Conservation Applications of Astronaut Photographs of Earth: Tidal-Flat Loss ( Japan), Elephant Effects on Vegetation (Botswana), and Seagrass and Mangrove Monitoring (Australia)

Abstract: National Aeronautics and Space Administration ( NASA) photographs taken by astronauts from low Earth orbit can provide information relevant to conservation biology. This data source is now more accessible because of improvements in digitizing technology, Internet file transfer, and availability of image processing software. We present three examples of conservation-related projects that benefited from the use of astronaut photographs. First, NASA scientists requested that astronauts photograph the area of the controversial Isahaya Bay reclamation project in Japan. Japanese researchers used photographs from before and after the reclamation as a tool for communication with the public about the effects of tidal-flat loss. The newly acquired images and the availability of high-resolution digital images from NASA archives provided timely public information on the observed changes. Second, we digitally classified and analyzed a Space Shuttle photograph of Chobe National Park in Botswana to identify the locations of woodlands affected by elephants. Field validation later confirmed that areas identified on the image showed evidence of elephant damage. Third, we used a summary map from intensive field surveys of seagrasses in Shoalwater Bay, Australia, as reference data for a supervised classification of a digitized photograph taken from orbit. The classification distinguished seagrasses, sediments, and mangroves with accuracy approximating that in studies using other satellite remote-sensing data. Astronaut photographs are in the public domain, and the database of nearly 400,000 photographs from the late 1960s to the present is available at a single searchable location on the Internet (  http://eol.jsc.nasa.gov/sseop ). These photographs can be used by conservation biologists as a source of general information about the landscape and for quantitative mapping.     

Determination of nonylphenol ethoxylates and octylphenol ethoxylates in environmental samples using 13C-labeled surrogate compounds

Alkylphenol polyethoxylates (APEOs) have been widely used as nonionic surfactants in a variety of industrial and commercial products. Typical compounds are nonylphenol polyethoxylates (NPEOs) and octylphenol polyethoxylates (OPEOs), which serve as precursors to nonylphenol (NP) and octylphenol (OP), respectively. NP and 4-t-OP are known to have endocrine disrupting effects on fish (medaka, Oryzias latipes), so it is important to know the concentrations of APEOs in the environment. Because the analytical characteristics of these compounds depend on the length of the ethoxy chain, it is necessary to use appropriate compounds as internal standards or surrogates. We synthesized two 13C-labeled surrogate compounds and used these compounds as internal standards to determine NPEOs and OPEOs by high-performance liquid chromatography (LC)-mass spectrometry. Method detection limits were 0.015 microg/L for NP (2)EO to 0.037 microg/L for NP(12)EO, and 0.011 microg/L for OP(3,6)EO to 0.024 microg/L for OP (4)EO. NPEO concentrations in water from a sewage treatment plant were less than 0.05-0.52 microg/L for final effluent and 1.2-15 microg/L for influent. OPEO concentrations were less than 0.05-0.15 microg/L for the final effluent and less than 0.05-1.1 microg/L for influent.     

Occurrence of selected pharmaceuticals in river water in Japan and assessment of their environmental risk

The existence of pharmaceuticals in the water environment is thought to be a potential problem for aquatic organisms. In this study, we conducted a nationwide survey to clarify the occurrence of 24 selected pharmaceuticals in major Japanese rivers and evaluated their environmental risk to aquatic organisms. We found a total of 22 substances in river waters at concentrations from several nanograms per liter to several micrograms per liter. We found the highest, which was 2.4 μg/L of caffeine, followed by 1.5 μg/L of crotamiton and 1.4 μg/L of sulpiride. We conducted an environmental risk assessment of the 22 pharmaceuticals detected in river water, for which predicted no-effect concentration (PNEC) values for crustacea and algae had been obtained. The measured environmental concentration/PNEC values of four substances, caffeine, carbamazepine, clarithromycin, and ketoprofen, exceeded 0.1 with the maximum value of 9.0 for clarithromycin. As clarithromycin exhibits a high environmental risk to aquatic organisms, particular attention is required.     

Characteristics of biosolids in dimethyl ether dewatering method

In this study, a method for removing water from biosolids that uses dimethyl ether (DME) as an extractant was considered. This study evaluates the applicability of the DME dewatering method to biosolid cakes by using a DME flow-type experimental apparatus. It was found that a high dewatering ratio is clearly achieved by increasing the liquefied DME/biosolid ratio and lowering the liquefied DME linear velocity. As the liquefied DME/biosolid ratio was increased, the carbon content in dewatered biosolid showed a slight decrease and the TOC concentration in separated liquid increased significantly. Finally, the input energy Es to remove 1 kg of water from the biosolid cake, using both the DME dewatering method and the conventional drying method was estimated. The calculation shows that Es for the DME dewatering process is approximately a third of Es for the conventional thermal drying process.     

