The cyanobacterium Scytonema cf. crispum produces a range of saxitoxins. Previous studies on othe... more The cyanobacterium Scytonema cf. crispum produces a range of saxitoxins. Previous studies on other saxitoxin-producing cyanobacteria have shown that toxin production can vary throughout the growth cycle. Monitoring cyanotoxin-production in S. cf. crispum is challenging because it is metaphytic and has a very slow growth rate (ca. 6 months to reach stationary phase). In this study, a new method was developed to track growth and toxin production in S. cf. crispum. Samples were collected once a week for 131 days, and cell concentrations and saxitoxin quotas determined. Cells in the lag and exponential growth phases had significantly (P < 0.05) higher saxitoxin quotas (162 ± 37 fg cell(-1) and 139 ± 32 fg cell(-1), respectively) than the stationary phases (83 ± 19 fg cell(-1)). Extracellular saxitoxin concentrations were present at low concentrations (2-16 ng mL(-1) of culture medium) throughout the experiment. The proportion of extracellular saxitoxin to total saxitoxin decreased throughout the experiment. New knowledge on growth and saxitoxin variability will assist in improving monitoring, risk assessment and management of this species.
Journal of environmental radioactivity, Jan 10, 2015
A study was undertaken to determine activity concentrations for (134)Caesium, (137)Caesium and (2... more A study was undertaken to determine activity concentrations for (134)Caesium, (137)Caesium and (210)Polonium in New Zealand seafood, and establish if activity concentrations varied with respect to species/ecological niche and coastal region. Thirty seafood samples were obtained from six fishing regions of New Zealand along with a further six samples of two commercially important species (hoki and arrow squid) with well-defined fisheries. (134)Caesium was not detected in any sample. (137)Caesium was detected in 47% of samples, predominantly in pelagic fish species, with most activities at a trace level. Detections of (137)Caesium were evenly distributed across all regions. Activity concentrations were consistent with those expected from the oceanic inventory representing residual fallout from global nuclear testing. (210)Polonium was detected above the minimum detectable concentration in 33 (92%) of the analysed samples. Molluscs displayed significantly elevated activity concentratio...
Benthic Phormidium mats can contain high concentrations of the neurotoxins anatoxin-a and homoana... more Benthic Phormidium mats can contain high concentrations of the neurotoxins anatoxin-a and homoanatoxin-a. However, little is known about the co-occurrence of anatoxin-producing and non-anatoxin-producing strains within mats. There is also no data on variation in anatoxin content among toxic genotypes isolated from the same mat. In this study, 30 Phormidium strains were isolated from 1 cm(2) sections of Phormidium-dominated mats collected from three different sites. Strains were grown to stationary phase and their anatoxin-a, homoanatoxin-a, dihydroanatoxin-a and dihydrohomoanatoxin-a concentrations determined using liquid chromatography-mass spectrometry. Each strain was characterized using morphological and molecular (16S rRNA gene sequences) techniques. Eighteen strains produced anatoxin-a, dihydroanatoxin-a or homoanatoxin-a. Strains isolated from each mat either all produced toxins, or were a mixture of anatoxin and non-anatoxin-producing genotypes. Based on morphology these gen...
Journal of environmental radioactivity, Jan 18, 2015
To support New Zealand's food safety monitoring regime, a survey was undertaken to establish ... more To support New Zealand's food safety monitoring regime, a survey was undertaken to establish radionuclide activity concentrations across the New Zealand diet. This survey was undertaken to better understand the radioactivity content of the modern diet and also to assess the suitability of the current use of milk as a sentinel for dietary radionuclide trends. Thirteen radionuclides were analysed in 40 common food commodities, including animal products, fruits, vegetables, cereal grains and seafood. Activity was detected for (137)Caesium, (90)Strontium and (131)Iodine. No other anthropogenic radionuclides were detected. Activity concentrations of the three natural radionuclides of Uranium and the daughter radionuclide (210)Polonium were detected in the majority of food sampled, with a large variation in magnitude. The maximum activity concentrations were detected in shellfish for all these radionuclides. Based on the established activity concentrations and ranges, the New Zealand ...
This is the first study to use a multiple biomarker approach on the green-lipped mussel, Perna ca... more This is the first study to use a multiple biomarker approach on the green-lipped mussel, Perna canaliculus to test its feasibility as a bioindicator of coastal metal contamination in New Zealand (NZ). Mussels were collected from six low intertidal sites varying in terms of anthropogenic impacts, within two regions (West Coast and Nelson) of the South Island of NZ. Trace elements, including arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn), were measured in the gills, digestive gland, foot and mantle, and in the surface sediments from where mussels were collected. Metal levels in the sediment were relatively low and there was only one site (Mapua, Nelson) where a metal (Ni) exceeded the Australian and New Zealand Interim Sediment Quality Guideline values. Metal levels in the digestive gland were generally higher than those from the other tissues. A variety of biomarkers were assessed to ascertain mussel health. Clearance rate, a physiological endpoint, co...
