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Invasive Silver Carp (Hpophthalmichthys molitrix) have established populations throughout the Missouri River basin, including in the Kansas River. Understanding the spatial extent under which these invasive fish function in large, open river systems is crucial to inform management efforts. The Kansas River may play a vital role in the life-cycle of Silver Carp in the Missouri River basin as the main-stem Missouri River has undergone a multitude of alterations, creating a channel with greater mean depths and velocities. Here, we used otolith microchemistry of Silver Carp from the Kansas River to reconstruct environmental histories as a means to assess the proportions of resident and transient individuals. Silver Carp within the Kansas River were predominantly residents (adults = 54%; juveniles = 65%) with the majority of reproduction coming from within the Kansas River itself. These results suggest removal efforts in the Kansas River may be effective means of managing this invasive fish species. Transient individuals exhibited short durations of signatures indicative of the Missouri River (mean percent of data points for adults = 10% and juveniles = 36%), suggesting movements into the Missouri River were brief. These results highlight the importance of connectivity of tributary habitat among large rivers and provides important information for invasive species management.

The use of cephalopod beaks in ecological and population dynamics studies has allowed major advances of our knowledge on the role of cephalopods in marine ecosystems in the last 60 years. Since the 1960’s, with the pioneering research by Malcolm Clarke and colleagues, cephalopod beaks (also named jaws or mandibles) have been described to species level and their measurements have been shown to be related to cephalopod body size and mass, which permitted important information to be obtained on numerous biological and ecological aspects of cephalopods in marine ecosystems. In the last decade, a range of new techniques has been applied to cephalopod beaks, permitting new kinds of insight into cephalopod biology and ecology. The workshop on cephalopod beaks of the Cephalopod International Advisory Council Conference (Sesimbra, Portugal) in 2022 aimed to review the most recent scientific developments in this field and to identify future challenges, particularly in relation to taxonomy, age, growth, chemical composition (i.e., DNA, proteomics, stable isotopes, trace elements) and physical (i.e., structural) analyses. In terms of taxonomy, new techniques (e.g., 3D geometric morphometrics) for identifying cephalopods from their beaks are being developed with promising results, although the need for experts and reference collections of cephalopod beaks will continue. The use of beak microstructure for age and growth studies has been validated. Stable isotope analyses on beaks have proven to be an excellent technique to get valuable information on the ecology of cephalopods (namely habitat and trophic position). Trace element analyses is also possible using beaks, where concentrations are significantly lower than in other tissues (e.g., muscle, digestive gland, gills). Extracting DNA from beaks was only possible in one study so far. Protein analyses can also be made using cephalopod beaks. Future challenges in research using cephalopod beaks are also discussed. Cephalopod International Advisory Council

The Moroccan Atlantic coast (21–36°N) is part of one of the most productive marine eastern boundary upwelling ecosystems worldwide. Nevertheless, information about the structure of its exploited fish populations is scarce. In this study, whole otolith elemental signatures of 111 hake (Merluccius merluccius) and 118 of sardine (Sardina pilchardus), sampled during the period June 2012 - July 2013 in 11 locations along the Moroccan coast, were analysed by solution based ICP MS. These 2 species were selected for their importance in the fisheries, their contrasted life histories, and differences in trophic behavior. Whole otolith comparisons used Ba/Ca, Li/Ca, Mg/Ca, Mn/Ca, Rb/Ca, Sc/Ca, Sr/Ca, to demonstrate the regional population structures. The linear discriminant analysis of whole otolith chemistry data of hake and sardine reached respectively 88 % and 71 % mean adequate classification, and rose to 100 % within the identified groups. The spatial variation in the elemental composition of the otoliths of the two species were significant, and all showed a clear geographic cut, thus identifying a northern and a southern group. The major split for the two species occurred in the same area corresponding to the transition zone between the northern temperate mud-shelf ecosystem and the arid ecosystem at the south (28–29°N). Complex oceanographic processes may act in this area as a barrier to planktonic dispersion favouring isolation processes that lead to distinct populations. These findings are new to hake and confirm previous studies on sardine population structure, and should be considered in fisheries management to better match management units and stock structure.

Accurate age data are essential for reliable fish stock assessment. Yet many stocks suffer from inconsistencies in age interpretation. A new approach to obtain age makes use of the chemical composition of otoliths. This study validates the periodicity of recurrent patterns in 25Mg, 31P, 34K, 55Mn, 63Cu, 64Zn, 66Zn, 85Rb, 88Sr, 138Ba, and 208Pb in Baltic cod (Gadus morhua) otoliths from tag–recapture and known-age samples. Otolith P concentrations showed the highest consistency in seasonality over the years, with minima co-occurring with otolith winter zones in the known-age otoliths and in late winter – early spring when water temperatures are coldest in tagged cod . The timing of minima differs between stocks, occurring around February in western Baltic cod and 1 month later in eastern Baltic cod; seasonal maxima are also stock-specific, occurring in August and October, respectively. The amplitude in P is larger in faster-growing western compared with eastern Baltic cod. Seasonal patterns with minima in winter – late spring were also evident in Mg and Mn, but less consistent over time and fish size than P. Chronological patterns in P, and to a lesser extent Mg and Mn, may have the potential to supplement traditional age estimation or to guide the visual identification of translucent and opaque otolith patterns used in traditional age estimation.

