An ecological study of the algae of the river Moosi, Hyderabad (India) with special reference to water pollution

Section: Discussionsupporting

confidence: 66%

Diatom distribution and status of organic pollution in sewage drains

Dakshini

Soni

1982

“…Therefore poor light penetration, coupled with high current velocity is the sole factor checking the development of phytoplankton in the Blue Nile during the flood season. This is similar to conditions in many other rivers (Berner, 1951;Lakshminarayana, 1965;Venkateswarlu, 1969).…”

Section: Discussionsupporting

confidence: 58%

A quantitative study of the phytoplankton in the Blue and White Niles at Khartoum

Sinada

Karim

1984

The variation in numbers of the major planktonic algae in the surface waters of the Blue Nile and White Nile were followed for 29 months (August 1968-December 1970. In terms of biomass, the phytoplankton was dominated by diatoms and blue-green algae; other groups were of minor importance. High phytoplankton densities occurred during winter in both rivers, and during summer in the Blue Nile, with values in the latter river greater than in the former. Melosira granulata and its variety angustissima and Anabaena flos-aquae var. intermedia f. spiroides were the most important taxa in the two Niles. Melosira distans and A ttheya zachariasi, which are reported for the first time in the present study, preponderated at certain times in the Blue Nile. Microcystisflos-aqua which had been a minor component of the phytoplankton in both rivers during the early 1950s, showed a profuse growth in the Blue Nile. Lyngbya limnetica, Anabaenopsis cunningtonii and A. tanganyikae, which constituted important components of the phytoplankton in the early 1950s, either disappeared or maintained themselves in reduced numbers during the present study. This change in the algal flora of the two Niles may be attributed to the construction of the Roseres dam across the Blue Nile in 1966 and to the invasion of the White Nile by Eichhornia crassipes in 1957.

“…Presumably these high concentrations, contributed by tributaries from Ethiopian soils. Venkateswarlu (1969) pointed out that rain plays an important role in bringing nitrates into the River Moosi, India. A similar finding was observed in River Volta (Biswas, 1968).…”

Section: Sunshine (Fig 3b)mentioning

confidence: 99%

“…In the White Nile, appreciable quantities of dissolved iron were maintained throughout the year (0.04-0.46 mg 1-1), with peaks during the rainy season. Holden & Green (1960), Lakshminarayana (1965), Venkateswarlu (1969), and Boyden et al (1978) observed, in different tropical rivers, that the level of dissolved iron increased with increasing discharge during the rainy season.…”

Section: O_()mentioning

confidence: 99%

Physical and chemical characteristics of the Blue Nile and the White Nile at Khartoum

Sinada¹,

Karim²

1984

Fortnightly measurements of physical and chemical variables were made at two locations on the Blue and White Niles near Khartoum from August 1968 to December 1970. Variables analysed from each river were: temperature, pH, total residue, current velocity, oxygen, alkalinity, phosphate, nitrate, ammonia, silica, sulphate, iron, calcium, magnesium, sodium, potassium and oxidizable organic matter. The seasonal variations of these factors in the two Niles are compared and the interrelationships existing between some of them are discussed. Comparisons with earlier studies on the Nile and with some tropical rivers are made.In the Blue Nile, the amounts of suspended matter and nutrients are largely dependent upon the flood regime. Nitrate, phosphate, iron, oxidizable organic matter and total residue increase considerably in the Blue Nile when the river is in flood (peaks: 1 880 /zg N0 3 -N 1; 0.31 mg Fe 1-1; 3 842 mg total residue · I 1).In the White Nile, concentrations of nitrate, phosphate, iron, oxidizable organic matter and total residue attain their peaks during the rainy season (270 g NO 3 -N 1 ; 163 tzg PO4-P 1-1; 0.46 mg Fe 1; 502 mg total residue-1-1).In both rivers, alkalinity, calcium, sodium and potassium tend to increase during the dry season while declining in the rainy season. Silica is depleted at certain times of the year, yet relatively high concentrations are maintained throughout the year and were not expected to limit growth of diatoms. Fall in silica concentrations, unlike nitrate, phosphate and iron, was always followed by a rapid restoration of a high level. Silica and magnesium showed no response to changes in discharge rates.