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191.
Farmyards, an overlooked source for highly contaminated runoff 总被引:1,自引:1,他引:0
Edwards AC Kay D McDonald AT Francis C Watkins J Wilkinson JR Wyer MD 《Journal of environmental management》2008,87(4):551-559
Summer sampling of storm runoff generated from areas of roofs and hardstanding situated on four dairy/beef farms has provided novel information regarding its microbiological and chemical quality. All farm hardstandings generated runoff that was contaminated with respect to those pollutants (faecal coliforms, FC, and faecal streptococci, FS, major nutrients, organic carbon) that are ubiquitously associated with faecal matter and urine. The separate analysis of roof runoff indicated that these can contribute significant concentrations of FS, phosphorus (P) and potentially toxic elements such as zinc (Zn), and suggests a level of 'background' contamination originating from wash-off of bird droppings and in the case of Zn galvanised surfaces. On average hardstanding runoff showed enhanced concentrations of >4 orders of magnitude for FC and 2-3 for major nutrients and carbon relative to roof runoff. Organic forms of nitrogen (N) and P contributed significantly (averaging >40%) to the total dissolved fraction in both roof and hardstanding runoff. Part of the substantial variability in composition of runoff samples could be attributed to differences between farms as well as the timing of sample collection during individual storms. Where situations allowed, a comparison of water upstream and downstream of the farmyard demonstrated they acted as a source of multiple contaminants not only during hydrologically active storm events but also during dry periods. Contamination pathways included a combination of both point (e.g., septic overflows) and non-point (e.g., seepage from livestock housing) sources. Farmyards situated within intensive livestock farming areas such as SW Scotland, would be expected to have significant local and accumulated downstream impacts on the aquatic environment. Localised impacts would be particularly important for headwaters and low order streams. 相似文献
192.
Katherine Seto Grantly R. Galland Alice McDonald Angela Abolhassani Kamal Azmi Hussain Sinan Trent Timmiss Megan Bailey Quentin Hanich 《Ambio》2021,50(1):242
Resource allocation is a fundamental and challenging component of common pool resource governance, particularly transboundary fisheries. We highlight the growing importance of allocation in fisheries governance, comparing approaches of the five tuna Regional Fisheries Management Organizations (tRFMOs). We find all tRFMOs except one have defined resources for allocation and outlined principles to guide allocation based on equity, citizenship, and legitimacy. However, all fall short of applying these principles in assigning fish resources. Most tRFMOs rely on historical catch or effort, while equity principles rarely determine dedicated rights. Further, the current system of annual negotiations reduces certainty, trust, and transparency, counteracting many benefits asserted by rights-based management proponents. We suggest one means of gaining traction may be to shift conversations from allocative rights toward weighting of principles already identified by most tRFMOs. Incorporating principles into resource allocation remains a major opportunity, with important implications for current and future access to fish.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01371-3) contains supplementary material, which is available to authorized users. 相似文献
193.
194.
Donald B. Thompson Bryan McDonald 《Journal of Agricultural and Environmental Ethics》2013,26(1):137-163
What makes a food good, for you? With respect to food, the expression “good for you” usually refers to the effect of the food on the nutritional health of the eater, but it can also pertain more broadly. The expression is often used by a person who is concerned with another person’s well-being, as part of an exhortation. But when framed as a question and addressed to you, as an individual, the question can require a response, calling for accountability beyond the realm of nutrition or other material qualities of the food. Economic value may be considered as a ratio: goodness/price. In this paper, we examine the numerator, exploring a broad range of values domains related to food, attempting to obtain a more comprehensive understanding of the meaning of goodness of food. We present a typology of values domains with respect to food, divided into three main categories: (1) material considerations, (2) psychological, psychosocial, and spiritual health, and (3) the well-being of society. This understanding that results from comprehensive consideration of these values domains has important implications for an individual for use in considering the question “what food is good for you?” in order to guide his or her future actions, helping to distinguish between what Dewey termed immediate good and reasonable good. A pragmatic approach to a fuller consideration of food-related values domains by individuals also has broad social, political, and economic implications. If, according to the FAO, food security involves both needs and preferences, consideration of what preferences are appropriate is fundamental to achieving food security. The questions about what is considered to be good food are central to questions about the sorts of food and agricultural systems human societies will seek to sustain. The approach to resolving this important aspect of sustainability might help inform a more general question as to appropriate limitations on preferences, a question fundamental to achieving sustainability in general. 相似文献
195.
