Consumption Of Aquatic Resources Research Articles

Aquatic resource consumption at the Odense leprosarium: Advancing the limits of palaeodiet reconstruction with amino acid δ13C measurements

Dietary patterns of leprosy patients from the medieval leprosarium at Odense (Denmark) were investigated via carbon isotope ratio analysis of individual amino acids (δ13CAA) in bone collagen. The aim of this research was to explore in detail the consumption of aquatic resources (freshwater and marine) by these individuals; especially during the last few years of life, which were likely spent in the leprosy hospital. The analysis was conducted on ribs (n = 30) and long bones (n = 10) from 30 individuals, as well as on 9 local and contemporary faunal samples. A comparison of the Odense δ13CAA results with published δ13CAA values from the Baltic Sea region indicate that the diet was primarily terrestrial, but 12 of the 30 individuals (40%) consumed a mixed terrestrial-aquatic diet based on Δ13CVal-Phe values. Further, comparison of the rib-long bone pairs from 10 individuals found statistically significant differences in the Δ13CVal-Phe and Δ13CGly-Phe results, but not the δ13CLys results. This intra-individual dietary difference is also supported by MLA-PCA, and tentatively suggests these leprosy patients increased their consumption of marine protein over the last few years of life, indicating perhaps an institutional dietary program in the leprosarium. This work represents one of the largest archaeological δ13CAA studies in Europe and the first to compare bones with different turnover rates. Compound specific isotope analysis of δ13CAA has great potential to reveal subtle intra-individual dietary shifts that may remain undetected by bulk isotopic analysis.

Cost-Benefit Trade-Offs of Aquatic Resource Exploitation in the Context of Hominin Evolution

While the exploitation of aquatic fauna and flora has been documented in several primate species to date, the evolutionary contexts and mechanisms behind the emergence of this behavior in both human and non-human primates remain largely overlooked. Yet, this issue is particularly important for our understanding of human evolution, as hominins represent not only the primate group with the highest degree of adaptedness to aquatic environments, but also the only group in which true coastal and maritime adaptations have evolved. As such, in the present study we review the available literature on primate foraging strategies related to the exploitation of aquatic resources and their putative associated cognitive operations. We propose that aquatic resource consumption in extant primates can be interpreted as a highly site-specific behavioral expression of a generic adaptive foraging decision-making process, emerging in sites at which the local cost-benefit trade-offs contextually favor aquatic over terrestrial foods. Within this framework, we discuss the potential impacts that the unique intensification of this behavior in hominins may have had on the evolution of the human brain and spatial ecology.

Ecological change and human responses to the YD in a subtropical area: Archaeological evidences and isotope records from Zhongshan site, south China

Climate change, a global challenge for human beings, is in the long term best documented through archaeological research. As this has shown, some cold reversal events, like Last Glacial Maximum and YD, greatly impacted of human behavior in mid-latitude areas of the northern hemisphere. A general recognition on how these events affected those in low latitude areas is yet to be determined. Previous studies have suggested that cold reversal events had a limited impact on humans in the latter parts of the world. This account discusses the effect of the YD on human behavior in a subtropical region, based on isotope analyses, and samples both faunal and artificial from the late Pleistocene site of Zhongshan in the Bubing Basin, Guangxi. During the YD, the environment became more open, and the consumption of aquatic resources increased. Polished stone artefacts first occurred in this period, probably for finer food processing. Our study highlights the significant impact of the YD on the ecology and human behavior in this subtropical region.

Source of strontium in archaeological mobility studies\u2014marine diet contribution to the isotopic composition

The strontium isotope composition of human tissues is widely used in archaeological mobility studies. However, little attention is paid to the relative contributions of terrestrial versus marine sources of strontium in these studies. There is some debate over the role of a solid diet versus drinking water as the most important source of strontium for the human body, with related possibilities of misinterpretation of the archaeological record if only strontium isotope compositions of the biosphere are studied. However, there is a third component, marine strontium, which is commonly not assumed to contribute towards the strontium isotope composition of archaeological skeletal remains, especially in locations that are not directly coastal. To illustrate the potentially obfuscating effects of mixed Sr sources in a human population, we present a case study of twelve individuals from the medieval Finnish site Iin Hamina with a known dietary history. Our study shows that marine consumption is a significant factor explaining the strontium isotope composition of the Iin Hamina human remains, with implication of erroneous conclusions about immigration without prior knowledge of diet composition. Thus, future studies should always incorporate a rigorous analysis of dietary history, with special regard to potential consumption of aquatic resources, when strontium isotope analysis is used as a method in the study of palaeomobility.

