and stored aboard the research vessel at −20 °C. Later they were freeze
dried in the laboratory, and crushed to powder within a porcelain
mortar. The sub-samples for grain size analysis were stored at 4 °C.
3.2. Grain size and total organic matter analyses
Grain size distributions were determined through standard sieving
technique for the coarse part and hydrometer technique for the finer
part of sediments (Hakanson and Jansson, 1983). The fine fraction was
separated from the sand fraction by wet sieving using a 63 μm screen.
The organic matter was determined by the method of loss on ignition. Dried sediment samples were weighted before and after their incineration in a muffle furnace at 600 °C for 2 h, in order to burn all the
organic matter (Castel et al., 1990; Rodier, 1996 and Oliver et al.,
2001). Total organic matter (TOM) values are reported as percentages
of dry weight.
3.3. Heavy metals analysis
40 mg of dry sediment sample were put into a Teflon vessel with a
mixture of concentrated acid (3 ml HCl + 4 ml HNO 3 + 1 ml
H 2 O 2 + 0.5 ml HF). Samples were digested in the microwave at 240 °C.
After digestion and cooling, the samples completely dissolved (total
digestion) were diluted with 3% HNO 3 to 10 ml for further analysis.
Concentrations of Fe, V, Mn, Ni, Cu, Zn, Pb, Cr, Co, Cd and As were
determined in the digested phase by inductively coupled plasma–mass
spectrometer (ICP–MS Perkin-Elmer NexION 300×) at the CEREGE
Laboratory. ICP-MS measurements were quality checked by analyzing
certified riverine water for trace metals (SLRS-5, National Research
Council of Canada).
Table 1
Characteristics of surface sediments samples along Algerian coast.
Location
Station
Latitude
Longitude
Depth (m)
TOM %
Mud %
Sand %
Sediment type
East coast
El Kala
S17
36°58.190 N
08°26.239 E
80
13.6
96
4
Mud
S18
37°08.255 N
08°01.741 E
562
16.6
96
4
Mud
S07
36°59.713 N
08°18.716 E
67
8.1
4
96
–
S14
36°59.011 N
08°18.596 E
28
3.4
4
96
–
S39
37°10.540 N
08°20.429 E
421
18.1
–
–
–
S43
37°07.872 N
08°09.789 E
544
18.0
89
11
Mud
Annaba
S40
36°53.419 N
07°56.525 E
37
6.6
46
54
Very fine sand
S16
36°57.859 N
07°50.180 E
59
12.2
99
1
Mud
S23
36°55.239 N
07°54.088 E
46
15.5
99
1.18
Mud
S35
37°50.948 N
07°53.835 E
332
17.7
–
–
–
Skikda
S42
36°58.256 N
07°07.851 E
91
9.5
85
15
Mud
S26
36°58.974 N
07°02.525 E
133
12.1
85
5
Mud
S15
37°00.718 N
07°12.980 E
36
8.0
58
42
Medium sand
S50
37°00.038 N
06°55.978 E
243
13.5
–
–
–
Jijel
S45
36°53.579 N
06°02.990 E
63
10.8
96
4
Mud
S27
36°44.551 N
05°29.277 E
151
12.0
84
6
Mud
S36
36°51.526 N
05°58.933 E
41
9.5
77
23
Very fine sand
S49
36°56.674 N
06°04.674 E
149
14.2
–
–
–
Centre coast
Béjaia
S37
36°41.165 N
05°19.579 E
78
10.0
96
4
Mud
S51
36°39.453 N
05°19.579 E
36
6.4
43
57
Very fine sand
Tizi Ouzou
S30
36°54.567 N
03°46.033 E
32
6.5
33
67
Very fine sand
S46
36°54.638 N
04°05.406 E
54
9.0
78
22
Fine sand
Boumerdes
S54
36°50.332 N
03°21.694 E
180
12.2
89
11
Mud
S31
36°47.004 N
03°28.367 E
45
8.0
53
47
Medium sand
S48
