Biodiversity Management Unit: Finding the Maloti Minnow

Lesotho Highlands Water Project

Advance Africa, in partnership with the Lesotho Highland Development Authority’s (LHDA) Biodiversity Management Unit (BMU), undertook two comprehensive electrofishing surveys that aimed to re-assess the distribution of the endangered and iconic Maloti minnow in the Lesotho Highlands.

Advance Africa played a dual role in both the execution of these electrofishing surveys as well as knowledge- and skills transfer to the BMU Aquatics team. Advance Africa’s role included survey logistics and planning, sampling methods and sampling site identification, scientific data collection (including fish and habitat data), multi-variate statistical analyses and scientific report writing. Mentoring included tuition on conducting safe electrofishing surveys, fish identification, and fish and habitat data collection.

The Maloti minnow (Pseudobarbus quathlambae) is a small cyprinid fish (max 14cm long) endemic to headwater streams in the highlands of Lesotho and the Kwazulu-Natal Drakensberg.  The minnow is comprised of two genetically distinct sub-populations or evolutionarily significant units (ESUs): An Eastern ESU and a Mohale ESU. The two ESUs are confined to only nine rivers and their distribution has become increasingly fragmented and limited due to habitat degradation, habitat loss, and competition and predation from non-native fishes.

The highlands of Lesotho are, in many areas, exceedingly remote and inaccessible and there is no road access to many of the sampling sites. The execution of the surveys therefore required extensive pre-trip planning and logistics coordination in the field.

Travel to the sampling sites was undertaken on horseback, and sampling equipment and food provisions were transported with the aid of pack donkeys. This included the transport of a generator and fuel for charging the batteries required for the electrofisher. Lodgings were arranged in the field with chiefs and community members who provided mud huts for the survey team and mbaulas and other provisions for cooking in the evenings. The team were received with incredible warmth and hospitality throughout the highlands which was critical given the challenging weather conditions that were encountered including heavy snowfalls typical of the high Drakensberg.

A total of 15 rivers and 43 sampling sites were surveyed over a three-week period. Sampling methods included electrofishing, and habitat and water quality assessments.

Two major recommendations that came out of the surveys were:

1. Conduct a comprehensive survey, incorporating a number of additional sampling sites, of the translocated minnow populations (Mohale ESU) in the Jorodane, Makhaleng and Maletsunyane Rivers

2. Conduct an assessment of the waterfalls on the Senqu- and Moremoholo Rivers as effective barriers to upstream invasions by yellowfish and trout.

Advance Africa have been appointed to undertake these surveys, continuing their long and successful relationship with the LHDA.

The involvement of Advance Africa in these surveys will serve a number of objectives, notably: successful coordination and execution of field work; collection of precise data; preparation of scientifically robust reports to inform future monitoring and conservation efforts; and the continuation of the mentoring process that will include additional skills and knowledge transfer unique to these surveys.

In continuing our long-term involvement in promoting the conservation of the Mountain Kingdom’s biodiversity, undertook a comprehensive fish distribution survey with the objective of assessing the health of the native and translocated populations of the Maloti minnow Mohale ESU in the Senqunyane, Bokong, Jorodane, Makhaleng and Maletsunyane Rivers, and the health of the Eastern ESU populations in the Senqu, Moremoholo and Matsoku Rivers.

The electrofishing surveys were combined with rangeland health assessments of these rivers to establish a baseline for catchment health. Assessments of the waterfalls were done to determine their suitability as barriers to upstream invasion by non-native fishes.

A total of nine rivers and 70 sites were surveyed. Travel to the sampling sites was undertaken on horseback and helicopters.

The survey provided the baseline information upon which a comprehensive monitoring programme was developed with the aim of ensuring the survival of the Maloti minnow, an iconic symbol of the Mountain Kingdom’s biodiversity.