ELSEVIER
Marine Micropaleontology
3 1 ( 1997) 157- 175
High benthic fertility and taphonomy of foraminifera:
the Skagerrak, North Sea
a case study of
Elisabeth Alve a,*, John W. Murray b,l
’ Department
‘Department
ofGeology,
University
qf Oslo,
of Geology, Southampton Oceanography
Received
F!O. Box 1047 Blindem,
Centre, European
8 July 1996; accepted
15 December
N-0316
Oslo, Norway
Way, Southampton SO14 3ZH, UK
1996
Abstract
The Skagerrak
basin is a deep water extension of the North Sea. It is of particular interest as an analogue for
past epicontintal shelf basins because it presents environmental contrasts with the adjacent shelf seas. In this study the
distribution patterns of benthic foraminifera have been used to infer taphonomic and oceanographic processes.
Only by separating living from dead assemblages is it possible to interpret taphonomic changes. The transport of
foraminiferal tests to the Danish slope is inferred from the presence there of dead exotic tests whose provenance is
considered to be from the south. The abundance of detrital organic matter on the Danish slope is likewise inferred to be
sourced from the same direction. Thus, the Danish slope is interpreted to be a depositional sink. Apart from transport,
another taphonomic process is the dissolution of calcareous tests. This is clearly demonstrated both by the fragility of
some tests as viewed under the microscope and by the disparity between the composition of the living and dead factor
associations. In the deep basin in particular, the two predominantly calcareous living associations are replaced by a single
predominantly agglutinated dead association due to carbonate dissolution.
The Danish slope of the Skagerrak Basin is demonstrated to be an area of high benthic fertility. This is based on
the high density of living (stained) benthic foraminifera (comparable with that of the Mississippi delta), particularly the
abundance of Stainforthia jiuiformis, an opportunistic species, and tubular agglutinated forms. The fertility is linked with
the high abundance of particulate organic matter here.
Previous regional studies have focused on total (living plus dead) distributions of > 100 or > 125 pm sized foraminifera.
These factor assemblages are distinct from the >63 pm living and dead associations described here.
Keywords:
benthic foraminifera; benthic fertility; taphonomy; Skagerrak; dissolution; opportunism
1. Introduction
The Skagerrak is a >650 m deep basin in a shelf
setting in the eastern North Sea. It has particular
* Corresponding
author.
Fax: +47-22854215.
’ Fax: +441703-593052.
E-mail:
elisabeth.alve@geologi.uio.no.
E-mail: jwml@mail.soc.soton.ac.uk.
0377-8398/97/$17.00
0 1997 Elsevier Science B.V. All rights reserved.
PI1 SO377-8398(97)00005-4
interest as an analogue for past epicontinental
shelf
basins because its hydrography is influenced both by
the ocean, via the Norwegian Trench, and by the
Kattegat, with its brackish Baltic Water outflow. The
Skagerrak is the major sink for fine-grained
sediments derived from the North Sea (e.g., Van Weering
et al., 1987; Kuijpers et al., 1993; Rodhe and Holt,
1996) and it also receives large quantities of anthro-
pogenic total nitrogen and phosphorus (North Sea
Task Force, 1993). A summary of the environment
and a review of the foraminiferal literature are given
by Alve and Murray (1995) and are not repeated
here.
The present study represents a continuation
and
conclusion of a regional ecological survey of benthic foraminifera
initiated in 1992 as part of an
environmental
programme under the leadership of
the Norwegian Geological Survey (NGU). In a preliminary study, foraminiferal
results from 1992 and
1993 from the northwestern
Skagerrak were compared with samples collected by Hoglund in 1937
(Alve and Murray, 1995). The principal conclusions
were that there were no obvious signs of fauna1
change since 1937 on the Norwegian slope but there
has been an increase in the rate of production of
tests and a change in the dominant species in the
deep basin (at depths of more than about 500 m).
The comparison also showed a progressive increase
in both the relative and absolute abundance of agglutinated tests with increasing water depth. This
was attributed to carbonate dissolution (destroying
calcareous tests) and increased production of agglutinated forms in the deep basin. Fauna1 analyses of
dated sediment cores from the deep basin suggest
that these changes have occurred primarily since the
early 1970’s (Alve, 1996).