The edge of the Empire: diet characterization of medieval Rome through stable isotope analysis

This paper aims to define the dietary profile of the population of early medieval Rome (fifth–eleventh centuries CE) by carbon and nitrogen stable isotope analysis. This period was characterized by deep changes in the city’s economic, demographic, and social patterns, probably affecting its inhabitants’ nutritional habits. Carbon and nitrogen stable isotope analysis of bone collagen was used to detect the nutritional profile of 110 humans from six communities inhabiting the city center of Rome and one from the ancient city of Gabii. Thirteen faunal remains were also analyzed to define the ecological baseline of the medieval communities. The isotopic results are consistent with a diet mainly based on the exploitation of C3 plant resources and terrestrial fauna, while the consumption of aquatic resources was detected only among the San Pancrazio population. Animal protein intake proved to be similar both among and within the communities, supporting a qualitatively homogenous dietary landscape in medieval Rome. The comparison with isotopic data from the Imperial Age allowed us to detect a diachronic nutritional transition in ancient Rome, in which the collapse of the Empire, and in particular the crisis of economic power and the trade system, represented a tipping point for its population’s nutritional habits.

“Fish Rescue us from Hunger”: the Contribution of Aquatic Resources to Household Food Security on the Rufiji River Floodplain, Tanzania, East Africa

Inland fisheries are essential to nutrition and food security in developing countries but remain undervalued. Worldwide, studies of aquatic resource consumption are rare. We use data from a monthly survey of 40 households in a Tanzanian village over 1 year combined with qualitative methods to analyse consumption of animal aquatic resources across wealth, seasons, fishing vs. non-fishing, and male- vs. female-headed households. We find that local freshwater fish are the most frequent source of animal protein, consumed on 57% of survey days. Wealth matters, with better-off households eating fish more often and in larger daily quantities on average. Middle-ranked households catch and sell fish more often, but all households double their consumption on average on days they catch rather than purchase fish. Female-headed households rely on gifts to increase consumption. Our results emphasise the need to preserve the livelihood functions of inland fisheries in the face of increasing threats.

How Fishy was the Inland Mesolithic? New Data from Friesack, Brandenburg, Germany

ABSTRACTRecent studies have shown that faunal assemblages from Mesolithic sites in inland Northern Europe contain more fish remains than previously thought, but the archaeological and archaeozoological record does not reveal the dietary importance of aquatic species to hunter-gatherer-fishers, even at a societal level. For example, the function of bone points, as hunting weapons or fishing equipment, has long been debated. Moreover, traditional methods provide no indication of variable subsistence practices within a population. For these reasons, paleodietary studies using stable isotope analyses of human remains have become routine. We present radiocarbon (14C) and stable isotope data from nine prehistoric human bones from the Early Mesolithic-Early Neolithic site of Friesack 4, and isotopic data for local terrestrial mammals (elk, red deer, roe deer, wild boar, aurochs, beaver) and freshwater fish (European eel, European perch). The reference data allow individual paleodiets to be reconstructed. Using paleodiet estimates of fish consumption, and modern values for local freshwater reservoir effects, we also calibrate human 14C ages taking into account dietary reservoir effects. Although the number of individuals is small, it is possible to infer a decline in the dietary importance of fish from the Preboreal to the Boreal Mesolithic, and an increase in aquatic resource consumption in the Early Neolithic.

“To ‘seafood’ or not to ‘seafood’?” An isotopic perspective on dietary preferences at the Mesolithic-Neolithic transition in the Western Mediterranean

Stable isotope investigations of the Prehistory of the Western Mediterranean have increased exponentially during the last decade. This region has a high number of Mesolithic and Neolithic carbon and nitrogen isotope ratio data available compared with other world areas, resulting from the interest in the “transition” between hunter-gathering and farming. This type of analysis is important as one of the few tools that give direct information on the poorly understood dietary transition from hunter-gatherer to agro-pastoralist subsistence in the Mediterranean Basin. Carbon and nitrogen stable isotope analysis on bulk collagen are especially useful for exploring marine vs. terrestrial protein input and therefore assess marine resource exploitation by these two different lifestyles. Gathering together all isotopic data for these chronologies we show that the Western Mediterranean underwent a unique/distinct Neolithisation process. These data show a gradual dietary shift in aquatic resource consumption during the transition to farming that contrasts to elsewhere in Europe.