WOS:000632691700001; Freshwater environments host roughly half of the world’s fish diversity, much of which is concentrated in large, tropical river systems such as the Amazon. Fishes are critical to ecosystem functioning in the Amazon River basin but face increasing human threats. The basic biology of these species, and particularly migratory behaviour, remains poorly studied, in part owing to the difficulty associated with conducting tagging studies in remote tropical regions. Otolith microchemistry can circumvent logistical issues and is an increasingly important tool for studying fish life histories. However, this approach is still new in the Amazon, and its potential and limitations to inform fish conservation strategies remain unclear. Here, otolith microchemistry studies in the Amazon are reviewed, highlighting current possibilities, and several key factors that limit its use as a conservation tool in the Amazon are discussed. These include the dearth of spatiotemporal elemental data, poor understanding of environment–fish–otolith pathways, and insufficient funding, facilities, and equipment. A research initiative is proposed to harness the potential of this technique to support conservation in the Amazon. Key aspects of the proposal include recommendations for internal and external funding, which are critical to acquiring and maintaining technical staff, cutting-edge equipment, and facilities, as well as fostering regular scientific meetings and working groups. Meetings can facilitate a systematic approach to investigating environment–otolith pathways, broadening the chemical baseline for most Amazonian tributaries, and exploring potential valuable elements. These outcomes are urgently needed to conserve biodiversity and ecosystem functioning in the Amazon, especially given threats such as widespread hydroelectric damming. The initiative proposed here could make otolith microchemistry an important, cost-effective tool to inform and foster conservation in the Amazon, and act as a template for other imperilled tropical river basins, such as the Mekong and the Congo.

Coagulation assays, prothrombin time (PT), and partial thromboplastin time (PTT) are tests to measure the clotting ability of plasma and used in evaluating patients suffering from bleeding disorders. These assays require 100 μl of human plasma. In zebrafish, dilute plasma with exogenously added human fibrinogen was used. Our objective is to create a microkinetic coagulation assay for human and zebrafish plasmas using 1 μl plasma under conditions similar to PT and PTTs. Here, we developed an assay using the Take3 plate with wells holding up to 6 μl, which can be loaded in a microplate reader for measuring the absorbance of fibrin formation. In this assay, we used 1 μl of citrated zebrafish or human plasma followed by the addition of either thromboplastin or Dade ACTIN or factor X activator from Russell viper venom as an activating agent and CaCl2. We found 4 or 3 μl of the final volume of reaction was optimal. Our results showed both zebrafish and human plasmas yielded kinetic PT, kinetic PTT, and kinetic Russel's viper venom time curves similar to previously established curves using dilute plasma. This kinetic coagulation was inhibited by heparin and was reduced significantly in coagulation factor deficient plasmas. These results validated our microkinetic coagulation assays. Moreover, we derived clotting times from these kinetic curves, which were identical to human PT, PTT, and Russel's viper venom time. In conclusion, we established a microkinetic assay that could measure blood coagulation activity in models like zebrafish and human blood samples obtained from a finger prick in adults or heel prick in infants.

Coho Salmon Oncorhynchus kisutch show fidelity to natal spawning watersheds. Fine-scale homing, however, within rivers is not well understood. Interior Fraser Coho (IFC) salmon eggs were incubated at known spawning locations in the Coldwater River, two main stem sites and one-off channel pond site, providing otolith reference data for comparison to otolith signatures for returning adults using laser ablation inductively coupled plasma mass spectrometry. Elemental ratios for Ba:Ca and Sr:Ca in otoliths of juvenile O. kisutch differed significantly among the spawning locations examined. Juvenile otolith data were used to conduct a linear discriminant analysis to assess fine-scale homing in adults. Juvenile data were all assigned to the location where they had been incubated, producing a robust data set used to compare adult otoliths and define natal locations based on elemental signatures in otoliths of adult spawners. Homing and straying were apparent at the reach level; 57.1% of adults returned to their natal spawning locations, while 42.9% strayed to other spawning sites within the Coldwater River. Straying to novel incubation sites at the reach scale demonstrated plasticity in homing within a watershed.

The current work investigates the influence of seawater on morphological properties during the hydration process of tricalcium silicate (C3S) at 3, 7, 14, and 28 days to better understand the effec...

The white mullet Mugil curema supports several fisheries in the neotropical region; nevertheless, the population structure is still elusive. The aim of this study was to assess the presence of adult management units and nursery areas from five sampling sites throughout the Gulf of Mexico and northern Brazil using otolith microchemistry. The Li/Ca, Na/Ca, Mn/Ca, Sr/Ca, Ba/Ca and Pb/Ca ratios were measured in otolith core (juvenile stage) and edge (adult stage) (N = 131) using laser ablation-inductively coupled plasma-mass spectrometry. Several ratios were significantly different between sampling sites for core and edge (P 0.05). For otolith edge, permutational multivariate analysis of variance showed significant differences (P 0.05) between all sampling sites from Mexico (except between Mecoacán and Tamiahua, P 0.05) and between Mexico (pooled samples) and Brazil. Quadratic discriminant analyses showed jackknifed classification higher in the edge (66.6% and 99.5% for Mexico and Brazil plus Mexico, respectively) than in the core (46.3% and 76.5% Mexico and Brazil plus Mexico, respectively). The two cluster analyses based on the core microchemistry (Mexico and Brazil plus Mexico) produced three main clusters, which did not coincide with catchment areas. These results support the segregation of the M. curema adult life stages among several sampling sites from Mexico and Brazil; moreover, core analysis suggested that the nursery areas did not correspond to the capture sites or adults stocks.

