Intertidal Foraging on Atolls: Prehistoric Forager Decision-Making at Ebon Atoll,Marshall Islands

Prehistoric molluscan assemblages provide insights into long-term patterns of human landscape use, environmental change, and human impacts to marine resources. The investigation of forager decision-making regarding the selection of certain mollusc taxa and/or the exploitation of particular habitats is fundamental to understanding human-environment interactions in the past, and is relevant for understanding trajectories of human impacts to the intertidal zone in coastal settings. We document variability in the collection of molluscs at two archaeological sites on Ebon Atoll, Republic of the Marshall Islands: one on a windward, intermittently occupied islet, and the other on a permanently inhabited leeward islet. All molluscan taxa were assigned to a range of habitats within a hierarchical classification scheme for intertidal marine environments. The relative abundance of taxa from each habitat was used as a proxy for forager decision-making. We report a generalized, non-selective, foraging strategy focused on gastropod taxa from the high intertidal and supratidal. These results indicate that rather than focusing intensively on select taxa, intertidal foragers targeted particular marine habitats, taking advantage of the predictable behaviors of the molluscs that inhabit them.     

The Palaeoenvironmental Implications of the Distribution of Intertidal Foraminifera in a Tropical Australian Estuary: a Reconnaissance Study

Modern intertidal foraminifera were investigated in a mangrove‐lined microtidal distributary channel of the Barron River Delta (Cairns, Queensland, Australia). A monospecific assemblage of Trochammina inflata characterises saltmarsh environments (Biozone 1), whilst the more regularly inundated tidal flat is dominated (≥55%) by Ammonia beccarii (Biozone 2). Within the tidal flat environment, two foraminiferal subdivisions can be recognised; a high tidal flat assemblage (Biozone 2a) characterised by ≥70% Ammonia beccarii and low diversity, and a low tidal flat assemblage (Biozone 2b) with 55–65% Ammonia beccarii and high diversity (due to the settling out of small allochthonous species transported into the estuary from shelf environments). Foraminiferal distributions are also compared with tide levels estimated in the field. It appears approximately that Biozone 1 occurs between High Water and Mean High Water (MHW), Biozone 2a between MHW and Mean Tide Level (MTL), and Biozone 2b between MTL and Low Water. From this preliminary study, it is concluded that foraminifera possess significant potential in palaeoenvironmental studies of tropical Australian estuaries as indicators of intertidal environments, and also tidal levels.     

On the Possible Origins of an Unusual (Mid to Late Holocene) Coastal Deposit,Old Punt Bay,South‐East Australia

An unusual coarse, shelly sedimentary unit is found elevated above present mean sea level in a sheltered pocket embayment at Old Punt Bay in south‐eastern Australia. The coarse sediments, diverse microfauna, and large shelly macrofauna of mixed affinity suggest that the deposit is the result of high‐energy deposition. The deposit was previously thought to have been deposited 1000–1300 cal bp based on one shell dated using ¹⁴C and amino acid racemisation. However, additional ¹⁴C dating indicates a likely age of ～2500 cal bp . Regardless of age constraints, the presence of rock‐encrusting oyster shells and large articulated bivalves, suggests that the depositional event must have been capable of removing and transporting coarse sediments (rock clasts), bivalves, and oysters shells from a variety of seaward environments and depositing them with little abrasion, something storm waves are unlikely to do. The deposit may be tsunamigenic. If a tsunami origin is accepted, the new dating results indicate that it is possibly coeval with a tsunami event previously reported to have affected several other sites along the coast of New South Wales at c. 2900 cal bp . Consequently, this deposit provides evidence for the event at a new site and importantly, a tighter constraint on the likely date of the events occurrence. It further adds weight to the developing catalogue of palaeotsunamis that may have affected the south‐eastern coast of Australia. Regardless of the deposit's origins, if viewed from a coastal planning perspective, this deposit indicates that this part of the coast has experienced large‐scale overwash events in the past that if repeated, would be catastrophic. There are serious implications for risk management.     