Studies on planktonic cyanobacteria have shown variability in cyanotoxin production, in response ... more Studies on planktonic cyanobacteria have shown variability in cyanotoxin production, in response to changes in growth phase and environmental factors. Few studies have investigated cyanotoxin regulation in benthic mat-forming species, despite increasing reports on poisoning events caused by ingestion of these organisms. In this study, a method was developed to investigate changes in cyanotoxin quota in liquid cultures of benthic mat-forming cyanobacteria. Iron and copper are important in cellular processes and are well known to affect growth and selected metabolite production in cyanobacteria and algae. The effect of iron (40-4000 μg L(-1)) and copper (2.5-250 μg L(-1)) on growth and anatoxin-a quota in Phormidium autumnale was investigated in batch culture. These concentrations were chosen to span those found in freshwater, as well as those previously reported to be toxic to cyanobacteria. Anatoxin-a concentrations varied throughout the growth curve, with a maximum quota of between...
Philosophical transactions of the Royal Society of London. Series B, Biological sciences, Jan 19, 2014
There has been a significant investment in research to define exposures and potential hazards of ... more There has been a significant investment in research to define exposures and potential hazards of pharmaceuticals in freshwater and terrestrial ecosystems. A substantial number of integrated environmental risk assessments have been developed in Europe, North America and many other regions for these situations. In contrast, comparatively few empirical studies have been conducted for human and veterinary pharmaceuticals that are likely to enter coastal and marine ecosystems. This is a critical knowledge gap given the significant increase in coastal human populations around the globe and the growth of coastal megacities, together with the increasing importance of coastal aquaculture around the world. There is increasing evidence that pharmaceuticals are present and are impacting on marine and coastal environments. This paper reviews the sources, impacts and concentrations of pharmaceuticals in marine and coastal environments to identify knowledge gaps and suggests focused case studies a...
ABSTRACT Planktonic cyanotoxin poisoning events are well documented. More recently, benthic cyano... more ABSTRACT Planktonic cyanotoxin poisoning events are well documented. More recently, benthic cyanobacteria have also been associated with bird, cattle and dog fatalities. Extensive mats of benthic cyanobacteria can contain high concentrations of toxins. This study investigated cyanotoxin production in cyanobacterial strains isolated from benthic freshwater mats dominated by cyanobacteria in Canterbury, New Zealand. Twenty-seven strains were isolated from ten water bodies and characterized using morphological and molecular phylogenetic characteristics. All strains were screened for genes involved in the biosynthesis of common cyanotoxins. Positive results were confirmed and cyanotoxin concentrations quantified using liquid chromatography–mass spectrometry. One chroococcalean, twenty oscillatorialean and six nostocalean strains were isolated into culture. All strains were cryopreserved and banked in the Cawthron Institute Culture Collection of Micro-algae. Genes associated with anatoxin-a biosynthesis were identified in nine Phormidium strains. Anatoxin-a was detected in all these strains, one of these strains also produced homoanatoxin-a.
Pharmaceutical and personal care products (PPCPs) are a major source of micropollutants to the aq... more Pharmaceutical and personal care products (PPCPs) are a major source of micropollutants to the aquatic environment. Despite intense research on the fate and effects of PPCPs in temperate climates, there is a paucity of data on their presence in polar environments. This study reports the presence of selected PPCPs in sewage effluents from two Antarctic research stations, the adjacent coastal seawater, sea ice, and biota. Sewage effluents contained bisphenol-A, ethinylestradiol, estrone, methyl triclosan, octylphenol, triclosan, and three UV-filters. The maximum sewage effluent concentrations of 4-methyl-benzylidene camphor, benzophenone-1, estrone, ethinylestradiol, and octylphenol exceeded concentrations previously reported. Coastal seawaters contained bisphenol-A, octylphenol, triclosan, three paraben preservatives, and four UV-filters. The sea ice contained a similar range and concentration of PPCPs as the seawater. Benzophenone-3 (preferential accumulation in clams), estradiol, ethinylestradiol, methyl paraben (preferential accumulation in fish, with concentrations correlating negatively with fillet size), octylphenol, and propyl paraben were detected in biota samples. PPCPs were detected in seawater and biota at distances up to 25 km from the research stations WWTP discharges. Sewage effluent discharges and disposal of raw human waste through sea ice cracks have been identified as sources of PPCPs to Antarctic coastal environments.
Environmental context. Antarctica has several scientific research stations located along its coas... more Environmental context. Antarctica has several scientific research stations located along its coast, where they discharge often untreated sewage containing organic micropollutants. Although degradation of these pollutants by microorganisms is limited by the cold conditions, other pathways such as photodegradation may be significant. Our results indicate that, during the summer, photolysis is a potentially significant degradation pathway for organic micropollutants in Antarctic surface waters, although the rate of loss would depend on ice cover and water depth.
