Coastal Shell Middens Research Articles

Complementary spaces in marine littoral exploitation? A comparative study of rock shelter and shell middens occupations from the lower basin of the Deseado River, Argentine Patagonia

The archaeological record of the Province of Santa Cruz’s north Atlantic coast in Argentine Patagonia is represented mainly by middens. These shell middens are made up of the calcareous exoskeletons of mollusks, as well as skeletal remains of vertebrate fauna, lithic artifacts, and carbonized plant remains, intermixed with a varying quantity of sedimentary soil. Recently, along the Lower Basin of the Deseado River, outcrops have been identified that would have functioned in the past as rock shelters for hunter-gatherers who occupied the area during the Middle and Late Holocene. With the aim of expanding our knowledge concerning the dynamics of use of coastal spaces, we began a stratigraphic study of the shell middens and rock shelters. Here, we present a comparative analysis of the occupation characteristics registered at both types of sites and their possible structuring in terms of mobility and functionality. Rock shelters would have functioned primarily as contexts for short-term activities related to the processing and consumption of fauna, mainly terrestrial and to a lesser extent marine fauna. These probably structured seasonal mobility strategies that linked coastal shell middens, defined as multiple activity contexts, with hinterland areas that might have been related to the specific pursuit of other activities.

The Prehistoric Fisheries of Akab Island (United Arab Emirates): New Insights into Coastal Subsistence during Neolithic in Eastern Arabia

The Neolithic period in Eastern Arabia (especially from 5500 to 3100 BC) is better understood due to recent excavations of stratified sites stretching from Kuwait to the Sultanate of Oman. When oasis agriculture developed from the Bronze Age onwards, herding, shellfish gathering, and fishing became the primary modes of subsistence, and despite strong regional aridity, coastal shell middens provide the best preservation conditions in the Persian Gulf. Akab, one of the many Neolithic shell middens of the United Arab Emirates coastline, is situated in the Umm al-Quwain lagoon. This settlement is dated to the second part of the fifth millennium BC and has provided more than 37,000 fish remains, derived from over 50 fish species. Ichthyofaunal analysis underlines the predominance of coastal pelagics, such as kawakawas and trevallies, and the exploitation of several coastal fishes, mostly seabreams and emperors. Inhabitants fished over a wide aquatic territory, which included shallow-water biotopes, situated inside the lagoon, and the open sea. The associated fishing gear, composed of stone sinkers and shell fishhooks, indicates that nets and lines were used. Here, we review the seasonal organization of activities and mobility schemes from an archaeo-ichthyological perspective.

Using bone fragmentation records to investigate coastal human ecodynamics: A case study from Čḯxwicən (Washington State, USA)

Coastal shell middens are known for their generally excellent preservation and abundant identifiable faunal remains, including delicate fish and bird bones that are often rare or poorly preserved at non-shell midden sites. Thus, when we began our human ecodynamics research project focused on the fauna from Čḯxwicən (45CA523, pronounced ch-WHEET-son), a large ancestral village of the Lower Elwha Klallam Tribe, located on the shore of the Strait of Juan de Fuca, Port Angeles, Washington (USA), we anticipated generally high levels of bone identifiability. We quickly realized that the mammal bones were more fragmented and less identifiable than we had expected, though this was not the case with the bird and fish bone or invertebrate remains. To better understand why this fragmentation occurred at Čḯxwicən, we evaluate numerous hypotheses, including both post-depositional and behavioral explanations. We conclude that multiple factors intersected (to varying degrees) to produce the extreme bone fragmentation and low identifiability of mammal bones at the site, including bone fuel use, marrow extraction, grease rendering, tool production, and post-depositional breakdown. Using a human ecodynamics framework, we further consider how both social factors and external environmental forces may mediate human choices, such as the economic decision to use bone for fuel or render bone grease. We place our findings from Čḯxwicən in a regional context and discuss the potential of the approach for other coastal archaeological sites worldwide.

Shellfish Exploitation in the Western Canary Islands Over the Last Two Millennia

ABSTRACTThe residents of the Canary Archipelago consumed limpets since the arrival of humans ∼2500 yrs. ago, and these harvested gastropods were deposited in large coastal shell middens. This work preliminarily explores shell margin oxygen isotope composition (δ18O) and body size of the black limpet (Patella candei d’Orbigny, 1840) from archaeological sites in the Canary Islands to assess possible seasonal variability and intensity of shellfish collection throughout the late Holocene. The shell margin δ18O values of 100 shells (radiocarbon dated between ∼500 and ∼1800 cal. yr BP) were analysed to estimate sea surface temperature (SST) at time of death. Paleotemperature estimates suggest shellfish harvesting was not year-round, and was avoided in the cooler months (when SST < 20°C). This pattern differs from most higher latitude Mesolithic and Neolithic human groups, which gathered shellfish year-round, targeting winter more heavily. Preliminary body-size measurements suggest shell sizes have experienced a decline from aboriginal times to the present, which possibly resulted from increasing anthropogenic pressures. During aboriginal inhabitation, maximum adult shell size remained stable, suggesting that present-day harvesting practices are more intense than harvesting from aboriginal human groups. This intensive collection has likely diminished the average adult size of limpet populations in the islands by ∼27%.

