罗非鱼-附着藻-沉水植物相互关系研究进展

在浅水富营养化湖泊中,沉水植被是决定湖泊清水态或混水态的关键因子。而附着藻对沉水植物强烈的遮阴作用以及对碳源、营养盐等资源强烈的竞争,成为限制沉水植物群落生长和发展的关键因子。罗非鱼作为一种杂食性鱼类,具有牧食附着藻的能力,其下行效应（top-down effect）可以在一定程度上减轻附着藻对沉水植物生长的这种不利影响。因此,作为我国南方水体中的优势种类,适当种群密度的罗非鱼在富营养化浅水湖泊生态修复过程中是可加以利用,并在一定程度上抑制了附着藻的生长和发展,有利于浅水湖泊的生态修复和管理。同时,罗非鱼也具有通过摄食、排泄等活动加速水体氮、磷营养盐再生,牧食浮游动物、沉水植物等不利的一面。因此,在综合考虑多种因素条件下,需要对罗非鱼-附着藻-沉水植物三者之间的相互关系进行深入研究,探讨生态系统对罗非鱼的响应,这对我国南方浅水富营养化湖泊的生态恢复与管理,尤其是沉水植被的重建与保护具有重要的理论意义和实践价值。

Relationship among tilapia,periphyton and submerged macrophyte:A review

In shallow and eutrophicated lakes,submerged macrophyte is the crucial factor for clear water state or turbid state.While strong competition of periphyton for illumination,carbon sources,and nutrition has become the determinant on growth and development of submerged macrophytes communities.Tilapia,as the dominant species in south freshwater ecosystem,its top-down effect could alleviate the negative influences of periphyton on submerged macrophytes growth because of its probability of gazing and consumption on periphyton.So,as the dominant species of waterbody in South China,author think that tilapia can be used to control growth of periphyton and prompt submerged macrophyte development in shallow and eutrophic lake.Besides,tilapia can also accelerate nutrition regeneration by excretion and herbivory on submerged macrophytes.Therefore,this paper summarizes predecessor＇s conclusions,and proposes some intensive studies should be down to the relationship among tilapia,periphyton and submerged macrophytes with consideration of all the factors.It is very important for management and ecological restoration of shallow and eutrophicated lakes in south of China.