Arsenic speciation in food chains from mid-Atlantic hydrothermal vents

Environmental contextArsenic occurs in marine organisms at high levels and in many chemical forms. A common explanation of this phenomenon is that algae play the central role in accumulating arsenic by producing arsenic-containing sugars that are then converted into simpler organic arsenic compounds found in fish and other marine animals. We show that animals in deep-sea vent ecosystems, which are uninhabited by algae, contain the same organic arsenic compounds as do pelagic animals, indicating that algae are not the only source of these compounds. AbstractArsenic concentration and speciation were determined in benthic fauna collected from the Mid-Atlantic Ridge hydrothermal vents. The shrimp species, Rimicaris exoculata, the vent chimney-dwelling mussel, Bathymodiolus azoricus, Branchipolynoe seepensis, a commensal worm of B. azoricus and the gastropod Peltospira smaragdina showed variations in As concentration and in stable isotope (δ13C and δ15N) signature between species, suggesting different sources of As uptake. Arsenic speciation showed arsenobetaine to be the dominant species in R. exoculata, whereas in B. azoricus and B. seepensis arsenosugars were most abundant, although arsenobetaine, dimethylarsinate and inorganic arsenic were also observed, along with several unidentified species. Scrape samples from outside the vent chimneys covered with microbial mat, which is a presumed food source for many vent organisms, contained high levels of total As, but organic species were not detectable. The formation of arsenosugars in pelagic environments is typically attributed to marine algae, and the pathway to arsenobetaine is still unknown. The occurrence of arsenosugars and arsenobetaine in these deep sea organisms, where primary production is chemolithoautotrophic and stable isotope analyses indicate food sources are of vent origin, suggests that organic arsenicals can occur in a foodweb without algae or other photosynthetic life.

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Stable isotope analysis reveals partitioning in prey use by Kajikia audax (Istiophoridae), Thunnus albacares, Katsuwonus pelamis, and Auxis spp. (Scombridae) in the Eastern Tropical Pacific of Ecuador

Neotropical Ichthyology ◽

10.1590/1982-0224-2020-0015 ◽

2021 ◽

Vol 19 (4) ◽

Author(s):

Rigoberto Rosas-Luis ◽

Nancy Cabanillas-Terán ◽

Carmen A. Villegas-Sánchez

Keyword(s):

Stable Isotope ◽

Food Web ◽

Stable Isotope Analysis ◽

Trophic Ecology ◽

Isotope Analysis ◽

Middle Level ◽

Food Sources ◽

Thunnus Albacares ◽

Katsuwonus Pelamis ◽

Δ13c And Δ15n

Abstract Kajikia audax, Thunnus albacares, Katsuwonus pelamis, and Auxis spp. occupy high and middle-level trophic positions in the food web. They represent important sources for fisheries in Ecuador. Despite their ecological and economic importance, studies on pelagic species in Ecuador are scarce. This study uses stable isotope analysis to assess the trophic ecology of these species, and to determine the contribution of prey to the predator tissue. Isotope data was used to test the hypothesis that medium-sized pelagic fish species have higher δ15N values than those of the prey they consumed, and that there is no overlap between their δ13C and δ15N values. Results showed higher δ15N values for K. audax, followed by T. albacares, Auxis spp. and K. pelamis, which indicates that the highest position in this food web is occupied by K. audax. The stable isotope Bayesian ellipses demonstrated that on a long time-scale, these species do not compete for food sources. Moreover, δ15N values were different between species and they decreased with a decrease in predator size.

