Fitness of Isidorella newcombi Following Multi-generational Cu Exposures: Mortality, Cellular Biomarkers and Life History Responses.

The effects of multigenerational Cu exposure on the freshwater gastropod Isidorella newcombi were investigated. Snails were exposed to a range of treatment-specific Cu concentrations in the parental to F2 generations, and a common Cu concentration in the F3 generation. In the parental to F2 generations, some general responses to 3 days Cu exposures included reduced survival and feeding in snails exposed to higher Cu concentrations. This suggested that the snails exposed to the high Cu concentration were experiencing Cu-induced stress that may apply selection pressure. In the F3 generation, when all treatments were exposed to a common Cu concentration, increased survival was correlated with the pre-exposure Cu concentration history. Snails that had been pre-exposed to Cu also displayed reduced stress at a sub-lethal level, indicated by lower lysosomal destabilisation (LD). Mortality and LD responses in the F3 generation were not related to Cu tissue concentrations, indicating increased tolerance and reduced stress were not related to changes in Cu bioaccumulation. Total antioxidant capacity increased in the higher Cu concentration pre-exposure treatments which could be associated with lower Cu-induced stress, however, this is not supported by the oxidative damage marker lipid peroxidation, which also increased. While Cu tissue concentrations and oxidative stress markers were assessed to determine underlying reasons for increased tolerance in snails from a population with a multi-generational exposure history to Cu, the results were not conclusive. Despite this, it was demonstrated through increased survival and reduced LD that Cu tolerance can develop over a short evolutionary time scale.

Non-attendance at an out-patient otolaryngology and head and neck clinic in New Zealand: impact of coronavirus disease 2019, and demographic, clinical and environmental factors.

BACKGROUND: Fear of contracting coronavirus disease 2019 may be the latest addition to the barriers to clinic attendance. This study aimed to examine the impact of coronavirus disease 2019 and other variables on non-attendance rate at an out-patient clinic. METHODS: Clinic attendance at the Department of Otolaryngology and Head and Neck Surgery, Waikato Hospital, New Zealand, was assessed. For each appointment, the impact of coronavirus disease 2019 and other variables on non-attendance rate were analysed. RESULTS: In total, 1963 appointments were scheduled, with 194 non-attendances (9.9 per cent). Patients who had their appointments confirmed beforehand were 10.0 times more likely to attend their appointment. Sex, socioeconomic status, ethnicity and age were found to impact non-attendance rate. CONCLUSION: In New Zealand, coronavirus disease 2019 does not appear to be a barrier to out-patient clinic appointment attendance. The patient's age, sex, ethnicity, socioeconomic status and prior appointment confirmation were found to influence clinic attendance.

Timing of cholecystectomy for acute cholecystitis impacts surgical morbidity and mortality: an NSQIP database analysis.

The aim of this study is to identify the optimal timing for cholecystectomy for acute cholecystitis. Patients undergoing cholecystectomy for acute cholecystitis from the National Surgery Quality Improvement Program database between 2014 and 2016 were included. The patients were divided into 4 groups, those who underwent surgery at days 0, 1, 2, or 3+ days. The primary outcome was short-term surgical morbidity and mortality. A total of 21,392 patients were included. After adjusting for confounders, compared to day 0 patients, those who underwent surgery at day 1 and day 2 had lower composite morbidity rate, while day 3+ patients had significantly higher bleeding and mortality rate. Subgroup analysis shows this trend to be more significant in the elderly and in diabetic patients who were delayed. Delay in cholecystectomy for over 72 h from admission is associated with statistically significant increase in bleeding and mortality.

The Response of the Planorbid Snail Isidorella newcombi to Chronic Copper Exposure Over a 28-Day Period: Linking Mortality, Cellular Biomarkers, and Reproductive Responses.

