Lesotho’s Maloti Minnow stands to benefit from extensive conservation Program

The tiny Maloti Minnow, Pseudobarbus quathlambae, has been the subject of a long, detailed and costly series of academic and field studies, which have resulted in a large body of information being available about this endangered, endemic fish.

The Lesotho Highlands Development Authority (LHDA) engaged a specialist consultant, Dr. Johan Rall from the Republic of South Africa to collect information on the status of the minnow in the LHWP. The consultant estimates that the Maloti Minnow has lost 90% of its original numbers. The construction of the Mohale Dam has placed a significant part of the minnow population at risk through the inundation of the upper reach of Phase 1B rivers. The decline of this diminutive fish began over 70 years ago in colonial times, when trout were introduced into Lesotho’s rivers to provide sport angling to those with leisure time. The predatory trout have subsequently eradicated the minnow as they spread into more of its habitat.

Similarly the barbus species has suffered the same fate as the minnow in the river systems of the Western Cape Province in South Africa, which are now highly endangered because of the introduction of trout to South African rivers. No effective measures to conserve these endemic species have been instituted, other than trying to discourage trout fishing in favour of angling for endemic species such as yellowfish.

It is against this historical background that the LHDA has been compelled to address the threatening extinction of the minnow in the LHWP rivers.

Genetic studies have revealed two distinct groups within the Maloti Minnow population, known as ESUs (Evolutionary Significant Units). One comprises the “Mohale ESU” from the Senqunyane, Bokong and Jordane rivers, while the rest fall into the “Eastern ESU”. The Mohale ESU comprises 77% of the total extent of occurrence of the Maloti Minnow. The Mohale Dam development is expected to affect 97% of the Mohale ESU from the introduction of trout and yellowfish into the system if no mitigation measures are put in place.

The Lesotho Biodiversity Trust (LBT) has been created to address the survival of the minnow. To this end the LHDA has set aside a significant donation amounting to M8 million and its first project is to address the practical steps that need to be taken to prevent the Maloti Minnow from becoming extinct.

The LBT was launched at a workshop on biodiversity, held in Maseru on 10 December 2004. The Lesotho Minister of Tourism, Sports and Culture, Hon. Lebohang Ntsinyi officiated at the event. The responsibility for continuing the research and conservation programme on the Maloti Minnow was also handed over by the Consultant to the Lesotho Biodiversity Trust.