Marine Protein Research Articles

Freshwater savings from marine protein consumption

Marine fisheries provide an essential source of protein for many people around the world. Unlike alternative terrestrial sources of protein, marine fish production requires little to no freshwater inputs. Consuming marine fish protein instead of terrestrial protein therefore represents freshwater savings (equivalent to an avoided water cost) and contributes to a low water footprint diet. These water savings are realized by the producers of alternative protein sources, rather than the consumers of marine protein. This study quantifies freshwater savings from marine fish consumption around the world by estimating the water footprint of replacing marine fish with terrestrial protein based on current consumption patterns. An estimated 7 600 km3 yr−1 of water is used for human food production. Replacing marine protein with terrestrial protein would require an additional 350 km3 yr−1 of water, meaning that marine protein provides current water savings of 4.6%. The importance of these freshwater savings is highly uneven around the globe, with savings ranging from as little as 0 to as much as 50%. The largest savings as a per cent of current water footprints occur in Asia, Oceania, and several coastal African nations. The greatest national water savings from marine fish protein occur in Southeast Asia and the United States. As the human population increases, future water savings from marine fish consumption will be increasingly important to food and water security and depend on sustainable harvest of capture fisheries and low water footprint growth of marine aquaculture.

Growth performance, survival and body composition of southern flounderParalichthys lethostigmalarvae fed different formulated microdiets

Three experiments were conducted to evaluate the effects of micro-bound diets (MBD) on southern flounder larvae. In experiment 1, four MBDs were formulated with different protein sources as follows: MBD 1: herring meal, MBD 2: menhaden meal, MBD 3: menhaden and squid meal; MBD 4: menhaden, squid and herring meal. In experiment 2, four MBDs were formulated as follows: MBD 5: menhaden, squid and herring meal; MBD 6: menhaden, squid, herring and attractants; MBD 7: menhaden, squid, herring and casein, and MBD 8: menhaden, squid, herring, casein and attractants. In experiment 3, three groups were maintained as follows: Group 1: live feed; Group 2: co-fed with MBD 6; and Group 3: MBD 6. In experiment 1 on 35 dph, survival and body weight (BW) of the fish fed MBD 4 was significantly higher than the MBDs 1 and 2. In experiment 2 on 34 dph, fish fed MBD 6 had significantly higher BW than the commercial microdiets. In experiment 3 on 21 dph, fish receiving only MBD had significantly lower survival than the other groups. Growth, survival and larval fatty acid composition suggested that co-feeding MBD 6, a mixture of marine protein sources plus attractants was more effective than the other MBDs.

Isotopic examination of links between diet, social differentiation, and DISH at the post‐medieval Carmelite Friary of Aalst, Belgium

Stable isotope ratios (δ(13) C and δ(15) N) were measured in human burials from the post-medieval (16th-18th c. AD) Carmelite friary burial grounds at Aalst, a town in Flanders, Belgium. Dietary patterns of 39 adult individuals were analyzed, from a mixed monastic and lay population buried in three different locations, reflecting groups with differing social status. The data show significant variation in the consumption of perhaps meat, but certainly also marine protein between females and males. This result represents a remarkable continuity with medieval dietary patterns, suggesting that the social and economic changes of the early modern period had a limited effect on everyday life. When both sexes were examined together, individuals buried in the cloister garth consumed significantly less marine protein compared to people buried in the church, likely reflecting social stratification. No statistical differences were observed between isotopic values from the church and the cloister alley, suggesting a similarly diverse diet of the monastic part of the buried population and that of the richer lay population. Finally, the hypothesis that diffuse idiopathic skeletal hyperostosis (DISH) is linked to a diet rich in animal protein was tested. No systematic or statistically significant differences between pathological and non-pathological bones from the same individuals affected with DISH were observed, and no statistical differences were found between individuals with DISH and individuals without DISH.

