This article continues the theme of early indigenous scientific knowledge which often centred around the collection of food. Most shell middens were created in ancient (pre-European contact) times and can provide valuable information about Aboriginal hunting and gathering practices.
For thousands of years, Aboriginal people caught and ate large numbers of shellfish species in and around the mangrove mud flats and coastal areas along the Queensland coast. Often they would cook the meat and use the shells for a number of different purposes, or dispose of the shells in large dump sites. These dump sites would normally be near where they were camped and eventually form what is called shell middens. Shell middens have provided important information and clues for researchers about the Aboriginal people and the environment they lived in. They tell the story of the Aboriginal peoples’ diet, food sources for that particular area, what species were available, the impact of biodiversity, environmental changes and marine ecosystems.
Different species of food sources found in shell middens include, mussels, oysters, clams, crabs, fish. These food sources were highly prized as today we know they contain valuable nutrients such as zinc, iron, calcium and vitamins such as A and B. These would have been hunted and gathered according to the seasons and particularly when they were in abundance. The Aboriginal people would have known when the oysters were at their fattest, the crabs were at their heaviest, the mussels in abundance from reading the seasonal signs around them. This practice is still used today by many Aboriginal people.
Some of the species found included Geloina coaxan (Mud Clam), Nerita balteata (Lined Nerida), Telescopium Telescopium (Telescope Mud Creeper. Most of the food sources were collected during low tide as that was the time they were exposed in the mud or sand or attached to rocks and branches of the mangrove trees.
Once they were collected they would have been immediately eaten and then discarded in a nearby heap eventually forming into a midden. The Aboriginal people also found uses for the shells and used them for cutting and slicing or decoration. Every year at the same time the shell midden would grow in size. In the Hinchinbrook area, between the North Queensland towns of Cardwell and Ingham shell middens sites have been found and from the research tells the story that it is a particular area that would have supported a large number of people. Whilst middens are found there, a number of fish traps have also been found which reinforces that the area was a valuable nutrient rich environment. All shell middens and fish traps today are protected sites. They are protected under the Aboriginal Cultural Heritage Act 2003 and Torres Strait Islander Cultural heritage Act 2003. One area protected for artefact scatters, shell middens and fish traps is an area at Palm Island.
Whilst shell middens have survived over thousands of years they are exposed to threats. Threats include cyclones, (a shell midden at the Townsville Town Common was damaged by a cyclone), erosion from water and wind, vandalism and development.