Insecticides, polychlorinated biphenyls and metals in african lake ecosystems. III. Lake Nakuru, Kenya

Greichus, Yvonne A.; Greichus, Algirdas; Ammann, B. D.; Hopcraft, John

doi:10.1007/bf01685825

Cited by 44 publications

(8 citation statements)

References 4 publications

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“…The causes of these die-offs are far from being completely understood but appear to be related to the degradation of their habitats. A combination of factors, such as infective diseases (Sileo et al 1979, Kock et al 1999) and poisoning by pesticides and heavy metals (Greichus et al 1978, Kairu 1996, are subjects of ongoing investigations. Nevertheless, the die-offs could also be linked to changes in food quantity (Sileo et al 1979, Ton 2007) and quality (Motelin et al 2000, Ndetei andMuhandiki 2005).…”

Section: Food Algae Of Lesser Flamingomentioning

confidence: 99%

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FLUCTUATING ALGAL FOOD POPULATIONS AND THE OCCURRENCE OF LESSER FLAMINGOS (PHOENICONAIAS MINOR) IN THREE KENYAN RIFT VALLEY LAKES¹

Krienitz

Kotut

2010

Journal of Phycology

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The last two decades have witnessed increasing episodes of lesser flamingo die-offs in East Africa. Based on data on phytoplankton composition, biomass, and flamingo population density in three alkaline-saline lakes of Kenya (Bogoria, Nakuru, and Oloidien) in 2001-2010, this study explored the link between sudden flamingo deaths and fluctuations in algal food quantity and quality. The phytoplankton biomass ranged from 13 to 768 mg AE L )1 . Similarly, flamingo numbers varied widely from <1,000 to >500,000 individuals in the study lakes. The dominance of the cyanobacterium Arthrospira fusiformis (Woron.) Komárek et J. W. G. Lund was interrupted at irregular intervals in each lake and replaced partly by populations of different species of the nostocalean Anabaenopsis or by the picoplanktonic chlorophyte Picocystis salinarum Lewin. The populations of Anabaenopsis have the potential of blocking the flamingo food filtration system with their large and slimy colonies; moreover, they are able to produce cyanotoxins. Estimates of flamingo populations suggest that low flamingo numbers coincided with periods of low algal food quantity and ⁄ or poor quality. A food deficit can be theorized to have two effects on the flamingos: (i) it weakens them to the point of being susceptible to attacks of infective diseases, such as the ones caused by Mycobacterium avium and Pseudomonas aeruginosa, and (ii) it predisposes them to poisoning by cyanotoxins and pollutants, by reducing their capacity to handle toxic substances. This study therefore concludes that the challenges facing the flamingos are associated with changes in their environment, which affect food and water supply.

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Section: Food Algae Of Lesser Flamingomentioning

confidence: 99%

“…1979, Kock et al. 1999) and poisoning by pesticides and heavy metals (Greichus et al. 1978, Kairu 1996), are subjects of ongoing investigations.…”

mentioning

confidence: 99%

FLUCTUATING ALGAL FOOD POPULATIONS AND THE OCCURRENCE OF LESSER FLAMINGOS (PHOENICONAIAS MINOR) IN THREE KENYAN RIFT VALLEY LAKES¹

Krienitz

Kotut

2010

Journal of Phycology

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“…DDT has in the past been detected in Kenya in fish from different areas. Koeman et al (1972) and Greichus et al (1978) reported very low levels of organochlorine residues in Tilapia grahami from Lake Nakuru, while Lincer et al (1981), in a study of DDT contamination in some Rift Valley lakes, reported DDT residue levels of below 1 ppm in T. grahami from Lake Nakuru and in T. nilotica, Clarias mossambicus, Barbus gregorii and Labeo cylindricus from Lake Baringo. Mitema & Gitau (1989) found DDT to range from 2 µg kg −1 (ppb) to 4.51 mg kg −1 (ppm) in the fillet of Nile perch from Lake Victoria.…”

Section: Organochlorinesmentioning

confidence: 99%

Organochlorine and organophosphorus pesticide concentrations in water, sediment, and selected organisms in Lake Naivasha (Kenya)

