Parrotfish Poo Context and it’s Rationale

This Youtube clip would be an excellent investigation for students in upper primary or lower secondary students.

There is scope for students to create their own questions to investigate like;

  1. Are the Parrotfish are a threat to the reef environments or benefit to them? i.e. ‘indiscriminate eating of coral reefs causing bioerosion’, ‘indiscriminate eating of algae which destroys coral reefs’ or ‘creating new island ecosystems with their poo’
  2. Where are Parrotfish located in our world?  Is there evidence of more islands in those locations?
  3. What are the mechanics of a Parrotfish’s jaw?

An interesting study on this by Bellwood and Choat (1990) as cited in Nanami (2016) categorises Parrotfish as ‘excavators’ or ‘scrapers’. Excavators have a short powerful bite and leave scars on the coral. Scrapers deliver weaker bites and graze less.

The study looked at the jaw mechanics of the two types as shown in Figure 3 (Nanami, 2016) This type of understanding could be used to compare the Parrotfish’s jaws to levers in real life situations like excavator machinery.

Screen Shot 2017-03-19 at 11.57.41 am.png

4. What are human impacts on Parrotfish i.e. overfishing, damage to ecosystem?

5. What are the evolutionary tricks Parrotfish have adapted for survival? i.e. mucus membranes, different jaws.

Building on the Youtube clip students could then listen to this Scientific American podcast.

Students could investigate the question

6. How long would it take a Parrotfish to create an island the same as Varruka Island in the Maldives given that 85% of the sand produced on the surrounding reef is created from their poo? (Rosen, 2015)

This investigation would need to be supported by data that Parrotfish ingest and redeposit 2300kg of sand per year on 1 hectare of reef. (Bardach, 1961)

The Rationale

This context supports that mathematical concepts can be applied to the world, It also develops an understanding of scientific concepts and systems as well as using evidence and explanation.

Students could definitely use digital technologies to present answers to the above questions (The Australian Curriculum v8.3, 2017).

STEM skills underpin the basis for solving the questions above.  Critical thinking, creative approaches to seeking and sorting information.  Problem solving and evaluation are also processes required in answering the big questions posed in this context.