Molecular taxonomy of vestimentiferans of the western Pacific,and their phylogenetic relationship to species of the eastern Pacific III. Alaysia-like vestimentiferans and relationships among families

The phylogenetic status of Alaysia-like vestimentiferans, which were collected at eight sites in the western Pacific, was analyzed on the basis of the nucleotide sequence of part of a mitochondrial gene for cytochrome oxidase I. The 123 individuals analyzed were tentatively classified into four species, which inhabit, respectively, seep areas off the central part of the Japanese mainland, hydrothermal vent fields in the Mid-Okinawa Trough, hydrothermal vent fields in the southern Okinawa Trough, and both seep and vent sites in the Bismarck Sea. From six additional lamellibrachiid specimens from two sites in the Bismarck Sea, two new tentative species were recognized, namely, one from a seep area off Papua New Guinea and another from the hydrothermal vent field at the DESMOS site in the Manus Basin. Phylogenetic analysis using all available sequences of six vestimentiferan families and Alaysia-like vestimentiferans revealed that vestimentiferans could be divided into three groups, namely, lamellibrachiids, escarpiids, and others, even though the monophyly of the third group was supported by only low bootstrap probabilities. Within the first group, the earliest divergence of a tentative lamellibrachiid species from the DESMOS site was apparent. All Alaysia-like vestimentiferans formed a monophyletic group with Arcovestia ivanovi from the Manus Basin, and it is suggested that this group might be derived from vestimentiferans that are endemic to the hydrothermal sites in the Eastern Pacific Rise.     

Larval survivorship, competency periods and settlement of two brooding corals, Heliopora coerulea and Pocillopora damicornis

Larval dispersal and recruitment are important in determining adult coral distribution; however, few studies have been made of coral larval dispersal. This study examined the larval behavior, survivorship competency periods and settlement of two brooding corals, Heliopora coerulea and Pocillopora damicornis, in relation to different potential larval dispersal patterns. We also examined the lipid content of H. coerulea as a means of flotation and a source of energy. Planulae of H. coerulea were on average 3.7 mm in length, lacked zooxanthellae, and were mostly benthic, probably because of restricted movement and low lipid content (54% by dry weight). Planulae of P. damicornis were on average 1.0 mm in length, had zooxanthellae and swam actively. The competency period of H. coerulea was shorter (30 days) than that of P. damicornis (100 days). Forty percent of H. coerulea planulae crawled onto the substrata within 1 h of release, and 47% settled within 6 h. By contrast, fewer than 10% of P. damicornis planulae crawled onto the substrata within the first hour and 25% settled within 6 h of release. The planulae of H. coerulea may have a narrower dispersal range than those of P. damicornis, settling and recruiting near parent colonies. Thus, brooding corals exhibit variations in larval dispersal patterns, which are characterized by their position in the water column and competency periods.     

Comparative evaluation of processes for heavy metal removal from municipal solid waste incineration fly ash

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Bioaccumulation of mercury in a vestimentiferan worm living in Kagoshima Bay,Japan

The present study reports on the mercury concentrations of the vestimentiferan worm, Lamellibrachia satsuma, (Annelida: Pogonophora) found near hydrothermal vents at a depth of 80-100 m in the northern parts of Kagoshima Bay. The vestimentiferan worms had total mercury concentrations of 238 ng/g in the anterior muscle of the body and 164 ng/g in the posterior trophosome. Methylmercury constituted only 7.6% of total mercury detected anteriorly and 16.3% posteriorly. The mean total mercury concentration in filtrated ambient seawater of the worm habitat was 1.1 ng/l. The worm should accumulate mercury in seawater by a one-step into the anterior and posterior parts as 2.2 x 10(%) and 1.5 x 10(5) times those of the filtered ambient seawater, respectively. The bioaccumulation factor of mercury by the worms with only their respiration would be actually larger than that by other marine animals through food webs. The high bioaccumulation factor of mercury in the worms suggest the following two possibilities: (i) the biological half-life of organomercury in the worm could be exceptionally long; or (ii) the lifetime of vestimentiferan worms examined in the present study could be extremely long. Various metals in one specimen of the worm were analyzed by using ICP-MS, and then gold as well as silver were detected in the worm. Gold was detected for the first time from marine animals.     

Effect of arsenic-contaminated irrigation water on agricultural land soil and plants in West Bengal, India

Total arsenic withdrawn by the four shallow tubewells, used for agricultural irrigation in the arsenic-affected areas of Murshidabad district per year is 6.79 kg (mean: 1.79 kg, range: 0.56-3.53 kg) and the mean arsenic deposition on land per year is 5.02 kg ha(-1) (range: 2-9.81 kg ha(-1)). Mean soil arsenic concentrations in surface, root of plants, below ground level (0-30 cm) and all the soils, collected from four agricultural lands are 14.2 mg/kg (range: 9.5-19.4 mg/kg, n = 99), 13.7 mg/kg (range: 7.56-20.7 mg/kg, n = 99), 14.8 mg/kg (range: 8.69-21 mg/kg, n = 102) and 14.2 mg/kg (range: 7.56-21 mg/kg, n = 300) respectively. Higher the arsenic in groundwater, higher the arsenic in agricultural land soil and plants has been observed. Mean arsenic concentrations in root, stem, leaf and all parts of plants are 996 ng/g (range: <0.04-4850 ng/g, n = 99), 297 ng/g (range: <0.04-2900 ng/g, n = 99), 246 ng/g (range: <0.04-1600 ng/g, n = 99) and 513 ng/g (range: <0.04-4850 ng/g, n = 297) respectively. Approximately 3.1-13.1, 0.54-4.08 and 0.36-3.45% of arsenic is taken up by the root, stem and leaf respectively, from the soil.     

