> the sheer scale of microbial life [...] ocean water There's also the sheer predation of it. IIRC, for some coastal surface biome I've long forgotten, viral h

> the sheer scale of microbial life [...] ocean water There's also the sheer predation of it. IIRC, for some coastal surface biome I've long forgotten, viral half-life was like an hour, and a third of bacteria were virally lysed each day. A cup of beach water is not just teaming with life, it's a war zone.