【摘要】 东洞庭湖是洞庭湖最大湖泊群，是我国重要湿地自然保护区之一，具有重要的生态价值。为了解禁渔初期东洞庭湖鱼类资源现状，于2021年5月和8月采用回声探测仪(EY60,200 khz)对湖南省东洞庭湖鱼类资源进行了昼夜全覆盖水声学探测。结果显示，在日尺度上，5月和8月夜晚的鱼类密度均大于白天，8月份昼夜密度差异显著(F=4.498,P<0.05),5月和8月的昼夜目标强度差异均不明显(P>0.05);在季节尺度上，5月鱼类平均密度显著大于8月(P<0.05);鱼类目标强差异不显著(P>0.05)。空间尺度上，鱼类密度水平分布不均，5月鱼类主要分布于东北湖区和东部湖区，8月鱼类主要分布于东部湖区和鹿角；垂直分布上5月份鱼类主要分布于水体中上层，8月份主要分布于水体中下层。应用资源密度体积法估算8月东洞庭湖昼夜鱼类资源量约为7.69×10~8尾和1.78×10~9尾，与历史数据相比出现了成倍增长。首次研究了禁渔初期东洞庭湖鱼类的时空分布特征，东洞庭湖的鱼类资源量的增长将为禁渔后东洞庭湖渔业资源的保护与合理利用提供数据基础。更多还原

【Abstract】 The East Dongting Lake is the largest lake group of Dongting Lake and one of the important wetland nature reserves in China, which has important ecological value. In order to investigate the current situation of fish resources in East Dongting Lake in Hunan Province in the early stage of lifting the fishing ban, an echosounder(EY60,200 KHZ) was used to detect fish resources in East Dongting Lake in May and August, 2021. The results showed that at the daily scale, the density of fish at night in May and August was higher than that at day, and there was a significant difference in the density between day and night in August(F=4.498, P<0.05), but there was no significant difference in the intensity of target between May and August(P>0.05); At the seasonal scale, the average density of fish in May was significantly higher than that in August(P<0.05). There was no significant difference in fish target strength(P>0.05). At the spatial scale, the distribution of fish density was uneven. Fish mainly distributed in northeast lake area and east Lake area in May, while fish mainly distributed in east Lake area and Lujiao area in August. In the vertical distribution, fish mainly distributed in the upper and middle layers of water in May, and in the lower and middle layers of water in August. The total number of fish in August was 7.69×10~8 and 1.78×10~9 ind. by using the resource density and volume method, which increased exponentially compared with the historical data. This paper is the first to study the spatial and temporal distribution characteristics of fish in East Dongting Lake in the early stage of fishing ban. The increase of fish resources in East Dongting Lake will provide data basis for the protection and rational utilization of fishery resources in East Dongting Lake after fishing ban.更多还原