2.4. Collection of estuary waters
In October and December 2010, and May 2011, we collected
surfacewater from the estuary zone of 2 major rivers (the Aono and
Inozawa) using a plastic bucket. These rivers are near Oura bay, but
their mouths are outside of the bay. We confirmed using a salinometer
(Atago, Maste-AS/Milla) that the salinity of the sample
was near zero. The samples were filtered through a GF/F filter, and
the filtrate was stored in polycarbonate bottles below 20 C until
analysis.