People for the Ethical Treatment of Animals is again demanding SeaWorld San Antonio release its dolphins from captivity after a newborn aquatic mammal died at the amusement park this week. On Wednesday, SeaWorld San Antonio released a Facebook statement revealing that a Pacific white-sided dolphin calf had died in its captivity. “Despite our round-the-clock care and attention, and the tremendous efforts of our dedicated animal care team, she did not survive,” park officials wrote in the post.