Uptake and effects of the cypermethrin-containing sea lice treatment Excis in the marine mussel,Mytilus edulis

Wild and farmed mussels, Mytilus edulis, coexist with salmon farms in Scottish sea lochs. A synthetic pyrethroid, cypermethrin, is licensed for use on fish farms to control sea lice infestations as a formulation called Excis. In this study, uptake of cypermethrin from Excis exposure is investigated through the use of gas chromatography with mass-spectrometry. The effects of Excis on mussels are also examined by measuring the neutral red retention time of lysosomes, aerial survival and shell closure. The isomeric ratios of cis:trans cypermethrin measured in mussels are around 80:20; a marked increase from 40:60 to which the mussels were exposed. This is most likely due to preferential metabolism of trans-isomers, as the same response is seen in vertebrates. There is a pronounced behavioural effect of shell closure, where mussels exposed to 1000 microg/l cypermethrin shut their shells within an hour of exposure. Arguments are presented for this effect being either a voluntary response on recognition of cypermethrin, or an effect arising from an involuntary action of cypermethrin on the adductor muscle. Even at 1000 microg/l cypermethrin, neutral red retention time and aerial survival are not affected. The data suggest that the responses of mussels shown here are unlikely to occur in the field, even at the concentrations of cypermethrin used in fish cages, for the treatment of sea lice.     

新型填料特性及其在生物脱硫中的应用

为解决生物脱硫反应器酸化问题,研制出一种具有pH缓冲能力的生物填料。填料主要由碳酸钙﹑纯丙乳液和羟丙基纤维素制得。填料在水中浸泡6个月不会分解,吸水率大于20%。考察填料pH缓冲能力,结果表明,填料能将pH=5.0水溶液调节至pH=6.5以上。选取缓冲能力较稳定的BT50填料填充于反应器,以排硫硫杆菌(Thiobacillus thio-parus)挂膜,5个循环后反应器有效体积内的最大固定化菌体数量约为5.86×108cells/mL,并且硫代硫酸钠的消耗速率基本稳定,表明该填料可用于生物挂膜。在长达50 d脱硫实验中,H2S脱除率均在95%以上,整个脱硫阶段不再加入任何pH调节剂,反应器内pH仍能维持在6.7～7.1之间。     

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) distributions in the Bay of Marmara sea: Izmit Bay

In 1999, the concentrations of 16 polycyclic aromatic hydrocarbons (PAHs), the total PAH and polychlorinated biphenyls (PCBs) were measured in sea water, sediment and mussels collected along the coast of Izmit Bay, the most important bay of the Marmara Sea. The total-PAH concentrations, measured by Spectrofluorometry were in the range of 1.16-13.68 microg/l in sea water, in the range of 30.0 1670.0 microg/g dry weight in sediments and in the range from 5.67 to 14.81 microg/g wet weight in edible part of mussel. HPLC revealed Phenanthrene (three rings), chrysene (four rings) and benz[a]antracene (five rings) to be the dominant PAHs in sea water, while 16 different PAHs compounds were observed and measured in mussel samples. The most pollution occured at Dogu Kanali and Dil Deresi where were the main rivers containing wastes fall into the the Izmit Bay. Although the maximum mono-ortho PCB concentrations in sea water were measured in the Dil Deresi River (26.33 ng/l) and the Solventa? (22.19 ng/l) stations, maximum PCB concentrations in mussels were measured in the SEKA (28.11 microg/kg) and the Dil Deresi River (25.68 microg/kg). The dominant congeners of PCBs were from tetra to hexachlorobiphenyls. The toxicity equivalent values were very low in sea water and mussels.     

Bioaccumulation of 4-nonylphenol in marine animals--a re-evaluation

The bioaccumulation of 4-nonylphenol (NP) has been studied in shrimps (Crangon grangon L.), mussels (Mytilus edulis L.) and sticklebacks (Gasterosteus aculeatus L.) exposed to (14)C-NP in running seawater. NP was extracted with high recovery from tissues which were pretreated with pancreatic enzymes. The bioconcentration factor determined of NP in fish was 1300 and in mussels, 3400. These values are 5 and 340 times higher, respectively, than values reported earlier.     

