Abstract: To study the activity of fish in a coastal area of the Yellow Sea, the first acoustic survey of fishery resources was carried out from November 22 to December 5, 2015 using the self-developed research-type fish finder, to obtain the fish activities data. First of all, four sets of fish finder instrument were put at four fixed points of the investigated area to monitor the fish stocks entering the area, and the echo data of fish was collected and analyzed and dealt with using acoustic technology, thus to get the distribution of the fish target strength in the vertical direction, the target strength size distribution of fish, and the distribution of fish amount in different water layers and at different time, as well as the amount of fish resources. Results showed that fish in the investigated sea area were mainly distributed in the layer of 4~10 m, and with the gradually increasing of the water depth, the amount of fish became smaller. In the investigated sea area, the fish activity frequency showed an increasing trend from 9am to 1pm, and reached the peak between 1pm to 2pm which was about 0.38. The fish target strength of -49~-40 dB accounted for the highest proportion, and the strength higher than -40 dB was evenly distributed in the whole water layers, while that smaller than -40dB was mostly distributed in the shallow water layer of 4~10 m. Survey results showed that the acoustic technology could monitor fish activities, and the fish target strength distribution was relatively concentrated in the investigated sea area. In the depth direction, the fish was mainly concentrated in the upper layer. The activities of fish in different time periods changed along with the variation of temperature: when the temperature rose, the frequency of fish activity increased, otherwise the frequency of fish activity decreased, from which we can conclude that most of the fish species in the investigated area were warm water species.

Key words: fish monitoring, acoustic technology, echo processing, the Yellow Sea coastal water

摘要： 为了研究黄海近海鱼类活动规律，采用自主研制的科研型鱼探仪于2015年11月22日至12月5日对调查海域的鱼类活动进行了首次声学调查，统计分析鱼类活动规律。在调查海域布放4套鱼探仪设备对鱼类进行定点长时间监测，并将采集到的鱼类回波数据利用水声技术进行分析和处理，得到调查海域单体鱼类目标强度在垂直方向上的分布、鱼类目标强度大小的分布以及鱼类在不同水层和不同时间段的活动情况。结果显示，调查海域冬季鱼类主要活动在4~10 m的中上水层，鱼类分布随着水层深度的逐步增加而急剧减少；从9:00至13:00鱼类活动频度呈增大趋势，并在13:00至14:00频度达到顶峰（约为0.38），随后频度减弱；统计得到该海域鱼类目标强度主要以-49~-40 dB占比最高，目标强度大于-40 dB的鱼类均匀分布在整个水层，目标强度小于-40 dB的鱼类主要分布在4~10 m浅水层。研究表明，采用水声技术能够实现对鱼类活动的监测；调查海域的鱼类目标强度分布比较集中，鱼类在深度上的分布主要集中于中上水层，鱼类的在不同时间段的活动情况随水温变化而变化，温度升高鱼类活动频度增加，反之则降低，由此可知，该海域鱼类的种类以暖水物种为主。

关键词: 鱼类监测, 水声技术, 回波处理, 黄海近海