Photodegradation of the organophosphorus pesticides chlorpyrifos,fenamiphos and vamidothion in water

The photodegradation of the pesticides chlorpyrifos, fenamiphos and vamidothion in water containing 2–4% methanol was examined. Acetone (5%) was added as photosensitizer in the photolysis of vamidothion. A suntest apparatus equipped with a xenon arc lamp which exhibits a radiation very close to natural sunlight was employed. Analyses were performed by direct injection of the water samples containing the photoproducts into a liquid chromatograph with diode array and thermospray mass spectrometric detection. The major photodegradation products were identified by matching their diode‐array spectra with the corresponding spectra of the authentic standards, their retention times and the spectra obtained using positive and/or negative thermospray mass spectrometry. 3,5,6‐trichloro‐2‐pyridinol, fenamiphos sulfoxide and vamidothion sulfoxide were the major photodegradation products from chlorpyrifos, fenamiphos and vamidothion, respectively.     

Higher rate of nest loss among primary than secondary females: infanticide in the great reed warbler?

An individually marked population of great reed warblers Acrocephalus arundinaceus was studied between 1984 and 1991 in South Central Sweden. The fates of 279 nests were analysed for the 25 days following clutch initiation. The average frequency of nest loss (43%) did not differ significantly between years or between four periods of the breeding season. After a breeding failure, 70% of the females laid a replacement clutch, most of them together with the same male. On polygnous territories, males assisted the female who first hatched young regardless of her initial mating status (Fig. 2). According to the acutal status of the females attending the nests, for each day nests were classified as being of either monogamous (M), primary (P) or secondary (S) status. From egg-laying to fledging the rate of nest loss decreased among nests of primary status whereas it increased among nests of monogamous and secondary status. During the egg-laying period, the rate of nest loss was 3 times higher among nests of primary than among nests of monogamous and secondary status (Fig. 3). Thus, the high loss level among nests of primary status during the laying period was closely associated with the presence of a female with a less advanced nest on the territory. All nests were situated in reed beds above deep water and most of them at a height at which possible inter-specific nest predators would have caused disturbance to the nest itself. The suspicion that secondary females committed sexually selected infanticide was supported by an experiment with dummy eggs that revealed bill peck markings identical to those obtained from great reed warblers (Fig. 4).     

Body temperature independence of solar radiation in free-ranging loggerhead turtles,Caretta caretta,during internesting periods

Body temperatures, ambient water temperatures, light intensities and vertical positions (depth) of eight loggerhead turtles, Caretta caretta, were monitored by small recorders during internesting periods from 1991 through 1993 off Wakayama Prefecture, Japan. Body temperatures of eight loggerhead turtles were higher than ambient water temperatures through-out their internesting periods. Light intensities were compared with body temperatures and no evidence was obtained to suggest that the raised body temperatures were caused by the direct influence of solar radiation. Body temperatures were kept higher than water temperatures in cloudy weather or even at night. Mean thermal differences between body and water temperatures were significantly different among individuals, and larger turtles had a greater mean thermal difference. Elevations in body temperatures of adult loggerhead turtles can reasonably be assumed to result from the accumulation of metabolically produced heat. Surfacing times (spent at depths shallower than 2 m) of seven turtles were only 10.3 to 38.9% of their internesting periods, with the exception of one turtle who spent 66.3% of her time at the surface. Loggerhead turtles did not seem to bask positively at the sea surface to absorb radiative heat.     

Determination of selected neonicotinoid insecticides by liquid chromatography with thermal lens spectrometric detection

We studied the analysis of trace amounts of neonicotinoid insecticides by liquid chromatography coupled with a thermal lens spectrometric detector (TLS). This multi-residue analysis method is based on the reversed phase separation on C₁₈ column, isocratic elution and collinear dual beam TLS detection. The insecticides thiamethoxam, imidacloprid, acetamiprid and thiacloprid were detected with retention times of 4.4, 5.7, 6.5 and 8.5 min and limits of quantifications of 50, 89, 10, and 25 μg/L, respectively. The retention times agreed well with those obtained by the same chromatographic method but using a diode-array detector (DAD). The limits of quantifications for imidacloprid were identical in both techniques. However, the limits of quantifications for thiamethoxam, acetamiprid and thiacloprid were up to 8.5 times lower using the TLS detector compared to the diode-array detector. The applicability of the developed procedure was tested on spiked river water and potato samples.     

