For thousands of years, Aboriginal clans across the continent traded with each other. Yolngu people from north-east Arnhem Land also traded with the Macassan people from Sulawesi (Indonesia) who were searching for trepang (bêche-de-mer, sea cucumber), which they valued as a medicine and as a food. In return for access to certain fishing areas, Yolngu people received from the Macassans goods such as cloth, tobacco, rice and knives. After harvesting the trepang, it was boiled and cured on the beach. Due to this contact and trade, it is likely that Aboriginal men worked on some of the ships and travelled to Sulawesi and back.
These visits had influences on the local people through the addition of new words to their language, the representation of Macassan ships in their rock art and the introduction of tamarind trees. Some Yolngu people spoke the Macassan language. The Macassan culture was also reflected in the songs and dances of the northern Indigenous peoples.
Indigenous language groups traded extensively across Australia, establishing trade routes covering thousands of kilometres. Similarly to other trade routes through history, exchange involved more than raw materials and goods. It involved the telling of stories and the sharing of ideas. Examples of items that were traded include pituri, stone for axes, bailer shells and pearl shells, grinding stones, ochre and foodstuffs such as smoked eels. Valuable items were eagerly sought after and travelled the greatest distances.
Pituri or Duboisia hopwoodii, a spindly shrub containing high levels of nicotine, is found in arid regions. The most sought after specimen was the shrub that grew in the sandy areas of the Mulligan-Georgina catchment area in south-west Queensland. Pituri is a stimulant used in ceremonies, and for poisoning waterholes to catch animals such as emus, parrots and kangaroos. When an animal drinks the water it becomes stupefied and is easily caught.
Pearl shell from north-west Australia was one of the most popular items for trade. They have been found thousands of kilometres away in southern Australia around the Great Australian Bight and in the Mallee area between Victoria and Adelaide. Bailer shells travelled from tropical beaches near Cape York to the Alice Springs area. Spears and ochres from the centre of the continent travelled to the coasts, and greenstone from Mount William in central Victoria was traded across south-eastern Australia.