Slowly lower the secchi disk into the water until it disappears , and note the depth 一个黑白相间既圆板,水平放入水底,慢慢下降,直到完全睇唔见,立即记下水深
3.
Taxonomic groups of zoobenthos were significantly correlated with biomass of submersed aquatic macrophytes , depths , secchi disk transparencies , total phosphorus and total nitrogen contents 底栖动物各个类群的现存量与水草生物量、水深、透明度、总磷和总氮的关系均较密切。
4.
For the relationships between zoobenthos and environmental factors , results showed that zoobenthic standing crops were positively correlated with submersed aquatic macrophytes , total phosphorus and total nitrogen contents but were negatively correlated with depths and secchi disk transparencies 环境分析表明底栖动物总的现存量与水草生物量、总磷总氮含量均正相关，与水深、透明度均负相关。