New insights into the formation of ammonium nitrate from a physical and chemical level perspective

● Factor analysis of ammonium nitrate formation based on thermodynamic theory. ● Aerosol liquid water content has important role on the ammonium nitrate formation. ● Contribution of coal combustion and vehicle exhaust is significant in haze periods. High levels of fine particulate matter (PM_2.5) is linked to poor air quality and premature deaths, so haze pollution deserves the attention of the world. As abundant inorganic components in PM_2.5, ammonium nitrate (NH₄NO₃) formation includes two processes, the diffusion process (molecule of ammonia and nitric acid move from gas phase to liquid phase) and the ionization process (subsequent dissociation to form ions). In this study, we discuss the impact of meteorological factors, emission sources, and gaseous precursors on NH₄NO₃ formation based on thermodynamic theory, and identify the dominant factors during clean periods and haze periods. Results show that aerosol liquid water content has a more significant effect on ammonium nitrate formation regardless of the severity of pollution. The dust source is dominant emission source in clean periods; while a combination of coal combustion and vehicle exhaust sources is more important in haze periods. And the control of ammonia emission is more effective in reducing the formation of ammonium nitrate. The findings of this work inform the design of effective strategies to control particulate matter pollution.     

Assimilation of dietary free amino acids,peptides and protein in post-larval Atlantic halibut (<Emphasis Type="Italic">Hippoglossus</Emphasis><Emphasis Type="Italic">hippoglossus</Emphasis>)

With the aim of improving the formulation of diets for early stages of marine fish, post-larval Hippoglossus hippoglossus (56 days after first feeding; 23 mg dry weight) were tube-fed liquid diets of radiolabelled L-(¹⁴C) free amino acids (FAA diet), peptides (PEPT diet) and protein (PROT diet), in order to compare the kinetics of transfer from gut into the liver and carcass. The test diets were prepared using equal concentrations of amino acids (AA) and fed as a single pulse (0.3 µl, 2.2 µg AA). The PROT diet consisted of methylated-¹⁴C-labelled (mainly lysine) bovine serum albumin (BSA), the PEPT diet was the PROT diet digested with trypsin and the FAA diet consisted of an amino acid mixture based on BSA composition with added ¹⁴C-lysine. The common labelling with ¹⁴C-lysine permitted a comparison of the three diets. Based on dissection and distribution of the tracer in each compartment, the FAA diet was almost completely absorbed 1 h after the tube-feeding; PEPT and PROT diets required more time before they were processed by the digestive tract. The FAA diet was absorbed about eight times as fast as protein and about six times as fast as peptides from the gut. A low retention of label in the liver for all diets at all sampling times suggests that the liver does not store the AA at these absorption rates. The FAA diet had a higher assimilation efficiency (about 90%) than the PEPT diet (about 12%) and PROT diet (about 32%). FAAs, thus, appear to be superior to protein and peptides as a dietary source of amino acids in post-larval Atlantic halibut.     

Performance of a hybrid anaerobic-contact oxidation biofilm baffled reactor for the treatment of decentralized molasses wastewater

A novel hybrid anaerobic-contact oxidation biofilm baffled reactor （HAOBR） was developed to simultaneously remove nitrogenous and carbonaceous organic pollutants from decentralized molasses wastewater in the study. The study was based on the inoculation of anaerobic granule sludge in anaerobic compartments and the installation of combination filler in aerobic compartments. The performance of reactor system was studied regarding the hydraulic retention time （HRT）, microbial characteristics and the gas water ratio （GWR）. When the HRT was 24h and the GWR was 20：1, total ammonia and chemical oxygen demand （COD） of the effluent were reduced by 99% and 91.8%, respectively. The reactor performed stably for treating decentralized molasses wastewater. The good performance of the reactor can be attributed to the high resistance of COD and hydraulic shock loads. In addition, the high solid retention time of contact oxidation biofilm contributed to stable performance of the reactor.     

Modelling the thresholds of nitrogen/phosphorus concentration and hydraulic retention time for bloom control in reclaimed water landscape

● A new model for bloom control in open land scape water was constructed. ● It considers the effects of temperature and light on algae growth. ● It describes threshold curve of nitrogen, phosp horus and hydraulic retention time. ● Light and temperature dependent growth para meters of typical algae were obtained. The risks posed by algal blooms caused by nitrogen and phosphorus in reclaimed water used in urban water landscapes need to be carefully controlled. In this study, the combined effects of the nitrogen and phosphorus concentrations and the light intensity and temperature on the specific growth rates of algae were determined using Monod, Steele, and Arrhenius models, then an integrated algal growth model was developed. The algae biomass, nitrogen concentration, and phosphorus concentration mass balance equations were used to establish a new control model describing the nitrogen and phosphorus concentration and hydraulic retention time thresholds for algal blooms. The model parameters were determined by fitting the models to data acquired experimentally. Finally, the control model and numerical simulations for six typical algae and mixed algae under standard conditions were used to determine nitrogen/phosphorus concentration and hydraulic retention time thresholds for landscape water to which reclaimed water is supplied (i.e., for a reclaimed water landscape).     

