Oysters (Ostreidae) are ecological and cultural keystone species that have been exploited by humans for millennia. Oyster size is a good proxy for population health, and researchers frequently use valve height and length measurements from archaeological and paleontological contexts that provide historical ecological baselines with potential to inform present-day management around the world. Oyster fragmentation in the archaeological record, however, is not commonly considered in studies of oyster size. This study presents the first systematic investigation of the effects of oyster fragmentation on eastern oyster (Crassostrea virginica) size metrics. Oyster assemblages including whole valves, valve fragments with hinges, and valve fragments lacking hinges were analyzed from stratified contexts at two Florida Gulf coast sites, Garden Patch (8DI4) and Calusa Island Midden (8LL45). Through comparisons of weight, height, length, and survival rates of whole valves, and the number and weight of fragmented valves, we show that survivorship bias-the selective preservation of whole valves of specific size ranges-explains significant variation in oyster valve size metrics. In some cases, survivorship bias is the primary driver of whole valve size differences between sampling units, indicating that whole valve samples are not representative of the pre-fragmented population. This conclusion has significant implications for current interpretations of archaeological oyster assemblage valve size as a proxy for past oyster reef health and effects of human predation and management. We suggest several methods for recognizing the confounding effects of survivorship bias in studies of archaeological oyster valve metrics and encourage continued critical evaluation of the archaeology of oyster and other shellfish assemblages and interrogation of their historical ecological implications in the present.

Well known for its relatively mild climate, productive fisheries, agriculture, and dense human settlements, California is being devastated by climate change. Drought, warming temperatures, and other processes are fueling intense fires and water shortages, while increased El Niño–Southern Oscillation and other changes pose threats to marine ecosystems. This chapter explores the importance of historical ecology for informing past climate change in coastal California. The synthesis herein illustrates how long-term environmental change and human activities shaped present conditions and how perspectives from the past can help prepare for future climatic instability and promote equitability and social justice.

Museum legacy collections, often derived from large-scale archaeological excavations, can serve as paleoenvironmental archives of Late Pleistocene megafaunal composition and dynamics. Many of these collections, however, contain large quantities of highly fragmented and morphologically indistinct bones that cannot be identified to a specific taxon and are therefore of limited use to paleoenvironmental and archaeological analyses. Here, we explore the potential of Zooarchaeology by Mass Spectrometry (ZooMS) to identify fossil bone fragments and complement morphological identifications in legacy collections housed at the Smithsonian’s National Museum of Natural History. To undertake this work, we collected fragmented bone specimens of Late Pleistocene megafauna from six archaeological sites in Colorado that are currently housed in the Department of Anthropology, and then performed pilot ZooMS screening. Our analysis successfully retrieved taxonomic information from 80% of the analyzed material, highlighting the potential of future ZooMS studies on museum collections to investigate human-megafaunal interactions in late Pleistocene North America.

There is growing interest in analyzing interdisciplinary datasets to better understand the evolution of ecosystems through deep time. One burgeoning area has been the integration of archaeological and fossil data to evaluate the long-term structure and function of habitats, floral and faunal communities, and ecosystems. Here, marine invertebrate data from Holocene archaeological sites and Pleistocene marine terrace deposits on California's Northern Channel Islands are combined to glean insights into the long-term structure of nearshore marine ecosystems, the composition of intertidal marine invertebrate communities, and the formation of archaeological shell middens. While a variety of methodological, analytical, and taphonomic challenges in comparing disparate datasets from fossil and archaeological contexts were identified, we offer perspectives for surmounting these challenges in future research. These findings indicate that the integration of fossil and archaeological data, spanning tens of thousands of years, offers important insights on the evolution of nearshore coastal ecosystems and marine climate change in California and around the world.

