Phages in Marine Ecology

Marine plankton is a mixture of photosynthesizing bacteria, eucaryotic phytoplankton, and other bacteria and microorganisms.
It is the base of the oceanic food chain, and contributes significantly to global oxygen production and the oceanic carbon sink.
Microscopic examination of marine surface plankton indicates 5-10 times more phage particles than bacteria.
Only a few marine bacteriophages have been cultured and characterized.
One model of the marine plankton ecosystem holds:

Lytic phages kill off their target species down to low concentrations (< 10³/ml, ~15% infected at any time).
At this level, the time to find a target bacteria comes to equilibrium with the survival time of the phages. (~5% mortality/hr. due to UV damage).
This would exert a diversifying effect on the bacterial community (meaning a little of many different species instead of a lot of one species).
One would expect a coadaptive struggle wherein bacteria evolve to escape their phages and the phages evolve to catch up.

Phages in Soil Ecology:

There is a complex food web of micro-organisms in soil engaged in decomposing organic materials to a form that supports plant growth.
There are more phages than bacteria in environmental samples.