| 摘要: |
| 2018年4月采用回声探测仪(EY60，200 kHz)对广西洪潮江水库鱼类资源进行了水声学探测。结果显示，在时间尺度上，洪潮江水库鱼类密度昼夜差异不显著(P>0.05)，但目标强度平均值为白天>夜间(P<0.05)，昼夜目标强度分别为(–43.30±0.32)和(–44.50±0.26) dB，主要是由于夜晚(–60 ~ –54 dB)的小型鱼类增加(–60 ~ –57和–57 ~ –54 dB 范围分别增加9.25%和4.76%)，而白天(–54 ~ –48 dB)的鱼类比例增加所致(–54 ~ –51和–51 ~ –48 dB范围分别增加7.42%和5.27%)。在空间尺度上，洪潮江水库鱼类分布呈显著的空间变化特征(P < 0.05)。鱼类密度呈上游高于下游、库汊高于库心的特征。密度平均值为109.52 ind./1000 m3，最大值出现在上游S3站，平均密度为330.21 ind./1000 m3。最小值为下游的S8站，平均密度为21.50 ind./1000 m3。相关性分析表明，鱼类密度分布与总磷(TP)、高锰酸盐指数(CODMn)、叶绿素a呈正相关，与水深呈负相关(P<0.05)；鱼类目标强度与水温、浊度、TP、CODMn呈显著的负相关(P<0.05)。研究表明，洪潮江水库鱼类空间分布是多种非生物因子(如叶绿素a、TP等)共同作用的结果，其在一定程度上也反映了生物因子(鱼类索饵、逃避敌害等)对鱼类分布的影响。该研究对了解洪潮江水库鱼类资源状况和环境影响因素，以及渔业资源保护与管理具有一定的参考价值。 |
| 关键词: 空间分布 环境因子 水声学探测 洪潮江水库 |
| DOI： |
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| Spatial distribution of fish resources and its correlation with environmental factors in the Hongchaojiang reservoir based on hydroacoustic detection |
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ZHOU Lei1,2, LI Yusen1,2, SHI Jun1, HAN Yaoquan1, KUANG Tianxu1, WU Weijun1, LEI Jianjun1, HE Anyou1
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1.Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Sciences, Nanning 530021;2.College of Marine Sciences, South China Agricultural University, Guangzhou 510642
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| Abstract: |
| To determine the distribution of fish resources in the Hongchaojiang Reservoir and its correlation with environmental factors, the fish resources available in the Hongchaojiang Reservoir were evaluated in April 2018 using an echo detector (EY60, 200 kHz). According to the results, there was no significant difference in fish density between day and night in the Hongchaojiang Reservoir (P>0.05); however, the mean target strength was greater in the daytime than in the nighttime (P<0.05). The mean target strength in the day and at night was (–43.30±0.32) dB and (–44.50±0.26) dB, respectively, because small fish between –60 dB and –54 dB (–60 to –57 dB and –57 to –54 dB increased by 9.25% and 4.76%, respectively) increased during nighttime, while fish between –54 and –48 dB increased during the daytime (–54 to –51 dB and –51 to –48 dB increased by 7.42% and 5.27%, respectively). Fish distribution in the Hongchaojiang Reservoir displayed significant spatial variation (P<0.05). Fish density was characterized by higher density upstream than downstream, and higher density in the Reservoir branch than in the Reservoir center. Average fish density was 109.52 ind./1000 m3 and the maximum density was observed in the upstream S3 site, with a density of 330.21 ind./1000 m3, while the minimum density was observed in the downstream S8 site, with a density of 21.50 ind./1000 m3. Correlation analysis revealed that fish density distribution was positively correlated with total phosphorus (TP), permanganate index (CODMn), and chlorophyll a, and negatively correlated with water depth (P<0.05). Fish target strength exhibited a significant negative correlation with water temperature, turbidity, TP and CODMn (P<0.05). The results suggest that abiotic factors such as chlorophyll a and TP drive the spatial distribution of fish in the Hongchaojiang Reservoir. In addition, the results also reflect the influence of biological factors (fish bait, escape from predators, etc.) on fish distribution. The results of the study provide insights that could enhance our understanding of the distribution of fishery resources in the Hongchaojiang Reservoir. |
| Key words: Spatial distribution Environmental factors Hydroacoustic detection Hongchaojiang Reservoir |