Copper is present in a range of fungicides as well as in some animal manures and biosolids that a... more Copper is present in a range of fungicides as well as in some animal manures and biosolids that are applied to agricultural soils as fertilisers. Elevated and increasing levels of copper in agricultural soils are of worldwide concern. Copper is toxic to soil microorganisms and has been reported to reduce the ability of soil microorganisms to degrade pesticides. A glasshouse study was undertaken to determine if copper inhibited the degradation of atrazine and indoxacarb in soil. A fine sandy loam agricultural soil was fortified with copper at five concentrations over a concentration range of 0e1000 mg/kg copper, then field-aged for 6 months prior to treatment with either indoxacarb or atrazine at a rate of 2 mg/kg. The soils were sampled twice at intervals based on published half-lives. The samples were analysed for a range of parameters including total and bioavailable copper, urease and phosphatase activity, ergosterol and either indoxacarb or atrazine and its degradation products. The soil microbial biomass and enzyme activities decreased with increasing copper concentration (p < 0.05). There were no significant differences in soil atrazine and indoxacarb concentrations between the copper levels. At sampling time two, the concentrations of hydroxyatrazine in treatments containing the three highest copper concentrations were significantly greater (p < 0.05) than for the control soil. Our results indicate that copper does not inhibit the first step of indoxacarb and atrazine degradation, but may affect degradation of secondary metabolites like hydroxyatrazine in soil.
New Zealand Journal of Marine and Freshwater Research, 2008
A total of 163 wells were sampled in New Zealand as part of the 2006 national survey of pesticide... more A total of 163 wells were sampled in New Zealand as part of the 2006 national survey of pesticides in groundwater. The aims of the survey were to update the national overview of pesticides in New Zealand&amp;amp;amp;#39;s groundwater systems, to investigate temporal variation in pesticide concentrations between surveys, and to identify environmental factors associated with pesticide contamination of groundwater. Thirty‐one
Metal roofing material is commonly used for residential and industrial roofs in volcanically acti... more Metal roofing material is commonly used for residential and industrial roofs in volcanically active areas. Increased corrosion of metal roofing from chemically reactive volcanic ash following ash deposition post-eruption is a major concern due to decreasing the function and stability of roofs. Currently, assessment of ash-induced corrosion is anecdotal, and quantitative data are lacking. Here, we systematically evaluate the corrosive effects of volcanic ash, specifically ash leachates, on a variety of metal roofing materials (i.e. weathered steel, zinc, galvanized steel, and ColorsteelÓ) utilizing weathering chamber experiments and direct acid treatments. Weathering chamber tests were carried out for up to 30 days, and visual, chemical, and surface analyses did not definitively identify significant corrosion in any of the test roofing metal samples. Direct concentrated acid treatments with hydrochloric (HCl), sulphuric (H 2 SO 4 ), and hydrofluoric (HF) acids demonstrate that roofing materials are chemically resilient. Our experimental results suggest that ash-leachate-related corrosion is a longer-term process ([1 month), potentially related to a multitude of factors including increased ash leachate concentrations, the dissolution of the glass matrix of the ash, moisture retention at the ash-surface boundary, and potential reactions involving photo-oxidation. Overall, corrosion is not a simple process related to the short-term release of acid and/or salt leachates from the ash surface, but a product of dynamic interactions involving ash and water at the surface of metal roofing material for extended periods.
