Mohandas K. Gandhi spread his ashes over Arabian Sea

The great-granddaughter of Mahatama Gandhi, Nilamben Parikh, pours his ashes into the Arabian sea after they were mixed with water

Mahatma Gandhi’s great-granddaughter today spread his ashes in the Arabian Sea in a ceremony marking the 60th anniversary of the Indian ...

Which preposition is correct when it comes to spreading ashes X sea? Thanks!
Your sentences include:


I think that I might use 'scatter...upon', but failing that, I choose 'spread...over'.
Teachers: We supply a list of EFL job vacancies
How about the word scatter? Which preposition would you use?
His fame spread all_ Banglades.