This study examined the migratory patterns of introduced rainbow trout (Oncorhynchus mykiss) in three rivers in Prince Edward Island, Canada, using acoustic telemetry and otolith microchemistry. Only 6% of acoustically tagged fish in three river systems left coastal embayments. A cohort of rainbow trout in all three rivers entered saline waters. Habitat use differed among migrants in the three rivers, as Montague River fish occupied estuary habitat (mean 20.79 PSU) more often than West River and Dunk River fish that tended to occupy both riverine tidal (mean 1.27 and 4.29 PSU, respectively) and freshwater habitats (

Otolith chemistry has gained increasing attention as a tool for analyzing various aspects of fish biology, such as stock dynamics, migration patterns, hypoxia and pollution exposure, and connectivity between habitats. While these studies often assume otolith elemental concentrations reflect environmental conditions, physiological processes are increasingly recognized as a modulating and/or controlling factor. In particular, biomineralization—the complex, enzyme-regulated construction of CaCO3 crystals scaffolded by proteins—is believed to play a critical role in governing otolith chemical patterns. This review aims to summarize the knowledge on otolith composition and biophysical drivers of biomineralization, present hypotheses on how biomineralization should affect element incorporation, and test the validity thereof with selected case studies. Tracers of environmental history are assumed to be dominated by elements that substitute for Ca during crystal growth or that occur randomly trapped within the crystal lattice. Strontium (Sr) and barium (Ba) largely comply with the biomineralization-based hypotheses that otolith element patterns reflect environmental concentrations, without additional effects of salinity, but can be influenced by physiological processes, typically exhibiting decreasing incorporation with increasing growth. Conversely, tracers of physiology are assumed to be elements under physiological control and primarily occur protein-bound in the otolith’s organic matrix. Physiological tracers are hypothesized to reflect feeding rate and/or growth, decrease with fish age, and exhibit minimal influence of environmental concentration. The candidate elements phosphorus (P), copper (Cu) and zinc (Zn) confirm these hypotheses. Magnesium (Mg) is believed to be randomly trapped in the crystal structure and hence a candidate for environmental reconstruction, but the response to all examined drivers suggest Mg to be coupled to growth. Manganese (Mn) substitutes for Ca, but is also a co-factor in matrix proteins, and therefore exhibits otolith patterns reflecting both environmental (concentration and salinity) and physiological (ontogeny and growth) histories. A consistent temperature response was not evident across studies for either environmental or physiological tracers, presumably attributable to variable relationships between temperature and fish behavior and physiology (e.g., feeding rate, reproduction). Biomineralization thus has a controlling effect on otolith element concentrations for elements that are linked with somatic growth, but not for elements that substitute for Ca in the crystal lattice. Interpretation of the ecological significance of patterns from field samples therefore needs to consider the impact of the underlying biomineralization processes of the element in question as well as physiological processes regulating the availability of ions for inclusion in the growing crystal lattice. Such understanding will enhance the utility of this technique to address fisheries management questions.

Complex material systems in which microstructure and microchemistry are nonuniformly dispersed require three-dimensional (3D) rendering(s) to provide an accurate determination of the physio-chemical nature of the system. Current scanning transmission electron microscope (STEM)-based tomography techniques enable 3D visualization but can be time-consuming, so only select systems or regions are analyzed in this manner. Here, it is presented that through high-efficiency multidimensional STEM acquisition and reconstruction, complex point cloud-like microstructural features can quickly and effectively be reconstructed in 3D. The proposed set of techniques is demonstrated, analyzed, and verified for a high-chromium steel with heterogeneously situated features induced using high-energy neutron bombardment.

The specific stock composition and dispersion of anadromous fish species aggregations in the marine environment are poorly known, while they can play a major role in the metapopulation dynamics. Otolith microchemistry has proven to be a powerful tool to address natal origins of anadromous fish. We used archived otolith microchemistry to investigate the population-specific composition of subadult European shads (Alosa alosa and Alosa fallax) in the ocean during the 1980s. The allocation of natal origin was addressed relying on contemporary water and juveniles’ signatures within a Bayesian model. A great discrimination of natal origin was obtained at the Biscay Gulf scale. However, the discrimination of 1980s natal origin for the southern rivers with similar geology based on 2013 water and juveniles’ baselines was doubtful. Our results showed that the most abundant southern populations were dominant, suggesting that population-specific composition was related to population relative abundance. The dispersion in the marine environment was plastic; alternatively, shads were found large distances away from their natal rivers, while others remained in the vicinity of their natal river plume.

Made available in DSpace on 2022-04-29T08:37:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-02-10 The Fundão dam collapse occurred in late 2015, resulting in the largest disaster in the world involving mine tailings, releasing at least 50 million m3 of iron ore tailings into the Doce river basin (Brazil). Studies realized along the Doce river after the disaster showed high concentrations of some elements above recommended Brazilian standards in different environmental matrices such as Al, Ba, Co, Fe, Hg, Mn, and Ni. This study aims to test the hypothesis that otolith microchemistry can be used as a pollution biomarker over time, that is, the otoliths sampled in the directly impacted area (Doce estuary) will present higher concentrations of the chemical elements in relation to the two other indirectly impacted estuaries (Ipiranga and São Mateus). The marine catfish Genidens genidens was chosen as a sentinel species, as this species presents several features that characterize it as a key species of the estuarine environment. The hypothesis was tested from a comparison between estuaries of the element/Ca ratios (Ba, Fe, and Mn) from the otolith edge (representing more recent deposition) and through the elemental composition profile, from core to edge of otolith. For the otolith edge analyses, it was possible to determine significant differences between estuaries in all three element:Ca ratios (Ba, Fe, and Mn). For the profile analysis (from core to edge), the Doce river showed consistent concentrations of Fe:Ca and Ba:Ca ratios higher than those of the Ipiranga and São Mateus estuaries throughout the life of the fish. In otoliths sampled in the Doce estuary, the possible identified peak of the Ba:Ca and Mn:Ca ratios, was probably associated with the Fundão Dam disaster. The present study showed that otolith microchemistry can be used as a sclerochronological biomarker of metallic aquatic pollution. Universidade Estadual Paulista “Júlio Mesquita Filho” (UNESP) Campus Experimental de Registro, Curso de Engenharia de Pesca Laboratório de Ecologia de Peixes Marinhos - LEPMAR Universidade Federal do Espírito Santo, BR-101, km 60 - Litorâneo Departamento de Ciências Agrárias e Biológicas - DCAB CEUNES Programa de Pós-Graduação em Oceanografia Ambiental (PPGOAM) Universidade Federal do Espírito Santo Universidade Estadual Paulista “Júlio Mesquita Filho” (UNESP) Campus Experimental de Registro, Curso de Engenharia de Pesca

