Harbour seals were the most commonly spotted marine mammal, with over 1,000 reported over the 10 year period.

Canary Wharf a hotspot for sightings

The Thames Estuary is teeming with marine mammals, according to a report published by the Zoological Society of London (ZSL).

Launched in 2004, the ZSL Thames Marine Mammal Sightings Survey was designed to help conservationists form a better understanding of how marine mammals use the Thames Estuary in order to help conserve them.

Over the past 10 years, the organisation has received reports from over 1000 Londoners who together spotted more than 2,700 seals, porpoises, dolphins and whales.

Joanna Barker, European Conservation Projects Manager at ZSL, said: "People are often surprised to hear that marine mammals are regularly spotted in Central London. As a top predator, 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."

According to the survey report, there were more sightings around Canary Wharf than any other area. Many sightings were recorded in Central London, particularly between the 02 Arena and the Houses of Parliament.

Harbour seals were the most commonly spotted marine mammal, with over 1,000 reported over the 10 year period. The majority of sightings lasted no more than two minutes and were of marine animals swimming.

Joanna added: "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."

ZSL relies on sightings to understand the whereabouts and behaviour of marine mammals in Central London.

To take part in the ongoing survey visit www.zsl.org/inthethames. 

Image (C)Andreas Trepte www.photo-natur.de