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Tracing sewage-derived organic matter into a shallow groundwater food web using stable isotope and fluorescence signatures

Marine and Freshwater Research ◽

10.1071/mf10110 ◽

2011 ◽

Vol 62 (2) ◽

pp. 119 ◽

Cited By ~ 18

Author(s):

Adam Hartland ◽

Graham D. Fenwick ◽

Sarah J. Bury

Keyword(s):

Organic Matter ◽

Stable Isotope ◽

Food Web ◽

Sewage Treatment ◽

Sewage Treatment Plant ◽

Treatment Plant ◽

Shallow Groundwater ◽

Organic Pollution ◽

Food Sources ◽

Δ13c And Δ15n

Little is known about the feeding modes of groundwater invertebrates (stygofauna). Incorporation of sewage-derived organic matter (OM) into a shallow groundwater food web was studied using fluorescence and stable isotope signatures (δ13C and δ15N). Organic pollution was hypothesised to limit sensitive species’ abundances along the contamination gradient and isotope signatures of stygofauna consuming sewage-derived OM were expected to be enriched in δ15N. Stygofauna communities near a sewage treatment plant in New Zealand were sampled over 4 months and microbial biofilms were incubated in situ on native gravel for 1 month. As anticipated, OM stress-subsidy gradients altered stygofauna composition: the biomass of oligochaetes and Paraleptamphopus amphipods increased in OM-enriched groundwater (higher dissolved organic carbon (DOC) and tryptophan-like fluorescence), whereas other, probably less-tolerant taxa (e.g. ostracods, Dytiscidae) were absent. Isotopic signatures for stygofauna from polluted groundwater were consistent with assimilation of isotopically enriched sewage-N (δ15N values of 7–16‰), but highly depleted in δ13C relative to sewage. Negative 13C discriminations probably occur in Paraleptamphopus amphipods, and may also occur in oligochaetes and Dytiscidae, a finding with implications for the application of δ13C for determining food sources in groundwaters. Organic pollution of groundwaters may have serious repercussions for stygofauna community structure with potentially irreversible consequences.

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Seasonal Variation in Stable Isotope Ratios of Cow Milk in Vilnius Region, Lithuania

Animals ◽

10.3390/ani9030069 ◽

2019 ◽

Vol 9 (3) ◽

pp. 69 ◽

Cited By ~ 4

Author(s):

Andrius Garbaras ◽

Raminta Skipitytė ◽

Justina Šapolaitė ◽

Žilvinas Ežerinskis ◽

Vidmantas Remeikis

Keyword(s):

Stable Isotope ◽

Dairy Products ◽

Geographic Origin ◽

Isotope Ratios ◽

Food Sources ◽

Cow Milk ◽

Ratio Method ◽

Stable Isotope Ratios ◽

Δ13c And Δ15n ◽

Artesian Water

Various studies have shown that stable isotope analysis has the potential to verify the geographic origin of foods and drinks. However, stable isotope composition is not always constant in the environment and can even change in the same area. Dairy products are of particular interest as a group of foods that play an important role in feeding the population. The composition of milk is fundamentally dependent on the feeding of the cows, and thereby on a particular environment. To better understand the amount of variation in δ18O, δ13C, and δ15N values in the milk from the same area, we measured stable isotope ratios in cow milk water, artesian water, and precipitation (δ18O) as well as in bulk milk samples (δ13C and δ15N) collected in 2014–2016. Different water and food sources were available during the winter (artesian water only and dry grass) and summer (artesian water and fresh grass), and spring and autumn seasons reflected transitional periods. Oxygen stable isotope ratios in milk water were relatively lower in winter and transitional seasons and higher in summer, showing the dependence on the main water source. δ13C values reflected particular food sources. This study shows the applicability of the stable isotope ratio method in linking cow milk to specific environments and reveals the amount of variation in stable isotope ratios in the same area. These results could be valuable for other studies on geographical origin determination of dairy products.

