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101.
Finding aquaculture development approaches to open up livelihood opportunities for the rural poor and in mainstreaming smallholder fish farmers to reduce poverty remain a challenge. This paper examines the community-based technology transfer mechanism of mudcrab nursery in ponds and its socioeconomic impacts on smallholder mudcrab growers in Northern Samar, Philippines. Results indicated that the technology is a viable enterprise done by a straight culture system method, which is the rearing of crablets from <1.0 to 4.0 cm for 42 days, or by-phases. However, technology adoption hinges on many factors like area ownership, farm distance from household, and market including the type of strategy needed to enhance technology uptake. Collaboration among research and development institutions and local partners is critical in training and empowering rural communities to adopt aquaculture technologies.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-014-0528-5) contains supplementary material, which is available to authorized users. 相似文献102.
Koengkan Matheus Santiago Renato Fuinhas José Alberto Marques António Cardoso 《Environmental Economics and Policy Studies》2019,21(4):507-532
Environmental Economics and Policy Studies - The impact of financial openness on environmental degradation, mainly via carbon dioxide emissions, was investigated for a panel of 21 Latin American... 相似文献
103.
The 28-hectare tilapia cage culture that occupied the 104-hectare Sampaloc Lake, a crater lake, shifted to intensive method in 1986 when tilapia growth slowed done at the beginning of 1982. Thus, commercial feeds became the main source of allochthonous organic matter in the lake. Total feeds given annually for the 28-hectare cage culture at 3 croppings per year amounted to 5250 tons. At feed conversion ratio of 1 : 2 a significant portion of the feeds given ended as organic wastes in the lake. In 1988, tilapia cage operators began experiencing their worst occurrences of fishkill, worth millions of pesos. An assessment of the dissolved oxygen condition of Sampaloc lake in late 1989, 1990 and mid-1991 showed ominous trends which might adversely affect the use of Sampaloc lake for fishery. 相似文献
104.
Mendoza-Salgado RA Lechuga-Devéze CH Ortega-Rubio A 《Journal of environmental management》2005,75(2):183-187
At Ensenada de La Paz, a coastal lagoon on the western side of the Gulf of California, nutrient and salinity data before and after rain events were evaluated using a mass balance model to estimate the exchange of conservative and non-conservative variables with the adjacent sea. Surface salinity, nitrogen (N-NO3, N-NO2), and phosphorus (PO4) were used in the model to obtain the hydraulic balance, water residence time, and nitrogen and phosphorus fluxes. Results showed that residual volume was mainly influenced by evaporation. Rainfall and runoff increased the mixed volume and reduced water residence time. Pre-rainfall hydraulic balance conditions were reestablished about 10 days after a rain storm. Rainwater inputs also modified the quality of the coastal lagoon: the pre-rainfall scenario showed that more nitrogen is consumed than produced, and there is a phosphorus sufficiency. A rain disturbance induces a nitrogen and phosphorus increase. Eleven days after a rain storm, nitrogen and phosphorus levels did not return to the pre-rainfall scenario. Rain disturbances in arid zone coastal lagoons modify their water quality and exchange with the adjacent ocean; some management strategies are suggested. 相似文献
105.
Selena Sironi Laura Capelli Paolo Céntola Renato Del Rosso Sauro Pierucci 《Atmospheric environment (Oxford, England : 1994)》2010,44(3):354-360
This work discusses how it is possible to assess odour impact in presence of multiple similar sources by illustrating a case study. The study was conducted on an area of northern Italy comprising three small municipalities where four rendering plants are located near to each other. Based on the emission data resulting from olfactometric surveys conducted in different periods of the year the overall odour emission rate emitted by each plant were evaluated, showing that the major contributor to the odour impact on the territory was plant 2. These data were linked with meteorological and orographical data in order to evaluate odour dispersion with a model (Calpuff). The results of the odour dispersion modelling confirmed the outcomes of the olfactometric survey and they were further validated through a “questioning” survey, conducted with the aim of involving the population by means of questionnaires for reporting the perceived odour episodes, which showed a good correspondence (86.5%) between odour perceptions and simulated odour immissions. 相似文献
106.
