> viruses in the sea are for marine life Yes of course. The Wikipedia article says "Most of these viruses are bacteriophages ... Bacteriophages are harmless

> viruses in the sea are for marine life Yes of course. The Wikipedia article says "Most of these viruses are bacteriophages ... Bacteriophages are harmless to plants and animals ... Viruses are the main agents responsible for the rapid destruction of harmful algal blooms" Likely next to none can infect land mammals. Such viruses would not have a way to replicate to large numbers in seawater, not in land mammals.