Dophins are intelligent, social and gregarious animals. The mistake is in thinking they act (and think) like the other intelligent, social and gregarious specie that we know – us. They are a wild animal and a predator. Placing them in captivity and training them to certain behaviors does not make them “tame”, it makes them “habituated”.
The amazing thing is that there have been so few incidents in captivity. We’ve taken a far ranging, free swimming animal that often covers hundreds of miles of open ocean and trapped them in a small tank or lagoon and make them perform for food.
I admit the temptation to be close to these wonderful animals is there for me….I have vascillated on whether swimming with free ranging dolphins that have been habituated (or fed) by humans is ethical or not. For me, the closest that I’ve found is a researcher in Key West that has followed a pod for almost ten years now and severly restricts the types of interactions allowed. I’ve also had multiple accidental meetings in the ocean while swimming – no doubt the closest thing to a non-invasive interaction (and sometimes scaring the bejeesus out of me when a huge grey form slides silently by me just out of reach).
As to the specific question of injury by dolphin, you can look to reports from SeaWorld to answer that. When I was woking as a keeper, I scheduled an interview with SeaWorld for a keeper position – then I started talking to former keepers and various zoo personnel. Marine mammal trainers and keepers have an high rate of attack and injury (not surprisingly, SeaWorld does not advertise this fact). I have heard of a keeper who was fatally attacked and had his speen ruptured, but I suspect that that is an urban myth.
@andrew, they do indeed have rape gangs. Multiple males will target a specific female and chase her until exhausted, bumping and pushing her until she cannot flee or fight back. We place an unfair burden on dolphins when we expect them to meet up to our expectations of them based on myth.