Orchard soils can contain elevated concentrations of 1,1-dichloro-2,2-bis( p-chlorophenyl)ethylen... more Orchard soils can contain elevated concentrations of 1,1-dichloro-2,2-bis( p-chlorophenyl)ethylene (p,p 0 -DDE), 1,1,1trichloro-2,2-bis( p-chlorophenyl)ethane (p,p 0 -DDT), and heavy metals as a result of historical agrichemical applications. The bioavailability of p,p 0 -DDE, p,p 0 -DDT, As, Cd, Cu, and Pb from five field-aged New Zealand orchards and three grazing soils was assessed by using a 28-d bioassay with Aporrectodea caliginosa and chemical assays. Significant relationships were found between total soil and earthworm tissue concentrations for p,p 0 -DDE ( p < 0.001), p,p 0 -DDT ( p < 0.001), Cu ( p < 0.001), and Pb ( p < 0.01). Two neutral salt solutions, 0.01 M CaCl 2 and 1 M NH 4 NO 3 , were used as surrogate measures of the bioavailability of heavy metals. Copper was the only heavy metal for which significant correlations were found between neutral-salt-extractable and earthworm tissue concentrations ( p < 0.001). Up to 28% of the aged DDT residues were released from the soils by Tenax over a 24-h extraction period. Significant relationships ( p < 0.01) between the Tenax-extractable and earthworm tissue concentrations for p,p 0 -DDE and p,p 0 -DDT showed that Tenax provides a good surrogate measure of the bioavailability of these compounds to A. caliginosa. Surprisingly, there was a similarly significant relationship ( p < 0.001) between the total soil and earthworm tissue concentrations for p,p 0 -DDE and p,p 0 -DDT, suggesting that total soil concentrations alone were sufficient to predict uptake by A. caliginosa. These results demonstrate that the aged agrichemical residues in orchard soils, and particularly p,p 0 -DDE and p,p 0 -DDT, remain highly bioavailable to A. caliginosa despite decades of weathering and continue to present an environmental risk. Environ. Toxicol. Chem. 2012;31:130631: -131631: . # 2012
Reliable environmentally realistic bioassay methodologies are increasingly needed to assess the e... more Reliable environmentally realistic bioassay methodologies are increasingly needed to assess the effects of environmental pollution. This study describes two estuarine sediment bioassays, one acute (96 h) and one chronic (14 d), with the New Zealand harpacticoid copepod Quinquelaophonte sp. utilising behavioural and reproductive endpoints. Spiked sediments were used to expose Quinquelaophonte sp. to three reference compounds representing important categories of estuarine chemical stressors: zinc (a metal), atrazine (a pesticide), and phenanthrene (a polycyclic aromatic hydrocarbon). Acute-to-chronic ratios (ACR) were used to further characterise species responses. Acute sediment (sandy and low total organic content) 96 h EC 50 values for the sublethal inhibition of mobility for zinc, atrazine and phenanthrene were 137, 5.4, and 2.6 mg/g, respectively. The chronic EC 50 values for inhibition of reproduction (total offspring) were 54.5, 0.0083, and 0.067 mg/g for zinc, atrazine, and phenanthrene, respectively. For phenanthrene, a potentially novel mode of action was identified on reproduction. Quinquelaophonte sp. was found to be more sensitive than several other estuarine species indicating choice of test organism is important to characterising the effects of environmentally relevant levels of contamination. The bioassay sediment results demonstrate the sensitivity and suitability of Quinquelaophonte sp. as a tool for the assessment use of estuarine health.
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2013
The transfer of mussels from field to laboratory, or transplantation between clean and contaminat... more The transfer of mussels from field to laboratory, or transplantation between clean and contaminated field settings, is a common protocol in ecotoxicology. However, collection and transport of mussels could lead to stress that may impact biomarker responses, and thus confound interpretation of results. Physiological responses (clearance rate, absorption efficiency, excretion rate, respiration rate and scope-for-growth) of green-lipped mussels (Perna canaliculus) exposed to four different transportation protocols were investigated. These protocols included immersion in site seawater (SSW), immersion in artificial seawater (ASW), and emersion (aerial transport; EMS) at two temperatures (15°C and 5°C). Physiological measurements were conducted after a simulated 24 h "transport" phase and a 48 h "recovery" phase. Clearance rates were significantly inhibited by the EMS 5°C and ASW protocols relative to SSW treatment, although the clearance rate of the latter recovered after 48 h. A similar pattern was observed for excretion and respiration rates for ASW. Decreased excretion rates for EMS 15°C and respiration rates for EMS 5°C were also recorded relative to values for SSW following "recovery". Negative scope-for-growth was observed for all treatments except EMS 15°C. These data suggest transport emersed at ambient air temperatures is the best method to maintain physiological health of green-lipped mussels.
ABSTRACT Bimetallic metal nanoparticles are often more catalytically active than their monometall... more ABSTRACT Bimetallic metal nanoparticles are often more catalytically active than their monometallic counterparts, due to a so-called &#39;synergistic effect&#39;. Atomically precise ruthenium-platinum clusters have been shown to be active in the hydrogenation of phenylacetylene to styrene (a reaction of importance to the polymer industry). However, the synthesis of these clusters is generally complex, and cannot be modified to produce clusters with differing metal compositions or ratios. Hence, any truly systematic study of compositional effects using such clusters is hindered by the inaccessibility of certain metal ratios. In this study, a series of larger bimetallic ruthenium-platinum colloids of varying metal ratios was synthesised in solution and immobilised on silica. Catalytic activity was evaluated by hydrogenation of phenylacetylene to styrene. Both bimetallic and monometallic colloids were active catalysts for the hydrogenation of phenylacetylene to styrene and further to ethylbenzene. Of those studied, a catalyst composed of 73% platinum-27% ruthenium (by moles) showed the highest activity. This suggests that synergistic effects play an important role in the catalysis of this reaction. To our knowledge this is the first systematic study of ruthenium-platinum nanoparticle catalytic activity on this reaction.