Spatial distribution and accumulation of brominated flame retardants, polychlorinated biphenyls and organochlorine pesticides in blue mussels (Mytilus edulis) from coastal waters of Korea

Blue mussels (Mytilus edulis) from 20 locations along the coastal waters of Korea were analyzed to elucidate the characteristic distribution and contamination status of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), polychlorinated biphenyls (PCBs) and organochlorine pesticides. To our knowledge, this is the first study to report on the contamination status of HBCDs from Korea. PBDEs and HBCDs were found in mussels at levels ranging from 6.6 to 440 and from 6.0 to 500 ng/g lipid wt., respectively. Concentrations of PBDEs in mussels from Korea were higher or comparable to available data in mussels from other countries. Among the organochlorine compounds (OCs) analyzed, levels of PCBs and DDTs were the highest followed by CHLs, HCHs and hexachlorobenzene. For all the compounds, higher concentrations were found in mussels from southeastern coast of Korea. The present study shows the importance of mussels as bioindicators for monitoring contaminants in coastal waters.     

Effect of carbon dioxide concentration on biomass production and partitioning in Betula pubescens Ehrh. seedlings at different ozone and temperature regimes

Seedlings of Betula pubescens were grown at two CO(2) concentrations, in combination with either two O(3) concentrations or two air temperatures, during 34-35 days at 24 h day(-1) photoperiod in growth chambers placed in a greenhouse. Increasing the CO(2) concentration from 350 to 560 micromol mol(-1) at 17 degrees C air temperature increased the dry weight of the main leaves, main stem, branches and root. The mean relative growth rate (RGR) was increased 10% by CO(2) enrichment, while increasing the O(3) concentration from 7 to 62 nmol mol(-1) decreased the RGR by 9%. The relative biomass distribution between the different plant components was not significantly affected by the CO(2) concentration irrespective of the O(3) concentration. No significant interactions between CO(2) and O(3) concentration were found except on leaf size, which was stimulated more by elevated CO(2) concentration at high, compared to low, O(3) levels. In another experiment, elevated CO(2) (700 micromol mol(-1)) significantly increased the dry weight of the different plant components, and more at 20 degrees C than at 15 degrees C. Raising the CO(2) concentration increased the RGR by 5 and 10% at 15 and 20 degrees C, respectively. CO(2) enrichment increased the branch dry weight relatively more than the dry weight of the other plant parts. Increasing the CO(2) concentration or temperature increased the plant height and stem diameter, however, no interactions between CO(2) and temperature were found.     

Accumulation and depuration of cyanobacterial toxin nodularin and biomarker responses in the mussel Mytilus edulis

Blue mussels (Mytilus edulis) were exposed to an extract made of natural cyanobacterial mixture containing toxic cyanobacterium Nodularia spumigena (70-110 microg nodularin l(-1), 24-h exposure followed by 144-h depuration period in clean water). Toxin concentration increased from initial 400 to 1100 mg kg(-1) after 24-h exposure, measured by liquid chromatography/mass spectrometry (LC/MS). Acetylcholinesterase activity (AChE), a biomarker of direct neurotoxic effects, showed inhibition after 12 and 24h exposure but returned to control level during the depuration period. Catalase (CAT) activity, an indicator of oxidative stress, showed significantly elevated levels in exposed mussels but only 72 h after the end of the exposure. No change in the activity of glutathione-S-transferase (GST) involved in conjugation reactions could be observed. A gradual yet incomplete elimination of nodularin (from 1100 to 600 mg kg(-1)) was observed during the depuration period, and the tissue levels were 30% lower in clean water after 24 h. The observed increase in oxidative stress indicated by elevated CAT activity is likely connected to detoxification reactions leading to the production of reactive oxygen species, including an apparent time lag in this specific enzymatic defence response. That no change in GST activity was observed suggests that this enzyme is not significantly involved in the detoxification process of nodularin-containing cyanobacterial extract in M. edulis.     

