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International Journal of Marine Science 2014, Vol.4, No.12: 108-118
http://ijms.sophiapublisher.com
110
sites using a HORIBA Multi-parameter meter for
pH/temperature/ORP/dissolved oxygen. Nitrite and
nitrate were determined using a UV visible
spectrophotometer (Thermo Spectronic, Heλios). For
the analysis of BOD, water samples were diluted, then
the samples were placed into 250 ml narrow neck
glass bottles and left in an incubator at 20
℃
without
light for five days. Dissolved oxygen of the diluted
samples and control (dilution water) was measured at
the beginning and end of the analysis (APHA 2005).
Calculations of the results were as follows:
BOD (mg/L) = [A*(
C
－
D)/B] + D
A = total volume after dilution (mL)
B = volume of undiluted sample (mL)
C = oxygen consumption of diluted sample after 5
days (mg/L)
D = oxygen consumption of dilution water after 5 days
(mg/L)
3 Results and Discussion
3.1 Summer
The percentage of organic matter is a parameter that
shows especially indicate the organic matter loads in
sediment. The organic matter loads are usually
originating from domestic discharges. The level of
organic content in the sediment of site 4 was maximal
(2.18%) as compared to all other sites. The lowest
value of organic matter is determined in station 8 with
0.32% (Figure 3A).
The porosity values are given in Figure 4. It can be
said that % water content and % porosity data are
parallel to each other (Figure 3B).
The redox potential (Eh) of the sediments ranged from
-45mV to -145mV, indicating oxygen deficiency
sediment in all stations except station 7 where redox
value was +11mV (Figure 3C).
3.2 Autumn
In autumn, it can be said that in surface sediment, the
organic matter content is accumulate in the areas
which are the % water content and water depth is high
in sediment (Figures 4A and B). The redox potential
(Eh) of the sediments ranged from -152 and -52 mV
(Figure 4C). In station 2, the domestic wastewater is
always discharge in marine coastal areas without any
treatment. The sediment samples aren’t black but, it
can be feel that the sulfide smells during the analyses
easily.
3.3 Winter
The highest value of organic matter content (6.5%) is
determined in station 4 in winter in sediment samples.
The lowest value of organic matter is determined in
station 3 with 0.11% (Figure 5A). Water content and
porosity values (%) are partly parallel to each other
(Figure 5B).
The maximum redox potential (Eh) was 203 mV. The
other redox potential values of the sediments ranged
from -125mV to -32mV (Figure 5C). In station 4, both
water and sediment samples had organic pollution in
winter. In this station, sediment samples had bad smell,
dark color and insufficient oxygen. Moreover there
was no Mollusca fauna, indicating that coastal zone
was affected from pollution of land-based sources
(Figure 6).
Figure 6 Station 4 in winter
Sediment structure of station 4 was small pieces, in
clay form, dark color and bad smell, indicating sulfide
and high organic matter. On the other hand sediment
was not oxygenated.
3.4 Spring
The highest value of organic content is determined in
station 4 with 0.69 % whereas the lowest value (0.15%)
of organic matter is determined in station 3 (Figure
7A). Water content and porosity values (%) are
parallel to each other (Figure 7B). The highest redox
potential (Eh) was 191 mV at station 7. The other
redox potential values of the sediments ranged from