Aquariums of the World

A zoo can be built anywhere there is ground to fence. An aquarium had to be invented, because water goes foul: seal it and it kills what lives in it.

The breakthrough was a balanced jar of water

The answer arrived in 1850, when the chemist Robert Warington reported to the Chemical Society that two goldfish, a stand of eelgrass and a few snails had held one another in balance in the same twelve gallons for the better part of a year — the plants returning the oxygen the fish spent — with the water never once changed.

Others had reached parts of it first

Jeanne Villepreux-Power was building glass observation tanks in Sicily from 1832; Anna Thynne kept corals alive in a London drawing room from 1846 by pouring seawater back and forth in front of an open window, before she thought to add seaweed.

What turned the principle into an institution was a tax

Britain repealed its duty on glass in 1845, panes became large and cheap, and water could be looked through rather than down into. London Zoo opened its Fish House in 1853, the first public aquarium in the world, and the naturalist Philip Henry Gosse gave the thing its name in a book the following year.

For a century, the limit was engineering

The animals absorbed the shortfall. P. T. Barnum installed two belugas in a brick tank in his museum basement in 1861, in tepid fresh water under gas lamps; they were dead within days, and he sent for more. Ambition outran plumbing in gentler ways too — Chicago's Shedd Aquarium, opening inland in 1930, ran twenty railway tank cars on eight round trips to Key West to import a million gallons of the Atlantic.

Then spectacle became an industry

Marineland followed in 1938, built as an underwater film studio and inventing the oceanarium along the way; SeaWorld made the orca show an industry from 1964; Monterey Bay grew a living kelp forest in 1984 on seawater pumped straight from the bay.

The hard question stopped being technical

Then the binding constraint stopped being material. Blackfish put Tilikum's story in front of a mass audience in 2013, SeaWorld ended orca breeding in 2016 and said that generation would be its last, and Canada banned the keeping of whales and dolphins in 2019, exempting only the animals already in tanks. What an aquarium can build stopped being the hard question some time ago. What it can justify holding is.