Thames Marine Mammal Survey

Members of the public are helping us to monitor the marine mammals of the Thames by completing sighting surveys. If you have spotted a seal, porpoise or dolphin in the Thames, please tell us about it by following the link below:
marine mammal sighting survey

Marine Mammal Survey

Common seal
The ZSL Thames Marine Mammal Sightings Survey was initiated in June 2004 and has been running continuously over the last nine years. The survey operates in the tidal Thames area, between Teddington to Shoeburyness and Sheerness in the outer estuary. The surveys will help us understand patterns and trends in species distribution, behaviour and habitat use. The findings will also be fed into national databases.

If you want more information on what marine mammals you can see in the Thames, please see our marine mammal poster (179 KB)

A range of people submit sightings to us, including those who work on and around the Thames, visitors enjoying the sights in central London and anglers or bird watchers. The success of the survey relies on the input from all these people and ZSL would like to thank everyone who has spent the time filling in a survey form. We'd like to remind you that if you managed to take a photo of the marine mammal, please send it to: marineandfreshwater@zsl.org

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Thames Marine Mammal Sightings Update 2013

January and February: over 30 people submitted sightings, most of which were single grey or harbour seals. But during the middle of February, a group of 3 porpoises swam all the way down to Richmond Lock! This slightly unusual event caused a surge in sightings - if you have any pictures of the porpoises, please email marineandfreshwater@zsl.org

If you see a stranded cetacean, please do not approach it as it's potentially dangerous to the public, but may also be harmful to the animal. If you suspect a marine mammal to be in distress or danger please contact the British Divers Marine Life Rescue

Thames Marine Mammal Reports

ZSL Thames Marine Mammal Survey Report 2004-2007 (1.1 MB)
ZSL Thames Marine Mammal Survey Report Appendices 2004-2007 Part 1/2 (1.6 MB)
ZSL Thames Marine Mammal Report Appendices 2004-2007 Part 2/2 (3.8 MB)

Other recording schemes:

Sealife Signpost is initiative of the MarLIN programme, providing guidance on marine life recording schemes that you can join, and on where to send your sightings of marine species. Sightings can also be reported via their message service. A full list of recording schemes is given at Sealife Signpost