Compound-specific amino acid isotopic proxies for distinguishing between terrestrial and aquatic resource consumption

Compound-specific amino acid carbon-isotope compositions have shown particular promise for elucidating dietary behaviors in complex environmental contexts, and may also be able to mitigate the effect of many of the limitations inherent to palaeodietary reconstructions. Here, we investigate the efficacy of compound-specific amino acid isotopic proxies in characterizing the consumption of different dietary protein sources using amino acid carbon-isotope compositions for humans and fauna from Rössberga (Early to Middle Neolithic), Köpingsvik (Mesolithic and Middle Neolithic), and Visby (Medieval Period), Sweden. We also assess the explanatory capabilities of an isotopic mixing model when used with essential amino acid carbon-isotope compositions of humans and local fauna. All three isotopic proxies distinguished among humans from the three sites consistently and informatively, and were able to enhance the broad interpretations made using bulk isotopic compositions. The mixing model palaeodietary reconstruction revealed considerable diversity in relative protein source contributions among individuals at both Köpingsvik and Visby. Comparing the mixing model for bulk carbon- and nitrogen-isotope compositions to the model for essential amino acid isotopic compositions further demonstrated the likelihood of underestimation and overestimation of marine protein consumption for both aquatic-dominant and mixed marine-terrestrial diets when using bulk isotopic compositions.

An overview of methods used for the detection of aquatic resource consumption by humans: Compound-specific delta N-15 analysis of amino acids in archaeological materials

The detection of aquatic resource consumption is important in paleodietary studies as it provides insights into the adaptive strategies of modern humans. Debate as to whether or not it is a recent innovation in hominid evolution also emphasizes its importance to the field. Stable carbon and nitrogen isotope analysis of bulk collagen has been powerful tool for the investigation of ancient human diet, especially for the detection of marine food consumption. However, the nitrogen isotopic composition could significantly vary even within the same animal species depending on environmental conditions, making a dietary reconstruction based on human remains difficult without enough specimens of referential animal prey. Nitrogen isotope analysis of individual amino acids in bone collagen has recently been proposed as a potentially useful technique for the detection of not only marine resources in diets but also freshwater ones. In this paper, we further test its applicability to human populations in a variety of regions and chronological time periods in the world. We found that: (i) irrespective of climatic conditions, nitrogen isotopic compositions of glutamic acid and phenylalanine of terrestrial animals group similarly; (ii) these two amino acids are particularly useful to detect marine or freshwater resource consumption; (iii) a multinomial logistic regression based on some combinations of isotope indicators successfully distinguishes aquatic and terrestrial animals; (iv) detection of aquatic resource consumption by prehistoric humans could be possible based solely on the isotopic compositions of human remains, even in the absence of coeval potential prey. This approach is therefore promising for the paleodietary reconstruction of isolated human remains with few associated faunal remains from archaeological sites.

Compound-specific amino acid isotopic proxies for detecting freshwater resource consumption

Of central importance to palaeodietary reconstruction is a clear understanding of relative contributions of different terrestrial (i.e., C3 vs. C4 plants) and aquatic (i.e., freshwater vs. marine) resources to human diet. There are, however, significant limitations associated with the ability to reconstruct palaeodiet using bulk collagen stable isotope compositions in regions where diverse dietary resources are available. Recent research has determined that carbon-isotope analysis of individual amino acids has considerable potential to elucidate dietary protein source where bulk isotopic compositions cannot. Using δ13CAA values for human and faunal remains from Zvejnieki, Latvia (8th – 3rd millennia BCE), we test several isotopic proxies focused on distinguishing freshwater protein consumption from both plant-derived and marine protein consumption. We determined that the Δ13CGly-Phe and Δ13CVal-Phe proxies can effectively discriminate between terrestrial and aquatic resource consumption, and the relationship between essential δ13CAA values and the Δ13CGly-Phe and Δ13CVal-Phe proxies can differentiate among the four protein consumption groups tested here. Compound-specific amino acid carbon-isotope dietary proxies thus enable an enhanced understanding of diet and resource exploitation in the past, and can elucidate complex dietary behaviour.

