ZSL survey receives seal of approval
Wednesday 24 August 2005
A ZSL survey reveals that dolphins, porpoises and seals are frequent visitors to the River Thames and its estuary.
© Peter Dyrynda
The Thames Marine Mammal Survey was launched in July 2004, to collect data that will help to develop patterns and trends in species distribution, behaviour and habitat use, and ZSL is making a fresh appeal to the public to take part in this ongoing project.
Riverside pub patrons, commuters and river users have all been involved in gathering the essential survey information about these unexpected Thames species and so far ZSL has received 103 sightings by the public, totalling 197 animals.
Included in the first year results were porpoises spotted off Vauxhall Bridge, common seals around Canary Wharf, the Thames Barrier and Tower Bridge, plus dolphins swimming near Southend in Essex, just inside the mouth of the river.
Seals were the most frequent marine mammals that were spotted with 46 common seals, 30 grey and 41 un-identified seal species being sighted.
Harbour porpoises were found to venture further up the estuary and the indications are that they remain in and around the estuary all year round. The dolphins were only reported around the mouth of the estuary during spring and summer, suggesting that they are seasonal visitors.
For full survey information and year one findings please download 
Thames Marine Mammal Report (299 KB)
Take part in the survey by completing a short questionnaire about your sighting.
