I don't know much about the Belle Island Aquarium but I see from the internet that it opened in 1904 - yet the Brighton Aquarium opened thirty-two years earlier in 1872.
The point I was makung was that I think "ZooBinh" gave the right answer to this question several posts ago.
The oldest, still operating public aquarium is the Musée Aquarium'de Arcachon in France, it was opend in 1867. Second oldest is Sea Life Brighton (1872), third place holds Naples Aquarium (1874) and the fourth oldest is the Exotarium at Frankfurt Zoo, opend in 1877. The oldest still extisting aquarium in the USA is the New York Aquarium, it was opend in 1896. Shedd opend its doors to the public in 1930.
I'm not sure that the New York Aquarium actually counts as the oldest in the U.S.A. because it's not on its original site. It opened in 1896 in Battery Park but moved to its current location, Coney Island, in 1957.
But it is the same institution. The zoo Frankfurt, like many zoos in the US, once moved,too, but still remains the same institution. There are different opinions about that, but officially the New York Aquarium is the oldest existing aquarium in the US.
I appreciate that it is the same institution which has moved site. However, applying similar logic, you could argue that the London Zoo Aquarium is the oldest in the world because it is operated by the same institution that opened the Fish House in 1853.
Good question, but from my point of view-I would say no, because there is too much time gone between the Fish-House was closed and the new aquarium, opened 1924.