We kept a basket hanging from the end of the dock and all tiny bream too small to eat that we caught while fishing were put into it for later use. Many days we would have contests to see who could catch the smallest bream or the most bream for bait. I found a very small bait with a tiny hook totally concealed in it, floating down naturally with no lead, would often get bites when they would ignore other bait. Since we could see the bream in the water under the dock we knew exactly what they were doing!
About the time I got married and started fishing trotlines in earnest for food, I somehow acquired an old seine about 25 feet long. Many nights Linda and I would pull that seine down the bank right after dark, catching all the bream we needed for bait in just a few minutes. That was fun too, and we caught lots of other stuff, ranging from bream big enough to eat to gar.
The cold water at night in March prompted me to figure out another way to get bait. Since I always got the deep end of the seine I was always wet from head to toe and it gets cold at night. All the bream swimming under the dock should be catchable during the day in a basket.
I bought a commercially made basket to use. It was round, about two feet long, came apart in the middle to get the bait out and had funnel shaped openings in each end to get the minnows to go in but not back out. I baited it with bread or dog food but never caught much in it. The tiny minnows that went in were too small for trotline hooks and the 2 to 3 inch bream I wanted were too small to fit through the 1 inch opening in the funnels.
The solution was easy - make my own basket for catching bait. I got some 1/2 inch hardware cloth and made one. That basket provided enough bait for trotlines for many years. I kept it under the dock baited with dry dog food and could pull up dozens of small bream at any time. It was really too big and cumbersome to use but I did not have to take it far, and its size let me leave the bream in it until I needed them.
We had some unusual catches in that basket. One day I pulled it up and there were 56 little crappie inside. Apparently a school of them had come through and been attracted by the dog food. They were all about 4 inches long - too little to eat - so I let them go after counting them. I hated to use them for bait but still wonder if they would have worked better than bream!
Several times we caught turtles in the trap. A few times they were still alive when it was pulled up but usually they drowned. A snake inside gave us a thrill one day until we realized it had drowned. I never caught a bass big enough to eat in the trap but several small ones were released to grow up!
You can make a basket like I did but make sure it is legal before using it! Hardware cloth is easy to work with and the 1/2 inch mesh will keep most bait size fish inside. If you want smaller bait, go to the 1/4 inch mesh. Make the basket as big or as small as you want - mine was two feet square but smaller would have been much easier to use. I think a one foot square basket would work.
I got a piece of hardware cloth two feet wide and eight feet long. By measuring two feet lengths and laying a board across it, I was able to bend 90 degree angles every two feet, making a box two feet deep and two feet on each side. The ends that met were laced together with small wire. A piece of hardware cloth was cut to cover one end and laced on with wire. I now had a box without a top that was two feet to the side
Some type funnel is needed to get the fish to go in but not allow them back out. I could not figure out how to make a round one so I cut two pieces of the hardware cloth and placed them in the open end to make a V shaped opening. They were both laced up at the outside edge and that allowed them to swing like doors. Since they were each a little longer than half as wide as the basket, they made a nice entrance to the trap without an exit. I would swing them together inside the basket with about a 3 inch gap between them, with the V toward the inside of the basket. By using a loop of wire to hold them in place, I was able to swing one side back out making it easy to dump the bream into a bait bucket.
Dry dog food made great bait and I always had some with me back in those days. Use it or bread and put the basket around cover in shallow water. Make a basket and give it a try if you need bait. Let me know how it works!