The native freshwater gastropod Isidorella newcombi attacks the roots of developing rice plants in southern Australia and is controlled using copper sulphate. The apparent tolerance of this species to moderate levels of copper (Cu) exposure led us to investigate its potential usefulness as a biomonitor species. To assess its response to chronic Cu exposure, adult I. newcombi were exposed to 0-120 µg L-1 of Cu for 28 days. Lethal and sublethal responses were investigated. The relationships between subcellular biomarkers and life history traits also were explored. At exposure concentrations of 60 µg L-1 Cu and above, 100% mortality was observed during the 28-day exposure period. In these treatments, there was an exposure concentration dependent decrease in the time that the snails survived. In the surviving snails, there was an exposure concentration-dependent increase in tissue Cu concentration. In the snails exposed to Cu concentrations above 15 µg L-1, no eggs were produced during the final week of copper exposure, indicating that populations would not persist at Cu concentrations above 15 µg L-1. The general stress biomarker lysosomal membrane destabilisation (LD) indicated organisms exposed to 10 µg L-1 Cu and above were experiencing Cu induced stress. This suggests that LD could act as an early warning system for responses at higher levels of biological organisation in I. newcombi exposed to copper.

Metal concentrations in waters, sediments and biota of the far south-east coast of New South Wales, Australia, with an emphasis on Sn, Cu and Zn used as marine antifoulant agents.

Tin, Cu, Zn, Cd, Pb, Ag and Hg concentrations were measured in waters, sediments and three ubiquitous sedentary molluscs: the oyster, Saccostrea glomerata, a rocky intertidal gastropod, Austrocochlea porcata, and a sediment-dwelling gastropod, Batillaria australis, at 12 locations along the far south coast of NSW, Australia, from Batemans Bay to Twofold Bay during 2009. Metal concentrations in water for Sn, Cd, Ag and Hg were below detection limits (< 0.005 µg/L). Measurable water metal concentrations were Cu: 0.01-0.08 µg/L, Zn: 0.005-0.11 µg/L and Pb: 0.005-0.06 µg/L. Mean metal concentration in sediments were Sn < 0.01-2 µg/g, Cu < 0.01-605 µg/g, Zn 23-765 µg/g, Cd < 0.01-0.5 µg/g, Pb < 0.01-0.3 µg/g, Ag < 0.01-0.9 µg/g and Hg < 0.01-2.3 µg/g. Several locations exceeded the Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand (Australian and New Zealand guidelines for fresh and marine water quality 2000) low and high interim sediment quality guidelines' levels for Cu, Zn, Cd and Hg. Some sites had measurable Sn concentrations, but these were all well below the levels of tributyltin known to cause harm to marine animals. Elevated metal concentrations are likely to be from the use of antifoulants on boats, historical mining activities and agriculture in the catchments of estuaries. All molluscs had no measurable concentrations of Sn (< 0.01 µg/g) and low mean Ag (< 0.01-1.5 µg/g) and Hg (< 0.01-0.5 µg/g) concentrations. Mean Cu (24-1516 µg/g), Zn (45-4644 µg/g), Cd (0.05-5µg/g) and Pb (0.05-1.1 µg/g) in oysters were close to background concentrations. Oysters have Cd and Pb concentrations well below the Australian Food Standards Code (2002).] There were no significant correlations between metal concentrations in sediments and in organisms within locations, and no relationship with levels of boating activity and suspected antifouling contamination. Although not pristine, the low levels of metal contamination in sediments and molluscs in comparison with known metal-contaminated areas indicate that this region is not grossly contaminated with metals and suitable for the development of mariculture.].

Factors influencing arsenic concentrations and species in mangrove surface sediments from south-east NSW, Australia.

