Basic HTML Version
International Journal of Marine Science 2014, Vol.4, No.18: 166-178
http://ijms.sophiapublisher.com
170
3.1.3 Particulate Organic Carbon (POC)
Particulate organic carbon (POC) represents one of the
main pools of organic carbon observed in the waters.
POC for three different locations of mesocosm
experiment showed different patterns (Figure 4).
However, there was a similar pattern of POC between
mesocosm experiment at Takalar and Barrang Lompo,
which were POC higher at 96 hours incubation than
48 hours incubation period for all CO
2
treatments
(Figure 4b and 4c). Interestingly, at Barru mesocosm
experiment, POC was higher at 48 hours incubation
period than 96 hours incubation period for all CO
2
treatments (Figure 4a). The highest POC was found at
Takalar mesocosm experiment at 96 hours incubation
period for 750 ppm CO
2
concentration account for 229
μg/L and the lowest POC was 15.59 μg/L at Barru
mesocosm experiment, 96 hours incubation period for
280 ppm CO
2
concentration. Generally, increasing
CO
2
concentration did not affect significantly to POC
production for both incubation period. However, for
Barru mesocosm experiment POC production was
higher at 48 hours incubation period than 96 hours
incubation periods for all CO
2
treatment. This result
showed that length of incubation period affected
significantly on POC production. Increasing length of
incubation period decreased significantly of POC
production.
3.1.4 Particulate Inorganic Carbon (PIC)
Particulate inorganic carbon was varied within
location of mesocosm experiments. Figure 5 showed
that there was a general trend of PIC which was
increasing PIC with increasing CO
2
concentration. For
Barru and Takalar mesocosm experiment, PIC
concentration was higher at 96 hours incubation
period than 48 hours (Figure 5a and 5b). However,
there was no significant different of PIC concentration
between incubation periods for all CO
2
treatments. On
the other hand, PIC concentration at Barrang Lompo
mesocosm experiment showed a higher at 48 hours of
incubation period than 96 hours for almost all CO
2
treatments (Figure 5c). This trend was contradicted
with two mesocosm experiments at two different
locations. The different trend of PIC concentration
between Barru, Takalar dan Barrang Lompo
mesocosm experiments probably due to different of
water quality parameters (Salinity, pH, DO, DIC and
alkalinity). Based on DIC and alkalinity data (previous
subpart of this report), there were a different trend of
DIC and alkalinity between Barru, Takalar and
Barrang Lompo. This finding indicated that PIC
concentration was strong related with DIC and
alkalinity was affected significantly by carbonate
system in the waters. Engel et al (2005) found that
several species of dissolved inorganic carbon (DIC)
exist in seawater, namely CO
2
, HCO
3
-
, and CO
3
-
, the
proportions of which are largely was determined by
the total DIC concentration, pH, and total alkalinity
(TA).
1.3.5 Ratio of particulate inorganic carbon (PIC) to
particulate organic carbon (POC) at three different
locations of mesocosm experiment
Ratio of PIC to POC indicated a physiology process
into the cell that correlated with carbonate systems
especially concentration of CO
2
. The change in [PIC] :
[POC] ratios was attributed to a decrease in
calcification rates, as well as an increase in organic
carbon production (Figure 6). Our results showed that
there was decreasing PIC:POC ratio with increasing
CO
2
concentration for 96 hours incubation periods for
mesocosm experiment at Barru, interestingly, there
was no significant difference of PIC:POC ratio for all
CO
2
concentration for 48 hours incubation period.
(Figure 6a). This result was consistent with previous
research, which was showed the ratio of particulate
inorganic carbon (PIC) to particulate organic carbon
(POC) production decreased with increasing CO
2
concentration (Riebesell et al., 2000; Zondervan et al.,
2001, 2002). Interestingly, the PIC:POC ratio tended
to increase with increasing CO
2
concentration at two
others mesocosm experiment (Takalar and Barrang
Lompo Island) for both incubation periods. The
PIC:POC value was higher at 48 hours than 96 hours
incubation periods for almost all CO
2
concentrations
(Figure 6b and 6c). The highest PIC:POC ratio was
found at Barrang Lompo mesocosm experiment for
1000 ppm of CO
2
, account for 2.11 at 48 hours
incubation period. The lowest PIC:POC ratio was 0.37,
which was found at Takalar mesocosm experiment for
280 ppm of CO
2
concentration, 48 hours incubation
period. This result was contradicted with previous
research. It was probably due to different carbonate
system, which affected the value of PIC and POC at
two locations of mesocosm experiment.