All three statements provided are incorrect.

I. Many viruses, including phages, can indeed survive in ocean waters, where they can play significant roles in marine ecosystems.

II. Viruses can and do infect bacteria, a fact that underlies the field of bacteriophage research, with implications for biotechnology and medicine.

III. Viruses can alter cellular transcriptional activity in host cells by inserting their genetic material or using the host's machinery to replicate, thus influencing various cellular functions.

These statements highlight the complexity of viral biology and the significant interactions that viruses have with their environments and host organisms, topics typically covered in biology and virology sections of UPSC prelims reference material.