Editor's note: Fisher Stevens is an actor, director and producer. He is a producer of "The Cove," an Oscar-nominated film that won the best documentary award from the National Board of Review in 2009. He co-founded Naked Angels theater company in 1986 and co-founded GreeneStreet films in 1996.

(CNN) -- Before I started working on the documentary "The Cove," I assumed like many others that dolphins and orcas enjoyed living at Sea World and other marine parks. They always seemed to be smiling, jumping merrily around their tanks, eager to put on a show for human spectators.

However, when I met Ric O'Barry, my perspective changed. O'Barry was the man responsible for capturing Kathy -- the original "Flipper" -- from the wild and helping to create the language used to train dolphins to do tricks and flips. When Cathy died in his arms some years later, O'Barry realized the whole process of capturing and training dolphins was wrong.

He eventually co-wrote the book "Behind the Dolphin's Smile," where he explains that the smiles you see on these animals are not true reflections of happiness. In actuality, they hate to be enclosed in their holding tanks and are often not fed until it is time to perform their daily routines. During his time as a trainer, O'Barry learned dolphins had true feelings -- they would get depressed, stressed out, even suicidal. In some parks, the trainers have to give the animals Maalox and Tagamet to treat the ulcers that develop from their stress.

The horrific tragedy that occurred last week at SeaWorld in Orlando, Florida, has left me deeply shaken. My heart goes out to Dawn Brancheau and her family. Dawn lost her life doing the job that she loved, yet I -- like O'Barry -- believe that this job should no longer exist.

We know now that the whale involved in this accident has a well-documented history of violent behavior. SeaWorld knew of this history yet continued to exploit the animal and endanger the lives of its employees to put money in its pockets. If this isn't a wake-up call, I don't know what is.

At this very moment, a dozen boats in the town of Taiji, Japan, are heading out and rounding up hundreds of dolphins in a secluded cove. The fisherman will close off the cove with nets, and with the help of employees from various dolphinariums, they will try to find the next "Flipper" among their catch. The fishermen will snatch these beautiful creatures from their natural habitats, hoist them into nets, load them onto airplanes and drop them into a cement tank in the middle of Turkey, Korea or other nearby Asian countries.

In some ways, these animals are the lucky ones. These dolphins escaped the fate of many of their pod mates, who are brutally slaughtered with primitive harpoons -- turning the cove into a scene straight from Melville's "Moby Dick." The water turns bright red with the blood of the slain. The fishermen then transport the meat -- despite health concerns of mercury content in the dolphins' systems -- back to shore, where they sell it to local vendors.

It's time for us to step up and make a difference in these animals' lives. Until we make marine parks obsolete, dolphins and other sea mammals will continue to be senselessly captured and slaughtered.

We can no longer fall for the argument that SeaWorld shows "make us love the dolphins and want to understand and protect them" -- this couldn't be further from the truth. As I see it, we will only truly love and understand these animals when we can watch them running wild and genuinely smiling in their natural habitat.

The opinions expressed in this commentary are solely those of Fisher Stevens.