Trends in an emerging artisanal fishery of the African cyprinid Rastrineobola argentea in Lake Nabugabo, Uganda

Fishing pressure can have strong impacts on fish populations, driving declines in abundance and, occasionally, changing life history traits. However, much of our current understanding of these phenomena derives from studies conducted decades or even centuries after the onset of fishing. Newly established fisheries provide an excellent opportunity to understand this critical early phase. Temporal trends in catch data and life history traits of the cyprinid fish Rastrineobola argentea (Pellegrin), now the target of a burgeoning artisanal fishery in Lake Nabugabo, Uganda, were analysed. Results showed that the R. argentea fishery intensified and became more selective during the first decade since its establishment (2008–2019), while catch-per-unit-effort of R. argentea (fisheries-independent abundance) at repeatedly sampled sites in the lake decreased over this same time period. Size-adjusted egg volume and ovary mass increased significantly over the time period, which may reflect a density-dependent response to a fisheries-induced population decline.