Walking across London’s bridges at night is one of my favourite things to do in the city. The beautiful north and south banks bejewelled with lights, and set off by the stunning Tower Bridge in one direction and The Eye and Houses of Parliament in the other. Apart from the pretty lights, one thing that is great about the Thames at night is that you can’t see how brown and murky the water is. It’s not much of an inspiring sight during daylight hours. However, does this relate to the health of the Thames?

Londoners and visitors to our great city can now see the health of the Thames visually represented in an artwork called Thames Pulse by artist Jason Bruges and supported by the river charity Thames 21. The light display is installed on the side of the sea containersbuilding, just down the river from us here at King’s College London, and is a dynamic series of lights representing the health of our river as informed by daily samples and accompanied by a twitter feed (https://twitter.com/thamespulse).

Sea containers 2
Sea containers building. Mainly blue lights represented no change in health of the river from the previous day. Images by Roksana Nikoopour

Apparently the darkness of the river is actually attributable to the London clay that is underneath the flowing river, and the increase in silt as it approaches the sea. However, even though the health of the river can’t be linked to its colour, the Thames has had a dark past. As the main artery for the city it was heavily used to transport goods, but sadly it was also a dumping ground for any and all waste produced on its banks. The city’s river was declared officially biologically dead in the 1950’s, however it has improved remarkably since then. There are now 125 species of fish present in the Thames, and there are regular seal sightings. This remarkable improvement in a relatively short time is fantastic, however the Thames still faces pollution challenges including plastic and sewage.

Although the Thames Pulse won’t report on specific plastic pollution, it will give a result for the overall health of the river, including oxygenation which is vitally important for the ecosystem of the river and is impacted by sewage pollution. The readout on the sea containers building will consist of one of three light patterns, based on whether the water quality is improving, static or declining compared to the previous weeks reading:

  1. Improving: Pink and blue lights pulsate up and down
  2. Static: A blue wave sweeping across the building
  3. Declining: Green and static

The project hopes to induce Londoners, and visitors to our city, to engage with the health of the Thames and consider what they can do to help keep the humble river healthy for many years to come.

An accompanying 10-point manifesto includes advice to Londoners on how to keep the water healthy.