Seals, dolphins and whales spotted in London

Cetaceans including whales, dolphins, and porpoises are also present in large numbers.

The sightings, often by members of the public, were recorded between 2004 and 2014 as part of the ZSL Thames Marine Mammal Sightings Survey, an extension of which is still ongoing.

Joanna Barker, manager of European conservation projects for the Zoological Society of London, said that many people only see a dirty and environment when they look into the River Thames.

It certainly comes as a surprise given that the capital’s famous river was declared “biologically extinct” just 50 years ago thanks to its high levels of pollution.

“But, actually, beneath the waves, it is full of life”. She said that the Thames has a wide range of invertebrates and fish, as well as animal predators.

But the public sightings confirm that the river is springing back to life. It was once the most congested and polluted waterway on the planet.

Porpoises and dolphins were seen at Teddington Lock, with pods sighted near Deptford and Kew Gardens.

A whale even visited central London in 2006, but the bottle-nose did not survive. Other whales were also sighted near Gravesend in Kent.

It may be the number of human eyes trained on the docks that accounts for the success or it may be the presence of Billingsgate fish market – either way, the presence of Sammy and friends has triggered more reported sightings than more desolate places closer to the sea. An annual survey from the air and on boats has shown a stable population of more than 600 seals in the greater Thames estuary.

The scientists estimate there are about 670 harbour seals along the estuary.

“We do think this area is really important”, said Miss Barker.

If you see a marine mammal in the Thames, report it to the Thames Marine Mammal Survey here. Many of these sightings were reported by people who saw the aquatic mammals from skyscrapers around the city.