If you want to swim with seals, porpoises and dolphins then central London might not be your first choice. But the Zoological Society of London (ZSL) Thames Marine Mammal Sightings Survey, which launched in 2004, has recorded more than 2,700 seals, porpoises, dolphins and whales in the Thames Estuary over the past 10 years.
“People are often surprised to hear that marine mammals are regularly spotted in Central London,” said Joanna Barker, European Conservation Projects Manager at ZSL. “Their presence is a good sign that the Thames is getting cleaner and supporting many fish species. The presence of these animals is also a great example of how urban environments are important for wildlife.”
The survey was designed to help conservationists develop a better understanding of how marine mammals use the Thames Estuary, in order to help conserve them.
The top spot for seal sightings was around Canary Wharf. Many sightings were also recorded in central London, especially between the Houses of Parliament and the O2 Arena, but seals were seen as far upstream as Hampton Court Palace. Harbour porpoises and dolphins were sighted as far up the Thames as Teddington Lock and whales as far as Gravesend.
Harbour seals were the most commonly spotted mammal, with more than 1,000 animals reported over the 10 year period.
“We were pleased to see that harbour seals were some of the most commonly spotted mammals. Their numbers have dramatically declined in some parts of Scotland, so the fact that they are frequently sighted in the Thames Estuary confirms that the South East is an important area for their conservation,” said Barker.
Although most sightings were of individual animals, occasionally large groups are seen. In September 2014, 100 seals were spotted at Greenwich and 30 pilot whales were spotted near Clacton-on-Sea in November 2014.
See the August/September issue of H2Open magazine for advice on how to get up close and personal with seals.