(LATO) IN LOWERED SEAWATER pH - Central Visayas Campus ...

pH necessary for cell function. In addition, Hinga (2002) also concluded that the low
concentrations of free CO2 may as well be the mechanism for reduced growth rate at
low pH. The pH also affects the rates of primary production of marine algae.
Accordingly, their growth rates change significantly with pH changes near the
equilibrium pH.
The results of the study showed that the growth rate of the species was
reduced in lowered pH, which also coincided with the results on the study by Hinga
(2002). At pH 8.0±0.3, the species are under their normal environment, enabling
them to perform its activities well.
4.3 Color Changes of the Samples
The samples treated at the acidic pH of 3.0±0.3 and 4.0±0.3 showed a change
in color, most specifically from green to pale white. Also, 100% of the sample at these
pH ranges did not survive the experimental period of 7 days. On the other hand, only
about 20% of the species treated at pH 6.0±0.3 showed a change in color (see
Appendix D). The species treated at pH 8.0±0.3 had shown an even darker green
color, implying an increase in growth (Atkinson and Marubini, 1999).
Chlorophyll is one of the most important part of a plant or algae. Chlorophyll
presence is indicated by a green-colored characteristic in plants mainly because
chlorophyll is green. The greener the algae, the more amount of chlorophyll it
contains (Iglesias-Prieto et al., 1992).
The results in the study by Iglesias-Prieto et al. in 1992 coincides with the
observations in the experiment conducted. The samples at pH 8.0±0.3 showed a
darker green color (see Appendix D), implying a higher chlorophyll a content
compared to the samples treated in lowered seawater pH. The samples under pH
20