Download Nutrient Moored Sensor Program Year 1 Progress Update

the Satlantic LOBO system, a package consisting of WQM multiparameter instrument built by
WETLabs plus the Satlantic SUNA v2 nitrate sensor; or the YSI EXO2 multiparameter instrument
combined with the Satlantic SUNA v2 nitrate sensor. Both options had pros and con and a summary
of the decision criteria, as well as the suitability of each option relative to these criteria, are
presented in Table 2.2. In upcoming years, the question of the most suitable instrument(s) package
will be revisited.
After considering the pros and cons of each option, we selected the EXO2 as the basic water quality
sensor package (Figure 2.4a), and the SUNA (Figure 2.4b) was determined to be the best option for
nitrate. While the convenience and biofouling prevention features of the LOBO/WQM were
compelling, its much greater cost would have capped deployments in Year 1 to only 1 site, limiting
program development in terms of comparisons among sites and wrestling with the varied logistics
associated with managing multiple stations with differing requirements. In addition, the LOBO
system is designed to be a complete buoy package, and not all its features were needed during Year
1. Lastly, the EXO2s have been used successfully by the USGS-Sac biogeochemistry group for the
past 2 years, and the USGS-SacSed group may transition to EXO2s within the next couple years
(they currently use an older YSI sensor package). The EXO2 sensor has 6 probes that measure,
depth, temperature (T), specific conductivity (SpC), pH, turbidity (turb), dissolved oxygen (DO),
fluorescent dissolved organic matter (fDOM), chl-a and phycocyanin fluorescence (pH and
phycocyanin results will not be discussed in this report). For the remainder of this document, we
refer to the entire EXO2 as the sensor, and the individual equipment for measuring specific
parameter as the probe(s).
pH
a
Wiper
T/SpC
Chl-a/
BGA
DO
fDOM
Turb
b
Figure 2.4 YSI EXO2 multiparameter sensor (a) and Satlantic SUNA v2 nitrate sensor (b) deployed
during year 1 of the NMSP. There were some challenges with deploying the SUNA, resulting in limited
field data and therefore it will not be discussed in this report.
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