Spawning migration and returning behavior of white-streaked grouper Epinephelus ongus determined by acoustic telemetry

White-streaked grouper (Epinephelus ongus) is an important fishery target that forms fish spawning aggregations (FSAs) at specific spawning grounds. The aims of the present study were to investigate migration behavior and returning behavior in terms of FSA using acoustic telemetry. Among the 30 specimens tracked, three types of movement pattern were observed: type 1, high site fidelity at the release area before the spawning period, migration to the spawning ground during the spawning period and return to the release area just after the spawning period (17 specimens); type 2, high site fidelity at the release area, disappearance from the area during the spawning period but was not detected at the spawning ground and return to the release area (8 specimens); and type 3, high site fidelity at the release area was observed before, during and after the spawning period (5 specimens). For the 17 specimens that were categorized into type 1, the dates of departure from their release area and the dates of return to the release area of males were, respectively, significantly earlier and later than those of females. The duration between the departure date and the return date (“duration away”) of males was significantly longer than that of females. The duration away tended to be positively related to the condition factor. All 25 specimens that were categorized as type 1 and type 2 showed returning behaviors to the release area.     

Trans-Pacific dispersal of loggerhead turtle hatchlings inferred from numerical simulation modeling

We used Lagrangian numerical simulations to examine the trans-Pacific dispersal processes of loggerhead turtle hatchlings. Ten thousand simulated particles were released from each of the three nesting regions in Japan and tracked for 5 years. Results showed many particles moving eastward, drifting in the Kuroshio Current followed by the Kuroshio Extension Current. However, no particles reached Baja California, a known feeding area, through passive processes, indicating that trans-Pacific transportation requires active swimming by turtles. The duration of the trans-Pacific dispersal was estimated to be at least 1.6–3.4 years, with some turtles drifting in the Kuroshio Countercurrent and remaining in the western Pacific even after 5 years. This indicates that as revealed by previous genetic studies, not all loggerheads always disperse along a trans-Pacific route. The findings showed that survival and expected growth rates varied widely according to ambient temperatures during drifting, which in turn depended on nesting location.     

Aromatization of waste polyolefin pyrolysate over H-ZSM-5 zeolite-supported gallium oxide catalysts

H-ZSM-5 zeolite-supported gallium oxides were studied as aromatization catalysts for polyolefin pyrolysate. The catalysts were prepared by a conventional physical mixing method with a gallium content of 1.0 and 4.5 wt% and were reduced in flowing hydrogen at 585°C. To test their activity, a polyolefin sample was pyrolyzed and passed over a heated catalyst layer; the product was analyzed by gas chromatography/mass spectrometry. A continuous-flow fixed-bed reactor was used for aromatization of a model gas of polyolefin pyrolysate. For chlorine-free sources at 450°C, the catalyst with only 1.0 wt% gallium exhibited activity comparable to a gallium silicate catalyst. For chlorine-contaminated sources, the catalyst with 4.5 wt% gallium sustained catalytic activity for long periods. From the activity test results, it was found that zeolite-supported gallium catalysts prepared by the physical mixing method are suitable for converting polyolefin into aromatic hydrocarbons.     

Recycling process for yttria-stabilized tetragonal zirconia ceramics using a hydrothermal treatment

The recycling process for 3 mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP) sintered at 1450°–1550°C was examined by applying low-temperature degradation of zirconia ceramics under hydrothermal conditions. Hydrothermal treatment at a temperature from 200° to 240°C can lead to the spontaneous disintegration of 3Y-TZP sintered bodies into powdery particles. The hydrothermally obtained zirconia powder was found to consist of primary particles and aggregated particles. Detailed X-ray diffraction measurement revealed the formation of a cubic zirconia phase in the 3Y-TZP sintered bodies, which seemed to inhibit the disintegration of aggregated particles toward the primary particle level. The reclaimed 3Y-TZP powder was sintered again through a conventional powder processing route. The mechanical properties and microstructure of recycled 3Y-TZP sintered specimens were examined by comparison with those of the original 3Y-TZP sintered bodies. Dense recycled 3Y-TZP sintered at a higher temperature exhibited higher fracture toughness to some degree than the original 3Y-TZP.     

