Statistical phylogeographic tests of competing 'Lake Carpentaria hypotheses' in the mouth-brooding freshwater fish, Glossamia aprion (Apogonidae)

Glacial cycles during the Pleistocene reduced sea levels and created new land connections in northern Australia, where many currently isolated rivers also became connected via an extensive paleo-lake system, 'Lake Carpentaria'. However, the most recent period during which populations of freshwater species were connected by gene flow across Lake Carpentaria is debated: various 'Lake Carpentaria hypotheses' have been proposed. Here, we used a statistical phylogeographic approach to assess the timing of past population connectivity across the Carpentaria region in the obligate freshwater fish, Glossamia aprion. Results for this species indicate that the most recent period of genetic exchange across the Carpentaria region coincided with the mid- to late Pleistocene, a result shown previously for other freshwater and diadromous species. Based on these findings and published studies for various freshwater, diadromous and marine species, we propose a set of 'Lake Carpentaria' hypotheses to explain past population connectivity in aquatic species: (1) strictly freshwater species had widespread gene flow in the mid- to late Pleistocene before the last glacial maximum; (2) marine species were subdivided into eastern and western populations by land during Pleistocene glacial phases; and (3) past connectivity in diadromous species reflects the relative strength of their marine affinity.

Finding Carpentaria

Invited – and inspired – by Rikki Gunn of GhostNets Australia, in September 2008 sixteen Queensland University of Technology (QUT) design and engineering students and four staff set off on a 2488km journey to spend a fortnight in Karumba on the Gulf of Carpentaria. We went to undertake a strategic planning project we called Linking Karumba, to encourage social, economic, environmental and cultural linkages across the town. During this visit, we and our local project partners realised there should be a second half to the project, in the other Carpentaria Shire town of Normanton, which saw another group of us travelling north again in 2010 to undertake Get EnGulfed: Normanton2020, looking back and forwards to propose strategies to strengthen local and regional identities. The responsiveness of our students’ work to the character of Carpentarian culture and environment indicate remarkable levels of immersion, and the community expressed their enjoyment of the process and outcomes. As for us - QUT staff and students - we had a marvellous time doing these projects, and this little book is the story of our finding of the landscapes and communities of Carpentaria “where the outback meets the sea”, and of the project work we did together with locals in the two towns. We go to press as news arrives of the official opening of the Karumba Walking track, linking the two parts of the town. We can’t wait to return and make the walk. Shannon Satherley, 2013

Mid-Holocene Aboriginal occupation of offshore islands in northern Australia? A reassessment of Wurdukanhan, Mornington Island, southern Gulf of Carpentaria, Australia

Claims for mid-Holocene Aboriginal occupation at the shell matrix site of Wurdukanhan, Mornington Island, Gulf of Carpentaria, Australia, are reassessed through an analysis of the excavated assemblage coupled with new surveys and an extensive dating program. Memmott et al. (2006, pp. 38, 39) reported basal ages of c.5000–5500 years from Wurdukanhan as 'the oldest date yet obtained for any archaeological site on the coast of the southern Gulf of Carpentaria' and used these dates to argue for 'a relatively lengthy occupation since at least the mid-Holocene'. If substantiated, with the exception of western Torres Strait, these claims make Mornington Island the only offshore island used across northern Australia in the mid-Holocene where it is conventionally thought that Aboriginal people only (re)colonised islands after sea-level maximum was achieved after the mid-Holocene. Our analysis of Wurdukanhan demonstrates high shellfish taxa diversity, high rates of natural shell predation and high densities of foraminifera throughout the deposit demonstrating a natural origin for the assemblage. Results are considered in the context of other dated shell matrix sites in the area and a geomorphological model for landscape development of the Sandalwood River catchment.

Environmental context for late Holocene human occupation of the South Wellesley Archipelago, Gulf of Carpentaria, northern Australia

A 2400 year record of environmental change is reported from a wetland on Bentinck Island in the southern Gulf of Carpentaria, northern Australia. Three phases of wetland development are identified, with a protected coastal setting from ca. 2400 to 500 years ago, transitioning into an estuarine mangrove forest from ca. 500 years ago to the 1940s, and finally to a freshwater swamp over the past +60 years. This sequence reflects the influence of falling sea-levels, development of a coastal dune barrier system, prograding shorelines, and an extreme storm (cyclone) event. In addition, there is clear evidence of the impacts that human abandonment and resettlement have on the island's fire regimes and vegetation. A dramatic increase in burning and vegetation thickening was observed after the cessation of traditional Indigenous Kaiadilt fire management practices in the 1940s, and was then reversed when people returned to the island in the 1980s. In terms of the longer context for human occupation of the South Wellesley Archipelago, it is apparent that the mangrove phase provided a stable and productive environment that was conducive for human settlement of this region over the past 1000 years.

