ImageJ analysis (see Experimental procedures) of the DGGE banding pattern shows less diversity in station 1 as compared to stations 2 and 3 (Fig.  1 ).

There were, however, two bands that migrated close to each other in the three stations (2, 8, 5 and 3, 9, 6, respectively) (Fig.  1 ).

This initial analysis suggested that there could be common bacterial species among the three stations (Fig.  1 ). .

These results approximated the number of bands detected in DGGE (Fig.  1 ).

Applying the ImageJ software analysis to our DGGE picture gave us the number of bands per station (Fig.  1 ), where each band, in theory, represents a single bacterial species.