A Multi‐disciplinary Approach to the Archaeological Investigation of a Bedrock‐Dominated Shallow‐Marine Landscape: an example from the Bay of Firth,Orkney, UK

Investigation of shallow‐marine environments for submerged prehistoric archaeology can be hampered in many localities by extensive bedrock exposure and thus limited preservation potential. Using the concept of ‘seamless archaeology’ where land‐based archaeology is integrated across the intertidal zone through to the offshore, a multi‐disciplinary approach is essential. This approach taken in the Bay of Firth, Orkney uses geophysics, historical archive and ethno‐archaeology, coastal geomorphology, palaeo‐environmental analyses and sea‐level science, and allows a clearer understanding of the landscape in which prehistoric settlers lived. While acknowledging the limitations of the preserved environment, we are successful in identifying areas of archaeological potential on the sea‐bed for both upstanding structural elements as well as sediment preservation that contains evidence for human occupation. This has wider implications beyond Orkney's World Heritage sites to provide a blueprint for similar studies elsewhere in the coastal zone. © 2012 The Authors     

Luminescence dating of young coastal deposits from New Zealand using feldspar

A new measurement protocol has been tested on K-feldspars from Whanganui Inlet and Parengarenga Harbour, New Zealand. A Single Aliquot Regenerative (SAR) dose protocol, using two successive infrared (IR) stimulations (post-IR IR SAR protocol) is setup for these young (<1000 years) coastal sediments. Significant anomalous fading (g _2days =7 %/decade) is observed using the conventional IR signal measured at 50°C. In contrast, the fading rate of the IR signal measured at elevated temperature (150°C) after the IR stimulation at 50°C (a post-IR IR signal) is not significant (g _2days ≤ 1 %/decade). Surprisingly low residual infrared stimulated luminescence (IRSL) signals were observed for a surface sample, suggesting that accurate ages as young as ∼50 years can be obtained for these recent deposits. IRSL ages ranging between 48±6 years and 1050±50 years are obtained from six samples, indicating that sediment accumulation has occurred at the two sites during the last millennia, despite a falling trend in relative sea-level in Whanganui Inlet and a stable relative sea-level at Parengarenga Harbour.     

Palaeoenvironmental reconstruction of La Olla,a Holocene archaeological site in the Pampean coast (Argentina)

The evolution of littoral palaeoenvironments in the southern Pampas region of Argentina towards the end of the early Holocene and the beginning of the mid Holocene is discussed, and the formation processes of the archaeological site of La Olla are analysed. This site is located in the intertidal zone of the present beach and is remarkably well-preserved. The human occupation at the site has been dated at between 7400 and 6480 yrs BP, and is interpreted as a place for the processing and consumption of the southern fur seal (Arctocephalus australis) and southern sea-lion (Otaria flavescens). It is concluded that biostabilization by microbial mats of the sedimentary structures and archaeological remains that developed and are present on the tidal flat prevented their erosion by wind, turbulence currents and waves. This is what has permitted the exceptional preservation of the site. On the basis of the analyses of one of the sectors of the site it can be concluded that the sedimentary succession of the La Olla site is the result of the coastal environmental changes during the early–mid Holocene in the pre-maximum transgressive episode. During this interval a tidal flat developed on the Pleistocene abrasion platform. Human occupation occurred during the formation of mixohaline marsh, an upper intertidal–lower supratidal zone ecosystem.     