The complex relationship between sociopolitical complexity, natural climatic change, and subsistence strategies on California's Northern Channel Islands has long been a topic of archaeological inquiry. One period of particular interest to researchers is the Middle-to-Late Period Transition (MLT, 800-650 cal BP), during which Chumash hierarchical sociopolitical organization is thought to have solidified. Multiple models of sociopolitical change have been proposed, all of which acknowledge the relationship between growing populations, shifting dietary patterns, climatic events, and sociopolitical structure. Considerable debate remains, with some pointing to the importance of events during the late Middle Period (similar to 1,500-800 cal BP) or earlier. While these models partly rely on dietary data from late Middle, MLT, and Late Period (650 cal BP-AD 1542) archaeological sites, research at late Middle Period sites has often been more limited than work at later sites, leaving an imbalance in our understanding of subsistence shifts and changing cultural and environmental dynamics. Here, we present faunal and dietary data from two well-dated Middle Period sites on Limuw (Santa Cruz Island) that document an intensification of finfishing in the Middle Period, supporting models that see the evolution of Island Chumash complexity as a more gradual phenomenon. La relacion entre la complejidad sociopolitica, el cambio climatico natural y las estrategias de subsistencia en las Islas del Canal del Norte de California ha sido durante mucho tiempo un tema de investigacion arqueologica. Un periodo de particular interes para los investigadores es la Transicion del Periodo Medio al Tardio (MLT, 800-650 cal BP), durante el cual se cree que se solidifico la organizacion sociopolitica jerarquica de Chumash. Se han propuesto multiples modelos de cambio sociopolitico, todos los cuales reconocen la relacion entre poblaciones en crecimiento, patrones dieteticos cambiantes, eventos climaticos y estructura sociopolitica. Sigue existiendo un debate considerable y algunos senalan la importancia de los acontecimientos ocurridos a finales del Periodo Medio (similar to 1,500-800 cal BP) o antes. Si bien estos modelos se basan en parte en datos dieteticos de sitios arqueologicos del Periodo Medio Tardio, MLT y Tardio (650 cal BP-AD 1542), la investigacion en sitios del Periodo Medio Tardio a menudo ha sido mas limitada que el trabajo en sitios posteriores, lo que deja un desequilibrio en nuestra comprension de los cambios de subsistencia y de las dinamicas culturales y ambientales cambiantes. Aqui, presentamos datos sobre fauna y dieta de dos sitios bien fechados del Periodo Medio en Limuw (Isla Santa Cruz) que documentan una intensificacion de la pesca con aletas en el Periodo Medio, respaldando modelos que ven la evolucion de la isla Chumash. La complejidad como un fenomeno mas gradual.

Archaeological bird remains from the Oregon coast provide important insight into local environments and the interactions between birds and people on the North American Pacific Coast. We contribute to this discussion with an analysis of bird remains from the Late Holocene Par-Tee site (35CLT20) in Seaside, Oregon. We sampled the Par-Tee avifaunal assemblage to near-redundancy, generating the largest sample from a single site on the Oregon Coast to date (N = 7204). The Par-Tee assemblage is dominated by nearshore or estuarine birds including scoters (Melanitta spp.) and Common Murres (Uria aalge), as well as pelagic Sooty Shearwaters (Ardenna grisea). Because of the large size of the sample, we identified unique species such as the California Condor (Gymnogyps californianus), which are currently endangered and face conservation challenges. Although the Par-Tee avifaunal assemblage is diverse, site residents appear to have focused on acquiring the most accessible species in the nearshore habitat complemented by opportunistic pelagic hunting and/or scavenging of beached birds. Most birds appear to have been processed for dietary consumption, with possible preferential use of larger-winged birds for tool manufacture. These findings underscore the value and challenges of using legacy collections for evaluating past human-environmental interactions in coastal and other aquatic regions.

The Anthropocene has been rejected as a formal epoch by the International Commission on Stratigraphy. Moving on and recognizing the deeper and more complex roots of human impacts on our planet will enable us to better, and more fairly, address them.

Tuqan (a.k.a. San Miguel) Island, totaling just 37 km2 and situated 44 km off the Southern California Coast, has been occupied by people for at least 13,000 years, a period in which the geography and ecosystems of the island have changed dramatically. Early historical accounts described Tuqan as a marginal and windswept island with limited fresh water, terrestrial plants and animals, and other resources, an island that supported a small and relatively impoverished Island Chumash population of fewer than 100 people. The archaeology and historical ecology of Tuqan tell a very different story, however, one of significantly larger and more prosperous Island Chumash communities, which survived and thrived despite sometimes dramatic geographic and ecological changes of the late Pleistocene and Holocene. These natural changes—including climatic warming, rapid sea level rise, shrinking land area, and greater isolation caused by the inundation of coastal lowlands—were accompanied by human impacts to local ecosystems visible in the archaeological record. The story of Island Chumash persistence, adaptability, and resilience, along with the continuing recovery of island ecosystems under the management of federal agencies, provides lessons of hope for modern island and coastal communities threatened by similar processes today.

Atlantic sturgeon (Acipenser oxyrinchus ssp. oxyrinchus) has been a food resource in North America for millennia. However, industrial-scale fishing activities following the establishment of European colonies led to multiple collapses of sturgeon stocks, driving populations such as those in the Chesapeake area close to extinction. While recent conservation efforts have been successful in restoring census numbers, little is known regarding genomic consequences of the population bottleneck. Here, we characterize its effect on present-day population structuring and genomic diversity in James River populations. To establish a pre-collapse baseline, we collected genomic data from archaeological remains from Middle Woodland Maycock's Point (c. 200-900 CE), as well as Jamestown and Williamsburg colonial sites. Demographic analysis of recovered mitogenomes reveals a historical collapse in effective population size, also reflected in diminished present-day mitogenomic diversity and structure. We infer that James River fall- and spring-spawning populations likely took shape in recent years of population recovery, where genetic drift enhanced the degree of population structure. The mismatch of mitogenomic lineages to geographical-seasonal groupings implies that despite their homing instinct and differential adaptation manifested as season-specific behaviour, colonization of new rivers has been a key ecological strategy for Atlantic sturgeon over evolutionary timescales.