Arsenic concentrations and speciation of 55 mangrove surface sediment samples from the south-eastern coast of NSW, Australia, have been measured. Arsenic concentrations were in the range 1.6-8.6 µg/g dry mass. All arsenic concentration values were well below 20 µg/g, the ANZEC/ARMCANZ interim sediment quality guideline-low trigger value. The bulk sediment pH was 6.0-7.3 and Eh -80 to -260 mV. The sediments contained variable silt-clay (2-30 % w/w), iron (668-12721 µg/g), manganese (1-115 µg/g), sulphur (70-18400 µg/g) and carbon (5-90 mg/g) concentrations. Arsenic concentrations correlated with silt and clay content, iron and manganese concentrations, indicating silt-clay particles covered and coated with iron and manganese (oxy) hydroxides scavenged arsenic. Arsenic extracted with 0.5 M phosphoric acid (68-95 %) was present only as inorganic arsenic (55-91 %), indicating that other arsenic species such as arsenobetaine derived from marine animal tissues rapidly degrade in sediments. The unextractable arsenic was correlated with increases in organic carbon, iron and manganese content. In conclusion, the cycling of arsenic in mangrove sediments is essentially the cycling of inorganic arsenic and primarily controlled by the redox cycling of carbon, sulphur, iron and manganese.

The use of the marine gastropod, Cellana tramoserica, as a biomonitor of metal contamination in near shore environments.

The use of the marine gastropod, Cellana tramoserica, as a biomonitor of metal exposure was investigated. The factors influencing metal concentrations, such as mass, gender, substrate, shoreline position and temporal variation were examined. Tissue metal concentrations were mostly found to be independent of mass and gender. When metal concentrations were significantly correlated with mass, correlations were low and explained little variability. The underlying substrate and position in the littoral zone had only a small influence on metal concentrations. Variation between individuals, inherent variability due to genetic variability, was the most significant contribution to the overall variation in metal concentrations, resulting in positive skewing of population distributions. The mean metal concentrations varied temporally; metal masses were relatively constant with fluctuations in metal concentrations related to fluctuations in metal body burdens. The populations from a metal-contaminated site had significantly higher tissue Cu, Zn, As and Pb concentrations than the populations from relatively uncontaminated locations. C. tramoserica therefore can be considered to be a net accumulator of metals. A sample number of >10 is required to detect changes of 25 % from the mean concentrations at uncontaminated locations. This species meets the requirements of a suitable biomonitor for metal contaminants in the environment i.e. hardy, sessile, widespread, sufficient tissue mass and a metal accumulator. As the measurement of metal concentrations in C. tramesoria were influenced by substrate and shore position and, sometimes, mass, sites with similar substrates and organisms of similar mass and shoreline position should be chosen for comparison. When comparing metal concentrations in gastropods from different locations, they should be collected over the same period to minimise variability due to mass differences, spawning and other seasonal/temporal effects.

Circumferential rotator cuff repair with the n+4 portal, subclavian portal, and high posteromedial portal.

Passing suture during a rotator cuff repair requires proper orientation and purchase of the rotator cuff tendon. Our technique uses a new portal to improve access to the supraspinatus and infraspinatus and uses additional portals for a circumferential repair of the tear, thereby restoring the footprint. Using a penetrating suture passer through the anterior, posterior, and superomedial portals allows 270° of coverage. The lateral anchors complete the circumferential repair. Sutures from the medial anchors are passed in a retrograde fashion using 3 small incisions with no cannula. A spinal needle is used to localize the orientation of each portal. The N+4 portal is the workhorse portal, allowing access to the supraspinatus and infraspinatus. The suture retriever enters the trapezius 5 cm from the medial border of the acromion and 1 cm anterior to the spine of the scapula. It enters the subacromial space on top of the supraspinatus. This provides protection to the suprascapular nerve in the supraspinatus fossa. The cuff is lifted with a grasper to allow perpendicular passage of suture. The suture is retrieved for tying. The tissue purchase and location of suture placement help restore the footprint of the supraspinatus and infraspinatus. Additional sutures are passed anteriorly through the subclavian portal and posteriorly through the high posteromedial portal. The repair is completed with lateral-row anchors as needed.

Response of the hairy mussel Trichomya hirsuta to sediment-metal contamination in the presence of a bioturbator.

