Water – multilayered knowledge
Anbangbang Billabong, Kakadu National Park. Source Wikimedia commons http://commons.wikimedia.org/wiki/File:Anbangbang_Billabong_Australia.jpg
Aboriginal children have much to learn about water resources. “As the early explorer and bushman Edward Eyre was later to observe, ‘they know the very rock where a little water is most likely to be collected, the very hole where it is the longest retained.’ In the western deserts, the people dug and maintained wells to store precious rainwater as it ran off great slabs of flat rock” (Cathcart, 2009, 16-17). Anthropologist, Ronald Berndt told of eight different types of landscapes that delivered water to Western Desert people: soaks where subsurface water was dug up, rock holes with semi permanent water, rare spring water, intermittent stream water that sometimes leave waterholes behind, billabongs that fill up after heavy rain, intermittent swamps that fill after rain, claypans, and salt lakes that can provide potable water in good seasons (Clarke, 2003,140).
Rather than embark on extensive water construction projects Indigenous personal geographies tend to work in concert rather than in opposition to the biophysical environment. On the other hand, there are examples of fish ands eel traps that demonstrate considerable engineering skills. The fish traps in the Darling River at Brewarrina made up of a series of stone weirs and pens built from river cobbles showed that Indigenous people understood both the hydrology of the river and the behaviour of the fish. The fish moved upstream during floods and then past the traps as the water receded. Bigger fish escaped the traps ensuring that females with the larger quantities of eggs had a higher survival rate than smaller ones because larvae from larger fish have a higher survival rate than those produced by smaller fish. “The fish traps constituted an ecological system for catching the maximum number of fish with the minimum effort, while at the same time sustaining the stock. The fish traps proved their effectiveness every year as they supported annual gatherings of more than 5000 people” (Sveiby & Skulthorpe, 2006, 88).
Equally impressive were the eel farms in southeast Victoria where Indigenous people cut 300 metre canals into bedrock, constructed 50 metre ling aqueducts and dug out many kilometres of channels to extend the eel grounds. Whether the system was in flood or drought pot traps were effective in these regulated flows (Gammage, 2011, 283).
Yidiny people living in the rainforests near Cairns were guided by the flowering of a small bean tree as the most propitious time to build stone fish-traps. The fish would be at their fattest easily trapped in the shallowest reaches of the river (Bottoms, 2008, 27).
Ingenious gurrka gurl traps used by Liyagalawumirri People in north Arnhem Land were constructed at the end of the ‘wet’, in late March and April, when ‘Rain finish: him flower everything; grass long, him fall down” (Thomson, 2005, 172); when the estuarine fish such as catfish and barramundi were returning to the estuarine waters of Castlereagh and Buckingham Bays. A weir is constructed out of poles, saplings and grasses plastered down with blue mud. Paperbark funnels lashed together with cane grass are inserted into the weir and a platform of saplings is constructed on the downstream side. Large fish are caught at night suspended in platform as the water pours through the web of saplings. The platforms are covered with leafy branches to disguise the catch from sea eagles and other flying predators (Thomson, 2005, 144-8).
Indigenous Rangers are currently working with computers loaded with CyberTracker software, digital cameras, sound recorders and video cameras to monitor selected wetland resources in Arnhem Land. Healthy country comprises lots of grass around the swamps and billabongs, water lilies, flat ground and clean water. Such areas are fenced off from feral animal incursions that initiate buffalo wallows, pads and pugs from pigs and horses and dirty water (Ens, 2012, 54-5). Djelk Women Rangers used the software and their traditional knowledge to investigate the dieback of paperbark trees in the billabongs. They concluded that feral animals had changed the conductivity of water stirring up ammonium in the turbid water. Culling of buffalo and pig and other feral animal populations was recommended, a course of action not popular with some traditional owners who do not want the animals killed because of they have “sentimental, spiritual, monetary and customary harvest values” Ens, 2012, 58-9).