Fish under threat from ocean oxygen depletion, finds study

Oxygen levels in oceans have fallen 2% in 50 years due to climate change, affecting marine habitat and large fish such as tuna and sharks

The depletion of oxygen in our oceans threatens future fish stocks and risks altering the habitat and behaviour of marine life, scientists have warned, after a new study found oceanic oxygen levels had fallen by 2% in 50 years.

The study, carried out at Geomar Helmholtz Centre for Ocean Research in Germany, was the most comprehensive of the subject to date. The fall in oxygen levels has been attributed to global warming and the authors warn that if it continues unchecked, the amount of oxygen lost could reach up to 7% by 2100. Very few marine organisms are able to adapt to low levels of oxygen.