Whales, dolphins and seals returning to the Thames.

01/08/2007 00:00:00 September 2007. A report released by the Zoological Society of London (ZSL) reveals there were more than 100 dolphin, seal and porpoise sightings in the Thames last year.

Bottlenose dolphins, common and grey seals and harbour porpoises are regularly being spotted in the Thames between Richmond and the estuary at Southend, according to data provided by members of the public. ZSL has also released a map showing the locations of the various sightings which includes dozens of seals and porpoises and at least one dolphin seen between Westminster Bridge and Tower Bridge.

The survey also indicates those that make their way as far upriver as Tower Bridge may find themselves in a precarious situation. In several cases dead harbour porpoise have been reported shortly after live sightings, with injuries that consistent with propeller or boat collision damage.

The ZSL Marine Mammal Sighting Survey is now going into its fourth year, building up the first ever comprehensive picture of marine mammal life in the River Thames. The survey invites members of the public who spot dolphins, seals or porpoises in the river to give details of the location, date and time to ZSL. It is well supported by anglers, bird watchers, pub staff working along the river, the Port of London Authority and Thames River Police, rowing clubs, Londoners and tourists. ZSL Aquatic Ecologist Dr Renata Kowalik said: ‘These findings are really important to enable us to build up a picture of the Thames’ role in the ecology of British marine mammals. Once we have established our baseline data over the next few years we will be able to determine trends, identify threats and effectively manage habitats in the Thames.’

She added: ‘We need more people to keep their eyes open and take time to detail their sightings at zsl.org – it could help conservationists in the future have a better understanding of situations like the Thames Whale.’

The online form can be found at www.zsl.org/thamessurvey