Impact of Community-Based Forest Management on Forest Protection: Evidence from an Aid-Funded Project in Ethiopia

Many African countries have adopted community-based forest management (CBFM) to prevent deforestation. However, empirical studies have not reached a consensus on the effectiveness of CBFM. The purpose of this study is to examine the impact of the establishment of participatory forest management associations in Ethiopia. We used remote sensing data to gauge the change in forest area and employed a two-stage least squares model to correct for possible biases. The results indicate that the forest area managed by forest associations declines more in the year of establishment than forest areas with no association. This finding suggests that villagers may engage in "last-minute" logging. However, 1 year after the establishment of the forest associations, the forest area of the associations increased substantially, most likely because the associations monitor illegal logging, enabling the regeneration of open areas within the registered forest area. On average, the forest area of the forest associations increased by 1.5?% in the first 2 years, whereas forest areas not managed as part of an association declined by 3.3?%. The cumulative impact over 2 years yields a net increase in the rate of change of 4.8?%. These results demonstrate that it is important to improve the monitoring of forest areas during the initial establishment of participatory forest management associations to maximize the effects of association establishment.     

Effect of carbon particles on heavy metal emissions under ash-melting conditions

In Japan, incineration ash is subjected to a melting process to reduce waste volume and to stabilize hazardous heavy metals. In previous articles, we reported that large quantities of volatile metals are emitted under ash-melting conditions at temperatures higher than 1200°C and that such emissions are considerably increased under reducing conditions. However, the emission behavior in the presence of large amounts of char particles was unclear, and we suspected that emissions under these conditions might differ from emissions under the previous conditions. Therefore, we investigated heavy metal emissions and the melting characteristics of ash in the presence of carbon particles. In this experiment, a small crucible with ash and carbon was rapidly heated using a high-frequency induction-heating furnace to simulate the melting ash gasification with carbon. As a result, it was found that additive carbon can promote emissions of heavy metals such as zinc and lead and control the melt of the ash.     

Site selection in CO2 ocean sequestration: Dependence of CO2 injection rate on eddy activity distribution

Site selection in CO₂ ocean sequestration is examined based on the idea that a site where injected CO₂ is efficiently diluted is favourable in reducing/avoiding biological impacts. Simulations of CO₂ injection into several sites by an eddy-resolving oceanic general circulation model (OGCM) show that the maximum CO₂ concentration differs by a factor of 10 among sites. The distribution of eddy activity is the most important causative factor producing the geographical differences in CO₂ dilution. Based on the relationship between the maximum CO₂ concentration and eddy activity, we estimated the distribution of the maximum CO₂ injection rate by a proposed method, which does not cause chronic impacts on biota. Around Japan, extensive ocean volume has the potential to dilute 20 million tonnes per year without chronic impacts, and some areas can be injected with 80 million tonnes per year.     

Effects of ozone on growth, yield and leaf gas exchange rates of four Bangladeshi cultivars of rice (Oryza sativa L.)

To assess the effects of tropospheric O₃ on rice cultivated in Bangladesh, four Bangladeshi cultivars (BR11, BR14, BR28 and BR29) of rice (Oryza sativa L.) were exposed daily to charcoal-filtered air or O₃ at 60 and 100 nl l⁻¹ (10:00-17:00) from 1 July to 28 November 2008. The whole-plant dry mass and grain yield per plant of the four cultivars were significantly reduced by the exposure to O₃. The exposure to O₃ significantly reduced net photosynthetic rate of the 12th and flag leaves of the four cultivars. The sensitivity to O₃ of growth, yield and leaf gas exchange rates was not significantly different among the four cultivars. The present study suggests that the sensitivity to O₃ of yield of the four Bangladeshi rice cultivars is greater than that of American rice cultivars and is similar to that of Japanese rice cultivars and that O₃ may detrimentally affect rice production in Bangladesh.