The Pleistocene of Rabat (Morocco): Mollusks,Coastal Environments and Human Behavior

The Rabat-Témara region of the Moroccan Atlantic coast reveals a succession of Quaternary palaeobeaches. This coastal area is dotted with numerous prehistoric caves. The study of the Upper Pleistocene coastal landscape associated with these caves is of paramount importance in the knowledge of human population subsistence. During the Upper Pleistocene, the ocean level changes drastically influenced the coastal geomorphology as well as the fauna assemblages. The chrono-lithostratographical analysis of the coastal sedimentary formations allows the distinction of three sequences rich in marine fauna. These sequences date from MIS 11 to MIS 5. The identification of malacofauna species from these deposits revealed 39 species, along with Bryozoans, Crustaceans, and Echinoids. These assemblages show a constant fauna cortege highlighted by the dominance of the amphi-Atlantic species Stramonita haemastoma. This species shows an increase in the number of specimens in the uppermost part of marine deposits, probably in relation with a climate warming in the MIS 5. This fauna of both intertidal rocky substrates and sandy substratum indicates environmental conditions close to the present-day Rabat-Témara coastline. As in other coastal locations of Africa from MIS 5, the Middle Stone Age Homo sapiens population benefitted from a littoral environment rich in coastal resources. Comparison between thanatocenoses and archaeological records allows us to identify both species available for Middle Stone Age population and those preferred for human use.     

Shoreline Change and Coastal Vulnerability Characterization with Landsat Imagery: A Case Study in the Outer Hebrides,Scotland

Abstract

Observation of cause–effect patterns of change in coastal environments provides insights into vulnerable areas and supports prediction and adaptation to flooding and erosion. Historic and periodic (6–8 year intervals) imagery from the Landsat archive is used to investigate transformations in the Atlantic coast of two Scottish islands over the period 1989–2011. Supervised classification of spectrally normalized images followed by change detection and spatial analysis reveals the patterns of change and the location of the most dynamic coastal areas. Quantitative measures of recent shifts and movement rates of relevant coastal lines, such as the lower limit of land-based vegetation, are assessed with the Digital Shoreline Analysis System. While very low rates are indicated for horizontal changes in the position of the lower limit of land-based vegetation (0.3?m?y^?1), specific areas have been subjected to high rates of coastal progradation as well as erosion (e.g. 2.5?m?y^?1 at Stilligarry). Information derived from satellite data supports the characterization of geomorphologically dynamic coasts at regional scales. With a rich and open access archive of imagery, a commitment to continuity, and compatibility with the Earth observation missions of other space programs, the Landsat mission offers useful and otherwise unavailable data for monitoring of coastal areas.     

Improving Coastal Vulnerability Assessment Methodologies for Integrated Coastal Zone Management: an Approach from South Australia

The global concern about human-induced climatic change and its potential effect on sea-level has dominated the debate on coastal vulnerability, particularly since a common assessment methodology was developed by the Intergovernmental Panel on Climate Change in 1991. There have been numerous attempts to use or adapt this methodology but the focus has remained on sea-level rise as the single most important issue for coastal vulnerability. This paper presents a revised and more holistic coastal vulnerability assessment methodology which incorporates spatial and temporal scales relevant to the predicted impacts of climatic change and current human-induced hazards. Three studies in contrasting coastal environments of South Australia demonstrate that there are significant regional variations in sea-level response, human-induced hazards and local planning issues and that these may present a greater immediate threat than the possibility of sea-level rise.     

Quantifying the effects of erosion on the archaeology of intertidal environments: A new approach and its implications for their management

Abstract

While the high archaeological and palaeoecological value of intertidal deposits has become well known, approaches to their management remain extremely restricted. Despite the often high levels of erosion experienced by some sites there has been very little development in methods aimed at understanding or quantifying the threats. This paper presents an approach aimed at monitoring erosion within the Humber estuary, UK, where previous finds including Bronze Age boat remains and trackways have made it an area of international importance. Two sites have been investigated and the results from these demonstrate both the high rate of sediment removal and also the highly variable nature of intertidal erosion. It is argued that global figures relating to rates of erosion are wholly inappropriate when attempting to manage archaeological deposits that have survived in intertidal environments. Rather, management of such archaeologically rich but threatened landscapes is only possible through regular quantitative monitoring. Such an approach offers coastal protection authorities a valuable opportunity to assess the long-term progress of erosion and coastal change. This methodology could be employed alongside management agreements within those particular coastal cells or process units that have been identified in a Shoreline Management Plan.     

