The Experts below are selected from a list of 31803 Experts worldwide ranked by ideXlab platform
Simon R. Thorrold - One of the best experts on this subject based on the ideXlab platform.
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a new method to reconstruct fish diet and movement patterns from δ13c values in Otolith amino acids
Canadian Journal of Fisheries and Aquatic Sciences, 2011Co-Authors: Kelton W Mcmahon, Marilyn L Fogel, B J Johnson, Leah A Houghton, Simon R. ThorroldAbstract:Fish ecologists have used geochemical values in Otoliths to examine habitat use, migration, and population connectivity for decades. However, it remains difficult to determine an unambiguous dietary δ13C signature from bulk analysis of Otolith. Studies to date have focused on the aragonite component of Otoliths with less attention paid to the organic fraction. We describe the application of compound-specific stable isotope analysis (SIA) to analyze amino acid (AA) δ13C values from small amounts (<1 mg) of Otolith powder. We examined δ13C values of Otolith and muscle AAs from a reef-associated snapper (Lutjanus ehrenbergii (Peters, 1869)) collected along a carbon isotope gradient (isoscape) from seagrass beds to coral reefs. Carbon isotope values in Otolith and muscle samples were highly correlated within and among coastal habitats. Moreover, δ13C values of Otolith AAs provided a purely dietary record that avoided dilution from dissolved inorganic carbon. Otolith AAs served as a robust tracer of δ13C value...
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temperature and salinity effects on magnesium manganese and barium incorporation in Otoliths of larval and early juvenile spot leiostomus xanthurus
Marine Ecology Progress Series, 2005Co-Authors: Gretchen Bath Martin, Simon R. ThorroldAbstract:The use of Otolith chemistry to delineate fish populations and trace migration pathways is premised on a significant correlation between the elemental composition of Otoliths and physico- chemical properties of the ambient environment. However, few experiments have been rigorously designed to address the effects of temperature and salinity on the elemental composition of Otoliths. We examined the effects of temperature and salinity on the incorporation of magnesium (Mg), man- ganese (Mn), and barium (Ba) in the Otoliths of larval and early juvenile spot Leiostomus xanthurus by rearing fish in the laboratory under controlled environmental conditions. L. xanthurus are an estu- arine dependent species that traverse varying temperature and salinity regimes throughout their life histories. It is important, therefore, to understand the influence of physicochemical properties of dif- ferent water masses before attempting to reconstruct important life history transitions based on vari- ations in Otolith chemistry. Both (Mg/Ca)Otolith and the Mg partition coefficient, DMg, were not signifi- cantly affected by either temperature or salinity, but were correlated with Otolith precipitation and somatic growth rates. Temperature and salinity had significant interaction effects on DMn, but not on (Mn/Ca)Otolith. Finally, DBa was influenced by salinity but not temperature. These results highlight the complex nature of elemental deposition in Otoliths, and suggest that both environmental and physio- logical effects likely influence elemental ratios in fish Otoliths.
Patrick Coutin - One of the best experts on this subject based on the ideXlab platform.
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barium variation in pagrus auratus sparidae Otoliths a potential indicator of migration between an embayment and ocean waters in south eastern australia
Estuarine Coastal and Shelf Science, 2006Co-Authors: Paul A. Hamer, Gregory P Jenkins, Patrick CoutinAbstract:Chronological variation in Otolith chemistry can be used to reconstruct migration histories of fish. The use of Otolith chemistry to study migration, however, requires knowledge of relationships between the chemical properties of the water and elemental incorporation into Otoliths, and how water chemistry varies in space and time. We explored the potential for Otolith chemistry of snapper, Pagrus auratus, to provide information on movement history between a large semi-enclosed bay, Port Phillip, and coastal waters in south-eastern Australia. Comparisons of water chemistry across two years demonstrated that ambient barium (Ba) levels in Port Phillip Bay were approximately double those in coastal waters (11 μg L -1 versus 6 μg L -1 ). Ba levels in Otolith margins of wild juvenile snapper were highly positively correlated with ambient levels across 17 sampling locations, and levels in Otolith margins of adult snapper collected from Port Phillip Bay were approximately double those of snapper collected in coastal waters. Mean partition coefficients for Ba (D Ba ) were similar for juvenile (0.43) and adult (0.46) Otoliths, suggesting that Otolith Ba incorporation relative to ambient levels was similar across life-stages. Low Ba variation across Otoliths from adult snapper maintained in tanks for three years indicated that annual temperature and/or growth cycles did not strongly influence Otolith Ba variation. We concluded that chronological Ba variation in snapper Otoliths would be a reliable proxy for life-history exposure to variable ambient Ba. We used water chemistry data and Ba levels across Otoliths of ocean resident snapper to estimate Otolith Ba levels indicative of residence in Port Phillip Bay (>10 μg g -1 ) or coastal waters (<6 μg g -1 ). Peaks in Ba exceeding 10 ug g -1 were common across Otoliths of snapper collected in Port Phillip Bay and a nearby coastal region. The location of strong Ba peaks within Otoliths was consistent with residence in Port Phillip Bay during the spring/summer when snapper move into the Bay from coastal waters to spawn. Our results for snapper support the use of Otolith Ba as a proxy for ambient levels throughout the life-history, however, confident interpretation of migration history from Otolith Ba chronologies will most likely require matching time series of ambient Ba in the water bodies of interest.