The accumulation of metals in tissue compartments of bivalve biomonitors is expected to reflect the phases in which metals are most bioavailable. In concurrent field and laboratory experiments we measured Zn, Cd and Pb concentrations in the gills and digestive glands of mussels exposed to sediments from Lake Macquarie in NSW, Australia. Mussels in the laboratory were also exposed to the bioturbating gastropod Batillaria australis. Zn, Cd and Pb concentrations in gills and digestive glands of mussels from both experiments were accumulated in proportion with levels of metal contamination in the sediments. An interaction in the field between site and tissue type was found for Cd and Pb suggesting variation in the phases in which metals are most bioavailable. No effect of bioturbation on metal accumulation in the bivalve was detected and we conclude that it is unlikely to be a significant factor in metal uptake when these species interact.

A novel technique for advancing the inferior labrum in a bankart repair.

Passing suture during a Bankart repair can be a difficult task. A key component of a Bankart repair involves shifting the anteroinferior capsule and labrum superiorly. This technical note describes a new technique of reaching the inferior aspect of the Bankart lesion from posterior. Typical suture passers push the tissue further away. Using a SutureLasso through the low posterolateral portal allows one to push the tissue from inferior toward the suture anchor, making it simpler to advance the capsulolabral complex. Three suture anchors are used in the anteroinferior quadrant. The lowest suture anchor is the critical anchor for advancing the capsule and labrum. The SutureLasso is placed into the axillary recess through the low posterolateral portal, and the nitinol wire is advanced through the capsule and labrum, retrieving the suture and pulling it back through the tissue for tying with a sliding locking knot. This ensures good superior advancement of the tissue and helps obtain an optimal arthroscopic result in Bankart repair. Additional anchors are placed, and suture passage for the middle and superior anchors is then completed from anterior. The advancement and restoration of the tissue tightness provide the optimal components for an excellent result.

Measurement of inorganic arsenic species in rice after nitric acid extraction by HPLC-ICPMS: verification using XANES.

The measurement of As species in rice is normally accomplished by extraction followed by HPLC-ICPMS analysis. This method, however, has not been comprehensively validated by comparing these speciation results with XANES, which does not require sample extraction, due to the challenge of conducting XANES analysis at very low As concentrations. In this study As speciation data using nitric acid extraction/HPLC-ICPMS and XANES are compared to verify the efficacy of using 2% v/v nitric acid extraction and HPLC-ICPMS to measure inorganic As, DMA, and MA in reference rice materials and common rice varieties obtainable in Australia. Total As and As species (As(III), As(V), DMA, and MA) concentrations measured in 8 reference materials were in agreement with published values. XANES analysis was performed on 5 samples having total As concentrations ranging from 0.198 to 0.335 µg g(-1). XANES results gave similar proportions of total As(III), As(V), and DMA to HPLC-ICPMS. XANES was able to distinguish two forms of As(III): As(III) and As(III)GSH. Total As concentrations in rice samples varied from 0.006 to 0.45 µg g(-1) As (n = 47) with a mean ± std of 0.127 ± 0.112 µg g(-1) As with most As present as inorganic species (63 ± 26%). DMA was found in nearly all the rice samples with the majority of samples containing concentrations below 0.05 µg g(-1) As while MA concentrations were negligible (<0.003 µg g(-1) As). Six rice varieties produced in Australia, China, and Spain all had elevated DMA concentrations (0.170-0.399 µg g(-1) As) that were correlated with total As concentrations (r(2) = 0.7518). In conclusion, comparison of As speciation by HPLC-ICPMS and XANES showed that similar As species were detected indicating the appropriateness of using 2% v/v nitric acid for extraction of rice prior to speciation. Common rice varieties obtainable in Australia generally have low As concentrations with most As present as inorganic As.

Sponges as sentinels: patterns of spatial and intra-individual variation in trace metal concentration.

