【作者】 王崇瑞；

【导师】 危起伟； 张辉；

【作者基本信息】 华中农业大学 ， 湿地资源与环境， 2011， 硕士

【摘要】 青海湖裸鲤(Gymnocypris przwalskii)俗称“湟鱼”,在青海湖区生态系统中处于核心地位,对维系青海湖区域生态系统的平衡和稳定起着不可替代的作用。上世纪中期,由于过度捕捞和其生境破坏,造成青海湖裸鲤资源急剧下降,形势极为严峻。从上世纪80年代末开始,开始实施“封湖育鱼”保护措施来促使青海湖裸鲤资源的恢复。本研究的主要目的是利用水声学技术研究评估青海湖裸鲤的资源量、密度分布特征、种群数量及个体大小分布特征等,以期为青海湖裸鲤资源的保护和合理利用提供依据。2007年～2010年连续四年,分别采用BioSonincs DT-X (199 kHz) (2007年和2008年)；Simrad EY 60(333kHz)(2009年和2010年)和BioSonincs DT-X (210 kHz)(2010年)分裂波式回声探测仪于8月中上旬对青海湖裸鲤资源量及时空分布特征进行调查；采用VisualAnalyzer4.1和Sonar 5-Pro两种分析软件对2010年两种水声学仪器所采集的数据进行鱼类密度和目标强度分析结果的对比。主要研究结果如下所述：1.2007年—2010年,每年8月水声学调查结果显示,青海湖裸鲤各相应年份的资源量(95%置信区间)分别为20176.02(19167.39-21185.01)t、24342.15(23125.04～255592.58)t、27260.41(25897.38～28623.42)t和30120.73(28798.04-31443.42)t；四次调查评估青海湖裸鲤总尾数(95%置信区间)分别为9.26x107 (8.80x107～9.72x107) ind,1.05x108 (9.98x107～1.10x108) ind, 1.23x108 (1.17x108～1.29x108) ind和1.42×108(1.35×108～1.49×108)ind.；四次调查青海湖裸鲤在青海湖整体平均密度(最小值,最大值)分别为1.25±0.41 (0.007,17.3) ind./1000m3,1.46±0.28 (0.01,19.1) ind./1000m3,1.64±0.23 (0.15, 19.96) ind/1000m3和1.83±0.36(0.06,22.89) ind/1000m3。2.四次调查渔获物采样点分别位于布哈河口、黑马河口、二郎剑湖区及151基地湖区。对四次渔获物生物学进行统计计算,平均体长和平均体重为275±29.9 mm,267.9±11.0g(n=68)、267.9±50.7 mm,263.7±6.9g (n=54)、240.3±38.4 mm, 192.44±13.9g (n=45)、234.7±25.3 mm,162.2±50.0g (n=261)。根据四次调查渔获物统计分析,青海湖裸鲤个体规格在青海湖内分布并非一致,其中以布哈河口规格最大,151基地湖区规格最小3.对不同水层青海湖裸鲤密度进行单因素方差分析(ANOVA),结果显示,在P=0.05水平下,1-6 m水层密度与其它水层密度之间差异性显著(F=5.521,P<0.05),青海湖裸鲤主要集中分布于1-6 m水层,最大密度位于泉吉河口1～6 m水层为28.08±1.08 ind./1000m3,最小密度值位于海心山北湖区21-26 m水层为0.08±0.026 ind./1000m3。青海湖裸鲤在青海湖中的水平分布也显现出不均性,4次调查结果显示,鱼类密度最高值都分布在布哈河口、泉吉河口和二郎剑湖区,分别为17.3 ind./1000m3、19.1 ind./1000m3、19.96 ind./1000m3和22.89 i nd./1000m3;最小密度出现于远离湖心的湖东区,分别为0.007 ind./1000m3、0. 01 ind./1000m3、0.15 ind./1000m3和0.06 ind./1000m3。4.对选取的6个代表湖区所采集的原始水声学数据进行初步处理之后,采用Visual Analyzer 4.1和Sonar5-Pro分析软件分别设置4组参数组合(B1-B4)、不进行噪音处理(E0)和4组噪音处理参数组合(E1-E4)。对两种软件和9组参数所得的鱼类密度和TS值进行方差分析,结果表明：Visual Analyzer4.1和Sonar5-Pro两种分析软件之间对鱼类密度和鱼类TS值分析结果都无显著性差异(P=0.524>0.05；P=0.997>0.05)；9组参数组之间鱼类密度结果分析有显著性差异(P=0.020<0.05)；9组参数组之间对鱼类TS值结果分析没有显著性差异(P=0.926>0.05)。由此得出,BioSonincs DT-X和EY60两种回声仪在青海湖中都有很好的适用性,根据水声学技术指导和谭细畅等人的研究,设置BioSonincs DT-X(B3)和EY60(E3)为两种回声仪数据分析的最佳参数组合。更多还原

