Statistics for catch data

Dear all,

I have study on catch for tuna longline. In here I have 3 independent variables (number of hooks, length of branch line & baits) and 3 dependent variables (catch of tuna, catch of marlin & catch of shark).

So what statistics should I use if I want to know:
1. The effect of different baits to the catch of tuna?
2. The effect of different baits to the catch of tuna, catch of marlin & catch of shark?
3. The effect of different number of hooks, length of branch line & baits to the catch of tuna?
4. The effect of different number of hooks, length of branch line & baits to the catch of tuna, catch of marlin & catch of shark?

Thanks,
Irwan