Evaluating marine diets through radiocarbon dating and stable isotope analysis of victims of the AD79 eruption of vesuvius

The stable carbon (δ(13) C) and nitrogen (δ(15) N) isotope values of bone collagen are frequently used in paleodietary studies to assess the marine contribution to an individual's diet. Surprisingly, the relationship between stable isotope these values characteristics and the percentage of marine foods in diet has never been effectively demonstrated. To clarify this relationship, the stable isotope values and radiocarbon dates of nine humans and one sheep from Herculaneum, all who perished simultaneously during the AD 79 eruption of Vesuvius, were determined. Significant differences were found in the radiocarbon dates which are attributable to the incorporation of "old" carbon from the marine reservoir. The magnitude of the observed differences was linearly correlated with both δ(13) C and δ(15) N values allowing the response of each isotope to increasing marine carbon in collagen to be independently verified. Regression analyses showed that for every 1‰ enrichment in δ(13) C and δ(15) N, 56 years and 34 years were added to the radiocarbon age, respectively. Predictions of the maximum marine reservoir age differed considerably depending on which stable isotope was considered. This discrepancy is attributed to some degree of macronutrient scrambling whereby nitrogen from marine protein is preferentially incorporated in collagen over marine carbon. It is suggested that the macronutrient scrambling explains the observed relationship between δ(13) C and δ(15) N from Roman coastal sites and should be considered when interpreting any diet which is not dominated by protein. Nevertheless, without knowing the degree of macronutrient scrambling in different dietary scenarios, the accuracy of dietary reconstructions is severely compromised.

Modeling sardine and anchovy low-frequency variability

The group of small pelagics (sardines, anchovies, herrings, etc.) is the largest source of wild marine protein worldwide, providing annually between 21% and 43% of the total marine capture production during at least the last 60 y (1). Even when large-scale fisheries have been operating for decades to centuries, their assessment and management remains difficult and highly uncertain (2). Such challenges are mainly because these species do not conform to the traditional assumptions of population dynamic models, such as a steady level of unexploited stock (carrying capacity), or that the influence of climate on the population is negligible when compared to fishing mortality. In other words, it has been clear for decades that the traditional toolbox of fisheries management is clearly unsuitable to these massive resources. The paper by Lindegren et al. (3) in PNAS provides an alternative framework to study and ultimately to develop management-supporting knowledge for these types of resources.

ACE Inhibitory Peptides Derived from Aquatic Protein

Among bioactive peptides derived from aquatic protein, those with ACE inhibitory activity are receiving special attention. This paper presented an overview of ACE inhibitory peptides derived from aquatic proteins, and the peptide sources were listed. The structure-activity relationship and mechanism of action of ACE inhibitory peptides were also discussed. Finally, the antihypertensive effects of ACE inhibitory peptides derived from marine protein, including short-term and long-term influence, were also discussed.

Human Paleodiet at Grand Bay, Carriacou, Lesser Antilles

ABSTRACT The island of Carriacou in the southern Grenadines, Lesser Antilles, has been the focus of interdisciplinary archaeological research since 2003, focused on ceramic-associated assemblages dating between c. AD 400 and 1300. Amerindians here exploited marine foods, but patterned subsistence has not been inferred directly from recovered human remains. Here, we present the first stable isotope data from bone collagen and bone apatite of individuals (n = 14) from the Grand Bay site that date to post–AD 1000. Average δ13Cco (−12.8‰), δ15N (11.1‰), δ13Cap (−8.6‰), and Δ13Cap-co (4.1‰) values substantiate a marine-based diet. No significant differences are observed between males and females; however, one subadult is an isotopic outlier based on its δ13Cco and Δ13Cap-co values. Bone collagen values suggest high marine protein at Carriacou, different from data reported for contemporaneous groups in the Greater Antilles, broadly similar to the northern Lesser Antilles, and most similar to the Bahamas, where reef-based systems are ubiquitous. Bone apatite and bone collagen isotope results underscore the importance of shellfish on Carriacou as previously observed in the zooarchaeological record. At present, these data do not provide the interpretative power to confirm or refute the presence/absence of maize in the diet during the mid-Ceramic Saladoid in the southern Lesser Antilles.

