The Thames provides habitats for numerous bird and fish species, but it occasionally receives some more unusual visitors. In 1899 a 30-ton whale was run ashore in North Woolwich (visible from the Air Line).

Local residents recall family members telling stories of the animal being beached on Bargehouse Shore, with people crowding down to take a look and even a souvenir piece of meat.

Perhaps surprisingly, between 2004 and 2014 more than 40 whales were sighted in the River Thames. Almost 2,000 seals and 450 porpoises and dolphins were also spotted during this time. Their presence is a good sign that the Thames is getting cleaner.