World The River Thames was declared ‘biologically dead’ 60 years ago. Now it’s making a comeback November 11, 2021 Taylor Avery, USA TODAY Comments Off on The River Thames was declared ‘biologically dead’ 60 years ago. Now it’s making a comeback Declared "biologically dead" in 1957, the River Thames is again home to seals, seahorses and certain kinds of birds, according to a report.