Study on the effect of temperature and pressure on nickel-electroplating characteristics in supercritical CO2

In this work, it was investigated the effect of solubility in supercritical CO2 on the nickel-electroplating characteristics. The plating characteristics could be controlled by electric resistance and dispersion in emulsion as well. CO2 concentration had better be controlled at lower concentration than 50 CO2 wt% to decrease electric resistance since supercritical CO2 is non-polar material. Non-ionic surfactant with EO/PO block copolymer was more efficient than any other surfactant and the dispersion at 0.2 surfactant wt% was better than at any surfactant concentration and over-added surfactant concentration over 0.2 wt% brought to the decrease of dispersion properties. Electric resistance was constant at 20Omega in ranging from pH 2.2 to pH 3.5 and increased slowly to 50Omega at pH 4 and rapidly to 400Omega at pH 5. Characteristics of nickel film has a close relation with solubility in supercritical CO2 and solubility is dependent on pressure and temperature. Solubility at 16 MPa was higher than that any other at pressure and at constant pressure of 16 MPa, solubility in supercritical CO2 increased with an increasing temperature from 31 to 45 degrees C and decreased over 45 degrees C.     

Oxidative damage in gill of Mytilus edulis from Merseyside, UK, and reversibility after depuration

Mussels were collected from the urban/industrialized site of New Brighton, Merseyside and the relatively non-industrial site of Llandudno, North Wales. All mussels were identified as Mytilus edulis by PCR amplification of Mefp1. DNA single strand breaks and 8-oxo-7,8-dihydro-2'-deoxyguanosine were measured in gill within 24h of collection, using the COMET assay, both with and without formamidopyrimidine glycosylase. Gill lipid peroxidation was also measured within 24h. No difference between sites was found for frank SSB and malonaldehyde levels, however 8-oxo-dG and 4-hydroxynonenal were significantly greater in New Brighton mussels compared to Llandudno mussels. After 1-month laboratory maintenance, lipid peroxidation and 8-oxo-dG levels were lower. In contrast, frank SSB were higher. This could reflect enhanced DNA repair excision, though we cannot exclude the possibility of other non-oxidative DNA damage. The results suggest that laboratory maintenance allows recovery from environmentally induced oxidative damage, which was more extensive at Merseyside.     

Interpretation of heavy metal data from mussel by use of multivariate classification techniques

Different strategies of multivariate analysis of metals concentrations (Mn, Fe, Ni, V, Co, Cu, Cd, Hg, Pb, Na, K) in mussel samples from different spanish markets are used to interpret a data base and identify differences between species and origin of the samples. Principal Component Analysis and Potential curves are applied to properly classify unknown samples from representative mussels samples (Mytilus edulis and Perna canaliculus). Also, Principal Components Analysis is used as display method to visualize the relation between the variables and objects of interest.     

Butyltin residues in blue mussels (Mytilus edulis) and arkshells (Scapharca broughtonii) collected from Korean coastal waters

Butyltin compounds (BTs) including tributyltin (TBT) and its degradation products, di- (DBT) and mono-butyltin (MBT), were determined in bivalves such as blue mussels (Mytilus edulis) and arkshells (Scapharca broughtonii) collected from Korean coastal waters. BTs were detected in all the blue mussels and arkshells analyzed. The concentrations of total butyltin (sigmaBTs: MBT + DBT + TBT) in blue mussels and arkshells ranged from 49 to 2500 ng/g and 29 to 87 ng/g wet weight, respectively. Higher concentrations of BTs were found in blue mussels collected from Okpo and Kohyonsong Bays and Jangsengpo Harbor where large shipyards and harbors are located with dry-dock facilities. This suggested that maritime activities nearby the harbors play a major role as the source of BTs. Concentrations of TBT in mussels collected from Korea were one of the highest values reported, suggesting ongoing TBT contamination in Korea. Among BTs, TBT was the predominant compound both in blue mussels and arkshells collected from almost all the sampling locations, indicating the fresh input of TBT in Korean coastal waters. Smaller mussels tended to accumulate BTs at higher concentrations than larger ones, which may be due to higher filtration rate of small mussels and/or contact with surface microlayer in intertidal zones.     