Ground-Penetrating Radar as a Cultural Resource Management Tool for Assessment of Eroding Shell Middens

ABSTRACTWith an increasing rate of sea level rise inherently linked to climate change, numerous coastal archaeological resources are under threat. In Maine, virtually all 2000+ coastal aboriginal shell middens are eroding. Given limited time and resources, an efficient method for making informed cultural resource management decisions is critical. Herein, we describe a six-step protocol for a minimally invasive and cost-effective ground-penetrating radar delineation of shell midden size and morphology. Benefits of the survey methodology outlined in this study include the efficiency of data collection, the non-destructive aspect of the technique, continuous records of site stratigraphy, and the lower cost as compared to large-scale excavation. Two case studies are presented to illustrate the advantages and challenges associated with this method.

Distinguishing offshore bird hunting from beach scavenging in archaeological contexts: The value of modern beach surveys

Determining whether seabirds recovered from coastal shell middens were obtained via active hunting or scavenging of beached carcasses is a challenge for archaeologists. Traditional methods have included analyzing skeletal part frequencies, abundance, age profiles, and contextual evidence. The assumption has been made, based on limited biological data, that an assemblage of carcasses scavenged from the beach will have more wing elements, and fewer legs and heads. Few studies, however, have embraced modern beaching data to verify this assumption and assess the potential faunal resources available for scavenging. We analyze the skeletal part representation of modern beached birds observed by the Coastal Observation and Seabird Survey Team (COASST), comparing the COASST dataset to two idealized hypotheses used by archaeologists: the human scavenging hypothesis (wings only are recovered, while heads and legs are absent) and the human hunting hypothesis (all body parts are found in equal proportions). Finally, we apply these results to analysis of the bird remains from the Minard site (45-GH-15), a late Holocene coastal site in Grays Harbor, Washington. We find that contemporary beached bird data are closer to replicating the human hunting hypothesis as compared to the human scavenging hypothesis, as >75% of the 19,599 carcasses in the COASST dataset had a combination of head, wings and legs. This result, and the similarity in taxonomic distribution between our contemporary beached bird data and Minard assemblage, suggests that indigenous peoples may have used scavenging as a viable means of resource acquisition in the past. Use of contemporaneous beached bird data may provide zooarchaeology with a statistically defensible baseline of information on the phenology, abundance and condition of bird carcasses.

Stratigraphic lithic assemblages from shell middens on the northern coast of Santa Cruz (Patagonia, Argentina)

Results of the study of artifact lithic assemblages recovered from systematic excavations of shell middens on the northern coast of Santa Cruz (Patagonia Argentina), are presented. The characteristics and composition of lithic assemblages are analyzed to discuss functionality and integrity of the archaeological sites, and also to evaluate general trends of the technological organization of human groups that inhabited the area. This work represents an initial approach to the interpretation of the archaeological record of coastal shell middens from the study of lithic artifact assemblages recovered in stratigraphic contexts.The evidence from the artifact assemblages allows discussion of the activities that hunter gatherers carried out on shell middens, as well as issues of technological organization of manufacture of stone artifacts and the strategies related to exploitation of lithic raw materials in the study area. Coastal shell middens are places were multiple activities were performed. Regarding lithic technology, the manufacture and maintenance of stone tools, the use thereof, and the discarding of tools and debitage are the activities most represented.

9,000 Years of Settlement in the Carrington Point Area of Santa Rosa Island, Alta California

Systematic radiocarbon dating of coastal shell middens is a useful method for obtaining basic chronological information about archaeological sites that are threatened by coastal erosion, or for conducting reconnaissance in an area where little is known about the settlement history. This study focuses on radiocarbon dating of archaeological sites across the marine terrace adjacent to Carrington Point, Santa Rosa Island, California. This area has seen limited archaeological research compared to other portions of the island. Results suggest that settlement of this area was not constrained by known environmental or cultural patterns. When compared to other areas where similar systematic radiocarbon dating has been performed, no single factor can explain settlement decisions throughout the Northern Channel Islands. Although resource use at a single site may be heavily determined by environmental factors and regional settlement patterns are influenced by broad cultural trends, mid-scale patterns may also be contingent on historical patterns or nearby land use. Settlement of marginal areas such as the Carrington Point terrace represents a steady, consistent background to land use in more productive parts of the Northern Channel Islands.