The cyanobacterium Scytonema cf. crispum produces a range of saxitoxins. Previous studies on othe... more The cyanobacterium Scytonema cf. crispum produces a range of saxitoxins. Previous studies on other saxitoxin-producing cyanobacteria have shown that toxin production can vary throughout the growth cycle. Monitoring cyanotoxin-production in S. cf. crispum is challenging because it is metaphytic and has a very slow growth rate (ca. 6 months to reach stationary phase). In this study, a new method was developed to track growth and toxin production in S. cf. crispum. Samples were collected once a week for 131 days, and cell concentrations and saxitoxin quotas determined. Cells in the lag and exponential growth phases had significantly (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) higher saxitoxin quotas (162 ± 37 fg cell(-1) and 139 ± 32 fg cell(-1), respectively) than the stationary phases (83 ± 19 fg cell(-1)). Extracellular saxitoxin concentrations were present at low concentrations (2-16 ng mL(-1) of culture medium) throughout the experiment. The proportion of extracellular saxitoxin to total saxitoxin decreased throughout the experiment. New knowledge on growth and saxitoxin variability will assist in improving monitoring, risk assessment and management of this species.
Journal of environmental radioactivity, Jan 10, 2015
A study was undertaken to determine activity concentrations for (134)Caesium, (137)Caesium and (2... more A study was undertaken to determine activity concentrations for (134)Caesium, (137)Caesium and (210)Polonium in New Zealand seafood, and establish if activity concentrations varied with respect to species/ecological niche and coastal region. Thirty seafood samples were obtained from six fishing regions of New Zealand along with a further six samples of two commercially important species (hoki and arrow squid) with well-defined fisheries. (134)Caesium was not detected in any sample. (137)Caesium was detected in 47% of samples, predominantly in pelagic fish species, with most activities at a trace level. Detections of (137)Caesium were evenly distributed across all regions. Activity concentrations were consistent with those expected from the oceanic inventory representing residual fallout from global nuclear testing. (210)Polonium was detected above the minimum detectable concentration in 33 (92%) of the analysed samples. Molluscs displayed significantly elevated activity concentratio...
Benthic Phormidium mats can contain high concentrations of the neurotoxins anatoxin-a and homoana... more Benthic Phormidium mats can contain high concentrations of the neurotoxins anatoxin-a and homoanatoxin-a. However, little is known about the co-occurrence of anatoxin-producing and non-anatoxin-producing strains within mats. There is also no data on variation in anatoxin content among toxic genotypes isolated from the same mat. In this study, 30 Phormidium strains were isolated from 1 cm(2) sections of Phormidium-dominated mats collected from three different sites. Strains were grown to stationary phase and their anatoxin-a, homoanatoxin-a, dihydroanatoxin-a and dihydrohomoanatoxin-a concentrations determined using liquid chromatography-mass spectrometry. Each strain was characterized using morphological and molecular (16S rRNA gene sequences) techniques. Eighteen strains produced anatoxin-a, dihydroanatoxin-a or homoanatoxin-a. Strains isolated from each mat either all produced toxins, or were a mixture of anatoxin and non-anatoxin-producing genotypes. Based on morphology these gen...
Journal of environmental radioactivity, Jan 18, 2015
To support New Zealand's food safety monitoring regime, a survey was undertaken to establish ... more To support New Zealand's food safety monitoring regime, a survey was undertaken to establish radionuclide activity concentrations across the New Zealand diet. This survey was undertaken to better understand the radioactivity content of the modern diet and also to assess the suitability of the current use of milk as a sentinel for dietary radionuclide trends. Thirteen radionuclides were analysed in 40 common food commodities, including animal products, fruits, vegetables, cereal grains and seafood. Activity was detected for (137)Caesium, (90)Strontium and (131)Iodine. No other anthropogenic radionuclides were detected. Activity concentrations of the three natural radionuclides of Uranium and the daughter radionuclide (210)Polonium were detected in the majority of food sampled, with a large variation in magnitude. The maximum activity concentrations were detected in shellfish for all these radionuclides. Based on the established activity concentrations and ranges, the New Zealand ...
This is the first study to use a multiple biomarker approach on the green-lipped mussel, Perna ca... more This is the first study to use a multiple biomarker approach on the green-lipped mussel, Perna canaliculus to test its feasibility as a bioindicator of coastal metal contamination in New Zealand (NZ). Mussels were collected from six low intertidal sites varying in terms of anthropogenic impacts, within two regions (West Coast and Nelson) of the South Island of NZ. Trace elements, including arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn), were measured in the gills, digestive gland, foot and mantle, and in the surface sediments from where mussels were collected. Metal levels in the sediment were relatively low and there was only one site (Mapua, Nelson) where a metal (Ni) exceeded the Australian and New Zealand Interim Sediment Quality Guideline values. Metal levels in the digestive gland were generally higher than those from the other tissues. A variety of biomarkers were assessed to ascertain mussel health. Clearance rate, a physiological endpoint, co...