The preliminary study was confined to the northwest and included the deepest parts of the Skagerrak
Basin as well as the Norwegian and Danish slopes
deeper than 285 and 266 m, respectively (Fig. I).
This new study concerns the south western continuation of the Basin where it shallows progressively
from around 550 to 400 m, and it also includes the
adjacent Norwegian and Danish slopes (deeper than
59.00OSLO{
FJORD’
-+
GWEDENI
58.50
58.00-
10
7.50
8.00
8.50
9.00
9.50
10.00
10.50
Fig. 1. Bathymetry
(m) of the Skagerrak and distribution of stations. Numbers are given only for stations not reported in Alve and
Murray, 1995. dots = 1992; circles = 1993; double circles = 1994 (those with open inner circles were used for foraminiferal assemblage
analyses; those with filled inner circles were examined only for organic detritus and tubular foraminifera).
E. Ah,
Table I
Details of samples collected
J.W.
Murray/Marine
Micropaleontology
31 (1997)
159
157-175
in 1994 plus samples 56 and 69 from 1993
Sample
No.
Latitude
Longitude
Depth
Tubes
(“N)
(“E)
(4
-
123
95
108
83
127
122
94
107
85
82
97
86
106
80
93
92
121
105
120
87
119
129
113
100
130
76
91
51.92
58.00
51.93
58.08
57.86
57.86
57.95
57.88
57.96
58.02
57.94
57.90
51.82
57.90
57.89
57.83
57.81
57.76
57.75
57.83
57.69
57.14
57.69
57.75
57.68
57.91
57.77
7.33
8.13
7.19
8.47
7.22
7.45
8.24
7.91
8.48
8.59
8.02
8.60
8.03
8.84
8.37
8.49
7.51
8.15
7.69
8.73
7.81
7.46
8.04
8.41
7.58
9.07
8.61
276
285
324
414
457
497
500
518
520
534
551
536
525
519
514
504
471
469
458
430
412
411
407
403
385
376
320
1
2
1
1
3
1
1
3
3
1
1
3
3
3
3
2
3
3
3
3
2
2
I
I
2
4
2
4
2
3
2
3
2
4
2
3
2
3
2
4
3
I
-
OD
2
2
2
3
4
3
2
3
3
2
1
4
Sample
No.
Latitude
Longitude
Depth
(%)
(“N)
(“E)
(ml
2.0
2.0
2.2
2.2
1.9
2.2
2.3
2.1
2.3
2.3
2.6
2.1
2.3
2.8
2.3
2.5
2.2
2.2
2.2
2.6
2.2
2.2
1.8
2.4
2.3
2.3
1.6
118
104
101
114
77
117
1:5
102
89
56
69
78
79
81
84
88
90
96
98
99
103
109
110
111
112
116
128
51.63
57.68
57.70
57.62
57.86
51.56
57.58
57.65
57.73
58.16
58.09
57.79
57.84
57.96
58.02
57.78
57.71
58.00
57.88
57.82
57.64
57.93
57.87
57.81
57.75
57.53
57.80
7.94
8.32
8.50
8.20
9.17
8.08
8.28
8.62
8.95
9.29
8.95
9.06
8.96
8.72
8.36
8.84
8.73
7.90
8.13
8.26
8.39
7.55
7.68
7.80
1.92
8.14
1.34
284
262
240
218
188
188
168
140
117
652
640
148
248
521
468
197
163
TOC
176
504
515
197
329
504
512
473
162
440
Tubes
OD
TOC
(So)
2
2
4
4
4
3
4
3
2
1.8
2.8
1.8
2.0
0.5
0.9
0.5
0.4
I
1
0.5
2
I
3
2
n.d.
n.d.
3
4
1
3
3
I
I
2
2
2
4
4
2
3
3
3
2
2
2
3
3
2.2
2.1
0.4
I .3
2.3
2.4
I.1
0.9
1.3
2.2
2.3
0.9
2.2
2.3
2.1
2.2
0.6
2.2
I
2
3
1
3
2
2
1
2
I
I
I
I
3
3
2
Tubes = abundance of tubular agglutinated foraminifera
on a relative scale from I (few) to 4 (abundant); OD = organic detritus (>63
LLrn wet fraction) on a relative scale from 1 (little) to 4 (abundant): n.d. = no data.