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Contribution of organic arsenic species to total arsenic measurements using ferrihydrite-backed diffusive gradients in thin films (DGT)

Environmental Chemistry ◽

10.1071/en11057 ◽

2012 ◽

Vol 9 (1) ◽

pp. 55 ◽

Cited By ~ 12

Author(s):

Heléne Österlund ◽

Mikko Faarinen ◽

Johan Ingri ◽

Douglas C. Baxter

Keyword(s):

Thin Films ◽

Natural Waters ◽

Arsenic Speciation ◽

Inorganic Arsenic ◽

Speciation Analysis ◽

Arsenic Species ◽

Future Studies ◽

Organic Arsenic ◽

Arsenic Determination ◽

Diffusive Gradients

Environmental contextBoth the mobility and toxicity of arsenic in natural waters are related to the aqueous species distribution. Passive sampling using ferrihydrite-backed diffusive gradients in thin films (DGT) devices has in previous studies been characterised to measure labile inorganic arsenic, and the possible contribution of organic species has been disregarded. This study shows that the two most prevalent organic arsenic species might be included in DGT measurements, which should be taken into consideration when evaluating DGT data in future studies. AbstractIn previous publications discussing arsenic determination using ferrihydrite-backed diffusive gradients in thin films (DGT) devices, organic arsenic forms have been disregarded, even though it is known that the two most prevalent in natural waters, dimethylarsinate (DMA) and monomethylarsonate (MMA), may adsorb to ferrihydrite and thereby be included in the measurement. In this work the accumulation of DMA and MMA, as well as inorganic arsenite and arsenate, to ferrihydrite-backed DGT devices was investigated. It could be demonstrated that MMA, and under acidic conditions also DMA, adsorbed to the binding layer and might therefore contribute to the total mass of measured arsenic. Diffusion coefficients were measured for all four species to enable quantification of DGT-labile concentrations of organic and inorganic arsenic. Elution of the analytes from the ferrihydrite binding layer was performed using 1 mL of 1 M NaOH to facilitate arsenic speciation analysis using chromatographic separation. Average recovery rates were between 87 and 108 %. This study shows that the contribution of DMA and MMA to the total accumulated mass must be taken into consideration when evaluating DGT data in future studies.

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Trophodynamics at the Longqi hydrothermal vent field and comparison with the East Scotia and Central Indian Ridges

Marine Biology ◽

10.1007/s00227-020-03755-1 ◽

2020 ◽

Vol 167 (10) ◽

Author(s):

W. D. K. Reid ◽

B. D. Wigham ◽

L. Marsh ◽

J. N. J. Weston ◽

Y. Zhu ◽

...

Keyword(s):

Stable Isotope ◽

Hydrothermal Vent ◽

Hydrothermal Vents ◽

Trophic Ecology ◽

Tricarboxylic Acid Cycle ◽

Isotope Analysis ◽

Southwest Indian Ridge ◽

Food Sources ◽

Model Based Clustering ◽

Indian Ridge

Abstract The Longqi vent field, situated on the Southwest Indian Ridge, is ecologically distinct among known hydrothermal vents fields. It hosts a combination of previously unknown species and those shared at species or genus level with other hydrothermal vents on the Central Indian Ridge (CIR) and East Scotia Ridge (ESR). We investigate the size-based and trophodynamics of consumers at Longqi vent field and compared these with ESR and CIR vent fields using stable isotope analysis. Intra-specific variability in δ13C and δ15N values in relationship to shell length was observed in Gigantopelta aegis but absent in Chrysomallon squamiferum. A model-based clustering approach identified four trophic groupings at Longqi: species with the lowest δ13C values being supported by carbon fixed via the Calvin–Benson–Bassham cycle, the highest δ13C values being supported by the reductive tricarboxylic acid cycle and intermediate values potentially supported by a mix of these primary production sources. These clusters were driven by potential differences in resource partitioning. There were also differences in the spread of stable isotope values at the vent field level when comparing Bayesian stable isotope ellipse areas among Longqi, CIR and ESR vent fields. This was driven by a combination of the range in δ13C value of macrofauna, and the negative δ15N values which were only observed at Longqi and CIR vent fields. Many of the shared species or genera showed inter-vent field differences in stable isotope values which may be related to site-specific differences in food sources, geochemistry or potential intra-field competition. This study provides important information on the trophic ecology of hydrothermal vent macrofauna found within an area of seabed that is licensed for seabed mining exploration.

