The Warruwi Pond enigma : pre- European aquaculture in Arnhem Land?
Creators: name: Dobson, Graeme Thomas
Publisher: name: The Australian National University
Year: 2015

description: This thesis sets out to determine if comparative aquaculture and marine wild stock management techniques can be used to identify early foreign activity in Arnhem Land, Northern Territory of Australia. There is one known pre-European example of aquaculture in Arnhem Land-Indigenous pearl cultivation by Yolngu, the Indigenous clans of northeast Arnhem Land. There is also a large hitherto undescribed stone walled, clay lined pond in the low intertidal area in Mardbulk Bay off the community of Warruwi on South Goulburn Island in west Arnhem Land (the Warruwi pond) which was potentially used for either aquaculture or wild marine stock management. Local clans do not claim this structure nor are they aware of its origins or uses. The Warruwi Pond is described in this thesis and that description used to compare it with structures used in four possible use scenarios. These were a ceremonial ground, a wild stock management tool, a fish trap and aquaculture. It is also compared to similar structures with known uses in the region. Two linked activities are identified as possible uses for the Warruwi pond, holding live sea cucumbers prior to processing and as a spawning enhancement device (where a single species is heavily stocked in a confined area and induced to breed, the proximity of individuals maximises breeding success). East Arnhem Land pearl cultivation is also described and compared to known modern and historic techniques to determine the origins of the Arnhem Land method. It is probable that the pearl industry, both wild harvested and cultured, was introduced to the Yolngu as they had no significant use for pearls other than to trade with foreigners and were, therefor, unlikely to have learned the technique themselves. Comparisons of the Warruwi pond and structures associated with pearl cultivation determined that the two were probably not linked, leading to the conclusion that two or more distinct groups of foreign people were active in Arnhem Land in pre-European times. Identifying these people (albeit tentatively) required a detailed examination of the history of the region, of sea cucumber cultivation, trade and consumption, and pearl trade and cultivation. Evidence in each of these topics is sparce for the most part, so use is made of several disparate sources and observations. Using aquaculture and marine wild stock management as central themes, this thesis draws together a range of sources to determine which were the most likely foreign groups active in pre-European north Australia, and proposes hypotheses on when they came, how long they stayed, what they did there and why they departed. This thesis adds two more significant pieces of evidence for foreign activity in north Australia prior to the mid-18th C, but given the scant and often controversial nature of other evidence the conclusions of this research remain tentative and provisional. Further research is suggested into several enigmatic artefacts identified in the course of this study which may serve to reinforce or undermine these conclusions.