长江泸州江段人工增殖放流长江鲟幼鱼栖息分布特征及关键影响因素分析

HABITAT DISTRIBUTION CHARACTERISTICS AND KEY INFLUENCING FACTORS OF ACIPENSER DABRYANUS JUVENILES IN LUZHOU RIVER SECTION OF THE YANGTZE RIVER

  • 摘要: 研究以人工增殖放流的长江鲟(Acipenser dabryanus)幼鱼为研究对象, 基于2023年在长江上游泸州江段的监测数据分析了长江鲟幼鱼资源密度的时空分布特征, 并通过广义加性模型(GAM)筛选影响其栖息分布的主要环境因子。结果显示, 长江上游泸州江段长江鲟幼鱼资源密度在时间和空间上均存在显著差异。时间上, 夏季长江鲟幼鱼资源密度显著高于秋季(P<0.05); 空间上, 在8个调查江段中, 龙马潭江段长江鲟幼鱼资源密度最高, 为0.43 kg/(h·次), 九聚村位点长江鲟CPUE最低, 为0.011 kg/(h·次), 龙马潭江段长江鲟幼鱼资源密度显著高于其他位点(P<0.05), 其他7个位点之间则无显著差异(P>0.05); 影响长江鲟幼鱼资源密度分布的主要环境因子为流速、底栖动物密度和水温, 其中流速偏差解释率最高为69.1%。幼鱼资源密度值在流速(0.15—0.86) m/s随流速增加而迅速减小, 后趋于平稳; 底栖动物密度与幼鱼资源密度呈正相关性, 即随着底栖动物摸底的增加, 长江鲟幼鱼资源密度呈现上升的趋势; 幼鱼资源密度在(18.9—20.7)℃随着水温的升高而减少。研究揭示了长江鲟幼鱼在长江干流泸州段的栖息分布特征及流速、底栖动物密度和水温对其分布的影响, 可为长江鲟栖息地保护与种群恢复提供科学依据。

     

    Abstract: The Yangtze sturgeon (Acipenser dabryanus), an endemic rare fish of the Yangtze River Basin, relies on specific juvenile habitat distributions and key environmental factors for population restoration. Using 2023 monitoring data from the Luzhou section of the upper Yangtze River, we analyzed the spatial and temporal patterns in A. dabryanus juvenile resource density and employed a generalized additivity model (GAM) to identify critical environmental factors influencing their habitat distribution, focusing on areas with artificially stocked juveniles. The results showed that there were significant temporal and spatial variations in A. dabryanus juvenile density within the Luzhou section. Temporally, summer densities were significantly higher than autumn values (P<0.05). Spatially, among the eight investigated river sections, Longmatan recorded the highest density at 0.43 kg/(h point operator times), while Jiujucun had the lowest CPUE at 0.011 kg/(h·times), and the A. dabryanus juvenile resource density in the Longmatan section was significantly higher than that of the other sites (P<0.05), with no differences among the other seven sites (P>0.05). Flow velocity, benthic fauna density, and water temperature emerged as primary drivers, with flow velocity bias explaining the highest rate of 69.1%. Juvenile density declined sharply as flow velocity increased from 0.15 to 0.86 m/s before stabilizing; benthic fauna density correlated positively with juvenile density, meaning higher benthic biomass was associated with greater juvenile abundance. Within the 18.9℃ to 20.7℃ temperature range, juvenile density decreased with the increase of water temperature. This study reveals the habitat distribution characteristics of A. dabryanus juvenile in the Luzhou section and the effects of flow velocity, benthic animal density, and water temperature, providing a scientific basis for the habitat protection and population recovery initiatives.

     

/

返回文章
返回