Without accurate age interpretation or validation, serious errors in the management and understanding of fish populations can occur. This study employs a novel approach to age validation using trace element microconstituent analysis of hardparts. The optical zones of annuli are hypothesized to be the result of seasonal changes in organic content and experienced temperature, either of which can result in cycles of trace elements associated with annulus formation. Using Laser Ablation ICP-MS analysis, we tested for periodicity in hardpart Ca, Cu, P, Sr, Mg, Mn, Zn, and Ba in comparison to the periodicity of annulus zonation (opaque and translucent zones). Initial tests were conducted for black sea bass, a species for which yearly annulus formation has been validated. Periodicities in elemental profiles in otoliths were identified using a Lomb-Scargle periodogram analysis that confirmed that cycles in Mg corresponded to annulus formation in the model species. This same approach was applied to Atlantic monkfish, a species without a valid ageing procedure. Annular chemical oscillations occurred in illicia hardparts that exhibited modest agreement (80.7%) with known-age samples.

This study investigates stock mixing of genetically distinct Atlantic cod (Gadus morhua) stocks in the Kattegat, an area geographically located between the North Sea and the Baltic Sea, by combining genetic population identification with habitat assignments from hatch to capture from otolith microchemistry. Cod captured in Kattegat were genetically assigned to either the North Sea or the endemic Kattegat population. Otolith chemical fingerprints differed significantly between populations during the larval and pelagic juvenile stage with higher strontium and lower barium and manganese concentrations in the North Sea population than the Kattegat population, indicating that North Sea cod are spawned in the North Sea or Skagerrak and drift into the Kattegat during the early life stages. Individual cod of both populations undertook frequent, but predominantly short-term, migrations to other areas than the Kattegat, with

Graphic abstract Microchemistry, i.e., the chemistry performed at the scale of a microgram or less, has its roots in the late eighteenth and early nineteenth centuries. In the first half of the twentieth century a wide range of spot tests have been developed. For didactic reasons, they are still part of the curriculum of chemistry students. However, they are even highly important for applied analyses in conservation of cultural heritage, food science, forensic science, clinical and pharmacological sciences, geochemistry, and environmental sciences. Modern pregnancy tests, virus tests, etc. are the most recent examples of sophisticated spot tests. The present ChemTexts contribution aims to provide an overview of the past and present of this analytical methodology.

The uptake of metals into the aragonite lattice of the fish otolith (ear-bone) has been used for decades as a historical record of exposure to metals in polluted environments. The relative abundance of two metals in particular, Ni and V, are used in forensic chemical analysis of crude oils to assist in confirming its origin. In this study we investigate the potential for metal accumulation in otoliths to act as a biomarker of exposure to crude oil. Using a 33-day static-renewal laboratory trial design, 56 juvenile Lates calcarifer (commonly known as Asian seabass or barramundi) were fed diets enriched with V (20 mg/kg), Ni (500 mg/kg), Fe (500 mg/kg), and two crude oils with distinctly different metals profiles: a heavy fuel oil (1% w/w) and a typical Australian medium crude (1% w/w). Fish exposed to crude oils showed Ba and Al retained in otoliths in a dose-dependent manner, but fish fed V-, Ni- and Fe-enriched diets showed no metal increase in otoliths, indicating that V, Ni and Fe are not incorporated into the otolith of L. calcarifer via dietary exposure. For crude oils, incorporation into otolith for many metals is likely limited due to porphyrin casing reducing their bioavailability. Principal components analysis (PCA) and subsequent linear discriminatory analysis (LDA) of selected otolith metals demonstrated that, even despite large variability in the metal abundances detected in otolith between individuals within the test groups (cv = 1.00), it is possible to discriminate between fish exposed to different crude oils using multivariate analysis of their otolith microchemistry.

International audience; In the context of the River Rhône restoration programme, the objective of this study was to assess the dispersal and population connectivity of the European chub, Squalius cephalus (Linnaeus, 1758) in a section of the natural, free-flowingpart of the lower River Rhône.2. The elemental water signatures for Sr:Ca and Ba:Ca were measured at seven stations within the river section, including its tributaries and backwaters, to determine whether they could be differentiated by microchemistry. From Augustto October the signatures differed among three sectors of the study reach: the Rhône; the Ardèche; and the backwaters.3. The elemental signatures of the otoliths of 178 young-of-the-year (YOY) chub from the stations were measured to assess spawning areas and identify early migratory life histories. Analyses of otolith microchemistry identified the natal origin of 95% of the fish. Sr:Ca signatures of otoliths showed early downstream migration for30.4% of the YOY chub; however, 70% of the fish recruited relatively close to their spawning origin suggesting a potential inshore retention of fish.4. The results showed (i) a non-negligible contribution of the tributaries and backwaters in the recruitment of fish into the main channel; and (ii) the ability of chub to migrate over several kilometres during their first few months of life.5. This study shows that the combination of water and otolith microchemistry analyses of fish growth increases the understanding of fish life history. Moreover, the study revealed that half of the YOY fish from this river section came from the tributaries and the other half came from reproduction in the River Rhône (despite its high anthropization).6. These methods offer promising future applications of otolith microchemistry for river management in the context of ecological rehabilitation, especially to assess the effectiveness of measures applied in the restoration of floodplain connectivity for riverine fish population conservation.

