After years of research into dolphin behavior and countless protests from activists about their life in captivity, the dolphins at the National Aquarium in Baltimore will be moved to an oceanside sanctuary.

The aquarium announced its decision on Tuesday, noting that the new environment would become the nation’s first dolphin reservation, and said the transition is expected to be complete by the end of 2020. Although there are already sanctuaries for elephants, chimpanzees and other animals, this will be the only one in North America for dolphins.

The change is the result of a five-year debate among aquarium officials, who weighed various options on how best to deal with the animals. The aquarium stopped offering shows in which the dolphins performed a few years ago, but tourists and visitors can still watch them in captivity.

Scientists say dolphins, which are highly intelligent, need the freedom to express themselves in their own habitat, and need to be able to form the tight social groups essential to their well-being.