نتایج جستجو برای: ponds and channels

تعداد نتایج: 16848695  

2015
Peggy W Lehman Shawn Mayr Leji Liu Alison Tang

The loss of inorganic and organic material export and habitat produced by freshwater tidal wetlands is hypothesized to be an important contributing factor to the long-term decline in fishery production in San Francisco Estuary. However, due to the absence of freshwater tidal wetlands in the estuary, there is little information on the export of inorganic and organic carbon, nutrient or phytoplan...

2016
M. J. Hill C. D. Sayer P. J. Wood

Ponds are sites of high biodiversity and conservation value, yet there is little or no statutory monitoring of them across most of Europe. There are clear and standardised protocols for sampling aquatic macroinvertebrate communities in ponds, but the most suitable time(s) to undertake the survey(s) remains poorly specified. This paper examined the aquatic macroinvertebrate communities from 95 p...

Journal: :Journal of environmental biology 2008
K Manjappa C Vasudevappa

Experiments were conducted in non-desilted and de-silted earthen nursery ponds for a period of fifteen days to evaluate the growth and survival of Catla spawn. The fry attained an average weight of 42.03 +/- 0.36 and 74.36 +/- 72 mg, with a survival rate of 23.44 +/- 0. 31 and 50.91 +/- 0.21% in non-desilted and de-silted ponds respectively Mentioned length data also indicate that growth and su...

2013
Taylor L. Hall Daniel Saenz Matthew A. Kwiatkowski

Differential jumping performance in newly metamorphosed Blanchard’s cricket frogs Acris blanchardi (Anura: Hylidae) from fishand invertebrate-dominated ponds. Organisms that adopt phenotypically plastic anti-predator strategies during larval stages may incur fitness costs later in development. These costs are typically difficult to define in many species. The difficulty of identifying ecologica...

Journal: :Social Psychological and Personality Science 2017

2002

in the southeastern United States is conducted in earthen ponds. Good production from ponds is encouraged by using manufactured feeds or increasing the availability of natural foods by adding fertilizers. Less than 30% of the nitrogen and phosphorus added in feed or fertilizer is recovered at harvest. The remainder of the nutrient load is left in the pond, and may be discharged when it rains or...

Journal: :international journal of environmental research 0

a research was conducted at kauma oxidation ponds, a sewage water treatment plant found in lilongwe, malawi with an aim of establishing the efficiency of these sewage treatment ponds in treating sewage wastewater. water samples from the effluent discharging points in the maturation ponds were collected and analysed in the labouratory for, bod, coliform bacteria, total nitrogen (tn), phosphorous...

Journal: :Journal of environmental biology 2007
J R Bhuiyan S Gupta

A hydrobiological study conducted in nine different ponds of a rural area of Barak Valley, Assam, showed that the concentrations of chemical parameters like dissolved oxygen, free carbon dioxide, pH, conductivity alkalinity nitrate, phosphate, calcium, magnesium, copper and zinc are within the permissible levels of drinking water quality standard of WHO and ISI. However iron content was higher ...

2012
Jesper Hedegaard Clausen Henry Madsen K. Darwin Murrell Van Phan Thi Hung Nguyen Manh Khue Nguyen Viet Anders Dalsgaard

BACKGROUND Fish-borne zoonotic trematodes (FZT) are a food safety and health concern in Vietnam. Humans and other final hosts acquire these parasites from eating raw or under-cooked fish with FZT metacercariae. Fish raised in ponds are exposed to cercariae shed by snail hosts that are common in fish farm ponds. Previous risk assessment on FZT transmission in the Red River Delta of Vietnam ident...

2005
D. G. Gledhill P. James D. H. Davies

Ponds have a range of ecological, social and aesthetic values. However, little work has been done to appraise the values assigned to ponds located in an urban setting. During 2004, 10 ponds were studied in urban areas of Merseyside. Standard ecological techniques were applied to assess diversity of invertebrates, plants and amphibians. A landscape character assessment technique was used to desc...

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