Evaluation of approaches to estimate fish catches on Lake Victoria: a case study using CAS and frame data from Uganda

Since 2005, harmonized catch assessment surveys (CASs) have been implemented on Lake Victoria in the three riparian countries Uganda, Kenya, and Tanzania to monitor the commercial fish stocks and provide their management advice. The regionally harmonized standard operating procedures for CASs have not been wholly followed due to logistical difficulties. Yet the new approaches adopted have not been documented. This study investigated the alternative approaches used to estimate fish catches on the lake with the aim of determining the most reliable one for providing management advice and also the effect of current sampling routine on the precision of catch estimates provided. The study found the currently used lake-wide approach less reliable and more biased in providing catch estimates compared to the district based approach. Noticeable differences were detected in catch estimates between different months of the year. The study recommends future analyses of CAS data collected on the lake to follow the district based approach. Future CASs should also consider seasonal variations in the sampling design by providing for replication of sampling. The SOPs need updating to document the procedures that deviate from the original sampling design.

Révision synonymique de l'Œuvre ichtyologique de G. Tirant

The present study deals with the revision of the ichtyological work made by G. Tirant in 1929. After several years the first work required an updating of scientific names and classifications. The order followed in presenting species is the same used by Mr. Tirant and even the same large groups have been adopted such as fishes from the coast of Hué, fishes from Samrong-Tong, fishes from Cochinchina and Cambodia.