A sensitive and efficient fluorescence labeling method was developed and validated for the microanalysis and detection of polysaccharides. Fluorescein isothiocyanate (FITC) was successfully labeled on mulberry fruit polysaccharides (MFP) through a reductive amination reaction with the assistant of tyramine. The fluorescent labeled polysaccharides (FMFP) was identified by fluorescence, UV–visible, flourier transform infrared (FT-IR) and 1H NMR spectrum. Results demonstrated that the labeling efficiency of FMFP was 0.32%, and the FMFP was stable in simulated digestion fluid without cytotoxicity. The pharmacokinetics and biodistribution after administration were analyzed in rats, which indicated that the FMFP obtained could be absorbed in a short time (tmax 0.50 h) but eliminated slowly (t1/2 8.77 ± 1.38 h). At 24 h after administration, the polysaccharide could be tested mainly in intestine, stomach, liver and kidney. The FITC labeling method lays a foundation for investigating the absorption and metabolism of MFP, and provides references for the microanalysis research of bioactive polysaccharides.

Effective conservation of endangered species requires knowledge of the full range of life-history strategies used to maximize population resilience within a stochastic and ever-changing environment. California’s endemic Delta Smelt (Hypomesus transpacificus) is rapidly approaching extinction in the San Francisco Estuary, placing it in the crossfire between human and environmental uses of limited freshwater resources. Though managed as a semi-anadromous species, recent studies have challenged this lifecycle model for Delta Smelt, suggesting the species is an estuarine resident with several localized “hot-spots” of abundance. Using laser-ablation otolith strontium isotope microchemistry, we discovered three distinct life-history phenotypes including freshwater resident (FWR), brackish-water resident (BWR), and semi-anadromous (SA) fish. We further refined life-history phenotypes using an unsupervised algorithm and hierarchical clustering and found that in the last resilient year-class, the FWR (12%) and BWR (7%) comprised a small portion of the population, while the majority of fish were SA (81%). Furthermore, the semi-anadromous fish could be clustered into at least four additional life-history phenotypes that varied by natal origin, dispersal age and adult salinity history. These diverse life-history strategies should be incorporated into future conservation and management efforts aimed at preventing the extinction of Delta Smelt in the wild.

Increasingly, otolith microchemistry analysis is used as a tool to trace fish migrations, especially migrations of diadromous fishes. Yet, few studies have used otolith microchemistry to trace migrations in small inland watersheds, leaving major knowledge gaps in our understanding of inland fish spatial ecology. Here, we evaluate the use of tributary habitat for spawning and describe and compare fluvial brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) natal origin distribution, time spent in natal streams, and spawning site fidelity. 63% of rainbow trout and 57% of brown trout migrated after hatching. Brown trout showed greater variation in time spent in natal tributaries, suggesting that individuals are temporally distributing risk among offspring. By contrast, rainbow trout showed greater variation in natal origin, suggesting that individuals are spatially distributing risk among offspring. Our results indicate there is high inter- and intraspecific migration variation in inland salmonid populations, which may be linked to access to a mosaic of spawning and rearing habitat types.

Tenualosa ilisha was found recently in the Perak River in western Peninsular Malaysia. Molecular phylogenetic and haplotype network analyses suggest that T. ilisha has two genetically distinct populations/groups: (i) Peninsular Malaysia (Malaysia population), and (ii) Peninsular Malaysia, Thailand, India and Bangladesh (Indian Ocean population). The results also suggest that the T ilisha population in Peninsular Malaysia is genetically heterogeneous with a typical anadromous migration pattern.

A primary application of otolith microchemistry is distinguishing natal origins of individual fish within a mixed-stock fishery. Stocks must be distinguishable according to stock-specific microchemistry patterns, with accurate stock assignment contingent upon microchemistry assessment of all sources contributing to the mixed-stock fishery. However, otolith microchemistry signatures of individual fish, upon which classification models are built, likely represent only a portion of the variability that exists for the stocks corresponding to each natal source. To statistically infer expected otolith microchemistry patterns among unsampled catchment areas proximal to sampled areas, we tested the hypothesis that variation in catchment geology among 35 stream sites across the Lake Michigan basin is correlated with the variation in otolith microchemistry signatures of age-0 steelhead collected at those sites. Matrices of Mahalanobis distances between all pairs of individual fish were calculated for each of the following: (1) assignment scores from discriminant function analysis of the variation among sites based on otolith microchemistry, and (2) the geology underlying the catchments upstream of each of the sites where fish were sampled. Based on Mantel tests, these matrices were found to be significantly correlated, indicating that age-0 steelhead that exhibit greater differences in otolith microchemistry signatures tended to come from sites exhibiting greater differences in catchment geology. Surficial geology alone was more correlated with otolith microchemistry than bedrock age, bedrock lithology, or any combinations of the three geological datasets. The significant relationship between geology and otolith microchemistry, although weak, supports tenuous hydrologic and geologic bases for delineating natal source geographic boundaries.