The effect of organic acids on gelation characteristics of protein gels made from silver carp (Hypophthalmichthys molitrix) protein recovered by isoelectric solubilization and precipitation

Isoelectric solubilization and precipitation (ISP), a protein recovery process, was applied to ground, headed and gutted silver carp (Hypophthalmichthys molitrix) at both acidic and basic solubilization pH values using either glacial acetic acid (AA) or a combination of formic and lactic acid (F&L). Functional and textural properties of protein pastes and cooked gels made from recovered protein with standard additives were examined. Thermal denaturation and viscoelasticity of protein pastes were measured; pastes presented with endothermic reactions typical of non-denatured protein. Protein solubilized using AA and F&L resulted in endothermic properties similar to Alaska Pollock surimi. ISP-recovered protein presented with rheological characteristics typical of myofibrillar proteins from other marine protein sources. Viscoelastic properties of proteins solubilized at basic conditions using F&L had a high elastic modulus (G′), which is an indication of good gelation and gel quality. Shear stress on cooked gels was highest (p < 0.05) in gels made from protein solubilized at pH 11.5 using AA. Protein recovered by ISP processing retained their functionality and gels made from the protein were similar to surimi; therefore, potential exists for its use as a high quality protein source.

Feeding Atlantic salmon diets with plant ingredients during the seawater phase - a full-scale net production of marine protein with focus on biological performance, welfare, product quality and safety

By feeding Atlantic salmon diets with 64% of the fish oil (FO) replaced by vegetable oil, and with decreasing fishmeal (FM) inclusion levels from 213, 178 and 143 g kg−1 (accumulated level during the seawater phase) in a full-scale experiment producing 3.1 thousand tonnes fish, no significant negative effects on fish performance, health and product quality were observed. All dietary groups showed, however, moderate intestinal inflammation. Reduced growth and feed efficiency were seen with decreasing fishmeal inclusion levels. Two dietary groups demonstrated net marine protein production, while none of the groups showed net fish production (FIFO ≥1.65) due to the equal low FO inclusion. High plant oil level gave lower fillet level of persistent organic pollutants (POPs) compared with the levels surveyed on the Norwegian market. The study gave predictable incorporation rates of essential n-3 long-chain fatty acids in the fillet. Cooked salmon fillet from all dietary groups showed minor differences in sensory quality. Based on the present full-scale production results, dietary FM inclusion down to 160 g kg−1 (accumulated) during the seawater phase, concurrent to replacing ~70% of the FO with a suitable plant oil, is not regarded to represent any risk to fish performance, health or quality.

Influence of marine and leguminous protein hydrolysates on oxidative stress and some markers of inflammation in hypercholesterolemic rats

Influence of marine and leguminous protein hydrolysates on oxidative stress and some markers of inflammation in hypercholesterolemic rats

Replacement of fish meal by plant protein sources up to 75% induces good growth performance without affecting flesh quality in ongrowing Senegalese sole