Australian Cenozoic Bryozoa, 2: Free-living Cheilostomata of the Eocene St. Vincent Basin,S.A., including Bonellina gen. nov

Schmidt, R., March 2007. Australian Cenozoic Bryozoa, 2: Free-living Cheilostomata of the Eocene St. Vincent Basin, S.A., including Bonellina gen. nov. Alcheringa 31, 67-84. ISSN 0311-5518.

Free-living bryozoans are diverse in the Eocene sediments of the St. Vincent Basin, South Australia. They include Bonellina pentagonalis gen. et sp. nov., Otionellina sp. cf. O. exigua (Tenison Woods), Otionellina sp. cf. O. cupola (Tenison Woods), Tubiporella magna (Tenison Woods), Celleporaria nummularia (Tenison Woods), and an indeterminate species only found as moulds. This diversity and abundance is highest in the sediments representing the initial transgressive marine facies, where they occur in ‘sand fauna’ bryozoan assemblages (e.g. with Melicerita and Siphonicytara). Free-living bryozoans decrease up-section and are absent from latest Eocene sediments, indicating a significant environmental shift.

Rolf Schmidt [rschmid@museum.vic.gov.au], Museum Victoria, Melbourne, Vic 3001, Australia; received 18.3.2005, revised 14.12.2005.     

Lapita subsistence strategies and food consumption patterns in the community of Teouma (Efate,Vanuatu)

The subsistence strategies of the Lapita populations (3100–2800 BP), the first colonisers of the pristine environments of the islands of Eastern Melanesia and Western Polynesia, have been a matter of ongoing debate for decades. Opinions have ranged between the two extremes of Lapita colonisers being either characterised as highly mobile foragers to fully horticultural communities. To further address the question, this paper presents stable carbon and nitrogen isotopic data obtained from analyses of human and animal collagen samples from the site of Teouma (Efate, Vanuatu) dated to between c. 3000–2500 BP. The isotopic signatures obtained from 28 samples (23 human and 5 animal), interpreted in combination with isotopic information from several coastal and insular environments, suggest a diet primarily made up of terrestrially derived animal protein with lesser contributions from vegetable produce and inshore marine species. Comparisons linking the isotopic data gleaned from the Teouma individuals and Lapita subsistence patterns reconstructed through archaeozoological and archaeobotanical remains support the hypothesis of a mixed economy, that included terrestrial foraging, inshore marine exploitation and a low level of food production for at least some of the earliest Lapita colonists in Vanuatu.     

Palaeobiogeography of the Ordovician trilobite Prosopiscus,with a new species from western New South Wales

Prosopiscus is particularly important in Ordovician palaeobiogeography because of its wide geographic distribution in Gondwana and peri-Gondwanan regions. It appears to have been confined to low palaeolatitudes, representing a characteristic member of the warm water eastern Gondwanan shelf faunas. Trends in the distribution of the Ordovician genus can be observed due to its long stratigraphic range. Prosopiscus was restricted to, and may have originated in, Australia during the late Early Ordovician (Bendigonian-Chewtonian). By the Middle Ordovician (Darriwilian), Prosopiscus had dispersed to other parts of Gondwana and peri-Gondwana, including the North and South China blocks, Tarim, central Himalayas, and the Argentine Precordillera (South America). Possible explanations for the distribution of Prosopiscus are that: (1) there were no oceanic barriers preventing dispersal of trilobites between different regions of Gondwana, thus permitting uninhibited migration over vast distances; (2) Prosopiscus was not restricted to a specific biofacies; (3) a major eustatic transgression during the early Darriwilian may have facilitated the dispersal of Prosopiscus in allowing further development and expansion of marine environments; and (4) a prolonged planktonic larval stage may have permitted wide dispersal.