If sponges are to be effective biomonitors we require a better understanding of the spatial scales over which metals vary in these organisms. We determined how concentration of Cd, Zn, Cu, Pb, Hg and Se varied over four spatial scales for two common estuarine sponge species in the Sydney region. We examined variability with a fully nested sampling design; between coastal lakes, within coastal lakes, between sponges and within sponges. Calculation of variance components confirmed that 'within-sponge' variation in Cd, Zn, Cu, Pb and Se concentrations were low (1-14%) relative to the two largest spatial scales (49-98%) examined. In contrast, Hg concentrations exhibited marked variability 'between-sponges' and were below detection at one location. There was little evidence that sponge size was a good predictor of metal concentration. Taken together, these outcomes confirm that fragments of these sponges could be successfully transplanted and therefore show promise as biomonitors of metal contamination.

Arsenic toxicity in a sediment-dwelling polychaete: detoxification and arsenic metabolism.

The accumulation, subcellular distribution and speciation of arsenic in the polychaete Arenicola marina were investigated under different laboratory exposure conditions representing a range of metal bioavailabilities, to gain an insight into the physiological mechanisms of how A. marina handles bioaccumulated arsenic and to improve our understanding of the potential ecotoxicological significance of bioaccumulated arsenic in this deposit-feeder. The exposure conditions included exposure to sublethal concentrations of dissolved arsenate, exposure to sublethal concentrations of sediment-bound metal mining mixtures, and exposure to lethal concentrations of sediment-bound metal mining mixtures and arsenic- and multiple metal-spiked sediments. The sub-lethal exposures indicate that arsenic bioaccumulated by the deposit-feeding polychaete A. marina is stored in the cytosol as heat stable proteins (~50%) including metallothioneins, possibly as As (III)-thiol complexes. The remaining arsenic is mainly accumulated in the fraction containing cellular debris (~20%), with decreasing proportions accumulated in the metal-rich granules, organelles and heat-sensitive proteins fractions. A biological detoxified metal compartment including heat stable proteins and the fraction containing metal-rich granules is capable of binding arsenic coming into the cells at a constant rate under sublethal arsenic bioavailabilities. The remaining arsenic entering the cell is bound loosely into the cellular debris fraction, which can be subsequently released and diverted to an expanding detoxified pool. Our results suggest that a metal sensitive compartment comprising the cellular debris, enzymes and organelles fractions may be more representative of the toxic effects observed.

Measurement of total antimony and antimony species in mine contaminated soils by ICPMS and HPLC-ICPMS.

This paper describes the measurement of total antimony and antimony species in "real world" mine contaminated sediments using ICPMS and HPLC-ICPMS. Low and high temperature microwave extraction procedures (90 degrees C and 150 degrees C, respectively) using a range of nitric-hydrochloric acid combinations were examined as to their efficacy to extract antimony from six mine contaminated soils and a certified reference material. The use of the higher temperature with nitric-hydrochloric acid (1:2 (v/v)) was suitable to release antimony from sediments and the certified reference material, NIST 2710 Montana soil. Antimony concentrations obtained using this acid mixture were similar to those obtained using a more aggressive extraction with nitric, hydrochloric, perchloric and hydrofluoric acid mixture. A 25 mM citric acid solution at 90 degrees C for 15 min extracted 47-78% of antimony from soils. A Hamilton PRP X-100 anion exchange column with 20 mM EDTA mobile phase, pH 4.5, flow rate 1.5 mL min(-1) and column temperature of 50 degrees C was used to separate antimony species. Column recoveries ranged from 78-104%. The predominant form of antimony was Sb(5+). Little conversion of Sb(5+) occurred (<5%) during extraction, however, significant conversion of Sb(3+) occurred (approximately 36%). The extraction of antimony species with citric acid should be useful in the determination of inorganic antimony available to plants, as plants commonly excrete carboxylic acids, including citric acid, into their rhizospheres to mobilise trace elements for nutritional purposes.