The Discovery and Excavation of a Human Burial from the Mini-athiliya Shell Midden in Southern Sri Lanka

Several shell middens of coastal Sri Lanka indicate human occupation in the mid-Holocene and are recognized as being of prime importance in the archaeological narrative of the island. A salvage archaeology operation conducted at the Mini-athiliya shell midden in the Southern Province of Sri Lanka, yielded ancient human remains associated with stone implements and culturally modified faunal remains. The main objective of this rescue operation was to mitigate the destruction to this archaeological site. We report the excavation strategy and dating of this mid-Holocene shell midden, while focusing on the discovery and extraction of a complete human burial that had not been disturbed by the shell mining activity at the site. This excavation is intended to serve as a precursor to systematic investigation of the coastal shell middens of southern Sri Lanka.

Using non-dietary gastropods in coastal shell middens to infer kelp and seagrass harvesting and paleoenvironmental conditions

Archaeologists analyzing shell middens typically focus on larger (>2 cm) mollusks to examine subsistence practices, impacts on littoral habitats, and paleoenvironmental conditions as well as a host of other natural and cultural phenomena. Small (<2 cm), non-dietary gastropods in archaeological shell middens also provide important clues regarding human resource procurement in littoral areas and coastal paleoenvironments. We present data from two sites on the California Channel Islands to demonstrate the range of information that can be gained by analyzing small gastropod shells. Identifications revealed the remains of over 4500 non-dietary small gastropods from 75 taxa. Human harvesting of marine macrophytes is suggested by the presence of 18 species that are predominantly associated with seaweeds and seagrasses. Quantification measures revealed high diversity and equitability indices, oscillating taxonomic richness, and decreasing densities through time at both sites. Likelihood ratio tests revealed differences in assemblage composition between Early Holocene and later components at one site, and demonstrated similarities in the relative composition of non-dietary shell assemblages between both sites during the Middle Holocene. Incorporating detailed studies of less conspicuous “incidental” shellfish remains in archaeological midden studies has the potential to contribute to our understanding of past human land use practices and littoral paleoecology. Our findings are applicable to archaeologists working in coastal settings around the world, as well as marine ecologists interested in intertidal paleo-habitats and kelp forest ecosystems.

Terrestrial hermit crabs (Anomura: Coenobitidae) as taphonomic agents in circum-tropical coastal sites

Hermit crabs are ever alert for more suitable shells to inhabit, but what this may mean for coastal shell middens has rarely been considered. Here, the impact of the most landward-based of hermit crab families, the tropical Coenobitidae, upon archaeological shell-bearing deposits is assessed using a case study: the Neolithic Ugaga site from Fiji. At Ugaga, hermit crabs were found to have removed the majority of shells from the midden and had deposited their old, worn shells in return. The behavioural ecology of genus Coenobita suggests a mutualistic interaction whereby humans make available shell and food resources to hermit crabs, which in turn provide a site cleaning service by consuming human and domestic waste. Diagnostic indicators of terrestrial hermit crab wear patterns on gastropod shells are outlined and the conditions under which extensive ‘hermitting’ of shell midden deposits may occur are investigated. The ability to recognise hermit crab modification of shells is considered not only important for archaeomalacologists analysing tropical shell deposits, but also for field archaeologists wishing to select suitable shell samples for radiocarbon dating.

From Asia to the Americas by boat? Paleogeography, paleoecology, and stemmed points of the northwest Pacific

Rising postglacial seas have flooded the world’s continental shelves, limiting our ability to reconstruct human migrations, the history of settlement along Pleistocene coastlines, and the antiquity of coastal shell middens. This includes the southern coast of Beringia, where dramatic landscape changes make it difficult to test the coastal migration theory, which proposes that Upper Paleolithic peoples followed Pacific shorelines from northeast Asia to the Americas. To help overcome such problems, this paper discusses the paleogeography and paleoecology of Late Pleistocene North Pacific coastlines, then examines Pacific Rim technologies for possible evidence of a coastal migration. By ∼16,000 ± 1000 cal BP, the Pacific Rim was a plausible migration route, entirely at sea level, with rich and diverse resources from both marine and terrestrial ecosystems. Within this vast region, scattered Late Pleistocene technological assemblages that include leaf-shaped bifaces and stemmed projectile points found in coastal or peri-coastal sites from Japan and Kamchatka to western North America, and much of South America may support the idea that a coastal migration contributed to the peopling of the Americas.

