Currently,the plastic garbage which drifted to the ocean, these have been picked them up mainly with lots of volunteer activity at the shore now. 
Plastic things which are floating in the harbors have been collected by the surface cleaning ship but like micro plastic things are very difficult to collect.
Therefore  as using the filter attached next page,(No1 in the world with low cost and simple) the micro plastic things which slipped from big garbage are collected through this filter and return to sea as clean seawater. 
Generally,the surface cleaning ship has pool in it.
Leave only small things in the pool temporarily, then return as clean seawater from the pool to sea through this filter.
If the ship has not like that function, vacuum pump to be installed in it then the water surface cleaning ship which can be collected the contaminant.
Then the seawater can be returned with clean through this filter directly to sea.
It is possible to use this filter to select 20μ, 10μ,and 5μ depending on its purpose.
As the rust problem will be occurred,the filter case made of PP only to be used.
Filter to be reused repeatedly until broken. Cost:40,000 Japanese yen/set. The number of the sets to be increased according to necessary of the flow quantity.
Refer to attached sheet for details