scholarly journals A further investigation into the bioaccumulation of lead and zinc in the organs and tissues of the African sharptooth catfish, Glorias gariepinus from two localities in the Olifants River, Kruger National Park

Koedoe ◽  
1998 ◽  
Vol 41 (2) ◽  
Author(s):  
H.M. Marx ◽  
A. Avenant-Oldewage

The bioaccumulation of lead and zinc in the gills, liver, muscle and skin of Glorias gariepinus from two locations, Mamba and Balule, on the Olifants River within the Kruger National Park is reported here. Over a one year period (1994), four surveys (February, May, July and November) were undertaken. Atomic absorption spectrophotometry was used to determine the concentrations of both metals in the tissues. The gills were the major route of uptake, with the liver accumulating high lead and zinc concentrations. The concentration of metals in the fish found at Mamba and Balule were found to be significantly different from each other. However, it could not be established at which location the greatest amount of bioaccumulation had taken place. The influences of temperature, alkalinity, salinity and pH on metal toxicity, bioavailability and bioaccumulation rates are discussed in detail. It is imperative that pollution levels in the Olifants River and its effect on fish is continually monitored and captured, so as to main- tain and conserve this river and the biota dependant on it.

Koedoe ◽  
2000 ◽  
Vol 43 (2) ◽  
Author(s):  
Annemarie Avenant-Oldewage ◽  
Hazel Marx

The gills, liver, muscle and skin were collected from Clarias gariepinus, during four surveys (February, May, June and November) in 1994 from two sites on the Olifants River in the Kruger National Park. With the use of atomic absorption spectrophotometry, metal concentrations of manganese, nickel and strontium bioaccumulated in these tissues were determined. This information was then used to differentiate between the concentrations found at the two locations and between the four survey periods. The con- centration of the metals were found to be highest in the gills, followed by the liver. This suggests the gills to be the primary uptake tissue for these metals following their intimate blood-water contact. The concentration of manganese and strontium, with particular reference to the gills, showed highest bioaccumulation at Mamba. Very little differences in the nickel concentrations were found at both Mamba and Balule. Water bioconcentration factors for manganese and nickel were much higher than that noted for sediment, suggesting a much lower bioavailability of these metals from the sediment. On the other hand, sediment bioconcentration factors for strontium were generally higher than that for water, which could imply higher bioavailability and concentration from the sediment.


Koedoe ◽  
1997 ◽  
Vol 40 (1) ◽  
Author(s):  
H.H. Du Preez ◽  
M. Van der Merwe ◽  
J.H.J. Van Vuren

The level of metal (Cr, Cu, Mn, Ni, Pb and Zn) bio- accumulation in tissues (muscle, gill, kidney, liver and gonads) and bile of the African catfish Clarias gariepinus, from the lower Olifants River was investigated. These metals were detected in all the tissues as well as in the bile, with the highest concentration found in either the gills, liver or gonadal tissue. The lowest concentration was usually detected in the muscle tissue. Although statistic comparisons revealed no significant differences between the localities, fish from the Selati River (Locality 1) generally had higher metal levels than fish from the localities along the Olifants River inside the Kruger National Park. The higher levels in the fish from the Selati River may be attributed to anthropogenic activities resulting in point and/or diffuse sources of metal pollution. These sources should be identified and reduced.


Koedoe ◽  
1999 ◽  
Vol 42 (1) ◽  
Author(s):  
V. Wepener ◽  
J.H.J. Van Vuren ◽  
H.H. Du Preez

Large sets of water quality data can leave water quality managers and decision-makers totally overwhelmed. In order to convey the interpretation of the data in a simplified and understandable manner, the water quality results from bi-monthly surveys undertaken at seven different sampling sites in the Letaba, Olifants, and Selati rivers over a two year period (February 1990 to April 1992) were reduced to index values, using a water quality index. The water quality index (Aquatic Toxicity Index or ATI) revealed spatial and temporal trends. The higher index values, recorded for the sampling sites towards the eastern part of the Kruger National Park (KNP), revealed that the water quality was better than the quality measured in the Olifants River on the western bound-ary. The lowest index values were calculated for the Selati River, with index values consistently below 50. Index values indicate that the water quality in the Selati River was unsuitable for supporting normal physiological processes in fish. The water quality of the Selati River had an immediate impact on the water quality of the Olifants River directly below the confluence. Lower index values recorded at sites further downstream was also attributed to the influence of the Selati River since there are no known point sources of contaminants within the boundaries of the KNP. The index scores also elucidated temporal trends with lower scores evident during winter months. This was due to reduced flow in the Olifants River and a greater contribution of contaminated water from the Selati River. Index values increased following the first seasonal rains due to a dilution effect. Very low index values were recorded at certain sites during flood periods due to increased turbidity, reduced oxygen, and increased metal concentrations.


