Using baited remote underwater video systems (BRUVS) in the conservation of a popular aquarium species, Metriaclima estherae and Potamonautes lirrangensis, in Lake Malawi/Niassa/Nyasa
Rama, Hima Kashmira
The use of Baited Remote Underwater Video Systems (BRUVS) is a well-established monitoring technique used to obtain long-term monitoring data on aquatic species populations. However, the method is not commonly used in freshwater surveys despite the potential it has to be useful for collecting data. Since freshwater ecosystems are some of the most threatened natural systems in the world, it is beneficial to determine whether BRUVS are a viable monitoring tool to inform their management. The primary aim of this thesis was to determine if BRUVS could be a used to extract critical population information about a small fish species and a crab species in the Meluluco reef system of Lake Malawi/Niassa/Nyasa. BRUVS were deployed within 329 different localities encompassing a range of different habitats within the Meluluco reef system over a period of 3 years (2016 to 2018). The results of the study showed that BRUVS were effective at capturing data on the abundance and habitat preferences of both Metriaclima estherae and Potamonautes lirrangensis. Potamonautes lirrangensis were more commonly observed in rocky substrate at shallower depths and seemed to be avoiding sandy substrate. Both male and female M. estherae were more frequently observed in rocky habitat, though males were more commonly found in sandier habitats in comparison to their female conspecifics. Stereo-Baited Remote Underwater Video Systems (Stero-BRUVS) deployed in the year 2018 were able to accurately determine the lengths of M. estherae which displayed that males were larger on average in comparison to females and displayed a wider length distribution. The data also showed that smaller males were more commonly observed in sand dominated habitats, whereas larger males were found more frequently in rock dominated habitats.
A dissertation submitted in fulfilment of the requirements for the degree Master of Science to the Faculty of Science, School of Animal, Plant and Environmental Science, University of the Witwatersrand, Johannesburg, 2022