Calcium uptake and net calcification rates in the octocoral Eunicella papillosa

This paper presents the results of a preliminary study on the uptake of ⁴⁵Ca in the mesoskeleton of the gorgonian Eunicella papillosa (Octocorallia). Hourly seawater aliquots over 12 h periods displayed considerable fluctuations of activity with time, reflecting a disappearance and reappearance of tracer during the experiment. Analysis of total coenenchyme mass showed an initial rapid but fluctuating uptake of tracer and a progressive decrease with time. Distinct differences in the calcification rate of specific growth regions of the coral were detected, the rate being higher in branch tips than in lower branch regions. Chase experiments on colonies previously incubated for 24 h revealed that up to 45% of the tracer taken up during labelling were returned to the seawater. A comparison of the tracer content of the coenenchyme and the calcite spicules revealed that up to 70% of the calcium taken up remained in the coral tissue. Quantification of isotopic exchange phenomena with dead corals and isolated spicules emphasized the importance of the live coral tissue as a barrier and regulator of Ca uptake. The results are discussed in the light of the limitations of radioisotope techniques for the determination of calcification rates, and an attempt to compare rates with data in the literature is made.     

Absorption and retention of polydimethylsiloxanes (silicones) in fish: Preliminary experiments†

Hydrophobicity and bioaccumulation potential of linear and cyclic polydimethylsiloxane (PDMS) oligomers were estimated by reversed‐phase liquid chromatography and feeding experiments with guppies (Poecilia reticulata). PDMS concentrations in fish were determined by capillary column gas chromatography and gas chromatography‐mass spectrometry. In contrast to polychlorinated biphenyls (PCBs), only very small amounts of PDMS were retained by the fish after six weeks feeding.     

Resting spore formation and biochemical composition of the marine planktonic diatom Chaetoceros pseudocurvisetus in culture: ecological significance of decreased nucleotide content and activation of the xanthophyll cycle by resting spore formation

The biochemical composition of vegetative cells and resting spores of Chaetoceros pseudocurvisetus Mangin was compared in cultures under various nutrient and light conditions. The cellular content of major nucleotides such as AMP, ADP, ATP and UTP decreased in the order: vegetative cells, nutrient-starved (vegetative) cells and resting spores, indicating that the general metabolism of resting spores is relatively inactive. ADP-glucose was only abundant in nutrient-starved vegetative cells, suggesting metabolic imbalance in these cells. The chl a–specific fluorescence yield of vegetative cells grown under all culture conditions was low, but very high in resting spores. The ratios of the cellular contents of diadinoxanthin to chl a and of diatoxanthin to chl a were higher in resting spores and nutrient-starved vegetative cells than in nutrient-replete vegetative cells. The diadinoxanthin–diatoxanthin xanthophyll cycle was active in resting spores; the xanthophyll cycle was synchronized with a 14 h light:10 h dark photoperiod. Also, the ratios of cellular content of diadinoxanthin and diatoxanthin to cellular content of chl a in resting spores were relatively high in high irradiance, and decreased gradually in conditions of darkness over long culture periods. Under conditions of strong light and high temperature, most resting spores survived more than 40 d while nutrient-starved vegetative cells died within 33 d. These results suggest that resting spore formation is a strategy for enhancing protection and lowering metabolic rate for survival. These physiological changes accompanying spore formation enable resting spores not only to overwinter but also to “oversummer” in the coastal euphotic layer. Received: 23 March 1999 / Accepted: 11 August 1999     