The distribution of the introduced European green crab, Carcinus maenas, was investigated in the central California embayments of Bodega Bay Harbor (BBH), Tomales Bay, and Bolinas Lagoon using
baited traps and snorkel surveys. Adult green crabs were very spatially limited in all three embayments and occurred primarily
in warm, shallow areas that lacked large native Cancer spp. crabs. The green crabs that were found in closest proximity to populations of Cancer spp. exhibited high levels of limb damage and loss; damage was strongly correlated with low ratios of intertidal area: edge,
indicative of narrow areas of intertidal that are more easily accessed by large Cancer spp. moving up to forage during periods of tidal inundation. Up to 70% of the green crabs tethered in areas of BBH that are
utilized by Cancer spp. experienced limb loss, while those tethered in the marsh, where there are no Cancer spp., were undamaged. The results suggest that the potential distribution of green crabs in the northeastern Pacific will
be far less than has been predicted, and that their impacts may be largely attenuated through predation by and competition
with native crab species. 相似文献
196.
Restoration of abandoned and degraded ecosystems through enhanced management of mature remnant patches and naturally regenerating (regrowth) forests is currently being used in the recovery of ecosystems for biodiversity protection and carbon sequestration. Knowledge of long-term dynamics of these ecosystems is often very limited. Vegetation models that examine long-term forest growth and succession of uneven aged, mixed-species forest ecosystems are integral to the planning and assessment of the recovery process of biodiversity values and biomass accumulation. This paper examined the use of the Ecosystem Dynamics Simulator (EDS) in projecting growth dynamics of mature remnant brigalow forest communities and recovery process of regrowth brigalow thickets. We used data from 188 long-term monitored plots of remnant and regrowth forests measured between 1963 and 2010. In this study the model was parameterised for 34 tree and shrub species and tested with independent long-term measurements. The model closely approximated actual development trajectories of mature forests and regrowth thickets but some inaccuracies in estimating regeneration through asexual reproduction and mortality were noted as reflected in stem density projections of remnant plots that had a mean of absolute relative bias of 46.2 (±12.4)%. Changes in species composition in remnant forests were projected with a 10% error. Basal area values observed in all remnant plots ranged from 6 to 29 m2 ha−1 and EDS projections between 1966 and 2005 (39 years) were 68.2 (±10.9)% of the observed basal area. Projected live aboveground biomass of remnant plots had a mean of 93.5 (±5.9) t ha−1 compared to a mean of 91.3 (±8.0) t ha−1 observed in the plots. In regrowth thicket, the model produced satisfactory projections of tree density (91%), basal area (89%), height (87%) and aboveground biomass (84%) compared to the observed attributes. Basal area and biomass accumulation in 45-year-old regrowth plots was approximately similar to that in remnant forests but recovery of woody understorey was very slow. The model projected that it would take 95 years for the regrowth to thin down to similar densities observed in original or remnant brigalow forests. These results indicated that EDS can produce relatively accurate projections of growth dynamics of brigalow regrowth forests necessary for informing restoration planning and projecting biomass accumulation. 相似文献
197.
Diana O. Fisher Susan Nuske Sally Green Jennifer M. Seddon Brenda McDonald 《Behavioral ecology and sociobiology》2011,65(4):593-605
One of the few mammal species reported to have a mating system of lek promiscuity is the tree-hollow nesting marsupial, the
agile antechinus, Antechinus agilis. Past conclusions about its mating system have been based on seasonal changes in social group size, sex-specific nest switching
and space use. Thermoregulation has also been suggested as an explanation for variation in social behaviour in this species
and its relatives. We tested predictions of the lekking and thermoregulation hypotheses to explain sociality in cavity nesting
antechinuses using published data, and new data on brown and subtropical antechinuses. We found that across four species,
social group size is negatively correlated with daily minimum temperature, but not with timing of breeding. Females have a
matrilineal fission–fusion social system, which continues during the brief mating season, and males range increasingly further
throughout their lives, contacting as many females as possible in nests. Males show no indication of fission–fusion sociality.
