These have been converted to basically ticking time bombs as the metal and fuel tanks corrode.
The amount of oil in these sunk ships is difficult to estimate, but even on a light estimate resulted in a wide-spread ecological disaster.
As usual the response from 95% of governments out there is simply to bury their heads to the problem.
Source from DW Documentaries (https://www.youtube.com/watch?v=OP0U62oiBlM)