Foraging movements and habitat niche of two closely related seabirds breeding in sympatry

As central-place foragers, pelagic seabirds are constrained by spatiotemporal heterogeneity to find productive marine areas and compete for prey. We analysed 97 foraging trips to study the movement and oceanographic characteristics of foraging habitats of two different—yet closely related—species of shearwaters (Scopoli’s shearwater Calonectris diomedea and Cory’s shearwater C. borealis) breeding in sympatry in the Mediterranean. We combined various methodological approaches (GPS-tracking, species distribution modelling and stable isotope analysis) to explore the foraging strategies of these two species. Isotopic results suggested that trophic habits of both shearwater species were similar, mainly based on pelagic fish consumption. Foraging areas of both species were characterized by shallow waters near the colony. Both shearwater species exploited persistent productive marine areas. The foraging areas of the two species broadly overlapped during the incubation period, but during chick-rearing period, Scopoli’s shearwaters apparently foraged in different areas than Cory’s shearwaters.     

Biological removal of selenate in saline wastewater by activated sludge under alternating anoxic/oxic conditions

Removal of selenate in saline wastewater by activated sludge was examined. Sequencing batch reactor was operated under alternating anoxic/oxic conditions. Above 97% removal of soluble selenium (Se) was achieved continuously. Major Se removal mechanism varied depending on the length of aeration period. Various Se-reducing bacteria likely contributed to coordinately to Se removal. Selenium (Se)-containing industrial wastewater is often coupled with notable salinity. However, limited studies have examined biological treatment of Se-containing wastewater under high salinity conditions. In this study, a sequencing batch reactor (SBR) inoculated with activated sludge was applied to treat selenate in synthetic saline wastewater (3% w/v NaCl) supplemented with lactate as the carbon source. Start-up of the SBR was performed with addition of 1–5 mM of selenate under oxygen-limiting conditions, which succeeded in removing more than 99% of the soluble Se. Then, the treatment of 1 mM Se with cycle duration of 3 days was carried out under alternating anoxic/oxic conditions by adding aeration period after oxygen-limiting period. Although the SBR maintained soluble Se removal of above 97%, considerable amount of solid Se remained in the effluent as suspended solids and total Se removal fluctuated between about 40 and 80%. Surprisingly, the mass balance calculation found a considerable decrease of Se accumulated in the SBR when the aeration period was prolonged to 7 h, indicating very efficient Se biovolatilization. Furthermore, microbial community analysis suggested that various Se-reducing bacteria coordinately contributed to the removal of Se in the SBR and main contributors varied depending on the operational conditions. This study will offer implications for practical biological treatment of selenium in saline wastewater.     

Nutrient export and material recycling using aquatic plants: Lake Kitagata case study

Lake Kitagata in Fukui Prefecture, Japan, was examined to collect fundamental data on nutrient export and material recycling using the native aquatic plants, common reed and wild rice. Common reed was located all over the lake shore, while wild rice was in the upper part of the lake. On average, the nutrient content was nitrogen: 2.1 and 2.6?%, P₂O₅: 0.38 and 0.64?%, K₂O: 2.1 and 2.4?% for common reed and wild rice, respectively, and decreased along with their growth. If harvested in October, the nitrogen and phosphorus exported from the lake were estimated to be only 1.1 and 1.9?% of the inflow, respectively. Methane fermentation of these plants showed an average of 134 and 150?mL-CH₄/g-VS added for common reed and wild rice, respectively, indicating possible use as an auxiliary source. The composting of these plants mixed with chicken manure, bean curd and rice bran was successful, and the products were rich in the major nutrients and well-balanced. A pretreatment method combining sulfuric acid and thermal treatment was able to convert about 50?% of cellulose in common reed to glucose, the precursor for bioethanol production. Therefore, these technologies are demonstrated to be helpful for the beneficial use of the biomass.     

Convenient dioxin measuring method using an efficient sampling train, an efficient HPLC system and a highly sensitive HRGC/LRMS with a PTV injector

An efficient sampling method for dioxins from flue gas, an efficient automatic purification and fractionation method by a new HPLC system using a sulfuric acid-silica/silica column, a Nitro column and a PGC column, and sensitive determination method by an economical HRGC/LRMS using a programmable temperature vaporization (PTV) injector were developed. It was confirmed that the dioxins could be easily collected by the proposed simple sampling train consisting of only two bottles, and the extracted sample could be purified sufficiently and separated as mono-ortho PCBs, non-ortho PCBs and PCDDs/PCDFs completely with the proposed HPLC system. The peak areas of GC/MS were increased linearly with the injection volume up to 40 microl by the PTV technique, and the sensitivity could be increased to 20 times higher than usual. This convenient measuring method can drastically reduce operation time, consumption of hazardous solvent and cost.     

Decomposition reactions of epoxy resin and polyetheretherketone resin in sub- and supercritical water

Epoxy resin and polyetheretherketone (PEEK) resin were decomposed into their monomers such as phenol, cresols, and their analogues by thermal treatment in sub- and supercritical water in a 10-ml tubing bomb reactor. The addition of basic compounds such as Na₂CO₃ was effective in promoting the decomposition reaction of the resins. In the reaction of epoxy resin, the yield of identified products reached 10% for the reaction at 703K over 1h. In the reaction of PEEK resin, the total yield of phenol and dibenzofuran reached 88% for the reaction at 703K over 3h. Chemical participation of water in the decomposition reaction was confirmed by the reaction of dinaphthylether.     

Obligate commensalism of <Emphasis Type="Italic">Curvemysella paula</Emphasis> (Bivalvia: Galeommatidae) with hermit crabs

Curvemysella paula is a markedly crescent-shaped bivalve that lives inside snail shells occupied by hermit crabs. Here, we describe the unique symbiotic life, growth pattern, and reproductive biology of this bivalve, based on specimens collected from the shallow, muddy bottom of the Seto Inland Sea, Japan. C. paula was found attached to columellae in the siphonal canal, mainly of nassariid snail shells occupied by two types of hermit crabs: Diogenes edwardsii (Diogenidae) and Spiropagurus spiriger (Paguridae). The crescent-shaped shell of C. paula is an adaptation to symbiotic life in the narrow interspace between the snail shell and the hermit-crab abdomen. C. paula is a protandric hermaphrodite. In our samples, each host snail shell harbored one (or rarely a few) large female and several males. All the female bivalves settled on the host shells with their anterior end facing outward and benefited from currents created by the hermit crab when feeding. In the muddy bottom, snail shells are a limited resource for both the hermit crabs and symbiotic bivalves. The bivalves benefit from the mobility of the hermit crabs, which prevent the shells from becoming buried in the mud. C. paula represents the only example of obligate commensalism with hermit crabs found in Bivalvia.     

Further study on the photochemistry of non-ortho substituted PCBs by UV irradiation in alkaline 2-propanol

The photochemical behaviors of six non-ortho substituted PCB congeners, i.e., 3,4-DiCB, 3,5-DiCB, 3,3',5-TriCB, 3,4,5-TriCB, 3,3',4,5-TetraCB, and 3,4,4',5-TetraCB, irradiated at 254 nm in alkaline 2-propanol were investigated. Besides the determination of the photodechlorination pathways of these compounds, the presence of photorearrangement was observed in the case of 3, 4-DiCB with its products being identified. The results indicate that dechlorination is much more important than rearrangement during the process of PCB photolysis.