The upper part lists those samples studied for foraminiferal
assemblages. The lower part on the right includes the additional samples for
which no foraminiferal assemblage studies were carried out.
276 and 117 m, respectively). The primary aims of
this study are to discuss transport and benthic fertility regimes. Additional themes are other taphonomic
processes and a broader discussion of the living and
dead assemblage distributions as compared to previous distributional works in the same area (Conradsen
et al., 1994; Bergsten et al., 1996). For completeness, there is discussion of the new results presented
here for 1994 together with those for 1992 and 1993
(Alve and Murray, 1995).
2. Material and methods
The new surface sediment samples (O-2 cm of
short cores using a multicorer)
were collected in
1994 during University of Bergen cruise no. 9404
(Table 1; Fig. 1). On the ship, a portion of each surface O-2 cm of sediment was transferred to a plastic
bottle and preserved in 70% ethanol. In the laboratory, the precise sample volumes (mostly 50-80 cm’)
were determined by measuring the height and diameter of the sediment in the containers. The samples
were washed on a 63 Frn sieve, stained with rose
Bengal for about one hour, then washed again on
the same sieve and dried at 50°C. A total of 52 surface sediment samples were processed as described
above.
However, before the 1993 and 1994 samples were
dried, it was obvious that there were major differences in the content of organic detritus. Therefore,
each whole sample was subjected to a visual examination under the microscope and the relative content
160
E. Ah,
J. W
Murry\/Marine
Micropalrontolog~
of this organic detritus was expressed on a subjective scale from 1 (few) to 4 (abundant). Likewise, a
visual assessment of the abundance of agglutinated
tubes was performed on each whole sample after it
was dried. Again, this was because there were major
differences between samples and the results were
expressed on a subjective scale from 1 to 4. The
reason for this procedure is that it was impossible to
measure the number of tubes in a quantitative way
because of unknown effects of fragmentation.
For foraminiferal
assemblage analyses, at least
250 living (stained) and 250 dead (unstained) individuals were picked from each of 36 samples. Fragments of tubular agglutinated forms were treated as
a separate category and are not included in the assemblage calculations (for rationale see Murray and
Alve, 1994).
Details of measurement
of species diversity of
the assemblages are presented in Alve and Murray
(1995). Varimax factor analysis was carried out on
species making up 25% of the assemblages in each
of the living and dead assemblage data using the
Q-mode factor analysis program CABFAC (Imbrie
and Kipp, 1971; Klovan and Imbrie, 1971). For the
factor analysis of the data for the dead assemblages,
all results from 1992, 1993 and 1994 were considered together. Data on living foraminifera were not
available for 1992 so the factor analysis comprises
just the 1993 and 1994 data.
A species references list is given in Appendix
A. With the exception of Textularia truncata all the
agglutinated
species referred to in this paper have
non-calcareous
cements.
Total organic carbon (TOC) analyses of replicate
surface samples from all stations were performed by
the Leco combustion method (courtesy of NGU).
3. Results
The foraminiferal
data, including
only those
species making up a minimum of 5% in at least
two of the 1994 samples, are presented in Tables 2
and 3 (including two newly processed 1993 samples,
nos. 56 and 69). In order to show the regional picture
and to prepare for discussion, Figs, 2-8 include our
previously published data as well as the new information for the south western part. However, in this
section, only the new 1994 results are described.
.I1
(IYY7)
157-175
3.1. Density of tests
The density of living individuals is highly variable
(overall range: 8-332 tests/cm’). However, the lowest densities (5-39 tests/cm3) are generally confined
to areas deeper than 400 m whereas all values 280
tests/cm3 are on the Norwegian and Danish slopes
(Fig. 2A). The maximum values (236-332 tests/cm’)
are found on the Danish slope between 200 and 300
m.
In a similar fashion, the abundance of dead tests
shows a very orderly pattern (Fig. 2B). The lowest
values are in the basin and on most of the Norwegian
slope with highest values on the Danish slope.