Otoliths, calcium carbonate (CaCO3) ear stones of fish, contain a wealth of information about fish life and environmental history yet the CaCO3 polymorph form the otolith is made of is a critical, but seldom considered, piece of information during otolith analysis. Otolith trace element chemistry data increasingly informs management decisions, but recent work has shown that CaCO3 polymorphs—aragonite, vaterite, and calcite—can bear on incorporation of trace elements in a non-trivial way. Most fishes are thought to have otoliths of the aragonite CaCO3 form, but this construct is potentially outdated with many recent literature reports showing otherwise. Our study used previously unpublished neutron diffraction data and reports from published literature to address three objectives: (1) summarize the relative effects of otolith CaCO3 polymorphism on otolith microchemistry, (2) summarize reports of otolith polymorphs to gain a better understanding of the extent of non-aragonite otoliths among fishes, (3) outline future research needed to align interpretations of microchemistry with our current understanding of otolith polymorph diversity. We found that while aragonite otoliths are the most common, so are exceptions. For example, the ostensibly rare (among species) CaCO3 form vaterite was reported in at least some otoliths of 40% of the species surveyed. Our work suggests that examination of the CaCO3 polymorph composition of otoliths should become more common particularly in studies where results will or may be used to inform management decisions. Future research should work to attribute controls on otolith CaCO3 polymorph expression using a combination of -omics and material characterization approaches to enrich the life history and environmental information output from otoliths and increase our understanding of the assumptions made in otolith trace element chemistry studies.

This article presents a novel method combining ion irradiation, in-situ transmission electron microscopy (TEM), and microchemistry analysis before/after irradiation, which allows to examine same microstructural areas throughout ion irradiation. A 12 wt% Cr Ferritic/Martensitic steel (HT9) was irradiated in the TEM to 1.17 × 1020 ions·m−2 at 440 °C using 1 MeV Kr2+ ions, and the in-situ characterization focused on radiation-induced precipitation and segregation. Results of in-situ experiments were compared with those obtained from ex-situ experiments, to showcase how this method helps to better understand precipitation kinetics in the irradiated material examined ex-situ, for which only snapshots are available at limited doses.

WOS:000459212600005; International audience; The gross energy content of spawning batches and the microchemistry of sagittal otoliths in individual female bonga shad Ethmalosa fimbriata were compared between contrasting sampling sites at the Senegalese southern coast and inside the hypersaline Sine Saloum Estuary. Results show that females spawning in the estuary's middle reaches invested almost three times more energy into reproduction (115 ± 65 J g?1 body mass) than their neritic counterparts (39 ± 34 J g?1 body mass). Also, female otolith levels of Ba:Ca, Sr:Ca and Zn:Ca either differed significantly between study sites or could be linked to heterogeneous environmental variables. A quadratic discriminant function analysis provided evidence of segregated spawning populations of E. fimbriata in southern Senegalese waters.

Understanding patterns in trace element concentrations and water quality within river systems provides a foundation to evaluate retrospective movements and habitat use of fish. Because trace elements are incorporated into calcified structures of fishes relative to water concentrations, baseline maps have application for fisheries management, including for rare species such as sturgeons. Therefore, trace elements [strontium (Sr), barium (Ba), manganese (Mn), zinc (Zn), and magnesium (Mg)], strontium isotopes (87Sr/86Sr), dissolved oxygen and salinity were measured in the Pearl River and Lake Pontchartrain watersheds, within Mississippi and Louisiana, USA for application in assessing riverine use by Gulf Sturgeon Acipenser oxyrinchus desotoi. Water samples were collected during the summer-fall period when juvenile Gulf Sturgeon were anticipated to be present and analyzed by solution and multi-collector inductively coupled plasma mass spectrometry. Trace element to calcium (Ca) ratios in Sr, Ba, Zn, and Mg were distinguishable between the upper Pearl River and the Bogue Chitto River tributary, and the upper Pearl River and lower Pearl River. For most trace elements and 87Sr/86Sr, there was a gradual increase from upper river regions to lower river regions, and large differences between freshwater and saline areas. Lake Pontchartrain watershed rivers were not easily differentiated, but regions of low dissolved oxygen concentrations in the lower reaches suggest available Gulf Sturgeon habitat may be seasonally limited. Therefore, maps of water microchemistry in the Pearl River watershed allow for retrospective analyses of fish watershed use.

Volumetric absorptive microsampling (VAMS) is a recent microsampling technique used to obtain dried specimens of blood and other biological matrices for application to a plethora of bioanalytical purposes. As such, it can be likened to dried blood spot (DBS) technique that has been in wide use for the last 40 years. However, VAMS promises to bring some significant advantages over DBS, related to sampling volume accuracy, haematocrit (HCT) dependence, pre-treatment and automation. Although some aspects still need to be investigated in depth, VAMS is increasingly recognised as a viable alternative to DBS and other dried microsampling techniques. In this tutorial, different aspects of VAMS approach are described and discussed, presenting the procedures adopted and the results obtained by those authors who have developed this kind of analytical workflow in the last few years. Hopefully, this will help other scientists to find new solutions to old and recent problems related to microsampling and to produce new, sound and interesting science in this field.

At present, the resources of anadromous fish in the world are drastically reduced and one of the solutions to promote its recovery may be to identify and protect its feeding grounds. To determine whether the feeding grounds of anadromous Coilia nasus in the Yangtze River are still in the sea area, the quantitative line analysis of Sr and Ca contents (Sr/Ca ratios) and the area distribution analysis of Sr content in the otoliths of C. nasus in three water areas (Poyang Lake, Yangtze River estuary and Shengsi Sea area) were carried out by electron probe microanalysis (EPMA) to analyze the habitat use and the migratory patterns of different estuarine C. nasus. These results showed that the Sr/Ca ratios of all otoliths fluctuated significantly. By comparison, it was found that C. nasus of Yangtze River might exist in the Shengsi Sea area, and the Shengsi Sea area might be one of the feeding grounds of migratory C. nasus. Therefore, it is urgent to carry out a comprehensive investigation on the distribution of related groups in the Shengsi Sea area and the influence of potential threat factors, such as fishing and harsh habitat, to effectively protect the resources and habitats of C. nasus in the Shengsi Sea area.