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barium variation in pagrus auratus sparidae Otoliths a potential indicator of migration between an embayment and ocean waters in south eastern australia
Estuarine Coastal and Shelf Science, 2006Co-Authors: Paul A. Hamer, Gregory P Jenkins, Patrick CoutinAbstract:Abstract Chronological variation in Otolith chemistry can be used to reconstruct migration histories of fish. The use of Otolith chemistry to study migration, however, requires knowledge of relationships between the chemical properties of the water and elemental incorporation into Otoliths, and how water chemistry varies in space and time. We explored the potential for Otolith chemistry of snapper, Pagrus auratus, to provide information on movement history between a large semi-enclosed bay, Port Phillip, and coastal waters in south-eastern Australia. Comparisons of water chemistry across two years demonstrated that ambient barium (Ba) levels in Port Phillip Bay were approximately double those in coastal waters (11 μg L−1 versus 6 μg L−1). Ba levels in Otolith margins of wild juvenile snapper were highly positively correlated with ambient levels across 17 sampling locations, and levels in Otolith margins of adult snapper collected from Port Phillip Bay were approximately double those of snapper collected in coastal waters. Mean partition coefficients for Ba (DBa) were similar for juvenile (0.43) and adult (0.46) Otoliths, suggesting that Otolith Ba incorporation relative to ambient levels was similar across life-stages. Low Ba variation across Otoliths from adult snapper maintained in tanks for three years indicated that annual temperature and/or growth cycles did not strongly influence Otolith Ba variation. We concluded that chronological Ba variation in snapper Otoliths would be a reliable proxy for life-history exposure to variable ambient Ba. We used water chemistry data and Ba levels across Otoliths of ocean resident snapper to estimate Otolith Ba levels indicative of residence in Port Phillip Bay (>10 μg g−1) or coastal waters (
Hélène De Pontual - One of the best experts on this subject based on the ideXlab platform.
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How do the organic and mineral fractions drive the opacity of fish Otoliths? Insights using Raman microspectrometry
Canadian Journal of Fisheries and Aquatic Sciences, 2013Co-Authors: Aurélie Jolivet, Ronan Fablet, Jean-françois Bardeau, Yves-marie Paulet, Hélène De PontualAbstract:We investigated the relationships between the opacity and the physico-chemical characteristics of fish Otoliths and more specifically their aragonite and organic fractions. The analysis of these two fractions on Otolith macrostructures was performed using Raman microspectrometry on both translucent and opaque zones of Otoliths of pollock (Pollachius virens) and European hake (Merluccius merluccius). The magnitude of the Raman signatures of the aragonite and organic fractions were strongly correlated to Otolith opacity with maxima in translucent zones. Opacity models, built from Raman signatures, successfully predicted the observed opacity for both species. A partial decorrelation of different aragonite signatures between translucent and opaque zones was revealed and discussed in terms of organisation (size, orientation) of aragonite crystals. Two categories of organic signatures with opposite effects on the opacity were identified, suggesting differences in organic compounds and (or) variations in their relative quantities. These original contributions provided new insight for understanding Otolith biomineralization mechanisms as well as for interpreting and discriminating Otolith macrostructures.
