The violin solo playing while Delko (Adam Rodriguez) dusts the Russian mobster's body for prints is from Rimsky-Korsakov's "Sheherazade".
The information about cattails is correct. Though native, they are invasive, destroying rich land. However, they have been used at times to separate sugar farms from the wetlands.
The "blunt tip ceramic dive knife" used in this episode is the same one used to kill the nanny in CSI: My Nanny (2007).