Assessment of metals in fish from Lake Macquarie, New South Wales, Australia.

The concentrations of the metals cadmium, copper, mercury, lead, silver, selenium and zinc were measured in the muscle and gonad tissues of five species of fish, yellowfin bream (Acanthopagrus australis), silverbiddy (Gerres subfasciatus) and trumpeter whiting (Sillago maculata), southern log finned goby (Favonigobious lateralis), and the halfbridled goby (Arenigobius frenatus) from the contaminated Lake Macquarie NSW and three relatively uncontaminated reference estuaries, Wallis Lake, Port Stephens, and St. Georges Basin NSW. Fish from Lake Macquarie were found to have elevated concentrations of selenium, lead, cadmium, and zinc in one or both of these tissues in these species. Increased concentrations relative to background concentrations were most often observed at Cockle Bay, the site with the highest concentrations of these metals in sediments. The degree to which fish accumulated metals appeared to be related to life history characteristics of the species, with sediment-dwelling fish showing the greatest propensity to accumulate metals.

Effects of light on microalgae concentrations and selenium uptake in bivalves exposed to selenium-amended sediments.

The purpose of the current study was to evaluate the role of visible light during trophic transfer of the essential metalloid, selenium (Se) from sediments by way of the microalgae Phaeodactylum tricornutum to bivalves. Initial experiments compared uptake of Se with algal cell number after deposit-feeding (Tellina deltoidalis) and filter-feeding (Soletellina alba) bivalves were exposed for 12 days under 16:8 h light:dark and 24-hour dark regimes to sediments amended with Se (17 mg/kg dry weight). Comparisons of filter-feeding with deposit-feeding organisms indicated >2-fold higher body burdens in the deposit-feeding organisms after 12 days. Darkness failed to significantly and consistently diminish algal cell densities. However, general trends indicated a decrease of pelagic algal numbers in +Se/dark treatments during the 12-day exposure. To determine whether time-dependent patterns were present in the uptake of Se by the deposit-feeding species, a second experiment was conducted using Se-laden sediments under light and dark conditions. Algal cell counts were measured and Se concentrations determined in animals sampled at days 0, 3, 6, 9, and 12. Deposit-feeding animals maintained in the dark accumulated, Se more rapidly than animals on light to dark cycles until 12 days at which time no significant differences were observed between treatments. Concentrations of Se in tissues of deposit-feeding bivalves were not directly related to algal cell density in lighted or dark chambers. These results indicate that pelagic microalgae may only play a key role in Se uptake during early hours of exposure, and feeding behavior may be a more important factor in deposite-feeding bivalves.

The accumulation of Zn, Se, Cd, and Pb and physiological condition of Anadara trapezia transplanted to a contamination gradient in Lake Macquarie, New South Wales, Australia.

The benthic bivalve, Anadara trapezia, was collected from a 'clean' reference site and transplanted along a suspected trace metal contamination gradient in Lake Macquarie, NSW. At monthly intervals, Zn, Se, Cd and Pb concentrations were measured in the surficial sediments and whole tissues of the cockle as well as their physiological condition (Scope for Growth). Zinc, Cd and Pb concentrations in sediments decreased together, southward, with the highest concentrations in the Cockle Bay area, suggesting that this is the main source of contamination. Zinc, Cd and Pb concentrations were near or above [ANZECC/ARMCANZ, 2000. National water quality management strategy paper 4. Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand. pp. 3.5.-1-3.5-10] sediment quality guidelines at Cockle Creek, Warners Bay and Koorooa Bay. Significant differences in trace metal concentrations could not be attributed to grain size or Fe concentration differences. Se concentrations were highest in fine grain Fe rich sediments of Whiteheads Lagoon, and likely to be associated with power generation operations. Trace metal concentrations did not vary significantly over time. Zinc, Cd and Pb concentrations in the tissues of A. trapezia followed a similar pattern to that of sediments. Zinc and Pb concentrations in cockles and sediments were highly correlated, indicating significant exposure-dose relationships. Selenium concentrations in the tissues of A. trapezia were higher after transplantation to the lake, however, Se concentrations were similar in all transplanted cockles, indicating that Se in contaminated sediments is not the major source of Se to organisms. There was a decline in the physiological condition of A. trapezia transplanted to Lake Macquarie after a 90-day-period with marked differences in clearance rates and respiration rates at some locations and absorption efficiencies at all locations. The mean Scope for Growth value at the most contaminated location, Cockle Bay, was markedly lower than at other locations. A significant Zn exposure-dose response relationship indicates that Zn bioaccumulation is occurring in response to sediment contamination. A significant Cd exposure-response relationship indicates that Cd may be influencing the health of cockles. Significant Pb exposure-dose, exposure-response and dose-response relationships indicate that Pb probably is affecting the health of cockles in Lake Macquarie. Therefore, Zn, Cd and Pb concentrations in sediments are likely to be affecting the health of cockles in Lake Macquarie.

