I think it is pretty hard to observe the law and still get your fish. If the local law states you can't transport llive fish, and there is no where to purchase them, it makes it difficult to get one if you want. I have read here that there are exceptions such as getting permits, being certified, or the fish you are catching to be for educational purposes. I'm not sure about any of that, I have not checked the local laws that in depth around where I live. But I do keep fish that I have caught in the wild, but I also know not to go telling everying and their brother about it, and definatly know better than to re-release the fish back into the wild for any reason, if I get caught for some reason, I will face the consequences, but that is the price I'd have to pay to keep native fish.
P.S. I catch the fish I plan on keeping with a cast net (throw net), that way I am able to catch younger speciments and am not injuring the fish by catching it with a hook.