A problem several have mentioned here, and one which I share, is the difficulty in knowing whether Tilapia are even still present, much less reproducing, once the pond blooms. The first indication I have each year is to wait until water runs over the spillway and check the pool beneath. About a week ago, this happened, and I could confirm the presence of the young of the Tilapia nilotica which had been stocked in late April this year. I decided to test a rough-and-ready method of checking which would be less dependent on capricious weather and which might give me some reassurance earlier in the summer.
Inside a standard wire minnow trap, without extender, I placed a can of creamed corn which I had punctured multiple times. I set the trap in a shady and protected place (in my boat house, under the pier) and waited 24 hours. I checked it a few minutes ago and identified 20 small Tilapia, averaging about 1 inch long. They seemed very active and healthy. I saw no other species in the trap.
I plan on sampling again when the water begins to cool to see if the young are still eating and at intervals thereafter to get an idea of the numbers of Tilapia small enough to enter the orifices and big enough not to exit through the mesh. I hope to get an idea of when they disappear, as well.
I am also planning to sample again next year, if I am still a pondmeister at the time, starting about six or eight weeks after Tilapia stocking. I will let you know what I find out. Seems a lot easier than running a seine and may tell more about fish behavior.
Lou (13.5)