Size-dependent natural mortality of juvenile banana prawns Penaeus merguiensis in the Gulf of Carpentaria, Australia

Natural mortality of marine invertebrates is often very high in the early life history stages and decreases in later stages. The possible size-dependent mortality of juvenile banana prawns, P. merguiensis (2-15 mm carapace length) in the Gulf of Carpentaria was investigated. The analysis was based on the data collected at 2-weekly intervals by beam trawls at four sites over a period of six years (between September 1986 and March 1992). It was assumed that mortality was a parametric function of size, rather than a constant. Another complication in estimating mortality for juvenile banana prawns is that a significant proportion of the population emigrates from the study area each year. This effect was accounted for by incorporating the size-frequency pattern of the emigrants in the analysis. Both the extra parameter in the model required to describe the size dependence of mortality, and that used to account for emigration were found to be significantly different from zero, and the instantaneous mortality rate declined from 0.89 week(-1) for 2 mm prawns to 0.02 week(-1) for 15 mm prawns.

Flow impacts on estuarine finfish fisheries of the Gulf of Carpentaria

The estuaries of Australia s tropical rivers support commercial fisheries for finfish and shellfish valued at over $220 million per annum. There are also significant tourism-related and local recreational and indigenous fisheries for icon species such as barramundi. Development of water resources in Australia's Tropical Rivers region is being considered for the Flinders, Mitchell, McArthur, Roper, Daly and Victoria catchments. Greater knowledge of the freshwater requirements of tropical aquatic ecosystems, including estuaries is crucial, so that the communities of catchments where water resource development occurs can be assured that the downstream effects of such development are considered and managed based on the best available knowledge.

The Bishop of Carpentaria and the Torres Strait pearlers' strike of 1936

The exploitation of Islander pearl divers in Torres Strait and the Queensland Government's control of divers' wages was the major cause of a strike by 400 divers in 1936. The strike was also fuelled by overall discontent with the Queensland Government's rule and a desire to be free of the Queensland Protectors. An address in 1935 by Stephen Davies, Bishop of Carpentaria, urging the Commonwealth of Australia to strip Queensland and other states of management of Island and Aboriginal affairs provided the catalyst. Davies's Torres Strait Island clergy played a pivotal role in the resistance to state control. One lasting effect of the strike lay in the introduction of elected Islander councils in 1937, but what happened subsequently allowed the perpetuation of Queensland control through the new Department of Native Affairs. The results of the strike fell short of the complete transfer to the Commonwealth that the Torres Strait pearl divers and clergy had envisaged.

Broken songs and ecology : writing about the Gulf of Carpentaria

Book review of Carpentaria by Alexis Wright.

A politics of the Dreamtime : destructive and regenerative rainbows in Alexis Wright's Carpentaria

A literary criticism of the book "Carpentaria," by Alexis Wright is presented. It discusses the representation of indigenous knowledge in the novel. It outlines the characters and explores the symbolic significance of these characters. It examines the themes of the novel, including the dreamtime mythology as an alternative form of scientific discourse. An overview of the story of the novel is also given.

Understanding Isolation and Change in Island Human Populations through a study of Indigenous Cultural Patterns in the Gulf of Carpentaria

This paper presents a set of hypotheses to explain the cultural differences between Aboriginal people of the North and South Wellesley Islands, Gulf of Carpentaria and to characterise the relative degree and nature of their isolation and cultural change over a 10,000-year time-scale. This opportunity to study parallelisms and divergences in the cultural and demographic histories of fisher-hunter-gatherers arises from the comparison of three distinct cultural groupings: (a) the Ganggalida of the mainland, (b) the Lardil and Yangkaal of the North Wellesley Islands, and (c) the Kaiadilt of the South Wellesley Islands. Despite occupying similar island environments and despite their languages being as closely related as for example, the West Germanic languages, there are some major differences in cultural, economic and social organization as well as striking genetic differences between the North and South Wellesley populations. This paper synthesizes data from linguistics, anthropology, archaeology, genetics and environmental science to present hypotheses of how these intriguing differences were generated, and what we might learn about early processes of marine colonization and cultural change from the Wellesley situation.

Palaeoenvironment records of six sediment cores collected in the Gulf of Carpentaria

The Gulf of Carpentaria is an epicontinental sea (maximum depth 70 m) between Australia and New Guinea, bordered to the east by Torres Strait (currently 12 m deep) and to the west by the Arafura Sill (53 m below present sea level). Throughout the Quaternary, during times of low sea-level, the Gulf was separated from the open waters of the Indian and Pacific Oceans, forming Lake Carpentaria, an isolation basin, perched above contemporaneous sea-level with outlet channels to the Arafura Sea. A preliminary interpretation is presented of the palaeoenvironments recorded in six sediment cores collected by the IMAGES program in the Gulf of Carpentaria. The longest core (approx. 15 m) spans the past 130 ka and includes a record of sea-level/lake-level changes, with particular complexity between 80 and 40 ka when sea-level repeatedly breached and withdrew from Gulf/Lake Carpentaria. Evidence from biotic remains (foraminifers, ostracods, pollen), sedimentology and geochemistry clearly identifies a final marine transgression at about 9.7 ka (radiocarbon years). Before this transgression, Lake Carpentaria was surrounded by grassland, was near full, and may have had a surface area approaching 600 km-300 km and a depth of about 15 m. The earlier rise in sea-level which accompanied the Marine Isotopic Stage 6/5 transgression at about 130 ka is constrained by sedimentological and biotic evidence and dated by optical- and thermoluminescence and amino acid racemisation methods.