The replacement of fish meal (FM) by increasing levels of plant protein (PP) sources 50% (PP50), 75% (PP75) and 100% (PP100) was compared to a control diet (FM) containing fish meal as the main protein source in ongrowing Senegalese sole (mean initial body weight:106g±15). These four diets were isonitrogenous and isolipidic (54% crude protein and 9% crude fat on a dry matter basis). By the end of the growth trial, groups fed PP50 and PP75 had a final body weight and daily growth index (DGI) similar to the FM fed group (200g and 0.8–0.9, respectively), whereas PP100 diet induced a significantly lower DGI (0.4). PP100 showed the highest feed conversion ratio (FCR) (2.4 vs 1.5) and the lowest protein gain (0.5 vs 0.9gkg−1ABWday−1). Nutrient intake of PP groups was statistically similar to the FM group. Apparent digestibility coefficients (ADCs) of nutrients did not differ significantly among treatments (p>0.05) and all PP diets induced lower fecal P losses than the FM group (33%).The highest PP levels (PP75 and PP100) resulted in decreased whole body lipid contents, thought PP100 showed the highest HSI and liver total lipids. In all groups, liver was the major lipid storage organ (13.96–28.57% WW). Muscle lipid content was low (1.3–1.6% WW) and did not vary significantly among treatments. Polyunsaturated fatty acid (PUFA) levels in muscle were also similar amongst dietary treatments and the two highest replacement levels (PP75 and PP100) were still effective in producing an n-3 PUFA rich product (29–30% of total fatty acids (WW)) similar to the FM group (33% of total fatty acids (WW)). Docosahexaenoic acid (DHA) was selectively retained in muscle (17–21% of total fatty acids (WW)) and neither DHA/EPA (Eicosapentaenoic acid) nor EPA/ARA (Arachidonic acid) ratios were significantly affected (p>0.05) by dietary treatments. The sensory evaluation of cooked slices showed that the replacement of marine protein sources (FM) by PP blends did not have a significant impact on the majority of the descriptors, though visual freshness and whiteness of the PP75 flesh yielded the highest scores.Our results indicate that ongrowing Senegalese sole can effectively use diets with high levels of PP sources, up to 75% of FM replacement, without impairing feed intake, growth performance and protein utilisation whilst preserving high n−3 PUFA and DHA flesh content.

A New Role for Marine Skeletal Proteins in Regenerative Orthopaedics

Use of ready-made marine skeletons is one of the simplest possible remedies to major problems hindering the future development of regenerative orthopaedics- such as, providing a richness of framework designs and now a potentially rich, accessible source of osteopromotive analogues and biomineralisation proteins. It has already been shown that coral and marine sponge skeletons can support self-sustaining musculoskeletal tissues and that extracts of spongin collagen and nacre seashell organic matrices promote bone mineralisation. This should not be surprising given that the pivotal biomineralisation proteins, which orchestrate bone morphogenesis are also found in the earliest calcifying marine organisms. This is because they are representatives of the first molecular components established for calcification, morphogenesis and wound healing. In support of this notion, it has emerged that BMP molecules- the main cluster of bone growth factors for human bone morphogenesis- are secreted by endodermal cells into the developing skeleton. In addition, the regenerative signalling proteins, TGF-b and Wnt-prime targets in bone therapeutics- are also present in early marine sponge development and instrumental to stem cell activation in Cnidarians. Based on this match between vertebrate and invertebrate main developmental proteins, we review the nature and extent of this evolutionary relatedness and use it to support the development of a new strategy, which is to mine selected marine origin organic matrices for novel metabolic, signalling and structural proteins/peptides and protein analogues to apply in regenerative orthopaedics, particularly when using adult stem cells. To support such a proposal we show early stage evidence-gathered in our own laboratory- of the presence of fibrinogen fragments and early osteopromotive effects of a coral organic matrix extract on stem cells. In practice the discovery of new osteopromotive and osteo-accelerant protein analogues will require use of traditional chromatography techniques, osteoactivity assays to hone in on potential proteins of significance and advanced proteomic tools to provide accurate sequencing, determine the mechanisms and molecular pathways involved in osteoactivation and determine the efficiency and effectiveness of marine skeleton-derived protein modulation of the stem cell (MSC) proteome. As more analogues are discovered using proteomic tools, skeletal organic matrices may have ever increasing utility for regenerative orthopaedics.