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Biosynthesis of Organic Arsenic Compounds in Brown Trout (Salmo trutta)

Journal of the Fisheries Research Board of Canada ◽

10.1139/f75-275 ◽

1975 ◽

Vol 32 (12) ◽

pp. 2385-2390 ◽

Cited By ~ 39

Author(s):

W. R. Penrose

Keyword(s):

Brown Trout ◽

Salmo Trutta ◽

Intramuscular Injection ◽

Inorganic Arsenic ◽

Arsenic Compound ◽

Organic Form ◽

Arsenic Compounds ◽

Brown Trout Salmo Trutta ◽

Organic Arsenic ◽

Altered Form

Radioactive, inorganic arsenic was administered to brown trout (Salmo trutta) orally and by intramuscular injection. The orally administered arsenic appeared in the tissues in an altered form that is presumed organic; this organoarsenical was also found in the gastrointestinal contents. The injected arsenic appeared in the tissues in inorganic form and was only slowly converted to organic form; meanwhile, large amounts of inorganic and organic arsenic were detected in the bile. These findings are consistent with biosynthesis of the organic arsenic compound within the gastrointestinal tract.

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Diet of the intertidal callianassid shrimps Biffarius arenosus and Trypea australiensis (Decapoda:Thalassinidea) in Western Port (southern Australia), determined with multiple stable-isotope analyses

Marine and Freshwater Research ◽

10.1071/mf97013 ◽

1997 ◽

Vol 48 (6) ◽

pp. 503 ◽

Cited By ~ 25

Author(s):

Paul I. Boon ◽

Fiona L. Bird ◽

Stuart E. Bunn

Keyword(s):

Stable Isotope ◽

Organic Carbon ◽

Food Source ◽

Avicennia Marina ◽

Benthic Microalgae ◽

Food Sources ◽

Mangrove Species ◽

Δ13c And Δ15n ◽

Green Macroalgae ◽

Isotope Analyses

Biffarius arenosus had a mean δ13C of –15·4 ± 0·2‰ and a mean δ15N of 5·9 ± 0·1‰ (n = 38), and Trypea australiensis had a mean δ13C of –16·3 ± 0·3 and a mean δ15N of 7·6 ± 0·1 (n = 20). The δ13C signatures of the only mangrove species present (Avicennia marina) and the most abundant saltmarsh plant (Sarcocornia quinqueflora) indicated that they were not major food sources. Seagrasses, predominantly Heterozostera tasmanica, had mean δ13C and δ15N values of –11·7 ± 0·2‰ (n = 65) and 3·9 ± 0·2‰ (n = 62), respectively. Seagrass epiphytes had mean δ13C and δ15N values of –17·9 ± 0·4‰ and 4·6 ± 0·3‰ (n = 27), respectively. A mixture of seagrasses and their epiphytes was the most likely source of organic carbon for B. arenosus. Benthic microalgae, such as diatoms, were a possible food source, but phospholipid biomarkers indicated a meagre abundance of diatoms in the sediments, and microscopy of shrimp guts revealed few or no diatom frustules. For T. australiensis, food sources were less easily distinguished than for B. arenosus, but they could include seagrass epiphytes plus the green macroalgae Enteromorpha spp. and/or the brown alga Chordaria cladisiphon.

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Determination of Inorganic Arsenic in Seaweed and Seafood by LC-ICP-MS: Method Validation

Journal of AOAC International ◽

10.5740/jaoacint.18-0148 ◽

2019 ◽

Vol 102 (2) ◽

pp. 612-618 ◽

Cited By ~ 4

Author(s):

Eri Matsumoto-Tanibuchi ◽

Toshiaki Sugimoto ◽

Toshiyuki Kawaguchi ◽

Naoki Sakakibara ◽

Michiaki Yamashita

Keyword(s):