Performance of a semi-industrial scale gasification process for the destruction of polychlorinated biphenyls

A semi-industrial scale test was conducted to thermally treat mixtures of spent oil and askarels at a concentration of 50,000 ppm and 100,000 ppm of polychlorinated biphenyls (PCBs) under a reductive atmosphere. In average, the dry-basis composition of the synthesis gas (syngas) obtained from the gasification process was: hydrogen 46%, CO 34%, CO2 18%, and CH4 0.8%. PCBs, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans (PCDDs/PCDFs) in the gas stream were analyzed by high-resolution gas chromatography (GC)-mass spectrometry. The coplanar PCBs congeners 77, 105, 118, 156/ 157, and 167 were detected in the syngas at concentrations < 2 x 10(-7) mg/m3 (at 298 K, 1 atm, dry basis, 7% O2). The chlorine released in the destruction of the PCBs was transformed to hydrogen chloride and separated from the gas by an alkaline wet scrubber. The concentration of PCBs in the water leaving the scrubber was below the detection limit of 0.002 mg/L, whereas the destruction and removal efficiency was > 99.9999% for both tests conducted. The concentration of PCDDs/PCDFs in the syngas were 8.1 x 10(-6) ng-toxic equivalent (TEQ)/m3 and 7.1 x 10(-6) ng-TEQ/m3 (at 298 K, 1 atm, dry basis, 7% O2) for the tests at 50,000 ppm and 100,000 ppm PCBs, respectively. The only PCDD/F congener detected in the gas was the octachloro-dibenzo-p-dioxin, which has a toxic equivalent factor of 0.001. The results obtained for other pollutants (e.g., metals and particulate matter) meet the maximum allowed emission limits according to Mexican, U.S., and European regulations for the thermal treatment of hazardous waste (excluding CO, which is a major component of the syngas, and total hydrocarbons, which mainly represent the presence of CH4).     

Effects of acid rain on growth and nutrient concentrations in Scots pine and Norway spruce seedlings grown in a nutrient-rich soil

The effects of artificially applied acid precipitation on growth and nutrient concentrations of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies [L.] Karst.) seedlings were investigated in a long-term acid irrigation experiment in field conditions. Seedlings of northern and southern origin were planted in boxes containing peat and composted soil rich in nutrients, and sprinkler irrigated with water acidified with nitric and sulphuric acids to pH 3 or pH 4 for periods varying from two to three and a half growing seasons during 1986-1989. Water irrigated (pH 5.4-7.6) and non-irrigated groups of seedlings were also included in the experiment. At the end of the experiment needles, main and lateral shoots and roots were collected from the seedlings for the determination of height growth and biomass partitioning, and for the analysis of S, N, Mg, P, K, Ca, Mn and Fe concentrations. The treatment effects compared to the irrigated control were studied using multivariate analyses of variance and covariance. In the pine seedlings the total dry matter production increased by 25-70% compared with the irrigated controls when the total wet deposition to the seedlings exceeded 67 kg S ha(-1) and 36 kg N ha(-1) (e.g. after two growing seasons' exposure of the pH 3 treatment). The increase was mainly due to an increase in needle dry weight (54-72% greater at pH 3) and root weight (20-65% greater at pH 3), whereas the height growth or shoot weight growth were less affected. The northern provenance pine seedlings responded more clearly to the pH 3 irrigation than the southern ones. The treatments had no consistent effects on any of the growth variables studied in the spruce seedlings, however. The pines had higher root and foliage Ca concentrations as a result of the acid irrigation, whereas in spruce, acid rain decreased the Ca concentration in needles and shoots. Root Mn and Fe concentrations were higher in both species as a result of the pH 3 treatment. A higher soil conductivity and Ca concentration resulted from the prolonged pH 3 treatment. The results strongly support the hypothesis that the long-term growth and nutrient allocation response of conifers to acid precipitation is dependent both on the tree species and on the nutritional status of the soil.     