International Symposium on Benguela - Opportunity, Challenge and Change, Univ Cape Town, Cape Town, SOUTH AFRICA, NOV, 2016; International audience; Otolith elemental signatures can be used to identify when individual or groups of fish are spending a significant amount of time in different environments. Elemental signatures of juvenile sardine Sardinops sagax caught in winter 2008 and 2009 around the coast of South Africa were measured using inductively-coupled plasma mass-spectroscopy. The otolith elemental signatures of 34 fish caught in 2008 and of 52 fish caught in 2009 were measured at the edge (to represent conditions 20-30 days prior to capture). Principal component analysis was used to visualise the relationships of individuals to each other, in terms of their otolith chemistry, in two-dimensional space, and multiple ANOVAs were used to investigate spatial and temporal variations among samples collected in 2008 and 2009. Significant differences among sites were found in MANOVAs, but the between-site differences varied among the elements. Magnesium concentration tended to decrease whereas barium concentration tended to increase from the west to the east coast. Barium indicate upwelling impact but for 2008 samples on the northern part of the west coast. Otolith microchemistry provides evidence of large and small-scale differentiation in sardine, but differences between years indicates that this is not necessarily temporally stable. The ocean off South Africa is a dynamic and variable environment and this is reflected in the inter-site, and also inter-annual, differences in elemental signatures of juvenile sardine.

Nonindigenous lake trout (Salvelinus namaycush) expansion in Yellowstone Lake has led to a large decline in the native Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) population. We assessed whether otolith microchemistry could be used to identify subbasin natal origins and long-term use by lake trout as a potential tool for optimizing removal efforts. 87Sr:86Sr and Sr:Ca ratios in otolith cores were used to assess natal origins and 87Sr:86Sr ratios in otolith transects were used to assess movement patterns. Water chemistry was similar throughout the lake, ranging from 0.70634 to 0.70642 and 3.94 to 4.38 mmol/mol for 87Sr:86Sr and Sr:Ca ratios, respectively. Lake trout otoliths also showed little variation in 87Sr:86Sr and Sr:Ca ratios of the natal region and 87Sr:86Sr across otolith transects. Thus, we found that microchemical differences among Sr isotope and Sr:Ca elemental ratios in otoliths were insufficient to detect the natal origin or extensive within-lake movement that has been established from telemetry investigations. Detailed analysis of other elements or isotopes in hard-part microchemistry, in combination with other tools for detecting movement, may improve detection of natal origin and life history movement among fishes within freshwater lentic systems.

Flavonoid compounds are known for their antibacterial, anti-inflammatory, and anticancer properties. Therefore, they can influence membrane properties that interest us, modifying both their structure and functions. We used kaempferol (K) and myricetin (M) as representatives of this group. We investigated the influence of the abovementioned compounds on model cell membranes’ properties (i.e., Langmuir monolayers and liposomes). The basic research methods used in these studies were the Langmuir method with Brewster angle microscopy and microelectrophoresis. The π–A isotherms were registered for the pure components and mixtures of these compounds with phosphatidylcholine (PC) in appropriate volume ratios. Using mathematical equations, we established that kaempferol, myricetin, and the lipids formed complexes at 1:1 ratios. We derived the parameters characterizing the formed complexes, i.e., the surfaces occupied by the complexes and the stability constants of the formed complexes. Using the microelectrophoretic method, we determined the dependence of the lipid membranes’ surface charge density as a function of the pH (in the range of 2 to 10) of the electrolyte solution. The presented results indicate that the PC membrane’s modification with kaempferol or myricetin affected changes in the surface charge density and isoelectric point values.

Background The cuticle is a protective layer playing an important role in plant defense against biotic and abiotic stresses. So far cuticle structure and chemistry was mainly studied by electron microscopy and chemical extraction. Thus, analysing composition involved sample destruction and the link between chemistry and microstructure remained unclear. In the last decade, Raman imaging showed high potential to link plant anatomical structure with microchemistry and to give insights into orientation of molecules. In this study, we use Raman imaging and polarization experiments to study the native cuticle and epidermal layer of needles of Norway spruce, one of the economically most important trees in Europe. The acquired hyperspectral dataset is the basis to image the chemical heterogeneity using univariate (band integration) as well as multivariate data analysis (cluster analysis and non-negative matrix factorization). Results Confocal Raman microscopy probes the cuticle together with the underlying epidermis in the native state and tracks aromatics, lipids, carbohydrates and minerals with a spatial resolution of 300 nm. All three data analysis approaches distinguish a waxy, crystalline layer on top, in which aliphatic chains and coumaric acid are aligned perpendicular to the surface. Also in the lipidic amorphous cuticle beneath, strong signals of coumaric acid and flavonoids are detected. Even the unmixing algorithm results in mixed endmember spectra and confirms that lipids co-locate with aromatics. The underlying epidermal cell walls are devoid of lipids but show strong aromatic Raman bands. Especially the upper periclinal thicker cell wall is impregnated with aromatics. At the interface between epidermis and cuticle Calcium oxalate crystals are detected in a layer-like fashion. Non-negative matrix factorization gives the purest component spectra, thus the best match with reference spectra and by this promotes band assignments and interpretation of the visualized chemical heterogeneity. Conclusions Results sharpen our view about the cuticle as the outermost layer of plants and highlight the aromatic impregnation throughout. In the future, developmental studies tracking lipid and aromatic pathways might give new insights into cuticle formation and comparative studies might deepen our understanding why some trees and their needle and leaf surfaces are more resistant to biotic and abiotic stresses than others.