Coastal shell middens in Florida: A view from the Archaic period

Current models generally place the appearance of shell middens along Florida’s coasts after 5000 B.P. This paper argues that substantial shellfishing began at least two millennia earlier. It reviews information on the earliest shell middens known in coastal Florida and traces their evolution through the Archaic period (10,000–3000 B.P.) in three areas: 1) the panhandle; 2) the northeast, and 3) southwestern Florida. In the panhandle, estuarine exploitation was well established by 7200 B.P. The subsistence base included minor but consistent amounts of freshwater and terrestrial resources throughout the Archaic. On the northeast Florida coast, midden contents demonstrate that a range of terrestrial, estuarine, and littoral resources were being exploited by 6000 B.P. By 4500 B.P., however, this diverse subsistence base was abandoned and a more targeted estuarine focus was adopted. In southwest Florida, the earliest (ca. 7000 B.P.) coastal populations gathered shellfish, but the total subsistence regime is not clearly understood until 5000–4000 B.P., when intensive exploitation of marine shellfish and fish is recognized along the shore. By 4500 B.P. in all three regions of Florida, estuarine subsistence bases supported population nucleation and the creation of monumental architecture. By the end of the Archaic period (ca. 3500 B.P.) however, the brief venture into large-scale social works was abandoned in some, but not all of Florida, as climate and/or sea level regression brought significant environmental changes.

Inland shell midden site-formation: Investigation into a late Pleistocene to early Holocene midden from Tràng An, Northern Vietnam

Over the course of the past two decades there has been growing research interest in the site formation processes of shell middens. This stands along-side and is being used to inform cultural, dietary and palaeo-environmental reconstructions. Just as midden site formation processes have turned out to be many and varied, however, the kinds of shell-bearing sites that past human communities created are likely to have been no less diverse. Subsuming such sites under a single category – shell middens – normalises that variation and may lead to the misinterpretation of site function. The greater part of research in this field also continues to focus on coastal shell middens; comparatively little attention has been paid to middens containing freshwater and especially terrestrial molluscs from hinterland locations. As a result, much of the current understanding about shell-midden sites carries a spatial as well as a functional bias. This paper hopes to contribute towards discussion on both fronts. It presents a detailed examination of the formation processes that went into the creation of a land snail-dominated late- to post-glacial midden from northern Vietnam, and considers the role that it may have played in the early settlement of this area. The data presented comes from ongoing archaeological excavations at Hang Boi, a cave located in the sub-coastal karstic uplands of Tràng An park, in the Vietnamese Province of Ninh Bình.

Coastal shell middens of the Abydos coastal plain, Western Australia

AbstractMiddens and mounds dominated by Anadara granosa began to be formed on the Abydos Coastal Plain sometime between 4400 and 5300 calibrated years before present, and while mounds appear to have ceased forming some 1800–1600 years ago, middens continued to form until the early twentieth century or later. In some cases, the earliest of these middens and shell mounds formed on top of older middens from which Anadara granosa is totally absent, and in which Terebralia spp. (while occurring in relatively low concentrations) is the dominant shell species. Anadara granosa dominated middens (sensu lato) occur in a variety of forms across the landscape, including large shell mounds, earth mounds (or mounded shell middens), lenses of shell eroding out of well‐developed dunes, and undifferentiated surface shell scatters. The large number of middens which occur throughout the region from the mid Holocene, and the volume of shell represented by these sites, point to the occurrence of significant economic and social changes from the mid to late Holocene. The Abydos Coastal Plain experienced increasing aridity, and, as a result, increased resource stress during the mid‐Holocene. We suggest that the large, single species Anadara granosa middens were occupied during regular periods when large groups of Aboriginal people undertook ceremonial activities after the wet season, when resources were abundant. Changes apparent in the archaeological record, including the occurrence of large numbers of Anadara granosa dominated middens and shell mounds, increased establishment of archaeological sites and increased complexity and distance of exchange systems, came about as a result of social, economic and logistical restructuring. This in turn was the result of the effects of resource stress on local Aboriginal people over the course of the mid to late Holocene.