Acid–base balance and metabolic response of the sea urchin Paracentrotus lividus to different seawater pH and temperatures

Purpose

In order to better understand if the metabolic responses of echinoids could be related to their acid?Cbase status in an ocean acidification context, we studied the response of an intertidal sea urchin species, Paracentrotus lividus, submitted to low pH at two different temperatures.

Methods

Individuals were submitted to control (8.0) and low pH (7.7 and 7.4) at 10°C and 16°C (19?days). The relation between the coelomic fluid acid?Cbase status, the RNA/DNA ratio of gonads and the individual oxygen uptake were studied.

Results

The coelomic fluid pH decreased with the aquarium seawater, independently of temperature, but this explained only 13% of the pH variation. The coelomic fluid showed though a partial buffer capacity that was not related to skeleton dissolution ([Mg²⁺] and [Ca²⁺] did not differ between pH treatments). There was an interaction between temperature and pH on the oxygen uptake (V _O2) which was increased at pH?7.7 and 7.4 at 10°C in comparison with controls, but not at 16°C, indicating an upregulation of the metabolism at low temperature and pH. However, gonad RNA/DNA ratios did not differ according to pH and temperature treatments, indicating that even if maintenance of physiological activities has an elevated metabolic cost when individuals are exposed to stress, they are not directly affected during short-term exposure. Long-term studies are needed in order to verify if gonad production/growth will be affected by low pH seawaters exposure.     

Chromium adsorption by aligned carbon nanotubes supported ceria nanoparticles

Ceria nanoparticles supported on aligned carbon nanotubes (CeO(2)/ACNTs), a novel adsorbent for Cr(VI) from drinking water, were prepared by chemical reaction of CeCl(3) with NaOH in aligned carbon nanotube solution and subsequent heat treatment. The best Cr(VI) adsorption effect of CeO(2)/ACNTs occurs at a pH range of 3.0-7.4. The largest adsorption capacity of CeO(2)/ACNTs reaches 30.2 mg g(-1) at an equilibrium Cr(VI) concentration of 35.3 mg l(-1) at pH 7.0. The experiment results suggest that CeO(2)/ACNTs have great potential applications in environmental protection.     

A comparison of mussels (Perna viridis) and semi-permeable membrane devices (SPMDs) for monitoring chlorinated trace organic contaminants in Hong Kong coastal waters

A comparison of mussels (Perna viridis) and semi-permeable membrane devices (SPMDs) was carried out at five sites, representing a gradient of contaminant concentrations, in Hong Kong coastal waters. Mussels, originally collected from a “clean” location, were deployed along with SPMDs at each site for 30 days. Analyses for chlorinated pesticides and polychlorinated biphenyls (PCBs) indicated that SPMDs have potential as monitoring tools, and to some extent can overcome the problems associated with mussels, such as natural variability, differing age, sex, and physical condition. However, in most cases, SPMDs failed to rank the sites in the same order as mussels in terms of contaminant concentrations. Nonetheless, in localities where mussels cannot survive – as shown at Kwun Tong in the present experiment – SPMDs may be valuable in providing an indication of potentially bio-available lipophilic pollutants.     

Polybrominated diphenyl ethers (PBDEs) in marine fish and blue mussels from southern Greenland

