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MHS Library | How can chemical principles be applied to create a more sustainable future?

Investigation topic 3: The chemistry of Aboriginal and Torres Strait Islander peoples’ practices

Throughout history, people all over the world have hypothesised, experimented, made empirical observations, gathered evidence, recognised patterns, verified through repetition, and made inferences and predictions to help them to make sense of the world around them and their place within it. Recent research and discussion have confirmed many Aboriginal and Torres Strait Islander groups use the environment and its resources to solve the challenges they face in the different Australian climates in ways that are more sustainable than similar materials produced in Western society. Their solutions can be explained by a variety of organic and non-organic chemical processes.

Questions that may be explored in this investigation include:

· How are plant-based toxins such as saponins used in Aboriginal and Torres Strait Islander peoples’ fishing practices, and how is this similar to other First Nation Peoples’ fishing practices around the world?

Aboriginal and Torres Strait Islander Peoples use the knowledge of plants containing saponin as a means of sustainably harvesting fish. On Mer Island in the Torres Strait, leaves of the vine Derris uliginosa (sad in the Meriam Mir language of the Eastern Islands of the Torres Strait) are pounded to release saponin and the crushed leaves are thrown into the water to stupefy fish. The Mitakoodi Peoples of the Cloncurry River region in north Queensland use the plant Tephrosia astragaloides for the same purpose. Again, the leaves are crushed and bruised before bundles of leaves are thrown into a waterhole, stunning the fish and allowing easy harvest as they rise to the surface of the waterhole. The development of this biochemical process required the scientific processes of observation of the phenomenon, hypothesising, gathering data, and using evidence. In addition, the understanding that the phenomenon of secondary poisoning did not occur required further scientific evaluation and complex physiological understanding. Secondary poisoning can occur when a second organism ingests a poisoned organism and is then also affected by the substance. Aboriginal and Torres Strait Islander Peoples who ingest fish that have been harvested using plant saponins are not affected by the poison.

The knowledge and understanding underpinning this process required the use of the scientific method such as careful observation, formulating predictions, testing of predictions, and gathering of data and evidence.

For example:

Which plant species contain poisons that only target fish?

Will using plant poisons kill other important living organisms in the ecosystem?

How much of the poison is required to be effective?

How do I administer the poison?

Will the poisoned fish make me sick after eating it?

Rotenone: The Fish Killer

A pile of Asian carp and other fish killed with rotenone. Read more at the source.

Sackett, D. (2012). Rotenone: The fish killer. Retrieved from


Further resources:

Cannon, J. G. G., Burton, R. A. A., Wood, S. G. L., & Owen, N. L. (2004). Naturally occurring fish poisons from plants. Journal of Chemical Education, 81(10), 1457-1461.

Edinger, D.C. (1997). Aboriginal fish traps in the Kimberley. Retrieved from

Howes, F. N. (1930). Fish-poison plants. Bulletin of Miscellaneous Information (Royal Botanic Gardens, Kew), 1930(4), 129-153.

Quigley, C. (1956). Aboriginal fish poisons and the diffusion problem. American Anthropologist, 58(3), 508-525. Retrieved from