I believe there would be an argument from people that it is ethically justifiable to capture dolphins or orca whales and train them for human entertainment. They would justify their argument by stating that these mammals are confined to areas that they are not use to. They would need to be in an environment where they can swim freely without constraints. People would also argue that orcas have a lower life expectancy when confined instead of being in the wild oceans.
Some may argue that it is ethically justifiable because these mammals make people of all ages happy with the tricks they perform. Attractions such as SeaWorld have millions of dollars invested in these parks and rely on people buying tickets to keep these attractions open. People would also argue that these attractions provide steady income for many people. They would also argue that dolphins and whales would not be able to survive in the wild oceans because they would not be able to hunt for food on their own.
Reflecting back on this topic, I initially came to a conclusion that this would be a pseudo argument and that both sides would not change their views given fair reasoning with conductive research. I still think that it would be hard to convince an avid animal lover to change their thoughts and keep dolphins and orca whales as human entertainment. I also think that acquarium owners would not want to release dolphins and orca whales since they would lose business when families pay money to come to see these dolphins and orca whales.