Studies on planktonic cyanobacteria have shown variability in cyanotoxin production, in response ... more Studies on planktonic cyanobacteria have shown variability in cyanotoxin production, in response to changes in growth phase and environmental factors. Few studies have investigated cyanotoxin regulation in benthic mat-forming species, despite increasing reports on poisoning events caused by ingestion of these organisms. In this study, a method was developed to investigate changes in cyanotoxin quota in liquid cultures of benthic mat-forming cyanobacteria. Iron and copper are important in cellular processes and are well known to affect growth and selected metabolite production in cyanobacteria and algae. The effect of iron (40-4000 μg L(-1)) and copper (2.5-250 μg L(-1)) on growth and anatoxin-a quota in Phormidium autumnale was investigated in batch culture. These concentrations were chosen to span those found in freshwater, as well as those previously reported to be toxic to cyanobacteria. Anatoxin-a concentrations varied throughout the growth curve, with a maximum quota of between...
Philosophical transactions of the Royal Society of London. Series B, Biological sciences, Jan 19, 2014
There has been a significant investment in research to define exposures and potential hazards of ... more There has been a significant investment in research to define exposures and potential hazards of pharmaceuticals in freshwater and terrestrial ecosystems. A substantial number of integrated environmental risk assessments have been developed in Europe, North America and many other regions for these situations. In contrast, comparatively few empirical studies have been conducted for human and veterinary pharmaceuticals that are likely to enter coastal and marine ecosystems. This is a critical knowledge gap given the significant increase in coastal human populations around the globe and the growth of coastal megacities, together with the increasing importance of coastal aquaculture around the world. There is increasing evidence that pharmaceuticals are present and are impacting on marine and coastal environments. This paper reviews the sources, impacts and concentrations of pharmaceuticals in marine and coastal environments to identify knowledge gaps and suggests focused case studies a...
ABSTRACT Planktonic cyanotoxin poisoning events are well documented. More recently, benthic cyano... more ABSTRACT Planktonic cyanotoxin poisoning events are well documented. More recently, benthic cyanobacteria have also been associated with bird, cattle and dog fatalities. Extensive mats of benthic cyanobacteria can contain high concentrations of toxins. This study investigated cyanotoxin production in cyanobacterial strains isolated from benthic freshwater mats dominated by cyanobacteria in Canterbury, New Zealand. Twenty-seven strains were isolated from ten water bodies and characterized using morphological and molecular phylogenetic characteristics. All strains were screened for genes involved in the biosynthesis of common cyanotoxins. Positive results were confirmed and cyanotoxin concentrations quantified using liquid chromatography–mass spectrometry. One chroococcalean, twenty oscillatorialean and six nostocalean strains were isolated into culture. All strains were cryopreserved and banked in the Cawthron Institute Culture Collection of Micro-algae. Genes associated with anatoxin-a biosynthesis were identified in nine Phormidium strains. Anatoxin-a was detected in all these strains, one of these strains also produced homoanatoxin-a.
Pharmaceutical and personal care products (PPCPs) are a major source of micropollutants to the aq... more Pharmaceutical and personal care products (PPCPs) are a major source of micropollutants to the aquatic environment. Despite intense research on the fate and effects of PPCPs in temperate climates, there is a paucity of data on their presence in polar environments. This study reports the presence of selected PPCPs in sewage effluents from two Antarctic research stations, the adjacent coastal seawater, sea ice, and biota. Sewage effluents contained bisphenol-A, ethinylestradiol, estrone, methyl triclosan, octylphenol, triclosan, and three UV-filters. The maximum sewage effluent concentrations of 4-methyl-benzylidene camphor, benzophenone-1, estrone, ethinylestradiol, and octylphenol exceeded concentrations previously reported. Coastal seawaters contained bisphenol-A, octylphenol, triclosan, three paraben preservatives, and four UV-filters. The sea ice contained a similar range and concentration of PPCPs as the seawater. Benzophenone-3 (preferential accumulation in clams), estradiol, ethinylestradiol, methyl paraben (preferential accumulation in fish, with concentrations correlating negatively with fillet size), octylphenol, and propyl paraben were detected in biota samples. PPCPs were detected in seawater and biota at distances up to 25 km from the research stations WWTP discharges. Sewage effluent discharges and disposal of raw human waste through sea ice cracks have been identified as sources of PPCPs to Antarctic coastal environments.
Environmental context. Antarctica has several scientific research stations located along its coas... more Environmental context. Antarctica has several scientific research stations located along its coast, where they discharge often untreated sewage containing organic micropollutants. Although degradation of these pollutants by microorganisms is limited by the cold conditions, other pathways such as photodegradation may be significant. Our results indicate that, during the summer, photolysis is a potentially significant degradation pathway for organic micropollutants in Antarctic surface waters, although the rate of loss would depend on ice cover and water depth.
