Title: Assessing the implications of the enforcement of the ban on illegal fishing on the dagaa (Rastrineobola argentea) fishery in Lake Victoria, East Africa: A historical analysis.

This study examined the impact of stringent enforcement measures on the dagaa (Rastrineobola argentea) fishery in Lake Victoria, East Africa. The study focused on analysing the temporal trends and the influences of various predictors on the catch per unit effort (CPUE) both before and after the introduction of enhanced fishing regulations. Using historical data, including Catch Assessment Survey and Frame Survey data, robust statistical models were applied to assess the effects of this regulation. The variable Regime before 2017 was highly significant and negative, indicating that regulatory conditions before 2017 were associated with a lower CPUE than those after 2017. Notably, a marked increase in CPUE was observed in Uganda and Tanzania following enforcement, indicating a reduction in fishing pressure. The application of a polynomial model to the log-transformed CPUE data uncovered a significant quadratic relationship with time, capturing a rise and subsequent fall in CPUE, which corresponded with the enforcement period defined by the regime variable. The polynomial model demonstrated a better fit over the Generalised Additive Model (GAM), underscoring the need for adaptive management strategies that account for changes in fishery dynamics over time and the need to design regulations that are flexible and responsive to the data-driven trends observed in fishery dynamics, such as the non-linear trends captured by the polynomial model. This study underscores the imperative of balancing enforcement with socioeconomic considerations to maintain sustainable fishery resources while supporting local communities’ livelihoods. This emphasises the importance of involving local stakeholders in crafting regulations and the necessity of transboundary cooperation for effective fishery management across Lake Victoria. These findings advocate for adaptive management practices, informed by ongoing monitoring and feedback, to continually refine enforcement measures. This study contributes to the broader discourse on sustainable fisheries management by providing empirical evidence to guide future policy interventions in Lake Victoria's complex fishery dynamics.