with a filter feeder of that size, I'm afraid that the zooplankton will all be taken up by these fish and none left to suport other pond life. They will deplete food needed to support minnows and small fish.
You have a point, Burgermeister, but most of the nitrogen and phospherous they take in will end up right back in the water pretty quick, and most of the rest will, eventually--unless you or your friendly neighborhood water turkey takes it out. Thus, they will feed the very phytoplankton they eat and that will feed the zooplankton they also eat. Even in a small pond, I don't see how one or two can deplete the local microzoosphere (I do enjoy making up names which sound sorta' like they may be scientific :p ) very much. Think of how many Tilapia a green pond can support, yet it stays green. Does anyone know of any studies on depletion of planktonic density by filter feeders?
Lou