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Preparation techniques alter the mineral and organic fractions of fish Otoliths: insights using Raman micro-spectrometry.
Analytical and Bioanalytical Chemistry, 2013Co-Authors: Aurélie Jolivet, Ronan Fablet, Jean-françois Bardeau, Hélène De PontualAbstract:The high spatial resolution analysis of the mineral and organic composition of Otoliths using Raman micro-spectrometry involves rigorous protocols for sample preparation previously established for microchemistry and trace elements analyses. These protocols often include Otolith embedding in chemically neutral resin (i.e., resins which do not contain, in detectable concentration, elements usually sought in the Otoliths). Such embedding may however induce organic contamination. In this paper, Raman micro-spectrometry reveals the presence of organic contamination onto the surface obtained from the use of epoxy resin, specifically Araldite. This contamination level varies depending on Otolith structures. Core and checks, known as structural discontinuities, exhibit the most important level of contaminations. Our results suggest that Otolith embedding with resin affects the organic matrix of the Otolith, probably through an infiltration of the resin in the crystalline structure. The interpretation of chemical Otolith signatures, especially Raman Otolith signatures, and stable isotope analyses should then be revised in light of these results. In this respect, we propose a method for the correction of Raman Otolith signatures for contamination effects.
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Are hake Otolith macrostructures randomly deposited? Insights from an unsupervised statistical and quantitative approach applied to Mediterranean hake Otoliths
Ices Journal of Marine Science, 2007Co-Authors: Nicolas Courbin, Capucine Mellon, Ronan Fablet, Hélène De PontualAbstract:Individual fish age data are crucial to fish stock assessment, so their accuracy and precision are vital. The acquisition of age data most often relies on interpreting fish Otoliths, a complex task in which expert subjectivity increases with the complexity of the structural patterns of the Otoliths. The question arises for certain fish species (e.g. hake, Merluccius merluccius) whether the deposition of Otolith macrostructures is meaningful for age estimation. A quantitative method based on the evaluation of Otolith similarity in terms of structural patterns is presented to investigate this issue. It relies on the determination of a typology of Otolith macrostructures from an unsupervised statistical analysis of the distributions of their characteristics. This typology provides a basis for analysing and comparing structural patterns of Otoliths through evaluation of structural Otolith similarities. Application to a set of Mediterranean hake Otoliths discriminates three types of macrostructure, one likely associated with fish responses to environmental or endogenous factors, and the other two meaningful at a population or group level. Comparisons of structural patterns based on the proposed structural similarity measure over two successive years support the assumption that Otolith patterns are stable over time, although male and female Otoliths differ significantly in structural pattern. The results bring new evidence that hake Otolith patterns are not random and may be relevant to age estimation.
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Are hake Otolith macrostructures randomly deposited ? Insights from an unsupervised statistical and quantitative approach applied to Meditteranean hake Otoliths
ICES Journal of Marine Science, 2007Co-Authors: Nicolas Courbin, Capucine Mellon, Ronan Fablet, Hélène De PontualAbstract:Individual fish age data are crucial to fish stock assessment, so their accuracy and precision are vital. The acquisition of age data most often relies on interpreting fish Otoliths, a complex task in which expert subjectivity increases with the complexity of the structural patterns of the Otoliths. The question arises for certain fish species (e.g. hake, Merluccius merluccius) whether the deposition of Otolith macrostructures is meaningful for age estimation. A quantitative method based on the evaluation of Otolith similarity in terms of structural patterns is presented to investigate this issue. It relies on the determination of a typology of Otolith macrostructures from an unsupervised statistical analysis of the distributions of their characteristics. This typology provides a basis for analysing and comparing structural patterns of Otoliths through evaluation of structural Otolith similarities. Application to a set of Mediterranean hake Otoliths discriminates three types of macrostructure, one likely associated with fish responses to environmental or endogenous factors, and the other two meaningful at a population or group level. Comparisons of structural patterns based on the proposed structural similarity measure over two successive years support the assumption that Otolith patterns are stable over time, although male and female Otoliths differ significantly in structural pattern. The results bring new evidence that hake Otolith patterns are not random and may be relevant to age estimation.
