长江禁渔对鄱阳湖溯河洄游型刀鲚资源恢复效果初报

Preliminary Report on the Effects of Resource Recovery on Anadromous Coilia nasus in Poyang Lake Under the National 10-Year Fishing Ban

中文关键词: 长江禁渔  刀鲚  鄱阳湖  资源恢复；效果评价

英文关键词: Fishing ban in the Yangtze River  Coilia nasus  Poyang Lake  Resource recovery  Effect evaluation

中文摘要:

      实施好长江10年禁渔是国家“十四五”工作中的一项重要内容，有效跟踪和客观评价禁渔效果业已成为当下的重大需求。长江刀鲚(Coilia nasus)是长距离溯河洄游型鱼类，在自海入江繁殖洄游过程中所受渔捞压力非常大，资源量已岌岌可危。长江禁渔已于2019年启动实施，以刀鲚为代表聚焦禁渔前后固定生境及相近渔季，对刀鲚资源群体及渔获量开展比较研究，可有效追踪和评价长江禁渔对珍稀濒危鱼类种群数量恢复的效果。本研究基于长达7年间的禁渔前(2014—2018年)、后(2019—2020年)同期采样监测数据，开展了长江禁渔的效果追踪和评价研究。结果显示，禁渔前(2014—2018年)溯河洄游型刀鲚单位捕捞努力量渔获量(catch per unit effort, CPUE)仅为(0.81± 1.73) [×10–5, ind./(h·m)] [即(1.13±2.42) ind./d]，数量占比仅为(1.42±2.41)%；而禁渔后(2019—2020年)刀鲚CPUE高至(66.14±69.74) [×10–5, ind./(h·m)] [即(92.60±97.64) ind./d]，较禁渔前增长约82倍；数量占比亦增至(60.56±40.87)%，较前者增长约43倍。本研究首次表明，受益于已实施2年的长江禁渔战略，鄱阳湖洄游刀鲚数量恢复的效果已经凸显。

英文摘要:

      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.