Gitahi¹,

Harper²,

Muchiri³

et al. 2002

Lake Naivasha, Kenya

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Water, sediment, red swamp crayfish (Procambarus clarkii) and black bass (Micropterus salmoides) from Lake Naivasha were analyzed for selected organochlorine and organophosphorus pesticide residues. The mean p,p'-DDT, o,p'-DDT and p,p'-DDE residue levels recorded in black bass (28.3 (± 30.0), 34.2 (±54.0) and 16.1 (±16.1) µg kg −1 , respectively) and crayfish (4.6 (±5.1), 3.2 (±2.8), and 1.4 (±1.1) µg kg −1 , respectively), were higher than previously recorded. This indicated recent usage of technical DDT in the lake's catchment. Levels of p,p'-DDT, higher than those of p,p'-DDE further emphasized this. Mean lindane, dieldrin, β-endosulfan and aldrin concentrations in black bass were 100.5, 34.6, 21.6 and 16.7 µg kg −1 , respectively. The same residues were detected at lower concentrations in crayfish at 2.0, 2.0, 2.0 and 1.9 µg kg −1 , respectively. The higher fat content (3.7 ± 2.7% SD) in black bass (compared to 0.6 ± 0.3% in crayfish) accounted for the significantly higher residue concentrations in black bass. Organophosphate pesticides were the most commonly used pesticides in the lake's catchment, but none was detected in any of the samples. The results indicate that there is need for further work to identify sources and fate of pesticide contaminants, as well as to improve monitoring of pesticide use throughout the catchment.

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“…These populations, in the East African Rift Valley lakes, have undergone episodic mass mortalities in recent years and it is likely that the cyanotoxins have been among several contributing causes [5]. In addition to cyanotoxins, a number of possible causes for the mass deaths of the flamingos have been suggested; including a Mycobacterium avium related epizootic, heavy metals, pesticides and other organic pollutants [6][7][8]. Cyanotoxins have also been suggested as initiators of avian botulism [9].…”

Section: Introductionmentioning

confidence: 96%

Analysis of the cyanotoxins anatoxin-a and microcystins in Lesser Flamingo feathers†

Metcalf

Morrison

Krienitz

et al. 2006

Toxicological & Environmental Chemistry

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Feathers from carcasses of the Lesser Flamingo (Phoeniconaias minor), which had died after ingesting cyanobacterial toxins (cyanotoxins) contained between 0.02 and 30.0 mg microcystin-LR equivalents per gram of feather according to HPLC and ELISA analysis of feather extracts. Anatoxin-a was detected less frequently in the Lesser Flamingo feathers, up to 0.8 mg anatoxin-a per gram of feather being recorded. When feathers from different body regions were analysed and compared for microcystins and anatoxin-a, wing feathers were found to contain the highest concentrations of these cyanotoxins, the order of concentration and frequency of analytical detection being wing > breast > head. Consistent with the presence of the microcystins and anatoxin-a in gut contents and the livers of the dead birds and negligible in vitro adsorption to feathers, the cyanotoxins associated with the feathers of the dead wild flamingos are inferred to be primarily of dietary origin.

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Insecticides, polychlorinated biphenyls and metals in african lake ecosystems. III. Lake Nakuru, Kenya

Cited by 44 publications

References 4 publications

FLUCTUATING ALGAL FOOD POPULATIONS AND THE OCCURRENCE OF LESSER FLAMINGOS (PHOENICONAIAS MINOR) IN THREE KENYAN RIFT VALLEY LAKES¹

FLUCTUATING ALGAL FOOD POPULATIONS AND THE OCCURRENCE OF LESSER FLAMINGOS (PHOENICONAIAS MINOR) IN THREE KENYAN RIFT VALLEY LAKES¹

Organochlorine and organophosphorus pesticide concentrations in water, sediment, and selected organisms in Lake Naivasha (Kenya)

Analysis of the cyanotoxins anatoxin-a and microcystins in Lesser Flamingo feathers†

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Insecticides, polychlorinated biphenyls and metals in african lake ecosystems. III. Lake Nakuru, Kenya

Cited by 44 publications

References 4 publications

FLUCTUATING ALGAL FOOD POPULATIONS AND THE OCCURRENCE OF LESSER FLAMINGOS (PHOENICONAIAS MINOR) IN THREE KENYAN RIFT VALLEY LAKES1

FLUCTUATING ALGAL FOOD POPULATIONS AND THE OCCURRENCE OF LESSER FLAMINGOS (PHOENICONAIAS MINOR) IN THREE KENYAN RIFT VALLEY LAKES1

Organochlorine and organophosphorus pesticide concentrations in water, sediment, and selected organisms in Lake Naivasha (Kenya)

Analysis of the cyanotoxins anatoxin-a and microcystins in Lesser Flamingo feathers†

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FLUCTUATING ALGAL FOOD POPULATIONS AND THE OCCURRENCE OF LESSER FLAMINGOS (PHOENICONAIAS MINOR) IN THREE KENYAN RIFT VALLEY LAKES¹

FLUCTUATING ALGAL FOOD POPULATIONS AND THE OCCURRENCE OF LESSER FLAMINGOS (PHOENICONAIAS MINOR) IN THREE KENYAN RIFT VALLEY LAKES¹