The northwest coast of Wimal (Santa Rosa Island) has long been a focus of archaeological research, including former Santa Barbara Museum of Natural History archaeologist, geologist, and paleontologist Phil Orr's work from the 1940s-1960s. Orr pioneered the use of radiocarbon dating on the California Channel Islands, built extensive archaeological collections, and constructed a detailed cultural sequence. Here, we discuss the history and status of Orr's island research camp, archaeological site CA-SRI-766H, describing monitoring and erosion of the site during the past several decades. Two radiocarbon dates obtained from adjacent CA-SRI-7 (Orr's Camp shell midden) document Island Chumash occupation of the site between similar to 2820-1160 cal BP, helping place the area into broader regional context. Revisiting the historical documents and physical remains of past research can help understand the evolution of archaeological practice, evaluate outdated procedures of conducting research without tribal consultation and consent, and promote a more inclusive future of the discipline.

People have influenced Earth’s biodiversity for millennia, including numerous introductions of domestic and wild species to islands. Here, we explore the origins and ecology of the Santa Catalina Island ground squirrel (SCIGS; Otospermophilus beecheyi nesioticus), one of only five endemic terrestrial mammals found on California’s Santa Catalina Island. We synthesized all records of archaeological/palaeontological SCIGS, conducted radiocarbon dating and stable isotope analysis of the potentially earliest SCIGS remains and performed genetic analysis of modern SCIGS. Squirrels were not identified in island palaeontological deposits, but at least 12 island archaeological sites contain SCIGS bones, including some that are butchered or burned. All directly dated SCIGS bones are Late Holocene in age and younger than approximately 1290 cal BP. The first mitochondrial genome for modern Otospermophilus beecheyi and 15 modern SCIGS mitogenomes document at least one introduction of squirrels. Stable isotope data indicate variable SCIGS diets and potential subsidies from marine environments to terrestrial plants consumed by some individuals. We cannot rule out a natural overwater dispersal, but the earliest SCIGS remains post-date the earliest evidence for people by several millennia and, along with other lines of evidence, support a human-assisted translocation of squirrels during the Late Holocene. These data illustrate the important role of Indigenous people in shaping and enhancing island biodiversity and ecology around the world.

The historical ecology and foraging behavior of many apex marine predators are poorly known. This includes highly mobile pelagic species such as billfish (Xiphiidae and Istiophoridae), which have long held cultural significance for coastal peoples. In California’s Santa Barbara Channel Region, Chumash people have hunted billfish for >2000 yr, providing a deep historical record of these species. We present bulk tissue δ 13 C and δ 15 N data for 15 Late Holocene archaeological swordfish Xiphias gladius and 1 striped marlin Kajikia audax previously identified to species through collagen fingerprinting. When compared to data sets of modern northeastern Pacific and archaeological Gulf of Maine swordfish, we identified significant overlap in the isotopic values of modern and archaeological swordfish from the Pacific, indicating that pre-industrial swordfish were reliant on food webs of the North Pacific Subtropical Gyre and the California Current System. We also identified differences in the isotopic composition of swordfish captured by island vs. mainland communities, with swordfish remains from mainland sites having lower and more variable δ 13 C values, potentially indicating different source populations. The isotopic range of swordfish from California archaeological sites was much broader than those from the Gulf of Maine, suggesting a wider range of habitats used by Pacific swordfish. Our results provide important pre-industrial data for an apex marine predator.

