Brian -- there are many different designs for fyke and trap nets. I'll answer what is true for most of them.
Most fyke, and modified fyke (those with frames at front, rather than just the round hoops), have either one or two funnels in the back (cod) end. Usually, we tie the back of the net with a heavy piece of twine, and usually just use a bow tie. A weight must be used to stretch those nets from shore (small bell anchor, sometimes coffee can of cement) and hold it in place. We usually tie a line and float to the weight.
When we come up to the net in our flat-bottom work, we go to the float, and then pull up the anchor. We are then at the back of the net. We usually collapse the entire fyke net over a tub. Then, you start at the front (e.g., the frames in a modified fyke net), and "shake" the fish down through the two funnels. Now, all fish are at the back end of the net. Untie the bow tie knot, and the fish fall into your tub.
These nets tend to catch lots of sunfish and crappies. So, if you put water in the tub, you usually end up being able to release nearly all fish alive. Of course, if you have hundreds of pounds of bullheads, the other fish can get roughed up. However, that only happens when bullie problems are severe.
I hope this is somewhat understandable. It's easier to show the videotape to the class than try to describe this in words! :-)