Decomposition of 2,2',4,4',5,5'-hexachlorobiphenyl with iron supported on an activated carbon from an ion-exchange resin

An activated carbon (AC) containing a high concentration (374 mg g⁻¹) of Fe was prepared by carbonization of an ion-exchange resin. To examine its chemical reactivity as a catalyst to decompose 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB-153), the decomposition parameters of temperature and time were varied under air or N₂. Decomposition at 350 °C was achieved within 15 min under air and 30 min under N₂, and the efficiency of PCB-153 decomposition was 99.7% and 98.0%, respectively. An analysis of inorganic chloride ions revealed that PCB-153 was mineralized effectively during the decomposition. The Brunauer-Emmett-Teller (BET) surface area and pore volume of the AC were measured to assess the adsorption capacity before and after the decomposition. The differences between decomposition under air and N₂ reflected the differences in the BET surface and pore volume measurements. A decomposition pathway was postulated, and the reactive characteristics of chlorine atoms loaded on the benzene rings followed the order of para > meta > ortho, which agrees with the calculated results from a density functional theory study.     

Surrogate study for dioxins from municipal waste incinerator in startup condition: applicability as a dioxin control indicator and an organohalogen emission warning

Dioxins and their surrogates were continuously monitored during the startup of two municipal waste in cinerators (MWIs). The surrogates studied included low-volatility organohalogen compounds (LVOH) sampled by online systems, as well as chlorobenzenes (CBs) and chlorophenols (CPs). The changes in levels of LVOH, CBs, and CPs corresponded well with the trend of the toxicity equivalent quantity (TEQ). The correlation of LVOH with TEQ was fairly good, whereas that of CBs and CPs with TEQ was not consistent. The correlation of LVOH with TEQ involved a memory effect related to the delayed emission of less volatile compounds. The isomer analysis of the dioxins present under startup conditions showed evidence of the memory effect, i.e., highly chlorinated isomers were emitted slowly, whereas low-chlorinated isomers and LVOH decreased rapidly as the temperature rose. LVOH cannot act as a perfect dioxin surrogate, but it can give a versatile, quick, and comprehensive warning of the presence of organohalogen compounds because it is free from the memory effect and covers many kinds of organohalogen compounds, including dioxins.     

Characteristics of dioxin emissions at startup and shutdown of MSW incinerators

Dioxin concentrations from municipal waste incinerators in Japan and elsewhere often show low concentrations that comply with legal limits (in this paper, the term "dioxin" designates WHO-TEQ: PCDD/Fs+dioxin-like PCB). However, such data is usually generated under normal steady state operational conditions, and there has been little investigation of releases occurring during startup and shutdown. It is important, therefore, to ascertain quantitatively emissions in an unsteady state (startup and shutdown) in order to correctly evaluate the relationship between emissions from a facility and the surrounding environment. The present study aimed to examine dioxin emissions of a continuously operated incinerator at startup and shutdown, and estimating the time period of greatest emission, and the processes causing dioxin generation. The startup process was divided into five stages and the shutdown into two; at each stage, dioxins in the flue gas were measured at the boiler outlet and the stack. From the concentration of dioxins and the flue gas volume at each stage, the amount of dioxins at startup and shutdown were calculated, and these were compared with that under steady state conditions. Dioxin concentration at the stack under steady state conditions was a very low level, while those at startup and shutdown were higher. In the case where dioxin concentration under a steady state is a low level like in this study, it is indicated that the total annual dioxin emission from a facility could be attributed to the startup periods.     

Enhancement of biodegradation of oil adsorbed on fine soils in a bioslurry reactor

Techniques for enhancing the biodegradation of oil-contaminated fine soils in a slurry-phase bioreactor were investigated. Using a model system consisting of kaolin particles containing adsorbed n-dodecane as a diesel fuel surrogate, we investigated how increasing the temperature and adding a surfactant and various hydrophobic support media affected the biodegradation rate of n-dodecane. Increasing the temperature from 25 to 35 degrees C decreased the time required for complete degradation of n-dodecane by 30%, from 110h to 80h. Addition of the surfactant polyethylene glycol p-1,1,3,3-tetramethylbutylphenyl ether decreased the degradation time to less than 48h at 35 degrees C, although a high concentration of the surfactant (3000mgl(-1)) was required. We suspect that the surfactant increased the degradation rate by solubilizing the n-dodecane into the solution phase in which the microorganisms were suspended. We tested five types of organic polymers as support media for the microorganisms and found that the biodegradation time could be reduced by approximately 50% with a support medium made from polyurethane; in the presence of this medium, only 36h was required for complete decomposition at 35 degrees C. The reduction in the degradation time was probably due to transfer of the n-dodecane from the soil to the support medium, which improved contact between the n-dodecane and the microorganisms. The polyurethane support medium bearing the microorganisms was stable and could be reused.