Copper is present in a range of fungicides as well as in some animal manures and biosolids that a... more Copper is present in a range of fungicides as well as in some animal manures and biosolids that are applied to agricultural soils as fertilisers. Elevated and increasing levels of copper in agricultural soils are of worldwide concern. Copper is toxic to soil microorganisms and has been reported to reduce the ability of soil microorganisms to degrade pesticides. A glasshouse study was undertaken to determine if copper inhibited the degradation of atrazine and indoxacarb in soil. A fine sandy loam agricultural soil was fortified with copper at five concentrations over a concentration range of 0e1000 mg/kg copper, then field-aged for 6 months prior to treatment with either indoxacarb or atrazine at a rate of 2 mg/kg. The soils were sampled twice at intervals based on published half-lives. The samples were analysed for a range of parameters including total and bioavailable copper, urease and phosphatase activity, ergosterol and either indoxacarb or atrazine and its degradation products. The soil microbial biomass and enzyme activities decreased with increasing copper concentration (p < 0.05). There were no significant differences in soil atrazine and indoxacarb concentrations between the copper levels. At sampling time two, the concentrations of hydroxyatrazine in treatments containing the three highest copper concentrations were significantly greater (p < 0.05) than for the control soil. Our results indicate that copper does not inhibit the first step of indoxacarb and atrazine degradation, but may affect degradation of secondary metabolites like hydroxyatrazine in soil.
New Zealand Journal of Marine and Freshwater Research, 2008
A total of 163 wells were sampled in New Zealand as part of the 2006 national survey of pesticide... more A total of 163 wells were sampled in New Zealand as part of the 2006 national survey of pesticides in groundwater. The aims of the survey were to update the national overview of pesticides in New Zealand&amp;amp;amp;#39;s groundwater systems, to investigate temporal variation in pesticide concentrations between surveys, and to identify environmental factors associated with pesticide contamination of groundwater. Thirty‐one
Metal roofing material is commonly used for residential and industrial roofs in volcanically acti... more Metal roofing material is commonly used for residential and industrial roofs in volcanically active areas. Increased corrosion of metal roofing from chemically reactive volcanic ash following ash deposition post-eruption is a major concern due to decreasing the function and stability of roofs. Currently, assessment of ash-induced corrosion is anecdotal, and quantitative data are lacking. Here, we systematically evaluate the corrosive effects of volcanic ash, specifically ash leachates, on a variety of metal roofing materials (i.e. weathered steel, zinc, galvanized steel, and ColorsteelÓ) utilizing weathering chamber experiments and direct acid treatments. Weathering chamber tests were carried out for up to 30 days, and visual, chemical, and surface analyses did not definitively identify significant corrosion in any of the test roofing metal samples. Direct concentrated acid treatments with hydrochloric (HCl), sulphuric (H 2 SO 4 ), and hydrofluoric (HF) acids demonstrate that roofing materials are chemically resilient. Our experimental results suggest that ash-leachate-related corrosion is a longer-term process ([1 month), potentially related to a multitude of factors including increased ash leachate concentrations, the dissolution of the glass matrix of the ash, moisture retention at the ash-surface boundary, and potential reactions involving photo-oxidation. Overall, corrosion is not a simple process related to the short-term release of acid and/or salt leachates from the ash surface, but a product of dynamic interactions involving ash and water at the surface of metal roofing material for extended periods.