Bronwyn M. Gillanders - One of the best experts on this subject based on the ideXlab platform.
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Otolith chemistry does not just reflect environmental conditions a meta analytic evaluation
Fish and Fisheries, 2018Co-Authors: Christopher Izzo, Patrick Reissantos, Bronwyn M. GillandersAbstract:Fish Otoliths are widely used to answer biological and ecological questions related to movements and habitat use based on their chemical composition. Two fundamental assumptions underlie Otoliths as environmental tracers and proxies for reconstructing exposure histories: (i) Otolith chemistry reflects water chemistry, and (ii) ambient environmental conditions affect Otolith element incorporation. Here, we test these assumptions for Sr and Ba through meta-analyses. Our first meta-analysis confirmed a correlation between concentrations of Sr:Ca and Ba:Ca in Otoliths and the surrounding water, both elements displaying positive Otolith–water correlations. The second meta-analysis examined the relative influences of salinity and temperature on Otolith Sr and Ba partition coefficients (an index of Otolith element regulation). Our environmental effects meta-analysis confirmed that Otolith Sr and Ba are affected by temperature and salinity; however, study-level covariates (e.g., water chemical concentrations and species ecological niche) influenced Otolith element incorporation, and this varied by element. These findings confirm that even though Otolith chemistry and elemental incorporation are differentially affected by environmental conditions, other factors play a decisive role. While we focused on studies that directly linked water and Otolith chemistry, systematic reviews are key to further demonstrate the link between Otolith chemistry and extrinsic and intrinsic factors. Ultimately, disentangling the relative effects of multiple factors on Otolith chemistry and a detailed understanding of biomineralization is critical to the continued use of Otoliths as natural tags for tracing fish movements and habitat use.
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Otoliths in archaeology methods applications and future prospects
Journal of Archaeological Science: Reports, 2016Co-Authors: Morgan C F Disspain, Bronwyn M. GillandersAbstract:Otoliths are small structures found in the inner ear of teleost fish that act as organs of equilibrium and as direction and sound detectors. They possess unique characteristics that set them apart from other skeletal structures, notably a continuous growth structure deposited on a daily basis. While Otolith analyses are widely employed in modern fisheries studies, they have slowly been increasing within archaeological and palaeoenvironmental research. This paper overviews the development and future prospects of Otolith studies in archaeology. The main methods of analysis are outlined and major advances and research in each area detailed. In spite of some limitations, the benefits and unique information that Otolith analyses can provide ensure that Otoliths should be an important part of archaeological research. Continuing development of methods and technologies within this area will serve to further increase the importance and use of Otoliths, while raising the profile of this unique resource.
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Quantitative electron microprobe mapping of Otoliths suggests elemental incorporation is affected by organic matrices: implications for the interpretation of Otolith chemistry
Marine and Freshwater Research, 2016Co-Authors: Aoife Mcfadden, Bronwyn M. Gillanders, Christopher Izzo, Benjamin P. Wade, Claire E. Lenehan, Allan PringAbstract:In an effort to understand the mechanism of Otolith elemental incorporation, the distribution of strontium (Sr) and sulfur (S) in Otoliths of Platycephalus bassensis was investigated in conjunction with Otolith growth patterns. Optimisation of electron probe microanalysis (EPMA) quantitative mapping achieved both high spatial resolution (
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alternative life history patterns of estuarine fish barium in Otoliths elucidates freshwater residency
Canadian Journal of Fisheries and Aquatic Sciences, 2005Co-Authors: Travis S. Elsdon, Bronwyn M. GillandersAbstract:Elemental concentrations in fish Otoliths (earstones) can reconstruct environmental histories of fish if predictable relationships between the environment and elemental incorporation are established. We assessed whether fresh water occupancy of black bream (Acanthopagrus butcheri) can be inferred from Otolith barium concentrations (Ba was standardized to calcium (Ca) and expressed as a ratio, Ba:Ca). Otolith Ba:Ca of fish was correlated with ambient Ba:Ca. Using the natural relationships of increasing ambient and Otolith Ba:Ca with decreasing salinity, fish from fresh- and salt-water environments were distinguishable. Fish caught in fresh water had approximately double the Otolith Ba:Ca of those from salt-water estuaries, for both summer and winter collections. Fish with Otolith Ba:Ca ≤5 µmol·mol1 were classified as resident in salt water, and those with ≥6 µmol·mol1 as resident in fresh water. Transects of Ba:Ca across fish Otoliths classified fish to fresh- or salt-water environments. Fish were identi...
