An aquarium or marine park can be successful without captive dolphins and killer whales. Just look at the Monterey Bay Aquarium. The only cetaceans they have are the life-sized replicas hanging from the ceiling. The aquarium is extremely popular and in 2006, 16,694 people visited on a single day to learn about California’s sea life. They also conduct research on great white sharks, sea otters, and tuna and educate people about making the right seafood choices with their Seafood Watch Sustainable Seafood Guide.