Arsenic and other heavy metals in soils from an arsenic-affected area of West Bengal,India

Domkal is one of the 19, out of 26 blocks in Murshidabad district where groundwater contains arsenic above 0.05 mg/l. Many millions of cubic meters of groundwater along with arsenic and other heavy metals are coming out from both the hand tubewells, used by the villagers for their daily needs and shallow big diameter tubewells, installed for agricultural irrigation and depositing on soil throughout the year. So there is a possibility of soil contamination which can moreover affect the food chain, cultivated in this area. A somewhat detailed study was carried out, in both micro- and macrolevel, to get an idea about the magnitude of soil contamination in this area. The mean concentrations (mg/kg) of As (5.31), Fe (6740), Cu (18.3), Pb (10.4), Ni (18.8), Mn (342), Zn (44.3), Se (0.53), Mg (534), V (44.6), Cr (33.1), Cd (0.37), Sb (0.29) and Hg (0.54) in fallow land soils are within the normal range. The mean As (10.7), Fe (7860) and Mg (733) concentrations (mg/kg) are only in higher side whereas Hg (0.17 mg/kg) is in lower side in agricultural land soils, compared to the fallow land soils. Arsenic concentrations (11.5 and 28.0 mg/kg respectively) are high in those agricultural land soils where irrigated groundwater contains high arsenic (0.082 and 0.17 mg/l respectively). The total arsenic withdrawn and mean arsenic deposition per land by the 19 shallow tubewells per year are 43.9 kg (mean: 2.31 kg, range: 0.53-5.88 kg) and 8.04 kg ha(-1) (range: 1.66-16.8 kg ha(-1)) respectively. For the macrolevel study, soil arsenic concentration decreases with increase of distance from the source and higher the water arsenic concentration, higher the soil arsenic at any distance. A proper watershed management is urgently required to save the contamination.     

Formation behavior of PCDD/Fs in PVC pyrolysis with copper oxide

Formation and decomposition behaviors of PCDD/Fs during pyrolysis of polyvinyl chloride (PVC) with CuO have been investigated. These reactions proceed simultaneously, and the rate of decomposition exceeds that of formation with further retention. More 2,3,7,8-TCDD is formed when the dechlorination of PCDD/Fs proceeds significantly. Homologue profile patterns of PCDD/Fs show that the fractions of O8CDD and H6CDFs are relatively larger within PCDDs and PCDFs, respectively. Extremely large amounts of PCDD/Fs are obtained with the long retention time at 200 degrees C. The formation of PCDD/Fs decreases drastically with increase in the molar ratio of CuO/PVC. The acceptability of thermodynamic calculations on the formation of PCDD/Fs is also investigated. The thermodynamic calculated tendency of the effect of oxygen on the formation of PCDD/Fs agrees well with the experimental results, although absolute values of the amount of PCDD/Fs are much different.     

CDNA microarray assessment for ozone-stressed Arabidopsis thaliana

Various detrimental factors in the environment damage plants, resulting in growth inhibition or withering. However, it is not easy to identify causal factors by visually inspecting the damaged plants. Therefore, we have developed a sensitive and reliable method for plant diagnosis, based on measuring changes in expression of a set of genes in a DNA microarray. With this method, we have been able to detect and discriminate between plants stressed by ozone, drought, or wounding.     

Bioleaching of metal from municipal waste incineration fly ash using a mixed culture of sulfur-oxidizing and iron-oxidizing bacteria

We investigated the behavior and characteristics of metal leaching from municipal solid waste incineration (MSWI) fly ash among pure cultures of a sulfur-oxidizing bacterium (SOB) and an iron-oxidizing bacterium (IOB) and a mixed culture. The IOB has a high metal-leaching ability, though its tolerability against the ash addition is low. The SOB might better tolerate an increase in ash addition than the IOB, though metal leaching ability of the SOB is limited. Mixed culture could compensate for these deficiencies, and high metal leachability was exhibited in the 1% ash culture, i.e., 67% and 78% of leachabilities for Cu and Zn, respectively, and 100% for Cr and Cd. Furthermore, comparably high leachabilities such as 42% and 78% for Cu and Zn were observed even in the 3% ash cultures. Characterization of metal leaching by the mixed culture revealed that the acidic and oxidizing condition had remained stable thorough the experimental period. Ferric iron remained in the mixed culture, and the metal leaching was enhanced by redox mechanisms coupling with the leaching by sulfate. An increase of ferrous iron enhanced the Cr, Cu, and As leaching. The optimum concentration of sulfur existed for As and Cr (5 gl(-1)) and Cu (2 gl(-1)). The presence of the degradable and non-degradable organic compound that must be existed in the natural environment or waste landfills made no significant change in the leachability of metals other than Zn. These results suggested that bioleaching using a mixed culture of SOB and IOB is a promising technology for recovering the valuable metals from MSWI fly ash.