Prosopiscus lauriei sp. nov. is described from the late Early Ordovician (Bendigonian-Chewtonian) Tabita Formation at Mount Arrowsmith, northwestern New South Wales, Australia. The new species is closely related to P. praecox, from the Nora Formation, Georgina Basin, central Australia, and to P. magicus from northwest China.     

Palaeontology of the Cerros Bayos section,Roca Formation (Danian), La Pampa Province,Argentina

Palynofloras from an outlier of Tertiary sediments in the One Tree Hill area north of Adelaide are nonmarine and correlate with similar assemblages from Middle Eocene North Maslin Sands from Maslin Bay and Golden Grove. Although there are similarities with time-equivalent Lower Nothofagidites asperus Zone palynofloras in the Gippsland Basin, a number of species in the South Australian palynofloras do not extend below the Late Eocene in the Gippsland sequences. This indicates earlier appearances for these species in southcentral Australia. The sediments overlie a highly weathered bedrock palaeosurface, indicating that a phase of significant weathering occurred prior to the Middle Eocene. A number of selected taxa are illustrated and their distribution in the palynofloras is discussed. Two new species, Proteacidites mildenhallii and Proteacidites parrawirrensis, are described and one species, Rhoipites byfieldensis, is emended.     

Mare Nullius: Indigenous Rights in Saltwater Environments

This article uses two case studies to illustrate the subjection of indigenous peoples’ marine territories to a ‘double jeopardy’ of exclusion — jurisdictional and proprietary — through the legal and administrative practices of European ‘settler’ states in Australia and Canada. While the fiction of terra nullius as a legal rationale for refuting indigenous rights of property and governance has steadily eroded in recent decades, its counterpart mare nullius has proven, so far, more resistant. The authors examine how state conceptions of jurisdiction, property and boundary‐making in coastal areas accomplish the distortion and fragmentation of the coastal and marine spaces of Torres Strait Islanders in northern Queensland, Australia, and of the Cree and Inuit peoples of James and Hudson Bays in northern Que´bec, Canada. Assumptions of land–sea continuity underlie these peoples’ cultural constructions of coastal and marine environments. In examining the progress that each has made in reasserting ownership and control of coast and sea, it seems that recognition and reinforcement of their institutions for managing marine spaces and resources offer the best prospect for reconnecting fractured jurisdictional domains, and for bringing about social equity, environmental protection, and self‐determined regional development.     

Electron Spin Resonance–A Relative Dating Technique for Quaternary Sediments Near Warrnambool,Victoria

An assessment is made of the application of electron spin resonance (ESR) analysis of aragonitic molluscs for chronostratigraphic studies of Late Quaternary marine and estuarine sediments in western Victoria. Evaluation of the gamma equivalent dose (ED) provides a measure of the amount of natural radiation a mollusc has received since its death. In the absence of significant uranium enrichment the ED values of samples collected from similar sedimentary environments provide a reliable measure of relative age The use of 95% confidence limits of ED values enables the discrimination of distinct age groups of molluscs The age groups are referred to here as ED zones. One coastal marine species, the gastropod Turbo (Subninella) undulatus shows a time dependent change in sensitivity to gamma radiation that can also be used to discriminate between ED zones ESR analysis can be used in combination with amino acid racemization studies to correlate Quaternary coastal deposits in southern Australia.     

Eocene palynology of the Mulga Rocks deposits,southern Gunbarrel Basin,Western Australia

Mack, C.L. & Milne, L.A., 19.2.2015. Eocene palynology of the Mulga Rocks deposits, southern Gunbarrel Basin, Western Australia. Alcheringa 39, xxx–xxx. ISSN 0311-5518