Practical work in chemistry education is playing a larger role with the introduction of context oriented chemistry. Several problems related to the practical work in the classroom can be ameliorated by the use of micro scale chemistry. This chapter discusses some problems related to the implementation of micro scale chemistry. A relation is made to the context of sustainable development in Africa.

In commercial Al–Fe–Si foil stock alloys, mechanical properties such as strength and ductility are influenced by the materials microchemistry. This study covers the general relation of microchemistry and the potential final softening behavior of aluminum foil, as described in the literature. In this paper, the focus lies on the evolution of solute content and microchemistry through different experimental homogenization practices for two 8xxx alloys with varying Fe and Si contents. The solute level, dispersoid phase volume fraction, and phase morphology of precipitated particles are investigated. The experimental results show a major temperature dependency of the solute content during homogenization.

Morphological and elemental composition of otoliths are a promising tool for fish stock identification. In this regard, European eel has not been sufficiently researched. The aim of this study was to determine otolith shape index values and microchemistry composition of 14 elements in otoliths of European eel between riverine and lacustrine stocks from the Adriatic Basin in Croatia and Montenegro. In terms of morphometry, the shape indices, form factor and circularity of the sagittal otolith were statistically different between lacustrine and riverine stocks. The European eel is considered to have a small otolith relative size. Canonical variate analysis indicated no statistical differences among the concentrations of trace elements in sagittal otoliths between riverine and lacustrine stocks. However, constrained redundancy analysis suggested a stronger relationship of width, total length, females and the silver stage with the Sr/Ca, Cr/Ca, Ba/Ca and K/Ca ratios of specimens from riverine than lacustrine habitats. Gender and stage dependent variations showed that females were better indicators of relationships between microchemistry composition and intrinsic factors. In conclusion, form factor and circularity of the sagittal otolith was able to distinguish between European eel stocks from different habitats. Also, it seems that the European eels' otolith fingerprint is homogenous, species specific and independent of ecological conditions.

Understanding migration patterns and habitat use is of great importance for management and conservation of marine living resources. The chemical composition of otoliths is influenced by the surrounding environment; therefore, they are indispensable data archives. To extract migration patterns and historical habitat use of individual fish, we analyse otolith chemical compositions obtained by laser ablation inductively coupled plasma mass spectrometry by a regime-switching state-space model. The state-space model filters the measurement noise from the environmental signal. In turn, the filtered signal is converted to geographical positions through a calibration of strontium to salinity. The method is validated by a simulation study and applied to 404 Atlantic cod (Gadus morhua) otoliths.

The short mackerel Rastrelliger brachysoma (Bleeker, 1851) is a commercially important fish in the Gulf of Thailand (GoT). The management strategy for this species in the entire GoT is based on the single-stock approach, which may not be efficient or effective. This study aims to identify the stock structure of short mackerel in the GoT. A total of 55 samples of short mackerel were collected throughout the GoT, sexed, weighed and measured. The pair of sagittal otoliths were removed from individual fish. The left sagittae were used for stock identification via microchemistry elements. The microchemical composition of the otoliths from four locations (Eastern, Upper, Central and Lower GoT) was different (MANOVA, P < 0.01) for both sexes. The linear discriminant function analysis (LDFA) using eight microchemical elements in the edge zone showed high classification accuracy of short mackerel with regard to their sampling location (89 % for males and 79 % for females). The LDFA results also showed high classification accuracy in both sexes (more than 85 %) and indicated that there were four short mackerel stocks in the GoT. The right sagittae, meanwhile, were used for fish ageing. Results showed that the adults had resided in the stock more than 50 % of their life before being captured.

For the first time, an overlooked aspect of partial migration was quantified using otolith microchemistry and brown trout, Salmo trutta, as a model species. Relative contributions of freshwater resident and anadromous female brown trout to mixed-stock sea trout populations in the Baltic Sea were estimated. Out of 236 confirmed wild sea trout sampled around the coast of Estonia 88% were of anadromous maternal origin and 12% were of resident maternal origin. This novel finding underscores the importance of the resident contingent in maintaining the persistence and resilience of the migratory contingent.

Because trace elements of otoliths are considered a natural marker capable of recognizing the chemical composition of ambient water and fish migration history, these elements could be potentially used to analyse the movement of reproductive (R) and non-reproductive (NR) mature-sized fish. Supposedly, it is not essential for NR individuals to migrate to rivers for spawning because they do not have developed gonads. To investigate the potential differences in migration history between female R and NR kutum, Rutilus frisii, in the southwest waters of the Caspian Sea, the ratios of Sr, Ba, Mg, Na, K and P to Ca in otoliths (from the core to the edge) were examined using laser ablation-inductively coupled plasma-mass spectrometry. In NR fish, a significant increase in Sr:Ca ratio in the otoliths' growth rings, likely due to greater seawater residency, and an increase in Ba:Ca ratio in the last two rings were observed. Increased Ba:Ca ratio could be due to the movement of NR mature-sized fish to the coastal zones for foraging. Seasonal physiological factors such as gonad maturation and spawning activity are more likely to be involved in differences in the other elemental ratios (Mg, Na, K and P). These results suggest that microchemical analyses of growth rings of otolith can be used as a valuable tool for better understanding the movement pattern of different types of adult fish, which could be completed with data from other methods like tagging.