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141.
Migratory behavior can be an important factor in determining contaminant exposure in avian populations. Accumulation of organochlorine (OC) pesticides while birds are wintering in tropical regions has been cited often as the reason for high concentrations in migrant populations. To explore this issue, we satellite tracked 16 Ospreys (Pandion haliaetus) over the period 1996-2003 from breeding sites in British Columbia, Canada, and integrated the results into a database on 15 Ospreys that were satellite tracked over the period 1995-1999, from breeding locations in Washington and Oregon, USA. Data on wintering sites of 31 Ospreys in Mexico and Central America were used for spatially targeted sampling of prey fish. Concentrations of the main organochlorine contaminant, p,p'-dichloro-diphenyl-dichloroethylene (DDE), in fish composites from Mexico ranged from 0.005 to 0.115 nicrog/g wet mass. Significant differences existed among fish families in p,p'-DDE, total dichloro-diphenyl-trichloroethane (sigmaDDT), sigmachlordanes, and total polychlorinated biphenyls (sigmaPCBs). Catfish (family Ariidae) generally had significantly higher levels of DDT metabolites and other organochlorine contaminants compared to other fish families collected. Differences in prey contaminant levels were detected among the collection sites around coastal Mexico, with fish from Veracruz State generally having higher levels of DDT metabolites, sigmachlordanes, sigmaPCBs, and hexachlorobenzene. Eggs collected from 16 nests throughout the Pacific Northwest (nine from British Columbia, seven from Oregon and Washington) where Ospreys had been satellite tagged, showed marked variation in levels of DDT metabolites (p,p'-DDE; range 0.02-10.14 microg/g). Wintering site had no significant effect on contaminant concentrations in sample eggs from those specific Ospreys; rather concentrations of p,p'-DDE, were predicted by breeding sites with highest levels in eggs of Ospreys breeding in the lower Columbia River, consistent with published reports of continued high concentrations of DDT and related compounds in that system.  相似文献   
142.
Samples of southern bluefin tuna, Thunnus maccoyii (Castelnau), taken from off the coasts of South Africa, Western Australia, South Australia and Tasmania from 1992 to 1994 were analysed for six polymorphic allozyme loci (ADA *, GDA *, GPI-A *, MPI *, PGDH * and PGM-1 *, n = 595 to 733 per locus) and for mitochondrial DNA variants revealed by three restriction enzymes (Bam HI, Bcl I and Eco RI) detecting polymorphic cut sites (n = 555). No significant spatial heterogeneity was detected. There were no sex-related differences in allele or mtDNA haplotype frequencies. Juveniles (30 to 35 cm and 46 to 54 cm) from what are thought to be two temporally-separated spawning peaks showed no significant genetic differentiation. There were also no significant differences in allele or haplotype frequencies between fish smaller than 70 cm and those larger than 70 cm. These data are consistent with the null hypothesis of a single unit stock of southern bluefin tuna, with a single spawning area. This is located to the south of Java and off the north-west coast of Australia. Received: 28 August 1996 / Accepted: 30 September 1996  相似文献   
143.
Modeling joint production of wildlife and timber   总被引:2,自引:0,他引:2  
Production of marketed commodities and protection of natural systems often conflict. A focus on only one goal can result in large losses in other goals and may result in inefficient and unsustainable outcomes. In this paper, we develop a method that combines economic and ecological models in a dynamic and spatial analysis to evaluate land use decisions and find cost-effective alternatives for which it is not possible to do better on one objective without harming another objective. The method is demonstrated using timber production and species conservation on a forested landscape over a 100-year planning horizon. Current land use strategies are simulated and compared with cost-effective alternatives. The approach is compared to a static reserve approach, similar to previous studies, and found to produce substantially more efficient management strategies for the case study landscape.  相似文献   
144.
Phosphorus-based nutrient management will inevitably be required for land application of biosolids. Water-extractable phosphorus (WEP) in livestock manures is an indicator of phosphorus loss from agricultural watersheds and this study evaluated its use for biosolids. The WEP to total phosphorus percentage (PWEP) in 41 biosolids (representing a variety of wastewater and solids treatment processes) was compared to dairy and poultry manures and triple superphosphate fertilizer. The mean PWEP for conventionally treated and stabilized biosolids was 2.4%, which was significantly lower than inorganic fertilizer (85%), dairy manure (52%), and poultry manure (21%). Low biosolids PWEP is attributed to elevated aluminum and iron content from chemical additions during wastewater treatment and solids dewatering operations. Facilities using biological phosphorus removal had the highest mean biosolids PWEP (approximately 14%), whereas heat-dried biosolids had the lowest average PWEP (< approximately 0.5%). Paired samples of digested cake and the corresponding biosolids treated by processes to further reduce pathogens (i.e., thermal treatment, composting, and advanced alkaline stabilization) showed that these processes tended to reduce biosolids PWEP. Biosolids composition and processing mode exert a controlling influence on the potential for off-site phosphorus migration at land-application sites. Nutrient management policies for land-based recycling should account for the widely varying potential of organic amendments to cause soluble phosphorus losses in runoff and leaching.  相似文献   
145.
