The New England Aquarium houses a wide variety of marine animals, from invertebrates to fishes to marine mammals. It’s located directly at Boston’s harbor and is strongly involved in the clean-up of the disaster that polluted the waters for miles in 2053.
The exhibit that draws the big crowds are three elkies who used to live in the harbor and are now kept safe until their return into their natural habitat is possible. There are protests against this since selkies are sentient lifeforms and should not be put on display.
Unknown persons steal the selkies from the aquarium.