滤食性底栖动物沼蛤极易入侵水利工程的输水通道,在输水结构上高密度附着,造成生物污损,堵塞管道,降低输水效率,污染水质,腐蚀结构,威胁工程运行,也给跨流域调水带来潜在危险。本文对输水工程水源长期密集采样观测,研究沼蛤幼虫发育阶段及运动特性;开展水力试验,研究幼虫的沉降、在脉动流场中的死亡特性,提出防治幼虫入侵的方法。研究结果表明:沼蛤幼虫在其水中浮游生活的阶段,依赖水流流动入侵输水通道,通过分泌足丝附着在结构壁面。沼蛤幼虫、稚贝具有沉降特性,尺寸合适的沉降池能够使大量幼虫、稚贝沉底。幼虫会被高频湍流灭杀,当湍流中小涡尺度与幼虫体长相当时,对幼虫的灭杀效果显著,灭杀率与湍流平均流速及湍流作用时间正相关。防止沼蛤入侵输水通道的关键是减少水流中沼蛤幼虫的数量,可采用沉降及高频湍流灭杀沼蛤幼虫的综合方法实现防治目标。
The golden mussel (Limnoperna fortunei) is a filtercollector species of macroinvertebrate originat ing from southern China. It easily invades into water transfer tunnels and attaches on tunnel walls and struc tures with extremely high density, resulting serious biofouling, clogging pipes, decreasing water transfer effi ciency, and causing water pollution and structure corrosion. It is an urgent need to seek effective measures for its prevention. Long term samplings and observations were performed to find planktonic golden mussel ve ligers in source water of a water transfer project. The characters of golden mussel veligers in settlement and death in turbulence were studied through experiments. Measures of preventing golden mussel veligers in vasion were proposed based on the veligers' characters. The results of long term observations indicate that golden mussel experiences planktonic veliger stages in water. The planktonic veligers invade into water trans fer tunnels with water flow, and attach to the tunnel walls using their byssuses. The veligers and juveniles can be settled to the bottom of settling pool of appropriate size. The veligers can be killed in high frequen cy turbulence when eddy scale is comparable with veliger length. The killing rate of veligers is positively correlated with the average flow velocity and action time of the turbulence. Prevention of golden mussel veli gers from invading into tunnels is the most important and effective measure. An integrated prevention is pro posed by combining settling veligers with appropriate settling pool and killing veligers with high frequency turbulence before veligers'entering into tunnels.