Maria,
There's no need to explain yourself. Many here feel the same as you do about fish conservation.
You just have to expect some goofy answers, part of the fun around here. Don't take it to heart.
As to your question, I like to use oily fish like Barracuda, Mackerel, and Blue fish. Those would be my first choices. My second choices would be large Pinfish, larger Mojarras, and Grunts.
For the barracuda, I fillet them butterfly style. I'll use a few as chum and the others as a bait. Mackerel, I'll use either a fillet or steak. Bluefish, depending on the size, I'll either just cut off the tail completely and let it bleed out while free lining or ballooning it or use it in chunks, skin removed. As for the rest, I give them 3 vertical cuts across the body and use them whole off the bottom or with a balloon rig. Don't score them too deep, you just want to cut them so that they bleed out slowly.
I don't know where you're shark fishing but my way ( Florida) it should be picking up by next month along with the mullet run. They'll be easy pickin's from just about anywhere you find a pod of mullet.~good luck catchin'