• Audience
    Primary school
  • Learning stage
    Stage 2, Stage 3, Stage 4
  • Learning area
    Climate change, Science
  • Type
    Teaching resources

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Corals are invertebrates that live in the ocean, and are relatives of anemones and jellyfish. They form colonies that are made up of identical 'polyps', which can create a hard skeleton to attach to. Polyps are cylinder-shaped animals that connect to the skeleton at their base and have a circle of tentacles at their mouth opening. Polyps can create large skeletons which in turn make up the ecosystems called coral reefs.

While some corals can catch and eat fish or plankton, most corals get their energy from the zooxanthellae that live inside their tissues. Zooxanthellae can photosynthesize (just like plants), converting sunlight into energy! They also give coral their bright and beautiful colours.

But what causes corals to lose their colour, get sick and die in the process called 'coral bleaching'? Watch Zara's video below to find out.

  • The Great Barrier Reef is the world's largest system of coral reefs, mangroves and estuaries and is made up of over 400 different species of coral.
  • The relationship between coral and zooxanthellae is a type of 'symbiotic mutualism'. But what does that mean? Symbiosis, or symbiotic, is a term used in biology when two species have a long-term relationship. There are lots of types of symbiosis, depending on whether both species benefit or not. For coral and zooxanthellae, both get something out of the relationship – the coral gets energy and the zooxanthellae get protection. Therefore it is mutually beneficial! Can you think of any other examples of 'symbiotic mutualism'?

  1. Scientists use a system for classifying living things called 'taxonomy'. The system uses different levels, starting with domain and ending in species. Research corals and find out how they are classified. Write down what domain, kingdom, phylum and class they belong to. Are you surprised by what you found out?
  2. How has the Great Barrier Reef been affected by coral bleaching in the last 30 years? How can it recover from these events?
  3. Create your own flow chart or diagram that explains the Greenhouse Effect and the process of global warming.
  4. Develop a class action plan that covers things you can do at home or at school to reduce the amount of carbon dioxide that goes into the atmosphere.

About the video

Big Problem: Coral Bleaching is an entertaining investigation into one of the most widespread issues affecting coral reefs. Inspired by her passion for the ocean, Zara sets out to educate viewers on some of the main causes of coral bleaching, the scientific process behind it and ways that everyone can work together to help minimise the issue.

Sponsored by the University of Sydney, the Sleek Geeks Science Eureka Prize is a national short film competition that encourages school students to communicate a scientific concept in a way that is accessible and entertaining to the public while painlessly increasing their science knowledge. It is intended to support budding young scientists across the nation, who will be our future leaders in research, discovery and communication. You can learn more about the Sleek Geeks Science Eureka Prize here.

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