Another rule of possession is that you may not remove the animal from its shell until preparing it for "immediate consumption". If you're camping and you're cleaning abalone when the ranger comes along, he's going to want to see your lit cooking fire as proof that it's for immediate consumption. Otherwise, it's very possible you'll get popped. Again during your drive home, if you're checked by law enforcement and those abalone in the ice chest are nicely cleaned and trimmed, you're also busted.