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Thames marine mammal survey

ZSL asks for people fortunate enough to spot dolphins, porpoises and seals in the Thames to participate in this survey.

Grey seal
© Peter Dyrynda
Marine mammals are known to visit the Thames estuary but, until now, sightings have not been formally recorded. This survey is ongoing (since 2004) and will address this information gap.

Data collected will help to develop patterns and trends in species distribution, behaviour and habitat use. Findings will also be fed into national databases.

Our survey is operating in the tidal Thames area, between Teddington upriver to Shoeburyness and Sheerness in the outer estuary.

Take part by completing a questionnaire about your sighting

Marine Mammals in the Thames

The Thames Marine Mammal Sightings Survey, initiated in June 2004, has been running continuously over the last four years. The survey is supported from a range of sectors including people who work on and around the Thames, visitors enjoying the sights in central London, anglers and bird watchers on the estuary to organisations such as the Port of London Authority (PLA), Environment Agency (EA), Thames River Police and Port of London Health Authority – all of whom send in sightings and images. The survey is reliant on input from all these areas and the Zoological Society of London (ZSL) would like to acknowledge everyone's support.

Thames Marine Mammal Sightings 2004-2007

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

bottlenose dolphin
© Mike Cable Feb 2007
Grey seal Thames Marine Mammal Survey
© Colin Houliston

Thames Marine Mammal Sightings Update 2008

  • January: 13 sightings in total were sent in, all of which were common and grey seals. Sightings ranged between Putney and Hammersmith Bridges, Chiswick, Westminster Bridge and West India Docks.
  • February: Eight sightings in total this month again all common and grey seals. Sightings ranged between Chiswick Pier, Battersea Bridge, Westminster Bridge, Waterloo Bridge and Canary Wharf.
  • March: Four sightings were received this month, all of which were common and grey seals. All sightings were made in the Canary Wharf and Isle of Dogs area.
  • April: 14 sightings were made this month, all of which were common and grey seals. Sightings ranged between Westminster Bridge and Canary Wharf.
  • May: Excitement abounded this month as we received our first Bottlenose dolphin sighting this year. He/she was spotted from Tower Hamlets on the Westferry Road. We also had four more common and grey seal sightings all spotted around the Isle of Dogs and within the docks themselves.

Links to other recording schemes:

Marlin 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