Fishing from past to present: continuity and resilience of red abalone fisheries on the Channel Islands, California

Archaeological data from coastal shell middens provide a window into the structure of ancient marine ecosystems and the nature of human impacts on fisheries that often span millennia. For decades Channel Island archaeologists have studied Middle Holocene shell middens visually dominated by large and often whole shells of the red abalone (Haliotis rufescens). Here we use modern ecological data, historical accounts, commercial red abalone catch records, and zooarchaeological data to examine long-term spatial and temporal variation in the productivity of red abalone fisheries on the Northern Channel Islands, California (USA). Historical patterns of abundance, in which red abalone densities increase from east to west through the islands, extend deep into the Holocene. The correlation of historical and archaeological data argue for long-term spatial continuity in productive red abalone fisheries and a resilience of abalone populations despite dramatic ecological changes and intensive human predation spanning more than 8000 years. Archaeological, historical, and ecological data suggest that California kelp forests and red abalone populations are structured by a complex combination of top-down and bottom-up controls.

Geoarchaeological and chronostratigraphical investigations of open‐air sites in the Geelbek Dunes, South Africa

AbstractThe Geelbek Dunes located north of Cape Town, South Africa, are an active, northward migrating dune field. Interdunal deflation hollows temporarily expose former land surfaces that are associated with archaeological sites. These open‐air sites shed light on large‐scale patterns of Middle and Later Stone Age settlement and augment the information gained from well‐stratified, but spatially limited caves, rock shelters, and coastal shell middens. Based on paleopedological and sedimentological parameters, three former land surfaces were identified and associated with different assemblages. A chronostratigraphy of the various land surfaces was established by applying optically stimulated luminescence (OSL) dating. The youngest former land surface is represented by a dune generation (AD2) which stabilized at a maximum of 5 ka. An older dune generation (AD1) shows a more heterogeneous age pattern where deposition started at ca. 27 ka with a maximum estimated age of stabilization at ca. 10 ka. Both of these dune generations overlie a weathered calcrete complex of Middle to Late Pleistocene age. While the third dune generation (AD0) was observed between underlying calcrete layers, samples taken from this unit could not be dated. © 2008 Wiley Periodicals, Inc.

Development of the Bronze Age landscape in the southeastern Arabian Gulf: new evidence from a buried shell midden in the eastern extremity of the Rub’ al‐Khali desert, Emirate of Ras al‐Khaimah, U.A.E.

Recent sand quarrying operations for building and construction work in the eastern extremity of the Rub’ al‐Khali sand sea has revealed sediment exposures through a number of coastal and inland dunes. In the al‐Daith district of Ras al‐Khaimah (U.A.E.) a Holocene shell midden was exposed 2.8 m below the present dune surface interstratified between phases of Late Pleistocene and late Holocene dune sands. C14 and OSL ages constrain the site giving an insight into phases of landscape instability, dune formation, rates of sediment accretion, and a period of stability and human occupation. To date, Hafit period sites (5200–4500 cal BP) have been recorded in large numbers in the mountains and gravel plains of the Oman mountains. Coastal shell middens have not, as yet, been ascribed to the Hafit period from this part of the region and the study presents the first radiocarbon age from such a site. This study indicates the potential that many other sites exist elsewhere buried under late Holocene dune sediments and these provide an important insight into the development of the coastal landscape of this region.

Shell morphometry of seven limpet species from coastal shell middens in southern Africa

Measurements of shell parts and features (elements) of marine limpets can be used to derive morphometric equations for estimating total shell lengths. This is demonstrated for seven limpet species commonly found on the southern African coast. The equations can be used to reconstruct whole shell lengths for highly fragmented limpet samples in prehistoric shell middens. A linear regression model is based on measurements of all shell elements, resulting in high coefficients of determination with excellent predictive power in most cases. These morphometric equations would enable archaeologists to derive more metrical information from fragmentary archaeological material than was previously the case. We also present a case study where morphometric equations of two limpet species are applied to an archaeological sample from the South African west coast for the purpose of investigating possible biases in limpet shell preservation. We conclude that small whole limpet shells survive longer than the bigger ones in this particular case, but that many more such case studies need to be conducted in order to fully understand differential preservation of southern African limpet shells in archaeological sites.

Terminal Pleistocene and Early Holocene Occupations of Isla de Cedros, Baja California, Mexico

ABSTRACT Isla de Cedros is a high, rocky island located on the Pacific Coast of Baja California 685 km south of San Diego. Its arid but temperate marine climate provides excellent conditions of archaeological preservation and visibility. Over the last five years, the Proyecto Arqueologico Isla de Cedros has documented a diverse and rich archaeological record on the island. In addition to many more recent deposits, at least two coastal shell middens have been identified that were occupied during the Early Holocene and Terminal Pleistocene. Initial investigation of these sites, including 14C dating and limited excavations at the largest and most intact example (PAIC-44, Cerro Pedregoso), provides an opportunity to address issues related to the nature and antiquity of maritime adaptations along the eastern Pacific Rim, and potentially the peopling of the New World.