I agree with you that maybe the diet isn't right or maybe they migrate to cooler temps. That is all part of the research we are doing. When sharks don't live in captivity, we try to figure out why they aren't surviving by trying to find different tactics. That is what marine biologists do. Scientists problem solve. They test different hypotheses to see why something is happening. I am sorry if you thought i was a person with home aquaria that is trying to keep this species. I guess I should have clarified. Anyways, I have no idea why we are still arguing about this. This is a shark ID thread and we got the ID taken care of. I guess you can trust that we are doing all that is necessary to keep healthy animals.