I am not familiar with the ivory trade. But I do wonder morphing could help protect the animals, without killing the trade.
Someone morphs and elephant, tusk removed, demorph, remove an elephant that still has tusks. You have a limitless supply, and that goes for any animal resource that you don't need to kill it for. I don't know if elephants and rhinos have to be killed to get the prize, or if that's just the practice (Granted I imagine a morpher would not want to be conscious when someone is collecting their tusks, so you'd have to find a way to knock them out for under 2 hours)