Levels of polybrominated diphenyl ethers (PBDEs) have not previously been reported in Greenland. In this study shorthorn sculpins (Myoxocephalus scorpius) were sampled at three locations in southern Greenland; Usuk (no population), Igaliko (population 40) and Qaqortoq (population 3200). Furthermore uvak (Gadus ogac), spotted wolffish (Anarhichas minor), starry ray (Raja radiata), and blue mussels (Mytilus edulis) were collected at Usuk. Pooled samples of fish liver and blue mussel were analysed for lower brominated PBDEs (BDE-47, BDE-99, BDE-100 and BDE-153). The highest PBDE levels were found in Qaqortoq followed by Igaliko and Usuk. The measured sum PBDE concentrations in shorthorn sculpin collected at Qaqortoq, Igaliko and Usuk, were 8.2, 3.1 and 2.1 all in units of microg kg(-1) wet weight. In female and male uvak collected at Usuk PBDE levels of 7.1 and 12.0 microg kg(-1) wet weight were measured, while the concentrations were 1.2 microg kg(-1) in spotted wolffish, 1.4 microg kg(-1) in starry ray and 0.11 microg kg(-1) in blue mussels from the same locality all measured on a wet weight basis. The highest concentrations were measured in uvak, a top-predator on fish indicating that PBDEs are biomagnifying. The level of tetra-hexa BDEs is 15-24 times lower than PCB levels measured in the same samples, except for shorthorn sculpin collected at Qaqortoq, where the level of PBDEs was 40 times lower than the level of PCBs. The high concentration of PCBs relative to PBDEs in shorthorn sculpin collected at Qaqortoq signifies a local emission of PCBs, which is higher than the local emission of PBDEs.     

Chlorpyrifos degradation in Turkish soil

Degradation of chlorpyrifos was evaluated in laboratory studies. Surface (0-15 cm) and subsurface (40-60 cm) clay loam soils from a pesticide-untreated field were incubated in biometer flasks for 97 days at 25 degrees C. The treatment was 2 micrograms g-1 [2,6-pyridinyl-14C] chlorpyrifos, with 74 kBq radioactivity per 100 g soil flask. Evolved 14CO2 was monitored in KOH traps throughout the experiment. Periodically, soil subsamples were also methanol-extracted [ambient shaking, then supercritical fluid extraction (SFE)], then analyzed by thin-layer chromatography. Total 14C and unextractable soil-bound 14C residues were determined by combustion. From the surface and subsurface soils, 41 and 43% of the applied radiocarbon was evolved as 14CO2 during 3 months incubation. The time required for 50% loss of the parent insecticide in surface and subsurface soils was about 10 days. By 97 days, chlorpyrifos residues and their relative concentration (in surface/subsurface) as % of applied 14C were: 14CO2 (40.6/42.6), chlorpyrifos (13.1/12.4), soil-bound residues (11.7/11.4), and 3,5,6-trichloropyridinol (TCP) (3.8/4.8). Chlorpyrifos was largely extracted by simple shaking with methanol, whereas TCP was mainly removed only by SFE. The short persistence of chlorpyrifos probably relates to the high soil pH (7.9-8.1).     

Biochemical responses of the marine mussel Mytilus galloprovincialis to petrochemical environmental contamination along the North-western coast of Portugal

Following the development of urban and industrial centres petrochemical products have become a widespread class of contaminants. The aim of this study was to investigate the effects of petrochemical contamination in wild populations of mussels (Mytilus galloprovincialis) along the NW Atlantic coast of Portugal by applying antioxidant and energetic metabolism parameters as biomarkers. For that, mussels were collected at five sampling sites presenting different petrochemical contamination levels. To evaluate the mussels' antioxidant status, enzymatic activities of catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione S-transferases, as well as glutathione redox status were evaluated in gills and digestive glands of mussels collected from the selected sites. Lipid peroxidation was determined in the same tissues to quantify cellular oxidative damage. Furthermore, to investigate how energetic processes may respond to these contaminants, the activity of NADP(+)-dependent isocitrate dehydrogenase was determined in mussels' digestive glands, and octopine dehydrogenase was determined in mussels' posterior adductor muscle. Furthermore, the concentrations of aliphatic hydrocarbons, unresolved complex mixture and polycyclic aromatic hydrocarbons (PAHs) were quantified in mussels' tissue, and abiotic parameters were quantified in water samples collected at each site. Several biomarkers showed statistically significant differences among sampling sites. The redundancy analysis (RDA) used to perform the integrated analysis of the data showed a clear separation of the sampling sites in three different assemblages, which are in agreement with the PAHs levels found in mussels tissues. In addition, the RDA indicated that some of the selected biomarkers may be influenced by abiotic parameters (e.g. salinity, pH, nitrates and ammonia). The approach selected for this study seems to be suitable for monitoring petrochemical contamination.