Observations on the measurement of total antimony and antimony species in algae, plant and animal tissues.

This paper describes our experiences with undertaking measurements of total antimony and antimony speciation in algae, plant and animal tissues. Digestion with nitric acid alone is suitable to release antimony from animal tissues. When organisms have high silica contents, e.g. some plants and algae, the addition of tetrafluorboric acid is required to dissolve silica as some antimony is retained by silica in extracts. Antimony in digested extracts is present as Sb5+ and hydride generation procedures can be used to determine total antimony concentrations, as total antimony in extracts will not be under estimated. Relatively non-aggressive solvents such as water, dilute nitric acid, sodium hydroxide and enzymes remove highly variable amounts of antimony (2-84%) from algae, plant and animal tissues. Addition of Sb3+ and Sb5+ to NIST CRM 1572 Citrus Leaves, pre- and post-extraction with water showed that Sb3+ is oxidised to Sb5+ while Sb5+ is redistributed amongst binding sites giving rise to artefacts. DOLT-2 and algae extracts indicated the presence of only inorganic antimony. A moss sample had inorganic antimony and a number of unknown antimony species in extracts. Future studies should explore the nature of the binding of antimony in tissues as solvents commonly used to extract metals and metalloids from algae, plant and animal tissues are not appropriate.

Arsenic occurrence and species in near-shore macroalgae-feeding marine animals.

This study was undertaken to improve the understanding of arsenic species and their pathways of formation in marine animals: fish (Odax cyanomelas), abalone (Haliotis rubra), and sea urchins (Heliocidaris erythrogramma and Centrostephanus rodgersii) that are directly exposed through their diets to dimethyl arsenoriboses in macroalgae (Phyllospora comosa and Halopteris platycena). The identification of dimethyl arsenoriboses (phosphate, sulfonate, and glycerol) in both dominant macroalgae species, and especially digestive tissues of marine animals that consume them, suggests these arsenic species, are to some degree accumulated directly from their diets without degradation or conversion. An unknown arsenic species in H. rubra intestinal tissue was identified using tandem mass spectrometry as 2',3'-dihydroxypropyl 5-deoxy-5-trimethyl arsonioriboside (trimethyl glycerol arsenoribose). The concentration of trimethyl glycerol arsenoribose in H. rubra intestinal tissue was estimated to account for 28% (5.0 microg g(-1) dry mass) of the methanol-water-soluble arsenic fraction. The presence of a trimethyl glycerol arsenoribose in marine animal tissues may be due to microbial-mediated processes that promote the reduction and methylation of dimethyl arsenoriboses released during the breakdown of macroalgae in their diets. Arsenobetaine formation may then occur in the lumen of the digestive tract (i.e., mediated by microorganisms) or in the liver catalyzed by enzymes. The identification of a large amount of trimethyl glycerol arsenoribose in H. rubra intestinal tissue suggests this species is a main constituent in the pathway for arsenic in this marine animal.