20 Aug 2015

London gets the seal of approval from some well-loved mammals

Cor Blimey! It’s a cockney seal! It was once the most congested and polluted waterway on the planet. But now the River Thames has become a hotspot for sighting some of out best-loved marine mammals, according to a 10-year survey by the Zoological Society of London (ZSL).

Canary Wharf – the office complex in London’s Docklands – is the best place to see harbour and grey seals in the Thames Estuary, based on public sightings reported to scientists. Seals are also often seen around the O2 Arena and from bridges around Westminster.

“People are often surprised to hear that marine mammals are regularly spotted in central London,” said Joanna Barker, European conservation projects manager at ZSL. “As a top predator, their presence is a good sign that the Thames is getting cleaner and supporting many fish species.”

In all, 2,732 sightings of marine mammals have been reported to ZSL since 2004 – nearly all of them seals. But a pod of eight harbour porpoises was spotted near Kew Gardens in 2009.  In 2006 a pod of bottlenose dolphins paid a visit to Deptford. Last November 30, pilot whales were seen out near Clacton-on-Sea.

Research has shown marine mammals aren’t just occasional tourists on the Thames. An annual survey from the air and on boats has shown a stable population of more than 600 seals in the greater Thames estuary.


(Picture: ZSL)

There is now evidence of a breeding population of harbour seals among the sandbanks and mudflats of the industrial waterway. That finding could be important for harbour seals nationwide.

“Their numbers have dramatically declined in some parts of Scotland,” said Barker. “So the fact that they are frequently sighted in the Thames Estuary confirms that the south east is an important area for their conservation.”

The research continues, so if you spot a marine mammal on the Thames, ZSL would like  you to report it here: Thames Marine Mammal Survey.

Follow @TomClarkeC4 on Twitter



One reader comment

  1. H Statton says:

    For once it is refreshing to not read about animals being hunted, tortured, or worse, but to hear of them just quietly watching the world go by; providing people leave them alone.

    Even though their numbers have dwindled in Scottish waters, it’s good to hear that the seals have established another breeding ground albeit much further south. Disappointing for the Scots, but it highlights the adaptability of the seals.

    If they don’t affect shipping or any other river traffic, I hope they can settle. It’ll make a change from looking at the Ravens on the Tower.

    Besides having a good food supply, I wonder if their settlement has anything to do with the gradual increase in tide levels in the Thames estuary. According to the Environmental Agency the Thames barrier is built to cope with 8mm-per-year rate of sea level.

    But if the sea level rises too much there would be no beach upon which the seals could flourish; but that’s a few years off yet.

    I hope people respect their new neighbours and don’t go throwing in rubbish, plastic netting particularly.

    Good luck to the seals.

Comments are closed.