast is about coral bleaching, specifically focussing on the bacterial side of bleaching. Certain bacteria penetrate the coral epidermis and prevent the production of photosynthetic algae (zooxanthellae). Once the zooxanthellae die, the coral loses pigmentation (which is what causes the bleached colour). The bacteria outlined in this vodcast have been shown to be influenced by temperature. media type="youtube" key="8ZZPYV5IEck" height="387" width="530" align="center"

Link to References here

** Effects Of Coral Bleaching In The Caribbean On The Marine Ecosystem ** ** Brett Foran **

 This vodcast will take you through the issue of coral bleaching and its effects on the reef ecosystem. Coral bleaching is caused from the loss of the symbiotic relation between the coral and zooxanthellae algae. This means the corals abilty to photosynthesise, calcify, grow and reproduce is impeded. It is predicted that bleaching events in the Caribbean will become an annual occurance by 2020.

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References are here

** Ocean Acidification: How CO2 Is Endangering Coral Reefs In The Caribbean And World Wide **** Nathanael Murray Semmler **

Carbon Dioxide (CO2) has been rising as a high rate of almost 2.0 parts per million (ppm) per year being emitted into the atmosphere both by human activities and natural emissions. However the increasing rate is changing the chemistry of the oceans, as more CO2 is emitted into the atmosphere more is absorbed in toe oceans. When the CO2 is absorbed into the ocean it creates carbonic acid, this depletes carbonates and melts away at calcium shells and exoskeletons which are both vital in the formation of Corals and Coral Reefs. The danger is that this might change at a rapid pace and intensely which could lead many thousands of species to extinction. Just a few species of coral reef extinctions breaks down habitats and food webs that ripple their way up the food chains that impact larger animals such as sharks and whales. The reality is that without strong changes to the current emission of carbon dioxide then coral reefs may end up extinct by the year 2100.

Vodcast

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Link to References here
This podcast will take you through the process of coral bleaching and the impacts that an increase in water temperature has on the symbiotic relationship between zooxanthellae and coral. This podcast also exams the secondary impact that warming water can have on coral communities.
 * The effects of a rise in water temperature on coral bleaching. **
 * Alex Peterson **

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