The first mermaid I spotted was in Deptford Creek. I’d heard local tales going back decades, of the ‘Deptford Necker’, a dark creature who lived near the bridge. At first I thought it was a little girl swimming, covered in mud, but in an instant she dived underwater and swam off with a flash of silver. Another time I was trying to photograph the Minky Whale that was lost in the Thames. I was near the Thames Barrier and a girl was on the shore looking forlorn, and pulling some old plastic off her arm, as I peered down I saw her tail stretched out, and she slithered into the sea.

At low tide, at dusk, when no one is about, the merfolk make themselves known to me. There is a spot on the Greenwich Penninsula where they can safely come ashore. The poor creatures are often bedraggled in plastic packaging and bearing scars from boats and nets. They remain dignified yet sombre. They tell me that humans think they know everything but they don’t. That the Thames should not be surrounded by concrete towers that block out the sun, and we should not throw chemicals and rubbish into the water that they breathe. There are things we can’t possibly understand, they say, they joke that we can’t understand any of what dolphins and whales talk about. “Respect the Thames because it gave life to your City” is the general message. They warn that it might decide to break its banks and engulf the concrete and humans, returning to its ancient flood plains.
We know more about the Moon that what happens in the untouched ocean depths, and they hope that our dumbness keeps them safe.
I can only “see” the mermaids through the victorian Cyanotype process which is sensitive to certain frequencies of UV light that we can’t see with the naked eye. I take home a flask of Thames water which magically turns the image into a blueprint. You won’t be able to capture mermaids on a digital camera, except perhaps as a brief silver sparkle.