Late Eocene palynomorph assemblages have been recovered from carbonaceous sediments within a tenement centred on the Mulga Rocks uranium deposits, currently under exploration by Energy and Minerals Australia. The Mulga Rocks deposits occur in a palaeovalley incised into rocks of the Cretaceous southern Gunbarrel Basin, and the underlying Neoproterozoic to Late Devonian southern Officer Basin, Western Australia. The palynomorph assemblages recovered from the Mulga Rocks deposits most closely resemble the Middle Nothofagidites asperus Zone equivalent of the Murray Basin. Many of the species recovered, and the abundance and diversity at which they are present, are considerably different from most of the southeastern Australian palynoassemblages of similar age. Common in the assemblages are species belonging to Nothofagus, Casuarinaceae, Myrtaceae and Picrodendraceae. Proteaceous species are diverse, with Banksia affiliates being prominent. Of most significance are assemblages dominated by Myrtaceidites species, which also contain affiliates of Petrophile and Xylomelum that occur in modern heathland, woodland and dry sclerophyll forests. The prominence of these taxa, and their co-occurrence, suggests that sclerophylly, at present linked closely with xeromorphy and now ubiquitous in the vegetation of Western Australia, was present in the late Eocene of southern Australia and suggests that at that time this trait may have been more prevalent than previously interpreted.

Charlotte Mack [charlotte.mack@postgrad.curtin.edu.au] and Lynne Milne [l.milne@curtin.edu.au], Department of Applied Geology, Curtin University of Technology, GPO Box U1987, Perth, WA 6845, Australia. Received 4.7.2014; revised 11.2.2015; accepted 19.2.2015.     

From Pleistocene Mariners to Complex Hunter-Gatherers: The Archaeology of the California Channel Islands

California’s Channel Islands were home to some of the most distinctive Native American peoples along the Pacific Coast. Never connected to the mainland during the Quaternary, the Channel Islands have an impoverished terrestrial flora and fauna, but some of the richest and most productive marine environments in the Americas, including diverse kelp forest, intertidal, and offshore marine habitats. Native Americans occupied the Channel Islands for roughly 13,000 calendar years until the early nineteenth century, providing one of the longest and best preserved records of maritime hunter-gatherers in the Americas. We provide an overview and analysis of Channel Islands archaeology, from the relatively mobile peoples who colonized the islands during the Late Pleistocene to the complex hunter-gatherers documented by early Spanish explorers. Our analysis demonstrates the importance of Channel Islands archaeology for enhancing knowledge on a number of broad anthropological issues, including coastal and aquatic adaptations, seafaring, cultural complexity, trade and exchange, and ancient human impacts on the environment.     

Strongly aligned coastal boulders on Ko Larn island (Thailand): a proxy for past typhoon‐driven high‐energy wave events in the Bay of Bangkok

Recent studies of elevated carbonate boulder deposits on several rock islands near Bangkok have indicated that Thailand's capital city may not be as protected from typhoon strikes as previously thought. Here, new evidence is presented for past high‐energy wave (HEW) events in the form of statistically significant patterns of boulder alignment on exposed rocky shorelines of Ko Larn island. The long‐axis orientations of 193 coastal sandstone boulders were analysed across four study sites. Several scenarios for the unimodal, bimodal, and polymodal patterns found can be envisaged. Either the most recent HEW event was the strongest—in which case most clasts were rearranged unimodally (one observation site), or the strongest HEW event was earlier and subsequent weaker ones realigned only smaller boulders to produce bimodal or polymodal patterns (three observation sites). Inferred northeastward or eastward onshore flow directions are consistent with palaeo‐typhoons penetrating into the Bay of Bangkok on northwestward curving tracks. The calculated minimum flow velocities required to transport all sampled boulders are 5.5–7.8 m s^?1, similar to other findings throughout the Asia‐Pacific region. It was observed that the absence of a fitted boulder geomorphology lends credence to the earlier proposed time frame of 150–200 years between typhoon phases in the upper Gulf of Thailand. The current work has provided additional insights into the characteristics of past HEW events that have a possibility of reoccurring again at some time in the future. Our findings continue to raise awareness for a reassessment of the risks of coastal hazards for the Chao Phraya River delta and densely populated Bangkok, for which storm surge modelling should be an urgent priority, so as to give better perceptions on how typhoon‐driven marine incursion would impact the city.