Maritime Aquarium, Norwalk Live Cam

Atlantic sturgeon circle a tank at the Maritime Aquarium in Norwalk, on the Connecticut shore of Long Island Sound. The webcam sits low behind the glass and looks up towards the surface, so the fish pass overhead against the light.

Sturgeon are armoured rather than scaled: five rows of bony plates run the length of the body, and the mouth slides out underneath to work the gravel. The Atlantic species reaches four metres and sixty years, and the runs that once supplied a caviar trade on the Hudson and the Delaware collapsed a century ago. It has been listed as endangered in United States waters since 2012.

The aquarium stands on the Norwalk River in the old ironworks quarter of South Norwalk and keeps to species of the Sound itself. The Sound is an estuary about 180 kilometres long, shallow along this side, and warm enough in late summer to draw in fish that belong further south.