Koedoe ◽  
2001 ◽  
Vol 44 (1) ◽  
Author(s):  
B.P. Moon ◽  
G.L. Heritage

The Letaba River drains part of Northern Province in north-east South Africa. Its catchment has been modified significantly by human activity which has affected the flow regime; it experiences only ephemeral flows through the Kruger National Park to its confluence with the Olifants River. Although the Letaba is similar to the other rivers in the Kruger National Park in that it displays some bedrock influenced channel features, increased sediment delivery from the degraded catchment upstream has resulted in extensive alluviation within the channel. Sections of channel flowing over bedrock with no sediment covering are rare, and the river comprises a series of channel types: mixed anastomosing, alluvial braided, mixed pool-rapid and alluvial single thread. Each is characterised by a different combination of morphological units which relate to the degree of alluviation in the channel. These channel types are described in detail and inferences are made concerning their formation and maintenance from field observation and measurement.


Crustaceana ◽  
1996 ◽  
Vol 69 (4) ◽  
pp. 509-523 ◽  
Author(s):  
A. Avenant-Oldewage ◽  
Hazel M. Marx

AbstractThe morphology of the gill parasite Lamproglena clariae Fryer, 1956, from the Olifants River, Kruger National Park, South Africa, was studied with the aid of light and scanning electron microscopy. Ultrastructural details of all appendages are given as well as a table and map with information on the occurrence and distribution of L. clariae in Africa. Important morphological findings include: the observation of only one claw on the maxilla; first time findings and descriptions of the nuchal organ, upper and lower lips, the fifth pair of legs and circular openings on all appendages.


1995 ◽  
Vol 32 (5-6) ◽  
pp. 103-109
Author(s):  
C. M. Breen ◽  
H. Biggs ◽  
M. C. Dent ◽  
A. Görgens ◽  
J. O'Keeffe ◽  
...  

Growing perceptions that ecological research is failing to meet the needs of resource managers has prompted a review of the structure and management of research programmes. In this paper we identify principles, frameworks and approaches to guide the restructuring of research programmes. Their application is discussed in relation to the restructured research programme on the rivers flowing through the Kruger National Park. A preliminary evaluation after one year of operation of this programme indicated beneficial changes in research and in stakeholder and client attitudes to research.


Koedoe ◽  
1995 ◽  
Vol 38 (2) ◽  
Author(s):  
Y. Buermann ◽  
H.H. Du Preez ◽  
G.J. Steyn ◽  
J.T. Harmse ◽  
A. Deacon

Silt loads in the Olifants and Sabie river systems inside the Kruger National Park, were monitored by collecting water samples every consecutive week for a period of 20 months. The variation in silt concentration, changes in selected physico-chemical water quality variables and fish mortalities during flushing (i.e. release of silt, by sluicing) of the Phalaborwa Barrage, were also monitored. The Olifants River inside the Kruger National Park carried high silt loads in summer; in the dry season the suspensoid load was greatly reduced. A similar pattern was observed in the Sabie River, but the silt loads were generally lower. It was apparent that silt loads released from the Phalaborwa Barrage led to large variations in the natural silt loads of the Olifants River. These increased amounts of silt (25 000 mg/1 to >70 000 mg/1) caused drastic reductions in the dissolved oxygen concentration of the water, ranging from >6 mg/1 to 0 mg/1. Depending on the severity and duration of the flushing, fish succumb to such silt loads. These findings, as well as published information, indicate that the management strategy of flushing to improve storage capacity is ecological unacceptable. It is therefore suggested that the use of the Phalaborwa Barrage as a future reservoir should be critically re-evaluated.


Koedoe ◽  
2000 ◽  
Vol 43 (2) ◽  
Author(s):  
D.G.J. Swanepoel ◽  
N.S. Ferguson ◽  
M.R. Perrin

Data on the nesting behaviour of Crocodylus niloticus along the Olifants River in the Kruger National Park were collected over a period of six years (1993 to 1998). A total of 165 nests were investigated for soil type, exposure to sunlight, distance to and above water, presence of other nests and vegetation. An attempt was made to determine important factors in the placement of nests, and exposure to sunlight, vegetation and distance to water seemed to be crucial in selecting a nesting site. During the last two seasons 20 nests were opened and the nest contents recorded. Some 795 eggs were measured and the data compared to similar studies in Africa. No significant differences were found. A strong correlation was found between egg mass, length and female size with larger females producing larger eggs. Rainfall influenced the size of nesting females as only larger females (>3 m TL) nested during the dry year. Breeding females along the Olifants were overall larger (TL) than in Zimbabwe with 2.1 m as the smallest and 4.1 as the largest females that nested.


Sign in / Sign up

Export Citation Format

Share Document