【Abstract】 The naked carp, Gymnocypris przwalskii, is strictly protected by the government of Qinghai province. This fish is the key species for the food chain of Qinghai Lake ecosystem, and plays an irreplaceable role in balance and stability of ecosystem. Due to over fishing and habitat destruction, the natural population of G. przwalskii was sharply declined, and this situation was extremely seriously in the middle of the last century. Some rehabilitation measures for G. przwalskii have been conducted since 1980s. In recent years, it seems that the population of G. przwalskii obviously increased. In this study, we attempted to estimate the abundance and biomass of G. przwalskii by using hydroacoustic technology. This study hopes to provide the basis knowledge for the protection and management of G. przwalskii stock.During the four summer of 2007-2010, the BioSonics DT-X (199 kHz; 210 kHz) and Simrad EY 60 (333 kHz) split beam echo-sounders were used to estimate the abundance and spatial distribution of G. przwalskii in Qinghai. A comparative study was conducted among the two kinds of echo-sounders so as to determine the best analyzing parameters. The main results are as follows:1. The biomasses (95% confidence) of G. przwalskii in Qinghai Lake were 20176.02 (19167.39～21185.01) t,24342.15 (23125.04～255592.58) t,27260.41 (25897.38～28623.42) t and 30120.73 (28798.04～31443.42) t for each August of the year 2007,2008 2009 and 2010, respectively; accordingly the amounts (95% confidence) were 9.26×107 (8.80×107～9.72×107) ind.,1.05×108 (9.98×107～1.10×108) ind.,1.23×108 (1.17×108～1.29×108) ind. and 1.42×108 (1.35×108～1.49×108) ind.; the average density (Min value, Max value) were 1.25±0.41 (0.007, 17.3) ind./1000m3,1.46±0.28 (0.01,19.1) ind./1000m3,1.64±0.23 (0.15,19.96) ind/1000m3 and 1.83±0.36 (0.06,22.89) ind/1000 m3.2. Four time net sampling were located in the Buha River estuary, the Heima River estuary the Erlang Jian and 151 Base, respectively. Statistical analysis, indicated that the average body length and weight of the G. przwalskii in the four times samplings were 275±29.9 mm and 267.9±11.0 g (n=68),267.9±50.7 mm and 263.7±6.9 g (n=54),240.3±38.4 mm and 192.44±13.9 g (n=45),234.7±25.3 mm and 162.2±50.0 g (n=261). It suggested that the size distribution of G. przwalskii was inconsistently in Qinghai Lake, the largest size was at Buha river estuary, and the smallest size was at 151 Bases.3. One-way ANOVA analyzing on fish density among different water layer indicated that, there were significantly difference between the 1～6 m water depth and the other water depth (F=5.521, P<0.05), The G. przwalskii mainly distributes at the 1～6 m water depth. The maximum density (28.08±1.08 ind./1000m3) occurred at the 1～6 m water depth of Quanjihe river estuary, and the minimum density (0.08±0.026 ind./1000m3) occurred at the 21-26 m water depth at the north of Haixin mountain. The horizontal distribution of the fish densities was also inconsistently. The results of the four times surveys indicated that the maximum fish density were 17.3 ind./1000m3 19.1 ind./1000m3,19.96 ind./1000m3 and 22.89 ind./1000m3, respectively. They were located at the Buha river estuary, Quanji river estuary and Erlang jian area. The minimum fish density were 0.007 ind./1000m3,0.01 ind./1000m3,0.15 ind./1000m3 and 0.06 ind./1000m3, respectively, and they were located at the east area of Qinghai Lake.4. Six sampling areas were selected from Qinghai Lake, and the raw data were processed with different parameters in the software Visual Analyzer 4.1 (B1～B4) and Sonar5-Pro (Eo and E1～E4). Variance analysis among fish densities and TS which calculated from two software indicated that there were no significant difference (P=0.524>0.05; P=0.997>0.05). There was significant difference (P=0.020<0.05) among fish density analyzed by the different parameters configuration groups, however there was no significant difference (P=0.926>0.05) among TS. Based on this analysis, we consider that the BioSonics DT-X and EY60 both were applicable for the fish stock assessment in Qinghai Lake. According to the previous studies and technical analysis guides, the parameters configuration B3 and E3 most probably were the best parameters configurations.更多还原