Sixty years ago, nothing could survive in Engalnd’s River Thames – but today it is home to seals, porpoises and even the occasional stray whale.
In 1957, the Natural History Museum declared the Thames biologically dead. News reports from that era describe it as a vast, foul-smelling drain.
More than 2,000 seals have been spotted in the Thames over the past decade, according to a survey by the Zoological Society of London that ran from 2004 to 2014 and was published in August 2015, along with hundreds of porpoises and dolphins and even the odd stray whale.
Even though other problems now are threatening the health of the river and its animals – namely, its abundance of plastic – that’s a big change for a river once so polluted, not even fish could survive in it.
There are now 125 species of fish in the Thames, up from almost none in the 1950s.
“You make the river as natural as possible, with clean water and proper flows, and then you’ll see the community return,” says Chris Coode, the deputy chief executive of Thames21. “This wasn’t about people breeding species in captivity and releasing them. The fish returned naturally.”