Archaeological Commentary on the Isotopic Study of the Greenland Thule Culture

An archaeological commentary is given on the results of the first isotopic study of the Greenland Thule culture. To test the isotopic data derived from human remains from the graves, comparative archaeological data of the faunal and artifactual material from the sites are presented. To make the two data sets comparable, the faunal material are presented in NISP and the artifactual material are presented as technounits. The three data sets given, i.e., the isotopic, the faunal, and the artifactual, confirm that the Inuit were heavily reliant on marine protein and resources. Exceptions are those from Northeast Greenland, whose isotopic signatures show evidence of consumption of terrestrial protein as well, a statement confirmed by the archaeological material, faunal as well as artifactual, showing that ca. 20% and 40% of bones as well as technounits found on coastal and inland sites, respectively, are related to terrestrial resources. The conclusion made is that the isotopic analyses are valid in archaeological contexts and support the archaeological material. Concerning the substantial use of inland resources in Northeast Greenland compared with the ethnographically documented intensive caribou hunting in West Greenland, the former region still remains most enigmatic from a cultural point of view.

A First Isotopic Dietary Study of the Greenlandic Thule Culture

The isotopic dietary method has been applied to samples of some 65 Thule Culture individuals from existing archaeological collections of Greenlandic human skeletal material. The aim was to use the Greenlandic Thule Culture as a test of the isotopic method, in that we know they were heavily dependent on marine resources, and should thus provide a direct measure of the isotopic values for humans consuming almost entirely marine protein. The sites from which the material was originally obtained encompass almost the entire periphery of Greenland. Isotopic data from a study of animals of Greenland was used as the basis for analysis. As expected, the results indicate that these people were almost entirely dependent on the marine biosphere for their protein. An exception is those from Northeast Greenland, whose isotopic signatures show evidence for consumption of terrestrial protein as well. Not expected were the observed differences at the regional and local levels.

Transcriptomic and physiological responses to fishmeal substitution with plant proteins in formulated feed in farmed Atlantic salmon (Salmo salar)

BackgroundAquaculture of piscivorous fish is in continual expansion resulting in a global requirement to reduce the dependence on wild caught fish for generation of fishmeal and fish oil. Plant proteins represent a suitable protein alternative to fish meal and are increasingly being used in fish feed. In this study, we examined the transcriptional response of Atlantic salmon (Salmo salar) to a high marine protein (MP) or low fishmeal, higher plant protein replacement diet (PP), formulated to the same nutritional specification within previously determined acceptable maximum levels of individual plant feed materials.ResultsAfter 77 days of feeding the fish in both groups doubled in weight, however neither growth performance, feed efficiency, condition factor nor organ indices were significantly different. Assessment of histopathological changes in the heart, intestine or liver did not reveal any negative effects of the PP diet. Transcriptomic analysis was performed in mid intestine, liver and skeletal muscle, using an Atlantic salmon oligonucleotide microarray (Salar_2, Agilent 4x44K). The dietary comparison revealed large alteration in gene expression in all the tissues studied between fish on the two diets. Gene ontology analysis showed, in the mid intestine of fish fed PP, higher expression of genes involved in enteritis, protein and energy metabolism, mitochondrial activity/kinases and transport, and a lower expression of genes involved in cell proliferation and apoptosis compared to fish fed MP. The liver of fish fed PP showed a lower expression of immune response genes but a higher expression of cell proliferation and apoptosis processes that may lead to cell reorganization in this tissue. The skeletal muscle of fish fed PP vs MP was characterized by a suppression of processes including immune response, energy and protein metabolism, cell proliferation and apoptosis which may reflect a more energy efficient tissue.ConclusionsThe PP diet resulted in significant effects on transcription in all the 3 tissues studied. Despite of these alterations, we demonstrated that high level of plant derived proteins in a salmon diet allowed fish to grow with equal efficiency as those on a high marine protein diet, and with no difference in biometric quality parameters.