Orchard soils can contain elevated concentrations of 1,1-dichloro-2,2-bis( p-chlorophenyl)ethylen... more Orchard soils can contain elevated concentrations of 1,1-dichloro-2,2-bis( p-chlorophenyl)ethylene (p,p 0 -DDE), 1,1,1trichloro-2,2-bis( p-chlorophenyl)ethane (p,p 0 -DDT), and heavy metals as a result of historical agrichemical applications. The bioavailability of p,p 0 -DDE, p,p 0 -DDT, As, Cd, Cu, and Pb from five field-aged New Zealand orchards and three grazing soils was assessed by using a 28-d bioassay with Aporrectodea caliginosa and chemical assays. Significant relationships were found between total soil and earthworm tissue concentrations for p,p 0 -DDE ( p < 0.001), p,p 0 -DDT ( p < 0.001), Cu ( p < 0.001), and Pb ( p < 0.01). Two neutral salt solutions, 0.01 M CaCl 2 and 1 M NH 4 NO 3 , were used as surrogate measures of the bioavailability of heavy metals. Copper was the only heavy metal for which significant correlations were found between neutral-salt-extractable and earthworm tissue concentrations ( p < 0.001). Up to 28% of the aged DDT residues were released from the soils by Tenax over a 24-h extraction period. Significant relationships ( p < 0.01) between the Tenax-extractable and earthworm tissue concentrations for p,p 0 -DDE and p,p 0 -DDT showed that Tenax provides a good surrogate measure of the bioavailability of these compounds to A. caliginosa. Surprisingly, there was a similarly significant relationship ( p < 0.001) between the total soil and earthworm tissue concentrations for p,p 0 -DDE and p,p 0 -DDT, suggesting that total soil concentrations alone were sufficient to predict uptake by A. caliginosa. These results demonstrate that the aged agrichemical residues in orchard soils, and particularly p,p 0 -DDE and p,p 0 -DDT, remain highly bioavailable to A. caliginosa despite decades of weathering and continue to present an environmental risk. Environ. Toxicol. Chem. 2012;31:130631: -131631: . # 2012
Reliable environmentally realistic bioassay methodologies are increasingly needed to assess the e... more Reliable environmentally realistic bioassay methodologies are increasingly needed to assess the effects of environmental pollution. This study describes two estuarine sediment bioassays, one acute (96 h) and one chronic (14 d), with the New Zealand harpacticoid copepod Quinquelaophonte sp. utilising behavioural and reproductive endpoints. Spiked sediments were used to expose Quinquelaophonte sp. to three reference compounds representing important categories of estuarine chemical stressors: zinc (a metal), atrazine (a pesticide), and phenanthrene (a polycyclic aromatic hydrocarbon). Acute-to-chronic ratios (ACR) were used to further characterise species responses. Acute sediment (sandy and low total organic content) 96 h EC 50 values for the sublethal inhibition of mobility for zinc, atrazine and phenanthrene were 137, 5.4, and 2.6 mg/g, respectively. The chronic EC 50 values for inhibition of reproduction (total offspring) were 54.5, 0.0083, and 0.067 mg/g for zinc, atrazine, and phenanthrene, respectively. For phenanthrene, a potentially novel mode of action was identified on reproduction. Quinquelaophonte sp. was found to be more sensitive than several other estuarine species indicating choice of test organism is important to characterising the effects of environmentally relevant levels of contamination. The bioassay sediment results demonstrate the sensitivity and suitability of Quinquelaophonte sp. as a tool for the assessment use of estuarine health.
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2013
The transfer of mussels from field to laboratory, or transplantation between clean and contaminat... more The transfer of mussels from field to laboratory, or transplantation between clean and contaminated field settings, is a common protocol in ecotoxicology. However, collection and transport of mussels could lead to stress that may impact biomarker responses, and thus confound interpretation of results. Physiological responses (clearance rate, absorption efficiency, excretion rate, respiration rate and scope-for-growth) of green-lipped mussels (Perna canaliculus) exposed to four different transportation protocols were investigated. These protocols included immersion in site seawater (SSW), immersion in artificial seawater (ASW), and emersion (aerial transport; EMS) at two temperatures (15°C and 5°C). Physiological measurements were conducted after a simulated 24 h "transport" phase and a 48 h "recovery" phase. Clearance rates were significantly inhibited by the EMS 5°C and ASW protocols relative to SSW treatment, although the clearance rate of the latter recovered after 48 h. A similar pattern was observed for excretion and respiration rates for ASW. Decreased excretion rates for EMS 15°C and respiration rates for EMS 5°C were also recorded relative to values for SSW following "recovery". Negative scope-for-growth was observed for all treatments except EMS 15°C. These data suggest transport emersed at ambient air temperatures is the best method to maintain physiological health of green-lipped mussels.
ABSTRACT Bimetallic metal nanoparticles are often more catalytically active than their monometall... more ABSTRACT Bimetallic metal nanoparticles are often more catalytically active than their monometallic counterparts, due to a so-called &#39;synergistic effect&#39;. Atomically precise ruthenium-platinum clusters have been shown to be active in the hydrogenation of phenylacetylene to styrene (a reaction of importance to the polymer industry). However, the synthesis of these clusters is generally complex, and cannot be modified to produce clusters with differing metal compositions or ratios. Hence, any truly systematic study of compositional effects using such clusters is hindered by the inaccessibility of certain metal ratios. In this study, a series of larger bimetallic ruthenium-platinum colloids of varying metal ratios was synthesised in solution and immobilised on silica. Catalytic activity was evaluated by hydrogenation of phenylacetylene to styrene. Both bimetallic and monometallic colloids were active catalysts for the hydrogenation of phenylacetylene to styrene and further to ethylbenzene. Of those studied, a catalyst composed of 73% platinum-27% ruthenium (by moles) showed the highest activity. This suggests that synergistic effects play an important role in the catalysis of this reaction. To our knowledge this is the first systematic study of ruthenium-platinum nanoparticle catalytic activity on this reaction.
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