基于声学技术定点监测海洋牧场鱼类资源昼夜变化研究

Study on diurnal and nocturnal variation of fish resources in marine ranching by fixed-point monitoring based on acoustic technology

为深入评估海洋牧场人工鱼礁的建设成效,促进海洋资源的有效管理和可持续利用,于2023年7和12月分别在广东珠海大蜘洲和广西北海银滩南部的海洋牧场人工鱼礁区,采用分裂波束式科学探鱼仪(Simrad EK80)对其鱼类资源进行渔业声学定点监测,系统分析了监测海域内的目标强度(Target strength, TS)分布、海域散射系数(Nautical area scattering coefficient, NASC)的昼夜变化及海流状态。结果显示:北海人工鱼礁区的鱼类资源TS变化范围为-51.9~-31.0 dB,平均为-44.8 dB;珠海人工鱼礁区的TS变化范围为-51.7~-25.5 dB,平均为-45.4 dB;人工鱼礁区的鱼类资源TS变化范围及平均值普遍优于对照区,鱼类资源主要在5 m以深的水层分布,且数量更丰富;北海人工鱼礁区底层的NASC与海流速度之间存在显著的正相关关系(p<0.05)。研究结果揭示了海洋牧场渔业资源的昼夜变化规律,丰富了海洋牧场渔业资源监测的研究方法,为海洋牧场效果评估提供了参考依据。

To thoroughly evaluate the effectiveness of artificial reefs in marine ranching,and to promote the sustainable use and effective management of marine resources,we conducted the fixed-point acoustic monitoring of fish resources by using a split-beam scientific echosounder(Simrad EK80)in two research areas:the artificial reef area of Zhuhai Dazhizhou Marine Ranch in July 2023 and the artificial reef area of the southern Beihai Yintan Marine Ranch in December 2023.The study systema-tically analyzed the distribution of target strength(TS),diurnal variations in the nautical area scattering coefficient(NASC),and current conditions within the monitored marine areas.The results show that in the Beihai artificial reef area,the TS of fish re-sources ranged from-51.9 to-31.0 dB,with an average of-44.8 dB.In the Zhuhai Dazhizhou Marine Ranch,the TS of fish re-sources ranged from-51.7 to-25.5 dB,with an average of-45.4 dB.Diurnal monitoring data indicate that the TS variation range and average values of fish resources in the artificial reef areas were generally better than those in the control areas,with fish resources primarily distributed at depths greater than 5 meters,more abundant in the artificial reef areas.In the Beihai artificial reef area,the correlation coefficient between the bottom NASC and current speed was 0.41674,indicating a significant positive correlation between them(p<0.05).The results demonstrate the diurnal and nocturnal variation patterns in the fishery re-sources of marine ranching,further enrich the research methodology for monitoring the fishery resources of marine ranching,and provide a reference basis for the dynamic management of the fishery resources of marine ranching.