EDEN IAS

CORAL BLEACHING | GS ARTICLES

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<li style=”margin-left:8px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>The stunning colours in corals come from a marine algae called zooxanthellae, which live inside their tissues.</span></span></span></span></span></span></li>
<li style=”margin-left:8px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>This algae provides the corals with an easy food supply thanks to photosynthesis, which gives the corals energy, allowing them to grow and reproduce.</span></span></span></span></span></span></li>
<li style=”margin-left:8px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>When corals get stressed, from things such as heat or pollution, they react by expelling this algae, leaving a ghostly, transparent skeleton behind. This is known as &lsquo;coral bleaching&rsquo;.</span></span></span></span></span></span></li>
<li style=”margin-left:8px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>&nbsp;Some corals can feed themselves, but without the zooxanthellae most corals starve.</span></span></span></span></span></span></li>
<li style=”margin-left:8px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>In some instances corals can recover from bleaching. If conditions return to normal, and stay that way corals can regain their algae, return to their bright colours and survive. </span></span></span></span></span></span></li>
<li style=”margin-left:8px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>However prolonged warmer temperatures and other stressors, like poor water quality, can leave the living coral in a weakened state.</span></span></span></span></span></span></li>
<li style=”margin-bottom:13px; margin-left:8px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>&nbsp;It can struggle to regrow, reproduce and resist disease &ndash; so is very vulnerable to coral diseases and mortality.</span></span></span></span></span></span></li>
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<p style=”margin-bottom:13px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><b><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>Causes of Coral Bleaching:</span></span></span></b></span></span></span></p>

<p style=”margin-bottom:13px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>&bull; <b>Rise in Sea Temperature</b>: Most coral species live in waters close to the warmest temperature they can tolerate i.e., a slight increase in ocean temperature can harm corals. El Nino elevates the sea temperature and destroys coral reefs.</span></span></span></span></span></span></p>

<p style=”margin-bottom:13px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>&bull; <b>Ocean Acidification</b>: Due to rise in carbon dioxide levels, oceans absorb more carbon dioxide. This increases the acidity of ocean water and inhibits the corals ability to create calcareous skeletons, which is essential for their survival.</span></span></span></span></span></span></p>

<p style=”margin-bottom:13px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>&bull; <b>Infectious Diseases</b>: Penetration of bacterium like vibrio shiloi inhibits photosynthesis of zooxanthellae. These bacteria become more potent with elevated sea temperatures.</span></span></span></span></span></span></p>

<p style=”margin-bottom:13px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><b><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>&bull; Chemical Pollution</span></span></span></b><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>: Increased nutrient concentrations affect corals by promoting phytoplankton growth, which in turn supports increased numbers of organisms that compete with coral for space.</span></span></span></span></span></span></p>

<p style=”margin-bottom:13px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>&bull; <b>Increased Sedimentation</b>: Land clearing and coastal construction result in high rates of erosion and a higher density of suspended silt particles which can</span></span></span></span></span></span></p>

<ul>
<li style=”margin-left:8px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>&nbsp;smother corals when particles settle out (sedimentation),</span></span></span></span></span></span></li>
<li style=”margin-left:8px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>&nbsp;reducing light availability (turbidity) and</span></span></span></span></span></span></li>
<li style=”margin-bottom:13px; margin-left:8px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>&nbsp;potentially reducing coral photosynthesis and growth.</span></span></span></span></span></span></li>
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<p style=”margin-bottom:13px”><span style=”font-size:11pt”><span style=”line-height:115%”><span style=”font-family:Calibri,sans-serif”><span style=”font-size:12.0pt”><span style=”line-height:115%”><span style=”font-family:&quot;Cambria&quot;,&quot;serif&quot;”>&bull; <b>Human Induced Threats</b>: Over-fishing, pollution from agricultural and industrial runoff, coral mining, development of industrial areas near coral ecosystems also adversely impact corals.</span></span></span></span></span></span></p>