Thames Marine
Mammal Survey

Spotted a marine mammal?

The Thames Estuary is home to harbour seals, grey seals, harbour porpoises and sometimes even dolphins and whales! ZSL has been collecting public sightings of these marine mammals since 2004 and they are frequently sighted all the way up to Richmond.

These sightings form a crucial part of our understanding of the biodiversity in the Thames and help us conserve these charismatic top predators.

If you are lucky enough to see a marine mammal, please follow our code of conduct and report your sighting below.

Sightings reported this year

harbour seals
grey seals
harbour porpoises
Number of unknown seals

Marine Mammal Code of Conduct