Nitrogen isotopic composition of collagen amino acids as an indicator of aquatic resource consumption: insights from Mesolithic and Epipalaeolithic archaeological sites in France

Aquatic resource exploitations in human evolution have raised many questions related to cognitive abilities and subsistence developments. It has been pointed out that the evaluation of freshwater resource consumption based on conventional stable CN isotopic composition of bulk bone collagen faces some difficulties, primarily because isotopic distinction between terrestrial and freshwater animals can be ambiguous and, even worse, can show similar values. In this study we tested the potential of nitrogen isotope analysis of individual amino acids in this evaluation. Our preliminary results for archaeological human and faunal remains from Mesolithic and Epipalaeolithic sites in France (Noyen-sur-Seine and Pont d'Ambon) show that estimated trophic positions for terrestrial animals based on δ15N of glutamic acid and phenylalanine are more precise than the bulk collagen isotopic method, allowing human aquatic resource consumptions to be identified. However, since the ability to quantify is still limited, a combination of several approaches is recommended.

Reply to Bocherens: Freshwater reservoir radiocarbon correction of Peştera cu Oase 1

Bocherens (1) asserts that the possibility of a potentially underestimated radiocarbon age for the Pestera cu Oase early modern human, given its apparent consumption of aquatic resources (2), may have implications for Neandertal–modern human interactions when the latter dispersed across Europe 40,000–45,000 calendar years ago. However, any possible shift in the Oase 1 14C age is likely to be well within the error margins for 14C dates in this time period [i.e., the errors on the Oase 1 human direct AMS date (GrA-22810) are +970, −870 at 1 sigma (3)] and also within the margin of error on calibrating radiocarbon ages at this period on human remains (3, 4) or on directly associated faunal remains (5). Moreover, it was a substantial distance from the Oase modern humans in Romania to the late Neandertals at Spy in Belgium and Palomas in southeastern Spain, so that the presence or absence of strict contemporaneity of these remains would tell us little about their populations' patterns of interaction.

Stable isotope dietary analysis of the Tianyuan 1 early modern human

We report here on the isotopic analysis of the diet of one of the oldest modern humans found in Eurasia, the Tianyuan 1 early modern human dating to approximately 40,000 calendar years ago from Tianyuan Cave (Tianyuandong) in the Zhoukoudian region of China. Carbon and nitrogen isotope analysis of the human and associated faunal remains indicate a diet high in animal protein, and the high nitrogen isotope values suggest the consumption of freshwater fish. To confirm this inference, we measured the sulfur isotope values of terrestrial and freshwater animals around the Zhoukoudian area and of the Tianyuan 1 human, which also support the interpretation of a substantial portion of the diet from freshwater fish. This analysis provides the direct evidence for the consumption of aquatic resources by early modern humans in China and has implications for early modern human subsistence and demography.

Docosahexaenoic acid, the aquatic diet, and hominin encephalization: Difficulties in establishing evolutionary links

Distinctive characteristics of modern humans, including language, tool manufacture and use, culture, and behavioral plasticity, are linked to changes in the organization and size of the brain during hominin evolution. As brain tissue is metabolically and nutritionally costly to develop and maintain, early hominin encephalization has been linked to a release of energetic and nutritional constraints. One such nutrient-based approach has focused on the n-3 long-chained polyunsaturated fatty acid docosahexaenoic acid (DHA), which is a primary constituent of membrane phospholipids within the synaptic networks of the brain essential for optimal cognitive functioning. As biosynthesis of DHA from n-3 dietary precursors (alpha-linolenic acid, LNA) is relatively inefficient, it has been suggested that preformed DHA must have been an integral dietary constituent during evolution of the genus Homo to facilitate the growth and development of an encephalizing brain. Furthermore, preformed DHA has only been identified to an appreciable extent within aquatic resources (marine and freshwater), leading to speculation that hominin encephalization is linked specifically to access and consumption of aquatic resources. The key premise of this perspective is that biosynthesis of DHA from LNA is not only inefficient but also insufficient for the growth and maturation demands of an encephalized brain. However, this assumption is not well-supported, and much evidence instead suggests that consumption of LNA, available in a wider variety of sources within a number of terrestrial ecosystems, is sufficient for normal brain development and maintenance in modern humans and presumably our ancestors.