Abstract:The implementation of the 10-year fishing ban in the Yangtze River is an important issue in the 14th Five-Year Plan of China, and the effective tracking and objective evaluation of its effects has become a major national demand. Coilia nasus is a long-distance migratory fish found in the Yangtze River. This fish has suffered from heavy fishing pressure during its spawning migration from the sea to the river, making its populations very vulnerable. The fishing ban on C. nasus in the Yangtze River was launched early in 2019 and has benefited the species for nearly two years; this includes the aforementioned 10-year ban, in place since 2020. Utilizing C. nasus as the representative species, a comparative study on the catch quantities before and after the start of national fishing ban strategies in fixed habitats and similar fishing seasons can undoubtedly effectively track and evaluate the effect of the policy on population recovery in the Yangtze River. Therefore, this study investigated the effects of the aforementioned ban on fishing in the Yangtze River by analyzing catch amount, catch per unit effort (CPUE), and the ratios of anadromous to freshwater resident individuals from the spawning ground and adjacent waters in Poyang Lake. Data were gathered from the same fishing season in the 7-year period before (2014—2018) and after (2019—2020) the fishing ban. The results showed that from 2014 to 2018, the CPUE of anadromous C. nasus was (0.81±1.73) [×10–5, ind./(h·m)], with anadromous individuals comprising only (1.42±2.41)%. In contrast, from 2019 to 2020, CPUE increased to (66.14±69.74) [×10–5, ind./(h·m)], an approximate 82× increase. In this period, the ratio increased to (60.56±40.87)%, an approximate 43× increase compared with 2014—2018. These results indicate for the first time that the quantity of anadromous C. nasus in Poyang Lake shows a tendency towards recovery, benefiting from national fishing ban strategies that have only been in place for two years.
