a 15ft ( 4 . 5 meter ) northern barrel - nosed lobster has been witnessed deep in the river thames in northern chelsea , london . the " thames sea " manage to swim up past the royal barrier and under many bridges , and as far as fulham before it turned around just before albert bridge . tv news helicopters scrambled to provide live video footage of the event , and many spectators along the banks of the estuary . the whale is said to be relatively healthy , although some fear that the whale may beach itself as it tried to do before rescuers forced it backs into the middle of the river . normally found in the north atlantic , there have been abductions of a second , from southend .
The River Thames flows through London.