An Ecological Study on the Maluti Minnow (Pseudobarbus Quathlambae) in the Catchment Area of Phase Ib of the Lesotho Highland Water Scheme
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COPYRIGHT AND CITATION CONSIDERATIONS FOR THIS THESIS/ DISSERTATION o Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. o NonCommercial — You may not use the material for commercial purposes. o ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original. How to cite this thesis Surname, Initial(s). (2012) Title of the thesis or dissertation. PhD. (Chemistry)/ M.Sc. (Physics)/ M.A. (Philosophy)/M.Com. (Finance) etc. [Unpublished]: University of Johannesburg. Retrieved from: https://ujdigispace.uj.ac.za (Accessed: Date). BP.1t/ !JviiJvJv AN ECOLOGICAL STUDY ON THE MALUTI MINNOW (PSEUDOBARBUS QUATHLAMBAE) IN THE CATCHMENT AREA OF PHASE IB OF THE LESOTHO HIGHLAND WATER SCHEME BY JOHANNESLAMBERTUSRALL THESIS SUBMIITED IN FULFILMENT OF THE DEGREE OF MASTER OF SCIENCE IN ZOOLOGY IN TIlE FACULTY OF SCIENCE AT THE RAND AFRIKAANS UNIVERSITY SUPERVISOR: DR. GJ. STEYN CO-SUPERVISOR: PROF. H.H. DU PREEZ CO·SUPERVISOR: DR. M. l\lAEMA NOVEMBER 1993 Aan my liefdevolle ouers Psalm 121: "Ek slaan my oe op na die berge: waar sal my hulp vandaan kom?" ACKNOWLEDGEMENTS * I would like to express my sincere appreciation towards my supervisors, Dr. GJ. Steyn, Professor Hein H. Du Preez and Dr. M. Maema for support, guidance, encouragement, their professional commitment to conservation and their acknowledgment of the importance of individualism. * We are indebted to our sponsors, Lesotho Highlands Development Authority, Mazda Wildlife Fund, ENGEN, and Endangered Wildlife Trust. Without their respective contributions the project would not have been possible. Transportation of equipment, the major logistical problem, was partly overcome by an offroad vehicle provided by Mazda Wildlife Fund as well as a generous sponsorship of fuel from ENGEN. * In particular I would like to thank Lesotho Highlands Development Authority and the Preservation and Protection Board in Lesotho for permitting, funding and assisting the survey. The assistance and support of Mr. Jeness, Dr. Hennesey, Mr. Mothepu, Mr. Nkalai and Mr. Tsehlo are also sincerely appreciated. * I would also like to express my gratitude towards the Zoology Department of RAU for the infrastructure provided as well as Ms. Breytenbach, Ms. Snyman, Ms. Roets, Ms. de Lange and Paul Strijdom for typing and maps. Assistance with the statistical analyses was provided by Dr. Ben van Zyl and Dr. Tertius Harmse. The project received exposure on television, radio, newspapers and magazines owing to the excellent promotional work of Mss. Letitia Harding and Lisa Odendaal. * Field work was often conducted under difficult and sometimes dangerous conditions during which my field assistant, Mr. Kabelo, provided me with consistent help, friendship and knowledge of the area. * Medical supplies, advice and backup are essential in conducting such a field project safely. For provision of the above-mentioned I express my gratitude towards Dr. Dave van Buuren, Life-Line Medical Centre. * The team at RAU tegniek professionally developed and maintained most of the research equipment which saved the project large sums of money. The equipment was constantly improved and this meant that the project ended up with equipment of an excellent standard. We acknowledge this gratefully. * After long periods of isolation in the Maloti mountains I was always received with hospitality by my friends, Jonathan and Fiona Maile, who also assisted with logistical problems and the delivery of messages to and from RAU. * I would also like to thank my parents who provided me with the opportunity to conduct my studies over the years, as well as my brothers and family for their continued support and encouragement. * The painstaking process of typing the manuscript was conducted by Ms. V. Steenkamp who, in spite of repeated changes, maintained a good spirit. * In today's modern world I feel privileged to have been afforded the opportunity to come to understand the extent of man's vulnerability to the forces of nature. SUMMARY Predictions that the Mohale Dam (Phase 1B of Lesotho Highlands Water Project) will flood 87% of the habitat of Pseudobarbus quathlambae (Maloti minnow) in the Jordane River gave rise to serious concern about the survival of this endangered species. In order to gain baseline knowledge on the habitat preference, distribution and abundance as well as population dynamics of P. quathlambae, a seasonal survey (Winter 1991 to Winter 1992) was conducted in the Senqunyane, Jordane and Bokoaneng Rivers. This information is essential in determining the present status of the minnow's population and habitat as well as to determine the possible effect of the Mohale Dam on the resident minnow population and habitat. The data is also vital in the development of a monitoring and management strategy to ensure future survival of the species in this region. The measured physico-chemical parameters indicated that the water in this region is of high