Anyone interested in this short non-fiction piece would also likely be interested in the recently released Blackfish documentary which chronicles much of the plight of orcas in captivity, including SeaWorld. http://blackfishmovie.com/
As for this story I felt as though the author managed to stay unbiased, although I do not see how someone could read it and walk away feeling there is nothing wrong with having immensely intelligent beings such as orcas in captivity. Would YOU like to spend your life in a bathtub? I'm pretty sure people would go insane under these conditions and unfortunately it appears some of the whales snap too (such as Tilikum). I cannot blame Tilikum for the death of 3 people, he is the killer whale equivalent of "not guilty by reason of insanity".
Tilikum was taken from his family pod when he was just about 2 years old (essentially equivalent to human years). Orca family units are extremely close and loss of contact alone can cause a member to die. Tilikum was not only taken from his family but then placed in a concrete tank for nearly a year only to then be sent to another location where two female killer whales tormented him (also due to their own imbalances). Tilikum suffered from repeated stomach ulcers due to stress at this early stage and I doubt he has been free of physical manifestations of captivity since. So it comes as no surprise that within 30 years of captivity he has killed 3 people. Honestly, the total could be much higher.
The idea of keeping these amazing beings in captivity is so twisted I cannot really wrap my head around thinking it is acceptable. Zimmermann does a good job in summarizing the plight of killer whales and marine parks (mainly SeaWorld) since the 1960s. I would greatly recommend this piece to anyone considering supporting institutions with orcas. Please consider what your money supports!