人工湿地植物量及其对净化效果影响的研究

人工湿地污水处理系统中,植物对污水净化效果起着非常重要的作用,而植物量是植物生长的关键参数之一。为了明确植物量对污水处理效果的影响,在2002--2008年期间,详细测定了芦苇（Ph．australisTrin）、再力花（Thaliadealbata）、荻（M．sacchariflorus）和美人蕉（Cannaindica）4种典型湿地植物不同年度的生物量、不同生长阶段的生物量、生物量年产率,以及同期湿地COD、BOD5、TN和TP等的去除率。结果表明：湿地植物在栽植成活、稳定生长以后,至少要再经过1个以上的生长周期才能完全适应湿地环境,达到生物量的最大值,其中芦苇根系和茎叶生物量显著高于其他植物;同种植物的植物量与COD、BOD5、TN去除率呈显著正相关,与TP相关性不强;植物量随生长周期的变化对湿地净化能力的影响显著,确定合理收割期有利于湿地的稳定运行;不同种类植物生物量年产率与各种污染物的去除率均显著相关,芦苇、再力花和美人蕉均具有较高的生物量年产率,污染物去除能力较好。在试验范围内,芦苇湿地的运行稳定性最好,再力花湿地具有最强的脱氮能力,美人蕉湿地能快速形成规模、实现稳定运行,这些为构建不同特点和不同需要的湿地提供了重要参考。     

Mast seeding under increasing drought: results from a long-term data set and from a rainfall exclusion experiment

Mast seeding, the synchronous, highly variable seed production among years, is very common in tree species, but there is no consensus about its main causes and the main environmental factors affecting it. In this study, we first analyze a long-term data set on reproductive and vegetative growth of Quercus ilex in a mediterranean woodland in order to identify the main environmental drivers of interannual variation in flower and seed production and contrast the impact of climate vs. adaptive factors as main causes of masting. Second, we conducted an experiment of rainfall exclusion to evaluate the effects of an increasing drought (simulating predictions of global change models) on both reproductive processes. The annual seed crop was always affected by environmental factors related to the precipitation pattern, these abiotic factors disrupting the fruiting process at different periods of time. Seed production was strongly dependent upon water availability for the plant at initial (spring) and advanced (summer) stages of the acorn maturation cycle, whereas the final step of seed development was negatively affected by the frequency of torrential-rain events. We also found clear evidence that seed masting in the study species is not only regulated by selective endogenous rhythms, but is mainly a physiological response to the variable environment. Our results from the rainfall exclusion experiment corroborated the conclusions obtained from the 26-year fruiting record and demonstrated that the high interannual variation in seed crop was mainly determined by the success in seed development rather than by the flowering effort. Under a global change scenario, it could be expected that the drier conditions predicted by climate models reinforce the negative effects of summer drought on seed production, leading to negative consequences for tree recruitment and forest dynamics.     

Composition chimique élémentaire (C,H, N) et équivalent énergie d'Acartia clausi (Crustacea: Copepoda), espèce importante dans la bioénergétique des écosystèmes côtiers de Méditerranée nord-occidentale

Fixed-point sampling of a shallow tidal estuary was performed hourly for 14 d in summer of 1982 and again in winter of 1983. This sampling regime was of statistically appropriate duration to allow characterization of the variability between periods of 2 to 96 h by spectral analysis of the time-series. The project (PULSE) took place in the Newport River Estuary, located behind the Outer Banks of North Carolina, USA. In all, twentyeight parameters were monitored, encompassing the meteorology, hydrology, water chemistry and phytoplankton-production physiology. Although the annual cycle was monitored, only the winter and summer seasons are compared here, i.e., the lowest water temperatures with the highest water temperatures. The physics, chemistry and biology of the estuary at the hourly scale were highly variable and non-random. The estuary is riverine in winter; growth-limiting nitrogen is supplied as nitrate (NO ₃ ^- ) and ammonium (NH ₄ ⁺ ) by runoff from the drainage basin. In summer, the estuary is lagoonal; nitrogen is supplied as NH ₄ ⁺ by biological regeneration. Chlorophyll a biomass varies primarily at the 4 d period in winter and at the diel period in summer. Although finely tuned to environmental variability, phytoplankton abundances were at equilibrium insofar as daily chlorophyll production was balanced by losses, i.e., grazing, export and deposition. Most important, high-frequency processes, here periods at the scale of cell-division times, can be very important in phytoplankton ecology.     