Effects of fish meal- and fish oil-free diets on growth responses and fatty acid composition of juvenile coho salmon (Oncorhynchus kisutch)

Commercial diets fed to coho salmon (Oncorhynchus kisutch) contain high levels of fish meal and fish oil. Given concerns about future supplies and prices of these commodities, more nutritional research aimed at identifying alternative dietary ingredients for Pacific salmon is needed. Thus, utilizing a factorial design, terrestrial proteins and lipids were evaluated in practical diets fed to coho salmon. The two basal diets, containing mostly marine proteins or containing only terrestrial proteins, were extruded and top-coated with either marine fish oil or a 63:37 mixture of canola and flaxseed oils. Each of the four dietary treatments was fed to quadruplicate groups of juvenile coho salmon initially weighing 7.5g/fish. At the end of the 15-wk feeding trial, weight gain (WG), feed efficiency (FE) and survival were significantly higher in fish fed diets containing marine protein compared with fish fed diets containing terrestrial proteins. Similarly, WG and FE were significantly higher in fish fed diets containing fish oil compared with fish fed diets containing plant oils. Survival was not significantly affected by dietary lipid source. Hemoglobin, hematocrit and total protein concentrations in whole blood were significantly higher in fish fed the marine protein diets compared with fish fed the terrestrial protein diets. Hematological responses were not significantly affected by dietary lipid source. Tissue (liver, muscle and carcass) lipids in fish fed the diets with added fish oil contained significantly higher proportions of 20:5n-3 and 22:6n-3 and significantly lower 18:1n-9, 18:2n-6 and 18:3n-3 percentages compared with fish fed the diets with added plant oils. Tissue fatty acid profiles also were significantly affected by dietary protein source, as liver, muscle and whole body lipids of fish fed the terrestrial protein diets contained significantly higher percentages of 18:2n-6 and total n-6 PUFA and a significantly lower total n-3:n-6 fatty acid ratio compared with fish fed the marine protein diets. Results of this study indicate complete replacement of dietary fish meal or fish oil individually have similar inhibitory growth effects in coho salmon, but have different effects on survival, hematological responses and tissue fatty acid percentages in this species.

Investigation of diachronic dietary patterns on the islands of Ibiza and Formentera, Spain: Evidence from sulfur stable isotope ratio analysis

We present sulfur isotope ratio measurements of bone collagen from animals (n = 75) and humans (n = 120) from five sites dating to four chronological periods (Chalcolithic, Punic, Late Antiquity-Early Byzantine, and Islamic) from the Balearic Islands of Ibiza and Formentera, Spain. This study is a follow up to previously published δ(13)C and δ(15)N values by [Fuller et al.: Am J Phys Anthropol 143 (2010) 512-522] and focuses on using δ(34)S values to better understand the dietary patterns of these populations through time and to possibly identify immigrants to these islands. The range of δ(34)S values (10.5-17.8‰) observed for the animals was relatively broad, which suggests that a significant sea spray effect has added marine sulfates to the soils of Formentera and Ibiza. The mean δ(34)S values of the different human populations were found to be: Chalcolithic (16.5 ± 1.4‰), Punic rural (13.6 ± 1.7‰), Punic urban (12.9 ± 1.8‰), Late Antiquity-Early Byzantine (12.3 ± 2.1‰), and Islamic (9.1 ± 2.7‰). These human δ(34)S results are similar to the animal data, a finding that supports the notion that there was little marine protein consumption by these societies and that the diet was mainly based on terrestrial resources. During the Punic and Late Antiquity-Early Byzantine periods the δ(34)S values were used to identify individuals in the population who likely were not born or raised on the islands. In addition, 18 of the 20 individuals analyzed from the Islamic period have δ(34)S values that indicate that they were immigrants to Ibiza who died before acquiring the new local sulfur isotopic signature.

