Algae are the population of microscopic single and multiple-celled aquatic plants that live in water. While most individual algal cells can only be viewed using an instrument such as a microscope, algal blooms give color to the pond water. When populations of algal cells multiply, thereby clouding or giving color to a pond, it is called an algal bloom. Another term used to describe algae is phy...

An intermittent discharge waste stabilisation pond system was trialled for treatment of a seasonal wastewater load from a campsite. The system showed rapid acclimatisation to incoming load, with chlorophyll-a exceeding 700 mg l(-1) within 2 weeks and filtered and unfiltered effluent biochemical oxygen demand below 20 and 30 mg l(-1) respectively. Good performance continued for some weeks, after...

An experiment on integrated walking catfish-tilapia culture was conducted for 5 months. The walking catfish were stocked at 400 and 800 fish/cage in two 4-m nylon cages, which were suspended in each of two 250-m earthen ponds. Sex-reversed male tilapia (Oreochromis niloticus) were reared at 1 fish/m2 in the open pond. Whereas the catfish were reared with supplemental feed, tilapia were solely d...

Studies related to nictemeral variation were executed in a fish growing pond, during all the seasons of the year, collecting data for dissolved oxygen; temperature; pH and electrical conductivity at the feeding channel on pond's surface, bottom and at streamlet bed. The results showed that Autumn was the season which had the lowest values of water temperature, the interval points, during Spring...

Eight, three-day workshops were given in Bangladesh, Cambodia, Laos, Nepal, Thailand, and Vietnam during June to July 2002. These workshops focused on practical aspects of how to use principles of pond dynamics to improve pond management and optimize fertilization efficiencies for natural food production in semi-intensive aquaculture systems. The centerpiece of the workshops was learning how to...

Small freshwater ponds host diverse and vulnerable biotic assemblages but relatively few conspicuous, specially protected taxa. In Europe, the amphibians Triturus cristatus and Pelobates fuscus are among a few species whose populations have been successfully restored using pond restoration and management activities at the landscape scale. In this study, we explored whether the ponds constructed...

Pre-emergence herbicide residues were detected in domestic wells sampled near Tracy, CA. This study sought to determine the source of contamination by comparing soil distribution of diuron [N'-(3,4-dichlorophenyl)-N,N-dimethylurea] and hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione] in an agricultural field where the soil was a cracking clay to infiltration ...

MULHOUSE, J. M. (University of Georgia, Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802), D. DE STEVEN (USDA Forest Service, Southern Research Station, Center for Bottomland Hardwoods Research, P.O. Box 227, Stoneville, MS 38776), R. F. LIDE (Northwest Florida Water Management District, 81 Water Management Dr., Havana, FL, 32333), AND R. R. SHARITZ (University of Georgia, Savannah ...

ABSTRACT The objectives of the present study are to determine the cycle and budget of nitrogen in larviculture ponds of the swimming crab Portunus rrituberculatus and to evaluate their impact on water quality and survival rate. Field surveys were carried out at the Hiroshima Prefecture Fish Farming Center from 1990 to 1993. Among nitrogenous compounds. concentrations of NH -N and particulate or...

Ammonium nitrate explosives are used in mining operations at Diavik Diamond Mines Inc. in the Northwest Territories, Canada. Residual nitrogen is washed into the mine pit and piped to a nearby retention pond where its removal is accomplished by microbial activity prior to a final water treatment step and release into the sub-Arctic lake, Lac de Gras. Microbial removal of ammonium in the retenti...