All evidence in species other than A. agilis, and some data on A. agilis, indicate a mating system of scramble polygyny, and not lek promiscuity. We conclude that across species, thermoregulation
is the main reason for seasonal variation in nesting group size in both sexes. 相似文献
198.
Subhas K. Venayagamoorthy Hyeyun Ku Oliver B. Fringer Alice Chiu Rosamond L. Naylor Jeffrey R. Koseff 《Environmental Fluid Mechanics》2011,11(4):329-352
Marine aquaculture is expanding rapidly without reliable quantification of effluents. The present study focuses on understanding
the transport of dissolved wastes from aquaculture pens in near-coastal environments using the hydrodynamics code SUNTANS
(Stanford Unstructured Nonhydrostatic Terrain-following Adaptive Navier–Stokes Simulator), which employs unstructured grids
to compute flows in the coastal ocean at very high resolution. Simulations of a pollutant concentration field (in time and
space) as a function of the local environment (bathymetry), flow conditions (tides and wind-induced currents), and the location
of the pens were performed to study their effects on the evolution of the waste plume. The presence of the fish farm pens
cause partial blockage of the flow, leading to the deceleration of the approaching flow and formation of downstream wakes.
Results of both the near-field area (area within 10 to 20 pen diameters of the fish-pen site) as well as far-field behavior
of the pollutant field are presented. These detailed results highlight for the first time the importance of the wake vortex
dynamics on the evolution of the near-field plume as well as the rotation of the earth on the far-field plume. The results
provide an understanding of the impact of aquaculture fish-pens on coastal water quality. 相似文献
199.
Christine S. Couturier Alice Rouault David McKenzie Robert Galois Serge Robert Lucette Joassard Guy Claireaux 《Marine Biology》2007,152(4):803-814
The French Atlantic coast contains large highly productive intertidal mudflats that are colonised by juveniles of numerous
flatfish species, including the common sole (Solea solea, L.). These ecosystems are also heavily exploited by the shellfish farming industry. Intensive bivalve culture is associated
with substantial biodeposition (1–6 t-dw ha−1 day−1), which directly or indirectly contributes to increase exopolysaccharide (EPS) concentrations at the interface between water
column and seabed. EPS are long-chain molecules organised into colloids, which influence rheological properties of water,
particularly viscosity. Increased water viscosity had consequences for ventilatory activity of juvenile flatfish, whereby
the minimal pressure required to ventilate the medium increases directly with EPS concentration. Moreover, the critical EPS
concentration ([EPS]crit) at which water was no longer able to flow through the branchial basket ranged from almost nil to over 30 mg l−1, depending on species and size. [EPS]crit was lower in small individuals and individuals from species with high metabolic rates (turbot and plaice). These differences
may depend upon gill and bucco-branchial cavity morphometrics. The ventilatory workload of sole increased with viscosity to
a maximum at 2 mg EPS l−1. Viscosity might, therefore, be a limiting factor for flatfish post larvae, which colonise the intertidal mudflats, depending
upon their size and species. EPS concentrations in the field can reach 15 mg l−1. A selective effect is conceivable but remains to be estimated in the field. 相似文献
200.
在脱贫攻坚的大背景下,社会工作专业力量积极参与农村精准扶贫,资源整合是其中的一个重要议题。当前农村贫困对象的资源呈现总体匮乏、资源无联动、资源流失的状态。在农村精准扶贫中,社会工作资源整合需要使贫困对象碎片化的资源状态能够系统化。开展社会工作资源整合,首先需要评估贫困对象的资源需求,然后盘点贫困对象现有资源,并优化资源输送机制,再次需要对整合的资源进行管理与评估。在农村精准扶贫中,也需要反思社会工作资源整合的本土化问题,以及思考后扶贫时代如何针对农村相对贫困群体开展社会工作资源整合服务。 相似文献