Stable isotope proxies measured in the proteinaceous fraction of archaeological mollusc shell represents an increasingly important archive for reconstructing past ecological and biogeochemical conditions of nearshore environments. A major issue, however, is understanding the impact of diagenetic alteration in sub-fossil shell isotope values. "Bulk" stable isotope values of nitrogen (delta N-15), and especially carbon (delta C-13) often shift strongly with increasing C/N ratios in degraded shell, resulting in unreliable data. Here, we examine preservation of an entirely new set of shell paleo-proxies, compound-specific isotopes of amino acids (CSI-AA). We examine carbon (delta(13)CAA) and nitrogen (delta(15)NAA) patterns and values from the organic fraction of California mussel (Mytilus cal-ifornianus) shells from the California Channel Islands. Archaeological shell samples ranging in age from ca. 6,100 to 250 cal BP exhibiting a wide range of degradation states were collected from varied depositional environments (e.g., exposed coastal bluff, buried strata, etc.), and were directly compared to modern shells of the same species and region. Our results indicate organic matter C/N ratios as the best bulk diagnostic indicator of the relative degradation state of shell organic fraction, including changes at the molecular level. Modern shell organic C/N ratios ranged from 2.8 to 3.5, while those in archaeological shell were substantially elevated (3.4-9.5), exhibiting strong and significant negative correlations with bulk delta C-13 values, weight %C, and weight %N, and a significant but weaker correlation with delta(15) N values. An additional "cleaning" step using weak NaOH helped to remove possible exogenous contaminants and improved bulk values of some samples. However, relative molar AA abundances revealed that some AAs, especially the two most abundant, Glycine and Alanine, progressively decreased with increasing C/N ratio. The loss of these amino acids permanently alters bulk isotope values regardless of removal of contaminants. Modeling the bulk isotope change expected due to amino acid molar composition showed major and predictable shifts in bulk delta C-13 values from selected AA loss, and similarly large but far more variable impacts from exogenous contaminants. In contrast to bulk data, key CSI-AA values and patterns remained almost entirely unaltered, even in the most degraded shell samples, closely matching expected biosynthetic isotope patterns in modern mussel shell. AA isotope proxies for "baseline" (delta N-15-Phenylalanine and average delta C-13-Essential AAs) and planktonic trophic structure (delta N-15-Glutamic Acid and delta N-15-Phenylalanine) were not statistically altered with degradation in any sample. Overall, we conclude that while bulk isotopes, particularly delta C-13, are very likely to be unreliable in archaeological or subfossil shell with C/N ratios higher than similar to 4.0, CSI-AA proxies can still be used to reconstruct past climatic and ecological conditions of the nearshore marine environment.

How do human communities integrate within food webs? Studies characterizing the historical flow of energy among people and local environments can yield important insights into managing sustainable ecosystems. Here, we combine zooarchaeological, bulk tissue, and compound-specific stable isotope data from late Holocene Santa Rosa Island to investigate the ecological role of people within a southern California nearshore marine ecosystem. We show people foraged in diverse marine habitats, including kelp forests and pelagic waters, and consumed a wide range of species. However, zooarchaeological results reveal >50% of recovered fish remains came from presumed kelp forest carnivores of mid-trophic level (3.0–4.0) such as surfperches and rockfishes. Local fishing strategies thus did not involve the preferential removal of large-bodied, high trophic level species – a pattern known as “fishing down the food web” which has been documented in modern commercial fisheries and results in the collapse of marine ecosystems. Essential amino acid δ13C analysis revealed that the historical fish community relied on basal resources from kelps and phytoplankton. This coupling of benthic and pelagic energy sources suggests late Holocene coastal food webs in the region were in a relatively stable configuration immediately prior to first European arrival. This stability likely contributed to sustaining densely populated Chumash settlements, intensive fisheries, and high local faunal diversity. Our findings provide important pre-industrial data for marine ecosystems and document some of the mechanisms behind the intensive, yet sustainable long-term fisheries of the Island Chumash.

Sea level rise and marine erosion threaten coastal archaeological sites around the world, forcing difficult decisions about how to prioritize which sites to document and analyze. Here we present the results of research at a heavily eroded Late Holocene shell midden at CA-SRI-26, Santa Rosa Island, California. Systematic surface collection and radiocarbon dating of the site revealed an assemblage that is about 1400 years old and contains a variety of shellfish, bird, fish, and mammal remains, stone and bone tools, and matted sea grass (Phyllospadix sp.). Of the more remarkable finds is a humerus from a subadult Guadalupe fur seal (Arctocephalis towndsendi) with a projectile point tip lodged in the bone. This rare archaeological example of direct marine mammal hunting and other evidence for diverse marine foraging activities demonstrate the research value of eroded sites threatened by rising seas around the world.

Previous articleNext article No AccessBook ReviewsOn Desert Shores: Archaeology and History of the Western Midriff Islands in the Gulf of California. Thomas Bowen. Salt Lake City: University of Utah Press, 2022, 288 pp. $70.00, cloth. ISBN 9781647690380.Torben RickTorben RickSmithsonian Institution Search for more articles by this author PDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmailPrint SectionsMoreDetailsFiguresReferencesCited by Journal of Anthropological Research Volume 79, Number 2Summer 2023 Article DOIhttps://doi.org/10.1086/724468 Views: 7Total views on this site For permission to reuse, please contact [email protected].PDF download Crossref reports no articles citing this article.