Correlation between stomach temperatures and ambient water temperatures in free-ranging loggerhead turtles,Caretta caretta

Instruments were attached to loggerhead turtles, Caretta caretta, at Kamoda Point, Japan in 1989 and on the Senri-coast, Japan in 1991. We simultaneously obtained stomach temperatures, ambient water temperatures and diving depths from four free-ranging loggerhead turtles during the internesting periods, using small recorders. These data were analyzed to understand how body temperature was maintained. Ambient water temperatures changed coincidentally when turtles moved up or down, but a stable stomach temperatures was maintained despite water temperature fluctuations of ca. 20 to 90 min in duration. Loggerhead turtles also experienced water temperature fluctuations longer than 24 h. Stomach temperatures responded to those water temperature changes with a time lag of several hours (160, 170, 230 and 240 min). Stomach temperatures were higher than ambient water temperatures throughout the experimental periods. The median values of the thermal difference between stomach and water temperatures were 1.1, 1.3, 1.5 and 1.7°C. The higher stomach temperatures are thought to be caused by metabolic heat production.     

Comparison of methods for determining the turnover times of dissolved organic compounds

A comparison of two different methods was made using the tracer technique. The first test was performed by adding only one defined amont of a ¹⁴C-labelled compound to the sample, the second one by adding different amounts of the same labelled compound, followed by a kinetic approach. In a coastal area of the western Baltic Sea (Kiel Fjord) the turnover times of various compounds (glucose, glucosamine, aspartic acid, leucine, lysine and acetate) were determined. In the open Baltic Sea (especially the Bornholm-Basin) the study was confined to glucose. The variations between the results of the two methods for determining the turnover times are only small for samples from eutrophic or polluted regions. However, larger discrepancies exist with samples from oligotrophic areas. Here, turnover times obtained with the first method were consistently shorter (sometimes only half as long) than, those obtained with the second method. This difference is attributed to the fact that in areas of low bacterial activity e.g. in oligotrophic water bodies, organic-substance uptake by the entire natural population of heterotrophic micro-organisms does not follow exactly the Michaelis-Menten equation. This is likely to be due to a greater population heterogeneity resulting in an increased diversity of uptake characteristics. However, since the calculation of turnover time according to the second method is based on a modification of this equation, errors are introduced.Contribution No. 164 of the Joint Research Programme No. 95 Interaction Sea-Sea bottom, Kiel University.     

人工湿地植物量及其对净化效果影响的研究

人工湿地污水处理系统中,植物对污水净化效果起着非常重要的作用,而植物量是植物生长的关键参数之一。为了明确植物量对污水处理效果的影响,在2002—2008年期间,详细测定了芦苇(Ph.australis Trin)、再力花(Thalia dealbata)、荻(M.sacchariflorus)和美人蕉(Canna indica)4种典型湿地植物不同年度的生物量、不同生长阶段的生物量、生物量年产率,以及同期湿地COD、BOD5、TN和TP等的去除率。结果表明:湿地植物在栽植成活、稳定生长以后,至少要再经过1个以上的生长周期才能完全适应湿地环境,达到生物量的最大值,其中芦苇根系和茎叶生物量显著高于其他植物;同种植物的植物量与COD、BOD5、TN去除率呈显著正相关,与TP相关性不强;植物量随生长周期的变化对湿地净化能力的影响显著,确定合理收割期有利于湿地的稳定运行;不同种类植物生物量年产率与各种污染物的去除率均显著相关,芦苇、再力花和美人蕉均具有较高的生物量年产率,污染物去除能力较好。在试验范围内,芦苇湿地的运行稳定性最好,再力花湿地具有最强的脱氮能力,美人蕉湿地能快速形成规模、实现稳定运行,这些为构建不同特点和不同需要的湿地提供了重要参考。     

气相色谱法测定工业废水中联苯与菲

文章研究了一种新的测定废水中联苯及菲含量的方法,该方法采用气相色谱薄涂柱,对联苯与菲进行了有效的分离与测定。该方法具有固定液用量少,柱温低,分离效果好,分析速度快等特点,利用该对废水样进行了测定,取得了满意的结果。     

Larval biology of six species of the genus Conus (Gastropoda: Toxoglossa) in Hawaii,USA

Among the Hawaiian species in the genus Conus, larval life histories range from long-term planktotrophy to nonpelagic lecithotrophy. Prehatching developmental time, hatching size, pelagic period and total prejuvenile developmental time are all significantly correlated with egg size, while settling size is correlated with none of these larval characteristics. Therefore, larval life history patterns in the genus Conus appear to be determined by 2 sets of selective forces: the first influencing egg size, and the second stipulating settling size. As egg sizes become larger, hatching sizes and prehatching developmental time increase while pelagic periods and total prejuvenile developmental times decrease. Settling size appears to be related to water depth, but food requirements of newly metamorphosed juveniles may also be important.