36°50.143 N
03°25.625 E
310
13.4
99
1
Mud
Alger
S04
36°47.872 N
03°11.208 E
46
17.2
94
6
Mud
S25
36°47.237 N
03°25.777 E
48
9.8
90
10
Mud
S41
36°42.906 N
02°45.352 E
47
8.9
64
36
Very fine sand
Tipaza
S33
36°52.287 N
02°42.950 E
530
15.1
96
4
Mud
S13
36°35.279 N
02°02.489 E
36
10.3
82
18
Mud
S21
36°36.498 N
02°34.682 E
43
9.1
68
32
Very fine sand
S08
36°38.076 N
02°43.351 E
23
5.7
–
–
–
S29
36°42.397 N
02°39.053 E
116
13.3
–
–
–
West coast
Mostaganem
S32
36°00.137 N
00°04.636 W
29
6.4
60
40
Medium sand
S24
35°59.884 N
00°01.324 W
70
12.7
85
15
Mud
Oran
S28
35°55.215 N
00°17.100 W
79
6.7
80
20
Biogenic
S52
36°02.763 N
00°08.979 W
307
16.2
96
4
Mud
S05
35°34.768 N
01°09.706 W
18
2.6
–
–
–
Beni Saf
S11
35°18.499 N
01°03.391 W
70
12.1
84
16
–
S01
35°27.297 N
01°14.698 W
20
2.3
83
17
Fine sand
S03
35°36.124 N
01°11.367 W
73
5.1
77
13
Fine sand
S02
35°20.579 N
01°20.798 W
25
3.5
–
–
–
S12
35°20.859 N
01°20.683 W
40
6.9
52
48
Fine sand
S20
35°13.291 N
01°39.235 W
72
13.5
89
11
Fine sand
S44
35°09.330 N
01°47.739 W
69
13.4
96
4
Mud
Ghazaouet
S34
35°06.271 N
02°07.807 W
22
5.7
21
79
Fine sand
S09
35°07.891 N
01°58.527 W
72
11.4
97
3
Mud
S10
35°09.341 N
02°07.565 W
87
11.6
–
–
–
S22
35°05.809 N
01°58.523 W
19
6.8
–
–
–
S38
35°07.622 N
01°47.101 W
20
4.1
3
97
Biogenic
S47
35°09.341 N
02°07.565 W
87
13.6
–
–
–
I. Ahmed et al.
Marine Pollution Bulletin 136 (2018) 322–333
324
dried in the laboratory, and crushed to powder within a porcelain
mortar. The sub-samples for grain size analysis were stored at 4 °C.
3.2. Grain size and total organic matter analyses
Grain size distributions were determined through standard sieving
technique for the coarse part and hydrometer technique for the finer
part of sediments (Hakanson and Jansson, 1983). The fine fraction was
separated from the sand fraction by wet sieving using a 63 μm screen.
The organic matter was determined by the method of loss on ignition. Dried sediment samples were weighted before and after their incineration in a muffle furnace at 600 °C for 2 h, in order to burn all the
organic matter (Castel et al., 1990; Rodier, 1996 and Oliver et al.,
2001). Total organic matter (TOM) values are reported as percentages
of dry weight.
3.3. Heavy metals analysis
40 mg of dry sediment sample were put into a Teflon vessel with a
mixture of concentrated acid (3 ml HCl + 4 ml HNO 3 + 1 ml
H 2 O 2 + 0.5 ml HF). Samples were digested in the microwave at 240 °C.
After digestion and cooling, the samples completely dissolved (total
digestion) were diluted with 3% HNO 3 to 10 ml for further analysis.
Concentrations of Fe, V, Mn, Ni, Cu, Zn, Pb, Cr, Co, Cd and As were
determined in the digested phase by inductively coupled plasma–mass
spectrometer (ICP–MS Perkin-Elmer NexION 300×) at the CEREGE
Laboratory. ICP-MS measurements were quality checked by analyzing
certified riverine water for trace metals (SLRS-5, National Research
Council of Canada).
Table 1
Characteristics of surface sediments samples along Algerian coast.