Brown Algae ◽

Inductively Coupled Plasma ◽

Mobile Phase ◽

Arsenic Speciation ◽

Inorganic Arsenic ◽

Food Samples ◽

Ion Pair ◽

Arsenic Compounds ◽

Intermediate Precision ◽

Icp Ms

Abstract Background: Seaweed and seafoodoften contain both inorganic and organic arsenic compounds showing distinct toxicities. Speciation must be taken into account when determining the concentrations of arsenic compounds and how they relate to overall toxicity. Objective: An analytical method for the quantitation of inorganicarsenic was validated in seaweed and seafood. Methods: Food samples were heated at 100°C in 0.3 mol/L nitric acid. Arsenic speciation was quantitatively determined by LC-inductively coupled plasma-MS (LC-ICP-MS) using an octadecilsilane (ODS) column with a mobile phase containing an ion-pair reagent. Results: Limits of detection (0.0023–0.012 mg/kg), LOQ (0.0077–0.042 mg/kg), repeatability (3.0–7.4%), intermediate precision (4.4–7.4%), and trueness (recoveries 94–107%) of the proposed method were satisfactory for inorganic arsenicin seaweed and seafood. Inorganic arsenic was detected in almost all the evaluated dried seaweed products, the Japanese oyster, nam pla, oyster sauce, and the intestinal organs of seafood. Conclusions: Among the dried seaweed products, significant inorganic arsenic was detected in the brown algae akamoku, hijiki, and mozuku. The small amounts of inorganic arsenic detected in nam pla and oyster sauce likely derive from the internal organs of the raw seafood used in their preparation. Highlights: Arsenic speciation in seaweed and seafood was measured by LC-ICP-MS using an ODS column with a mobile phase containing an ion-pair reagent. Among the dried seaweed products, brown algae akamoku, hijiki, and mozuku contained significantly high levels of inorganic arsenic. The intestinal organs of oyster, sardine, and scallop contained higher arsenic levels than the muscles.

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Dual stable isotope analysis (δ13C and δ15N) of soil invertebrates and their food sources

Pedobiologia ◽

10.1016/j.pedobi.2003.12.003 ◽

2004 ◽

Vol 48 (2) ◽

pp. 171-180 ◽

Cited By ~ 78

Author(s):

Olaf Schmidt ◽

James P Curry ◽

Jens Dyckmans ◽

Emilia Rota ◽

Charles M Scrimgeour

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Isotope Analysis ◽

Soil Invertebrates ◽

Food Sources ◽

Δ13c And Δ15n

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Speciation of Six Arsenic Compounds in Korean Seafood Samples by HPLC-ICP-MS

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.277-279.431 ◽

2005 ◽

Vol 277-279 ◽

pp. 431-437 ◽

Cited By ~ 3

Author(s):

Kyung Su Park ◽

Jeong Sook Kim ◽

Hyo Min Lee ◽

Hee Soo Pyo ◽

Soon Tae Kim ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

High Performance ◽

Certified Reference Materials ◽

Arsenic Speciation ◽

Inorganic Arsenic ◽

Arsenic Species ◽

Arsenic Compounds ◽

Inductively Coupled ◽

Plasma Mass Spectrometry ◽

Fish And Shellfish

Extracts of 33 samples of seaweed, shrimp, fish and shellfish, including two certified reference materials, were investigated for their contents of arsenic compounds (arsenic speciation).An anion exchange high performance liquid chromatography procedure was optimized to separate six arsenic compounds present in the seafood samples with dynamic reaction gas cell by inductively coupled plasma mass spectrometry. The concentration of each species in the sample were: arsenobetaines - 0.019-1.04 mg/kg, arsenocholine - 0.033-69.0 mg/kg, arseniousacid - ND-1.25 mg/kg, dimethylarsinate - ND-3.75 mg/kg, monomethylarsonate - ND-8.33 mg/kg, arsenic acid - ND-0.55 mg/kg. Additionally, unknown arsenic species were present in most of samples. The intake of inorganic arsenic via ingestion of the seafood samples that were analyzed did not represent a toxicological problem to humans. The limits of detection (LOD) were in the range of 0.5-2.5 µg/kg .

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