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fish Otolith chemistry influenced by exposure to multiple environmental variables
Journal of Experimental Marine Biology and Ecology, 2004Co-Authors: Travis S. Elsdon, Bronwyn M. GillandersAbstract:There is an increasing desire for researchers to use the elemental concentrations in fish Otoliths to reconstruct environmental histories of fish. These reconstructions may be plausible due to the unique incorporation of elements into discrete layers of Otolith material that correspond to daily growth, and because environmental variables of temperature, salinity, and water chemistry can influence Otolith chemistry. However, it is essential to establish exactly how temperature, salinity, and the ambient concentration of elements influence Otolith chemistry in order to interpret environmental histories of fish. Using a controlled laboratory experiment we tested the relative and interactive effects of temperature, salinity, and ambient concentration of strontium (Sr) and barium (Ba) on the resulting concentration of Sr and Ba in Otoliths of black bream Acanthopagrus butcheri (Munro 1949). Salinity and concentration, and temperature and concentration interacted to affect the elemental concentration of Sr:Ca and Ba:Ca in Otoliths. Regression analysis revealed that temperature and ambient concentration contributed most to the trend in Otolith chemistry for both elements. Importantly, this is the first experiment to combine three environmental variables and assess their effect on Otolith chemistry. Based on these results, it should be possible to use changes in the elemental concentration in Otoliths to better reconstruct previous environments of temperature, salinity, and ambient water chemistry, which is especially useful when determining occupancy in habitats such as estuaries that display variable environmental characteristics.
Paul A. Hamer - One of the best experts on this subject based on the ideXlab platform.
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Comparison of spatial variation in Otolith chemistry of two fish species and relationships with water chemistry and Otolith growth
Journal of Fish Biology, 2007Co-Authors: Paul A. Hamer, Gregory P JenkinsAbstract:Spatial variation in the chemistry (Mg, Mn, Sr and Ba) of recently deposited Otolith material (last 20–30 days of life) was compared between two demersal fish species; snapper Pagrus auratus (Sparidae) and sand flathead Platycephalus bassensis (Platycephalidae), that were collected simultaneously at 12 sites across three bays in Victoria, south-eastern Australia. Otolith chemistry was also compared with ambient water chemistry and among three sampling positions adjacent to the proximal Otolith margin. For both species, variation in Otolith chemistry among bays was significant for Ba, Mn and Sr; however, differences among bays were only similar between species for Ba and Mn. Only Ba showed significant variation at the site level. Across the 12 sites, mean Otolith Ba levels were significantly positively correlated between species. Further, although incorporation rates differed, mean ambient Ba levels for both species were positively correlated with ambient Ba levels. Spatial variation in multi-element Otolith chemistry was also broadly similar between species and with multi-element water chemistry. Partition coefficients clearly indicated species-specific incorporation of elements into Otoliths. Mg and Mn were consistently higher in snapper than sand flathead Otoliths (mean ±s.d., Mg snapper 22·1 ± 3·8 and sand flathead 9·9 ± 1·5 μg g−1, Mn snapper 4·4 ± 2·6 and sand flathead 0·5 ± 0·3 μg g−1), Sr was generally higher in sand flathead Otoliths (sand flathead 1570 ± 235 and snapper 1346 ± 104 μg g−1) and Ba was generally higher in snapper Otoliths (snapper 12·1 ± 12·8 and sand flathead 1·8 ± 1·4 μg g−1). For both species, Mg and Mn were higher in the faster accreting regions of the Otolith margin, Sr was lower in the slower accreting region and Ba showed negligible variation among the three sampling regions. This pattern was consistent with the higher Mg and Mn, and generally lower Sr observed in the faster accreting snapper Otoliths. It is hypothesized that the differences between species in the incorporation of these elements may be at least partly related to differences in metabolic and Otolith accretion rate. Although rates of elemental incorporation into Otoliths appear species specific, for elements such as Ba where incorporation appears consistently related to ambient concentrations, spatial variation in Otolith chemistry should show similarity among co-occurring species.