Location
Station
Latitude
Longitude
Depth (m)
TOM %
Mud %
Sand %
Sediment type
East coast
El Kala
S17
36°58.190 N
08°26.239 E
80
13.6
96
4
Mud
S18
37°08.255 N
08°01.741 E
562
16.6
96
4
Mud
S07
36°59.713 N
08°18.716 E
67
8.1
4
96
–
S14
36°59.011 N
08°18.596 E
28
3.4
4
96
–
S39
37°10.540 N
08°20.429 E
421
18.1
–
–
–
S43
37°07.872 N
08°09.789 E
544
18.0
89
11
Mud
Annaba
S40
36°53.419 N
07°56.525 E
37
6.6
46
54
Very fine sand
S16
36°57.859 N
07°50.180 E
59
12.2
99
1
Mud
S23
36°55.239 N
07°54.088 E
46
15.5
99
1.18
Mud
S35
37°50.948 N
07°53.835 E
332
17.7
–
–
–
Skikda
S42
36°58.256 N
07°07.851 E
91
9.5
85
15
Mud
S26
36°58.974 N
07°02.525 E
133
12.1
85
5
Mud
S15
37°00.718 N
07°12.980 E
36
8.0
58
42
Medium sand
S50
37°00.038 N
06°55.978 E
243
13.5
–
–
–
Jijel
S45
36°53.579 N
06°02.990 E
63
10.8
96
4
Mud
S27
36°44.551 N
05°29.277 E
151
12.0
84
6
Mud
S36
36°51.526 N
05°58.933 E
41
9.5
77
23
Very fine sand
S49
36°56.674 N
06°04.674 E
149
14.2
–
–
–
Centre coast
Béjaia
S37
36°41.165 N
05°19.579 E
78
10.0
96
4
Mud
S51
36°39.453 N
05°19.579 E
36
6.4
43
57
Very fine sand
Tizi Ouzou
S30
36°54.567 N
03°46.033 E
32
6.5
33
67
Very fine sand
S46
36°54.638 N
04°05.406 E
54
9.0
78
22
Fine sand
Boumerdes
S54
36°50.332 N
03°21.694 E
180
12.2
89
11
Mud
S31
36°47.004 N
03°28.367 E
45
8.0
53
47
Medium sand
S48
36°50.143 N
03°25.625 E
310
13.4
99
1
Mud
Alger
S04
36°47.872 N
03°11.208 E
46
17.2
94
6
Mud
S25
36°47.237 N
03°25.777 E
48
9.8
90
10
Mud
S41
36°42.906 N
02°45.352 E
47
8.9
64
36
Very fine sand
Tipaza
S33
36°52.287 N
02°42.950 E
530
15.1
96
4
Mud
S13
36°35.279 N
02°02.489 E
36
10.3
82
18
Mud
S21
36°36.498 N
02°34.682 E
43
9.1
68
32
Very fine sand
S08
36°38.076 N
02°43.351 E
23
5.7
–
–
–
S29
36°42.397 N
02°39.053 E
116
13.3
–
–
–
West coast
Mostaganem
S32
36°00.137 N
00°04.636 W
29
6.4
60
40
Medium sand
S24
35°59.884 N
00°01.324 W
70
12.7
85
15
Mud
Oran
S28
35°55.215 N
00°17.100 W
79
6.7
80
20
Biogenic
S52
36°02.763 N
00°08.979 W
307
16.2
96
4
Mud
S05
35°34.768 N
01°09.706 W
18
2.6
–
–
–
Beni Saf
S11
35°18.499 N
01°03.391 W
70
12.1
84
16
–
S01
35°27.297 N
01°14.698 W
20
2.3
83
17
Fine sand
S03
35°36.124 N
01°11.367 W
73
5.1
77
13
Fine sand
S02
35°20.579 N
01°20.798 W
25
3.5
–
–
–
S12
35°20.859 N
01°20.683 W
40
6.9
52
48
Fine sand
S20
35°13.291 N
01°39.235 W
72
13.5
89
11
Fine sand
S44
35°09.330 N
01°47.739 W
69
13.4
96
4
Mud
Ghazaouet
S34
35°06.271 N
02°07.807 W
22
5.7
21
79
Fine sand
S09
35°07.891 N
01°58.527 W
72
11.4
97
3
Mud
S10
35°09.341 N
02°07.565 W
87
11.6
–
–
–
S22
35°05.809 N
01°58.523 W
19
6.8
–
–
–
S38
35°07.622 N
01°47.101 W
20
4.1
3
97
Biogenic
S47
35°09.341 N
02°07.565 W
87
13.6
–
–
–
I. Ahmed et al.
Marine Pollution Bulletin 136 (2018) 322–333
324