1978 (Ref.1): "The water in the estuary is rarely clear. Dredging at the Umgeni Sandworks upstream is constantly stirring the bottom ooze. Only in winter, with low river flows, and on a high spring tide can the water be considered as clear"
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MGENI ESTUARY: Water Quality |
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Physio-chemical Characteristics |
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1978 (Ref.1): "Whilst the Mgeni river system is of reasonably good water quality, conditions deteriorate markedly in the estuary due to sources of pollution in the lower Mgeni. Van der Riet has recently studied certain aspects of the chemistry of the Beachwood creek, mainly to investigate the exchange of suspended and dissolved material between the estuary and the mangroves, over a full (both spring and neap) tidal cycle. The results obtained reveal the net gain or loss of such materials with each tide. On three of the four tidal cycles studied, there was a net export of particulate organic matter, nitrite and total phosphorus from the mangrove swamp into the estuary" |
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1978 (Ref.1): "The water in the estuary is rarely clear. Dredging at the Umgeni Sandworks upstream is constantly stirring the bottom ooze. Only in winter, with low river flows, and on a high spring tide can the water be considered as clear" |
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1978 (Ref.1): Salinity - "At spring tide, salinities of 31% can be recorded at the bottom of the estuary, 2 km from the mouth. Distinct stratification becomes evident ±1 km from the mouth, but at the mouth itself salinities are high (35%) and evenly distributed from top to bottom. During high flow periods, salinities naturally fall dramatically and the system assumes ‘river mouth’ characteristics. In May and August 1972 salinities of 4,6% and 3,3% respectively were recorded from near the mouth of the estuary. Information on salinities inn the Beachwood creek are available for three months of 1976. At low tide the creek carries water which is almost fresh" |
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Pollution |
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1978 (Ref.1): "Industrial areas on the Palmiet river have been known to pollute the system, but the chemistry of the estuary is dominated by the overpowering degree of pollution from the Zeekoe (or Piesang) river sewage discharge. Indices such as a rise in phosphorus from 16 micrograms/litre to 270 micrograms/litre in August 1972 are indicative of the magnitude thereof. Industries immediately above the estuary also pollute the system at times. In July 1971 a spill of crude furnace oil and on two occasions the release of some respiratory poison, all had disastrous results in the estuary. Fibre desposal by the S.A. Board Mills is a problem. Pollutants are said to seldom enter the Beachwood creek, with the result that this area acts as a reservoir of life to re-populate the estuary." |
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