Figure 20.2 shows that sharp changes of physical-chemical profile of bottom
surface in this area have led to the fact that in 2009, the sediments with such
conditions (positive Eh) have not been detected on any of the sampling stations.
Fig. 20.2 Diagram Eh and
pH in bottom sediments of
Sevastopol Bay (2000,
2009)
Table 20.1 Physical-chemical indices and the concentrations of oil hydrocarbons (OH, mg 100 g
À1
sed. dry weight) in different types of bottom sediments of the Sevastopol Bay (2000, 2009)
2000
Type/indices
%
a
Moisture, %
pH
Eh, mV
OH, mg 100 g
À1
Black silt
47.4 42.00. . .78.51 7.05. . .8.04 (þ21). . .(À189)
82.0. . .1708.8
Dark-gray silt 26.3 54.83...66.35
7.16. . .7.60 (þ1). . .(À167)
34.0. . .250.8
Gray silt
10.5 49.90. . .67.53 7.30. . .7.55 (þ21). . .(À 89)
40.0. . .114.0
Other
b
15.5 26.56. . .72.69 7.90. . .8.17 (þ251). . .(À114) 1.0. . .14.0
2009
Black silt
31.6 50.40. . .69.26 7.08. . .7.85 (À178). . .(À114) 143.8. . .1369.5
Dark-gray silt 31.6 50.56. . .67.49 7.38. . .7.82 (À174). . .(À55)
90.4. . .856.6
Gray silt
26.3 35.85. . .54.07 7.47. . .7.56 (À69). . .(À247)
19.0. . .196.0
Other
b
10.5 18.05. . .33.50 7.52. . .7.75 (À20). . .(À29)
24.3. . .189.3
Note:
a
% (quota) from total number of sampling stations
b
mixed substratum (the sands, mollusk shells, silt etc.)
360
T.S. Osadchaya