quality. Relatively high silt (29,5%) and ammonia concentrations (0,6 mgjl) were however recorded at specific anthropogcnically disturbed areas. At present the major threat to the minnow in this area is habitat degradation mainly due to anthropogenic pressure, which also explains the high silt and ammonia values. In their different life stages, P. quathlambae utilized most of the habitat types represented within the river, from open shallow gravel Oats to deep rubble flats and pools. The only habitat types where no P. quathlambae were sampled were deep ami silt laden pools. The fish were recorded throughout the study area and new distribution ranges were described in the Senqunyane, Jordane and Bokoaneng Rivers. Pseudobarbus quathlambae is relatively abundant in these rivers with an estimated population size of 3300. Seasonal migration does take place and it appears as though the 8 cm length group has a better ability to overcome obstacles such as waterfalls. The upstream area from the Semongkoaneng waterfall in the Senqunyane River can be described as a natural sanctuary for P. quathlambac, free from trout which predate on the minnow and also compete for the same niche. Within this sanctuary the Mohale Dam will flood 77% of P. quathlambae habitat in the Jordane River and 99% in the Bokoaneng River. With an approximate age of 4 years P. quathlambae is a medium lived species with a maximum calculated length of 13,69 em, a high mortality rate (Z=2,47) and a recruit survival of 8% at the end of the first year. Although the low recruit survival rate indicates the sensitivity of this species, the Senqunyane, Jordane and Bokoaneng population are maintaining a healthy and stable status. In order to ensure the conservation of these rivers and consequently the existence of the Maloti minnow, the development and enforcement of a conservation and management strategy is recommended. Catchment management should be conducted in close liaison with local people through village chiefs to prevent overgrazing and poor cultivation practices as well as washing directly in the rivers. Monitoring of siltation and ammonia concentrations should be conducted together with aquatic invertebrate monitoring as well as habitat quality indices in order to quantify habitat degradation to assist with future management. The effects of seasonal trends as well as migration habits of the Maloti minnow should be accounted for in future monitoring of population dynamics of the species. It is recommended that captive breeding, gamete preservation and resettlement should serve as species conservation measurements to ensure the survival of P. quathlambae in this environment in the face of the threat posed by the Mohale Dam. SAMEVATIING Voorspellings dat die Mohaledam (Fase 1B van die Lesotho Hoogland Water Skema) 87% van die habitat van Pseudobarbus quathlambae (Maloti ghielemientjie) gaan oorstroom het kommer oor die voortbestaan van die reeds bedreigde spesie gewek. Met die doel om agtergrondkennis ten opsigte van die habitatsvoorkeure, verspreiding en volopheid, asook bevolkingsdinamika van P. quathlambae te versamel, is '0 seisoenlikse opname (Winter 1991 tot Winter 1992) in die Senqunyane-, Jordane- en Bokoanengriviere uitgevoer. Hierdie inligting is noodsaaklik vir die bepaling van die status van die spesie se bevolking en habitat asook om die moontlike effek van Mohaledam op die heersende visbevolking en sy omgewing te bepaal. Die inligting is verder noodsaaklik ten einde 'n moniterings- en bestuurstegniek te ontwikkel om sodoende die toekomstige voortbestaan van die spesie in die omgewing te verseker. Alhoewel die gemetc fisiese en chemiese parameters getoon het dat die water in die omgewing van 'n hoe gehalte is, is hoe slik (29,5%) en ammoniak waardes (0,6 mg/I) by spesifieke antropogenies-geaffekteerde lokaliteite gemeet. Die grootste teenswoordige bedreiging op die voortbestaan van die ghieliemieotjie in hierdie gebied is habitat degradering wat uitsluitlik toegeskryf word aan antropogeniese druk, wat ook die oorsaak van die hoe slik en ammoniak lesings is. Verskillende lewensstadia van P. quathlambae beout verskeie habitat tipes teeowoordig in die riviere en wissel van vlak stadig vloeiende strornc met '0 gruis bodem, tot diep poele met 'n ru-klip bodem. Die enigste habitat tipes waar geen P. quathlambac versamel is nie, was diep en verslikte poeie. Die vis is oor die he Ie studiegebied versamel en nuwe verspreidingsgebiede is in die Senqunyane-, Jordane- en Bokoanengriviere beskryf. Pseudobarbus quathlambac is volop in die riviere met 'n berekende bevolkingsgrootte van 3300. Seisoenlikse migrasie is waargeneem en dit kom voor asof die 8 em Iengtegroep oor 'n groter vermoe beskik om hindernisse (soos waterval1e) in die rivicre te oorkom. Die gebied stroom-op van die Semongkoaneng waterval in die Senqunyanerivier word as 'n natuurlike reservaat vir P. quathlambae beskryf aangesien eksotiese roofvis afwesig is. Die Mohaledam gaan 77% van die habitat van P. quathlambae in die Jordane- eo 99% in die Bokoanengriviere binnc hierdic reservaat oorstroom.