نتایج جستجو برای: eutrophication
تعداد نتایج: 4268 فیلتر نتایج به سال:
The aim of this study was to assess the eutrophication and trophic status of the Caspian Sea based on different indices and also compare its status with the reference threshold values in the Iranian coastal waters of Caspian Sea (hereafter ICWCS). The water samples (three replicates) were collected along four transects (off the coast from Anzali, Tonekabon, Nowshahr and Amirabad) between spring...
In order to evaluate life cycle assessment (LCA) for rice agroecosystems based on mean of nitrogen fertilizer levels (less than 190, 190-200, 200-210, 210-220 and more than 220 kg N ha) during 1999-2012, an experiment was conducted. Four steps includung goal definition and scoping, inventory analysis, life cycle impact assessment and integration and interpretation were computed. Functional unit...
To investigate the influence of eutrophication on organochlorine dynamics in lotic systems, we related polychlorinated biphenyl (PCB) concentrations in brown trout (Salmo trutta) to the periphyton density and total phosphorus concentrations (Tot-P) in 10 Swedish rivers. Tot-P concentrations in the water ranged from 37 6 4 to 156 6 51 mg L21. Periphyton density in the rivers during the experimen...
Current intensive pig production is often associated with environmental burdens. However, very few studies deal with the environmental performance of both current and alternative systems of pig production. The objectives of this study were to evaluate the environmental impacts of three contrasting pig production systems using the life cycle assessment method and to identify hot spots for each s...
Chesapeake Bay has been the subject of intensive research on cultural eutrophication and extensive efforts to reduce nutrient inputs. In 1987 a commitment was made to reduce controllable sources of nitrogen (N) and phosphorous (P) by 40% by the year 2000, although the causes and effects of eutrophication were incompletely known. Subsequent research, modeling, and monitoring have shown that: (i)...
Coral reefs of the Central Red Sea display a high degree of endemism, and are increasingly threatened by anthropogenic effects due to intense local coastal development measures. Overfishing and eutrophication are among the most significant local pressures on these reefs, but there is no information available about their potential effects on the associated microbial community. Therefore, we comp...
iran is among the biggest emitters of greenhouse gasses in the world. agricultural sector has a remarkable role in non-renewable energy consumption and then, the environmental impacts in this country. in this regard, the environmental impacts of watermelon production as the most important melons produced in guilan province of iran were investigated through the life cycle assessment (lca) approa...
Background and purpose: The study aimed to investigate the trophic state of Ekbatan Dam Lake. In the current research, the quality of water behind the dam was studied during the months July and January in order to compare the trophic state and zonation of the reservoir in two different seasons (dry and wet). Materials and Methods: 15 sites were selected in different points of Ekbatan Dam Lak...
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