沼蛤在澜沧江典型水电站的分布规律及防控建议

    Distribution pattern of Limnoperna fortunei in typical hydropower stations of Lancang River and corresponding prevention and control recommendations

    • 摘要: 中国西南地区水能资源丰富, 水电站数量众多, 部分电站正面临沼蛤污损问题。对澜沧江某典型水电站连续开展了3 a监测, 初步掌握了沼蛤成贝和幼虫在该水电站的分布规律, 并识别了影响其生长发育的关键驱动因子, 进而提出了大型水电站及库区的沼蛤防治措施。结果表明:①库区沼蛤幼虫密度变化范围为0~920 ind./m3, 随水流自库区上游到坝下逐渐递增富集。在垂向分布上, 幼虫密度随水深呈先增后减的趋势。在0~28 m水层, 密度随深度增加而逐渐升高, 平均密度从20 ind./m3增至150 ind./m3; 在28~50 m水层, 密度则随深度加深而逐渐降低, 至50 m深处平均密度仅为37 ind./m3。②该电站3~11月均监测到沼蛤幼虫, 且湿季幼虫密度显著高于干季, 湿季幼虫总密度月平均值为311 ind./m3, 干季则仅为52 ind./m3。③对各点位沼蛤幼虫密度及水质参数进行随机森林分析、线性回归及相关性分析发现, 沼蛤幼虫分布的关键驱动因子为生境质量、溶解氧、叶绿素a和水体流速。其中, 幼虫密度与生境质量(或具体指标)呈极显著负相关(p < 0.01), 与溶解氧呈显著负相关(p < 0.05), 与叶绿素a浓度和水体流速呈显著正相关(p < 0.05)。④基于沼蛤的分布规律、附着特性和生活习性, 构建了以“监测预警-源头控制-过程阻断-末端处置—运行调度”为核心的综合防控体系, 并为后续防控方向提出了建议。

       

      Abstract: Southwest China is rich in hydropower resources, with numerous hydropower stations, some of which are facing bio-fouling issues caused by Limnoperna fortunei. A three-year monitoring program was conducted at a typical hydropower station on the Lancang River, which preliminarily revealed the distribution patterns of adult Limnoperna fortunei and larvae within the station and identified key driving factors affecting their growth and development. Based on these findings, prevention and control measures for Limnoperna fortunei in large hydropower stations and reservoirs were proposed. The monitoring results showed that the larval density of Limnoperna fortunei in the reservoir area ranged from 0 to 920 ind./m3, showing a gradual increase and accumulation from the upstream reservoir area to the downstream area near the dam. In terms of vertical distribution, larval density exhibited an initial increase followed by a decrease with water depth. In the 0~28 m water layer, density increased with depth, with average density rising from 20 ind./m3 to 150 ind./m3. In the 28~50 m water layer, density gradually decreased with depth, reaching an average of only 37 ind./m3 at 50 m depth. Larvae of Limnoperna fortunei were detected from March to November at the station, with significantly higher larval densities during the wet season than during the dry season. The monthly average total larval density during the wet season was 311 ind./m3, compared to only 52 ind./m3 during the dry season. Through an analysis of larval density and water quality parameters at various sampling points using Random Forest analysis, linear regression, and correlation analysis, we found that the key driving factors for larval distribution include habitat quality, dissolved oxygen, chlorophyll-a concentration, and water flow velocity. Specifically, larval density showed a highly significant negative correlation with habitat quality (or specific indicators) (p < 0.01), a significant negative correlation with dissolved oxygen (p < 0.05), and a significant positive correlation with chlorophyll-a concentration and water flow velocity (p < 0.05). Based on the distribution patterns, attachment characteristics, and life habits of Limnoperna fortunei, a comprehensive prevention and control system centered on "monitoring and early warning-source control-process interruption-end treatment-operation and scheduling" was established, along with recommendations for future prevention and control efforts.

       

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