Mute Math - Obsolete Bass

Mute Math's bassist for this song uses a fretless bass, heres how i play it to give it 
same effect on a fretted bass.

G----------6/8-9---------8h9p8-----------------------------|
D-------------------------------11/9-----------------------|
A----------------------------------------------------------|
E-----9-------------9---------------------9----------------|

heres some other riffs he uses:

G----------------------------------------------------------|
D----------------------------------------------------------|
A---------9/11--9p7/6--------------------------------------|
E----9-----------------7/9---------------------------------|

G---------11/13--11p9/8------------------------------------|
D----------------------------------------------------------|
A----------------------------------------------------------|
E----9--------------------9--------------------------------|