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barium variation in pagrus auratus sparidae Otoliths a potential indicator of migration between an embayment and ocean waters in south eastern australia
Estuarine Coastal and Shelf Science, 2006Co-Authors: Paul A. Hamer, Gregory P Jenkins, Patrick CoutinAbstract:Chronological variation in Otolith chemistry can be used to reconstruct migration histories of fish. The use of Otolith chemistry to study migration, however, requires knowledge of relationships between the chemical properties of the water and elemental incorporation into Otoliths, and how water chemistry varies in space and time. We explored the potential for Otolith chemistry of snapper, Pagrus auratus, to provide information on movement history between a large semi-enclosed bay, Port Phillip, and coastal waters in south-eastern Australia. Comparisons of water chemistry across two years demonstrated that ambient barium (Ba) levels in Port Phillip Bay were approximately double those in coastal waters (11 μg L -1 versus 6 μg L -1 ). Ba levels in Otolith margins of wild juvenile snapper were highly positively correlated with ambient levels across 17 sampling locations, and levels in Otolith margins of adult snapper collected from Port Phillip Bay were approximately double those of snapper collected in coastal waters. Mean partition coefficients for Ba (D Ba ) were similar for juvenile (0.43) and adult (0.46) Otoliths, suggesting that Otolith Ba incorporation relative to ambient levels was similar across life-stages. Low Ba variation across Otoliths from adult snapper maintained in tanks for three years indicated that annual temperature and/or growth cycles did not strongly influence Otolith Ba variation. We concluded that chronological Ba variation in snapper Otoliths would be a reliable proxy for life-history exposure to variable ambient Ba. We used water chemistry data and Ba levels across Otoliths of ocean resident snapper to estimate Otolith Ba levels indicative of residence in Port Phillip Bay (>10 μg g -1 ) or coastal waters (<6 μg g -1 ). Peaks in Ba exceeding 10 ug g -1 were common across Otoliths of snapper collected in Port Phillip Bay and a nearby coastal region. The location of strong Ba peaks within Otoliths was consistent with residence in Port Phillip Bay during the spring/summer when snapper move into the Bay from coastal waters to spawn. Our results for snapper support the use of Otolith Ba as a proxy for ambient levels throughout the life-history, however, confident interpretation of migration history from Otolith Ba chronologies will most likely require matching time series of ambient Ba in the water bodies of interest.
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barium variation in pagrus auratus sparidae Otoliths a potential indicator of migration between an embayment and ocean waters in south eastern australia
Estuarine Coastal and Shelf Science, 2006Co-Authors: Paul A. Hamer, Gregory P Jenkins, Patrick CoutinAbstract:Abstract Chronological variation in Otolith chemistry can be used to reconstruct migration histories of fish. The use of Otolith chemistry to study migration, however, requires knowledge of relationships between the chemical properties of the water and elemental incorporation into Otoliths, and how water chemistry varies in space and time. We explored the potential for Otolith chemistry of snapper, Pagrus auratus, to provide information on movement history between a large semi-enclosed bay, Port Phillip, and coastal waters in south-eastern Australia. Comparisons of water chemistry across two years demonstrated that ambient barium (Ba) levels in Port Phillip Bay were approximately double those in coastal waters (11 μg L−1 versus 6 μg L−1). Ba levels in Otolith margins of wild juvenile snapper were highly positively correlated with ambient levels across 17 sampling locations, and levels in Otolith margins of adult snapper collected from Port Phillip Bay were approximately double those of snapper collected in coastal waters. Mean partition coefficients for Ba (DBa) were similar for juvenile (0.43) and adult (0.46) Otoliths, suggesting that Otolith Ba incorporation relative to ambient levels was similar across life-stages. Low Ba variation across Otoliths from adult snapper maintained in tanks for three years indicated that annual temperature and/or growth cycles did not strongly influence Otolith Ba variation. We concluded that chronological Ba variation in snapper Otoliths would be a reliable proxy for life-history exposure to variable ambient Ba. We used water chemistry data and Ba levels across Otoliths of ocean resident snapper to estimate Otolith Ba levels indicative of residence in Port Phillip Bay (>10 μg g−1) or coastal waters (