Influence of seabird guano and camelid dung fertilization on the nitrogen isotopic composition of field-grown maize (Zea mays)

Organic fertilizers have the capacity to alter the nitrogen isotopic composition of plants. Camelid dung and seabird guano are two potentially important fertilizers in the agricultural systems of western South America, particularly Peru and Chile. This paper presents isotopic data (δ13C and δ15N) from field grown plants (maize, Zea mays) fertilized with the following four treatments: CO (control, no fertilizer applied), AS (ammonium sulfate, a chemical fertilizer), DU (camelid dung), and SG (seabird guano). Plants were grown in experimental plots in the Virú Valley, northern Peru. Plants fertilized with the chemical fertilizer presented very similar isotopic compositions compared to the control. Conversely, the camelid dung fertilized plants were characterized by higher δ15N values compared to the control plants (by 1.8 to 4.2‰ depending on the plant part). The seabird guano fertilized plants were greatly enriched in 15N in comparison to the control plants (by 11.3 to 20.0‰). The results of this study have important implications for the reconstruction of human diet using isotopic data derived from bone collagen and related tissues, particularly in the prehispanic Andes, but also in Europe and North America during the 19th century, when Peruvian seabird guano was used extensively. Specifically, the interpretation of the relative contributions of plant and animal protein to the diet on the basis of bulk isotopic compositions of bone collagen (or similar tissues) may be confounded by camelid dung fertilization if the carbon isotopic compositions of the two sources are similar. Likewise, the interpretation of the relative contributions of maize and marine protein may be confounded by seabird guano fertilization.

Net production of Atlantic salmon (FIFO, Fish in Fish out &lt; 1) with dietary plant proteins and vegetable oils

Adult Atlantic salmon (Salmo salar; approximately 800 g start weight) were fed diets with a high replacement of fish meal (FM) with plant proteins (70% replacement), and either fish oil (FO) or 80% of the FO replaced by olive oil (OO), rapeseed oil (RO) or soybean oil (SO) during 28 weeks in triplicate. Varying the lipid source only gave non-significant effects on growth and final weight. However, a significantly reduced feed intake was observed in the SO fed fish, and both feed utilization and lipid digestibility were significantly reduced in the FO fed fish. Limited levels of dietary 18:3n-3, precursor to EPA and DHA, resulted in no net production of EPA and DHA despite increased mRNA expression of delta-5-desaturase and delta-6-desaturase in all vegetable oil fed fish. Net production of marine protein, but not of marine omega-3 fatty acids, is thus possible in Atlantic salmon fed 80% dietary vegetable oil and 70% plant proteins resulting in an estimated net production of 1.3 kg Atlantic salmon protein from 1 kg of FM protein. Production of one 1 kg of Atlantic salmon on this diet required only 800 g of wild fish resources (Fish in - Fish out < 1).

Variation of bone collagen amino acid δ13c values in archaeological humans and fauna with different dietary regimes: Developing frameworks of dietary discrimination

We present bone collagen amino acid (AA) δ(13)C values for a range of archaeological samples representing four "benchmark" human diet groups (high marine protein consumers, high freshwater protein consumers, terrestrial C(3) consumers, and terrestrial C(4) consumers), a human population with an "unknown" diet, and ruminants. The aim is to establish an interpretive palaeodietary framework for bone collagen AA δ(13)C values, and to assess the extent to which AA δ(13)C values can provide additional dietary information to bulk collagen stable isotope analysis. Results are analyzed to determine the ability of those AAs for which we have a complete set, to discriminate between the diet groups. We show that very strong statistical discrimination is obtained for all interdiet group comparisons. This is often obvious from suitably chosen bivariate plots using δ(113)C values that have been normalized to compensate for interdiet group differences in bulk δ(13)C values. Bi-plots of non-normalized phenylalanine and valine δ(13)C values are useful for distinguishing aquatic diets (marine and freshwater) from terrestrial diets. Our interpretive framework uses multivariate statistics (e.g., discriminant analysis) to optimize the separation of the AA δ(13)C values of the "benchmark"' diet groups, and is capable of accurately assigning external samples to their expected diet groups. With a growing body of AA δ(13)C values, this method is likely to enhance palaeodietary research by allowing the "unknown" diets of populations under investigation to be statistically defined relative to the well-characterized or "known" diets of previously investigated populations.