107.
Negative density-dependent mortality can promote species coexistence through a spacing mechanism that prevents species from becoming too locally abundant. Negative density-dependent seedling mortality can be caused by interactions among seedlings or between seedlings and neighboring adults if the density of neighbors affects the strength of competition or facilitates the attack of natural enemies. We investigated the effects of seedling and adult neighborhoods on the survival of newly recruited seedlings for multiple cohorts of known age from 163 species in Yasuni National Park, Ecuador, an ever-wet, hyper-diverse lowland Amazonian rain forest. At local scales, we found a strong negative impact on first-year survival of conspecific seedling densities and adult abundance in multiple neighborhood sizes and a beneficial effect of a local tree neighborhood that is distantly related to the focal seedling. Once seedlings have survived their first year, they also benefit from a more phylogenetically dispersed seedling neighborhood. Across species, we did not find evidence that rare species have an advantage relative to more common species, or a community compensatory trend. These results suggest that the local biotic neighborhood is a strong influence on early seedling survival for species that range widely in their abundance and life history. These patterns in seedling survival demonstrate the role of density-dependent seedling dynamics in promoting and maintaining diversity in understory seedling assemblages. The assemblage-wide impacts of species abundance distributions may multiply with repeated cycles of recruitment and density-dependent seedling mortality and impact forest diversity or the abundance of individual species over longer time scales. 相似文献
108.
Fish as indicators of disturbance in streams used for snorkeling activities in a tourist region 总被引:1,自引:0,他引:1
A set of metrics that reflect various aspects of population and fish community structure in streams used for snorkeling was
evaluated in the tourist region of Bodoquena Plateau, Brazil, with the purpose of biomonitoring the impacts of such activities.
Observations were made while snorkeling in two sites (active = with tourism; inactive = without tourism) and along the gradient
of daily tourist activity (before, during and after the passage of tourists) in two streams. Five metrics discriminated active
from inactive sites: (i) the abundance of Crenicichla lepidota and (ii) the incidence of reproductive activity in Crenicichla lepidota which were greater in inactive sites, regardless the gradient of daily tourist activity; (iii) the feeding pattern of Prochilodus lineatus, which differed among sites and along the gradient of daily tourist activity; (iv) the abundance of Moenkhausia bonita, which was higher in the active sites and significantly increased along the gradient of daily tourist activity in one stream
but decrease along the gradient in other stream; (v) the abundance of Hyphessobrycon eques, which was greater in inactive sites, regardless the gradient of daily tourist activity. With the exception of metric “iv”,
the metrics were mediated by the reduction in habitat structural complexity due to snorkeling disturbance. The definition
of these metrics is relevant because the degradation of ecosystem structural elements is one of the main impacts of recreational
activities on aquatic environments. The easy recognition of target species and high water transparency throughout the year
ensures the feasibility of these metrics in monitoring programs and may be applied by technicians after quick guides and training. 相似文献
109.
Gabriele LanducciAlessandro Tugnoli Valentina BusiniMarco Derudi Renato RotaValerio Cozzani 《Journal of Loss Prevention in the Process Industries》2011,24(4):466-476
On June 29th, 2009 the derailment of a freight train carrying 14 LPG (Liquefied Petroleum Gas) tank-cars near Viareggio, in Italy, caused a massive LPG release. A gas cloud formed and ignited triggering a flash-fire that resulted in 31 fatalities and in extended damages to residential buildings around the railway line. The vulnerability of the area impacted by the flash-fire emerged as the main factor in determining the severity of the final consequences. Important lessons learnt from the accident concern the need of specific regulations and the possible implementation of safety devices for tank-cars carrying LPG and other liquefied gases under pressure. Integrated tools for consequence assessment of heavy gas releases in urban areas may contribute to robust decision making for mitigation and emergency planning. 相似文献
110.