Completar frases Climate change and the Great Barrier ReefVersión en línea Fill-in-the-blanks to complete this information on how climate change threatens the Great Barrier Reef. por Belinda Schirmer 1 lifecycle stationary animals location The larvae of hard corals are tiny that move around in the open water for up to a month , until they find a place to settle . Once a suitable is found , a larvae moves into the next stage of its and becomes a polyp . Polyps are organisms . Large numbers of polyps usually live together in a colony - called a coral . 2 colour inside algae food Reef - building corals are a type of hard coral . They rely on a symbiotic relationship with tiny called zooxanthellae . These algae live and multiply the polyps . Zooxanthellae are photosynthetic organisms . They provide for the coral polyps and also give reef - building corals their . 3 tissues source temperature beautiful die degrees short Reef - building corals are very sensitive to water . Increases to water temperatures of only a couple of puts these corals under thermal stress . When a coral is stressed , it expels the tiny symbiotic algae that live within their . This is problematic , as these algae are the coral's main food . Incidentally , when the algae leave , it also causes the corals to lose their colours . If water temperatures return to normal within a relatively period of time ( weeks ) , the zooxanthellae will return to the coral . However , if warm temperatures persist , the bleached coral will from starvation . 4 dioxide Barrier water bleaching Increased levels of coral have been observed in ecosystems such as Australia's Great Reef . These are directly associated with increases in average temperature due to increased carbon levels in the atmosphere .