Eggs of sharp-shinned hawks (Accipiter striatus), Cooper's hawks (A. cooperii), and northern goshawks (A. gentilis) were collected from nests in south-central Ontario from 1986 to 1989. Detectable levels of the chlorinated hydrocarbons DDE, DDT, DDD, mirex, photomirex, cis-nonachlor, trans-nonachlor, oxychlordane, dieldrin, heptachlor expoxide, HCB and PCB were present in all the eggs analyzed. Mean contaminant levels were highest in sharp-shinned hawks, slightly lower in Cooper's hawks, and significantly lower in goshawks; for example, mean DDE values were 7.23, 4.48 and 0.90 mg kg(-1) (wet weight), respectively. Total PCB levels were generally less than 1.5 mg kg(-1), lower than those associated with reproductive effects in field and laboratory studies with other species. Mean shell thicknesses of sharp-shinned and Cooper's hawk eggs were significantly less than mean pre-DDT era thicknesses (-10 and -8%, respectively), reductions that were probably not relevant to reproductive success. Goshawk eggs exhibited no significant reduction in shell thickness. Contaminant levels among the three species probably reflect differing food habits and migratory patterns.  相似文献   
146.
A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 g g-1 wet weight (ww), PCBs 0.69 g g-1, 2,3,7,8-TCDD 2.3 ng kg-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.  相似文献   
147.
Abandoned radar line stations in the North American arctic and sub-arctic regions are point sources of contamination, especially for PCBs. Few data exist with respect to human body burden of organochlorines (OCs) in residents of communities located in close proximity to these radar line sites. We compared plasma OC concentration (unadjusted for total lipids) frequency distribution data using log-linear contingency modelling for Fort Albany First Nation, the site of an abandoned Mid-Canada Radar Line station, and two comparison populations (the neighbouring community of Kashechewan First Nation without such a radar installation, and Hamilton, a city in southern Ontario, Canada). This type of analysis is important as it allows for an initial investigation of contaminant data without imputing any values. The two-state log-linear model (employing both non-detectable and detectable concentration frequencies and applicable to PCB congeners 28 and 105 and cis-nonachlor) and the four-state log-linear model (using quartile concentration frequencies for Aroclor 1260, PCB congeners [99,118,138,153,156,170,180,183,187], beta-HCH, p,p'-DDT +p,p'-DDE, HCB, mirex, oxychlordane, and trans-nonachlor) revealed that the effects of subject gender were inconsequential. Significant differences (p < 0.05) between the groups examined were attributable to the effect of location on the frequency of detection of OCs or on their differential distribution among the concentration quartiles. In general, people from Hamilton had higher frequencies of non-detections and of concentrations in the first quartile (p < 0.05) for most OCs compared to people from Fort Albany and Kashechewan (who consume a traditional diet of wild meats that does not include marine mammals). An unexpected finding was that, for Kashechewan males, the frequency of many OCs was significantly higher (p < 0.05) in the 4th concentration quartile than that predicted by the four-state log-linear model, but significantly lower than expected in the 1st quartile for beta-HCH. The levels of PCBs found for women in Fort Albany and Kashechewan were greater than those reported for Dene (First Nation people) and Métis (mixed heritage) of the western Northwest Territories (NWT) who did not consume marine mammals, and for Inuit living in the central NWT (occasional consumers of marine mammals). Moreover, the levels of total p,p'-DDT were greater for Fort Albany and Kashechewan women compared to these same aboriginal groups.  相似文献   
148.
Strategies for remediation of drilling mud wastes at a typical deep sour gas well site in the foothills of Alberta were assessed in terms of financial and social costs and benefits, in alignment with established sustainable remediation and decision analysis principles. Managers of contaminated sites containing historical drilling wastes are challenged with managing liability through several regulatory changes over time. Excavation and disposal of the contaminated soil from the site was the only means of securing regulatory release, with the nearest landfill located 150 km away. A perception exists that in many cases excavation and disposal inflicts unnecessary levels of site intrusiveness and public disturbance when other options achieving a similar risk end point may do so for lower social cost. The study tested this hypothesis to ascertain whether the currently accepted solution is the best option when the wider costs and benefits to society and the environment are included. Eight remedial strategies were assessed using cost–benefit analysis, including using environmental economics techniques to quantify social and environmental impacts. The economic model showed that methods such as capping in‐place or engineered encapsulation were superior to full excavation and disposal from financial and sustainability perspectives. Quantified external costs and benefits such as road damage, greenhouse gas emissions, public nuisance and safety, and community amenity value were influential in identifying superior options. It was demonstrated that $0.2 million of societal costs could be avoided by choosing capping over landfill disposal. This represents substantial implications when viewed in the context of this and other operators’ portfolios of hundreds of abandoned wells in the area. ©2016 Wiley Periodicals, Inc.  相似文献   
149.
150.
In The Imperative of Responsibility, Hans Jonas elevates the practice of ecological scenario planning in political analysis. Not only does he provide an ethical justification for ecological scenario planning, but he also uses it as a means to discern an ethical imperative for the technological age. Jonas engages in regime analysis while keeping before him a vision of the worst-case ecological scenario, a combination that is morally and politically necessary due to the colossal consequences of cumulative human actions. Jonas’s work thus provides a good, even necessary, starting point for examining the relevance of scenario planning for environmental political theory.  相似文献   
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