3.2. Associations
For the living assemblages,
the 1994 data plus
stations 56 and 69 from the 1993 area have been
combined with the previously published 1993 data
(56 stations in total). The varimax factor associations
are named after the species with the highest absolute
score within each factor. In two instances, the difference between the highest and second highest score
was 50.07, so both names were used.
Four
factor
associations
are
distinguished
(Table 4) and account for 83% of the variance.
Factor 1, comprising Nonionella iridea with Melonis barleeanum and Pullenia osloensis as important
components, occupies the deep eastern parts of the
study area whereas factor 4, H. membranaceum/E.
vitrea, occupies the western part (Fig. 3A). Factor
3, Globobulimina auriculata association with accessory l? osloensis and Textularia tenuissima, covers
most of the Norwegian slope. The Danish slope is
dominated by factor 2 characterised by Stainforthia
fusiformis. There is only a single occurrence of factor
2 (station 123) on the Norwegian slope.
For the dead assemblages,
the 1994 data plus
station 56 and 69 from the 1993 area have been
combined with those previously published for 1993
and 1992 (69 stations in total, Table 5).
The four factor associations account for 88% of
the variance. They show a clear pattern of distribution which is not entirely tied to water depth
(Fig. 3B). The deep basin is occupied by factor
3 comprising Haplophragmoides
bradyi, with subsidiary Saccammina
SpQ.,
Trochamminopsis
pusil-
live
o-2
goes,
Of sp*c1es
agglutmated
r&x
2
0
20
16
2
6
14
4
22
25
4
17
11
16
11
12
9
0
3
9
1 3
1
4
1
12
7
*
6
1,
20
3,
25
19
94
90
21
44
70
16
24
29
6.010.0
33
22
4
4,
4,
33
36*632625o2621o11oo,o,,3
264
261
265
286291
200
3
4
3 1
0
1
0
3
15
6
13
13
3
2
4
12
4
72
90
22
30
266
9
63
70
32
25
263
0
3
6
2
10
32
65
19
21
260
4
5
5
36
21
516
94 107
500
ooooooooooooooooooooooooooooo,o7o~5l4
6
29
12
5
15
16.0
2
0
,1
021O*30,6303,*02,,79,o~~6~,0~,00~~~~o0
7
7
0
2
4
1 2
2
0
1
3
36
17
123 95 108 83 127 122
276 285 324 414 457 497
3
3
2
6
16
60
14
31
349
1
6
7
17
17
17
520
85
19
66
10
25
296
3
0
1
6
0
7
0
2
2
16
534
82
1
1
1
7
3
114
95140
64
33
302
16
7
10
10
4
651
97
2
26
24
43
297
9
6
13
2
9
1
3
,
24
536
27
70
1,
2,
322
9
1
1
8
4
1
6
4
17
30
525
86 106
4
126
65
1
7
26
324
3
11
4
0
0
6
0
44
28
40
267
4
12
2
15
8
20
34
I6
293
4
4
10
1
1
1
4
26
20
477
23
105
36
13
297
1
4
1
4
1
5
*
16
12
30
469
22
90
1
7
4
32
13
312
2,
1
6
6
2
13
19
458
92 121 105 120
504
1 1,
6
70130100
10
27
377
10
4
7
2
0
0
93
514
1 28 1
1
4
1
2
II
74
519
80
slope across the basin to the Danish slope
6
60
65,2.0,,0
34
16
437
5
6
26
15
10
6
1
3
3
B”,,mi”a
margrnata
,!&a
barleeanum
medrus
SCBb,“S
spp
f*““l*srma
index
dead/cm
In SW dead/cm’
Transported
Alpha
0, speues
-b agglutlnaled
No
NOcounted
s.3ccamm,na
Textularia
Hapiophragmordesbradyl
EggsENordes
Eggsre~lardes
P”lle”ia oskxnsrs
Sfaintorthia
fusA7rms
No”io”el,a
M*,o”l*
B”lalKla
s.4agemkens~~
Cawdubna
,aewgata
Elphrdium
Eprstcvnl”ella excavalum
wma
0
2
11
2,
14
30
35
35
36
7
7
10
19
0
253
0
255
0
87
II
3,
313
0
32
0
162
41
12
6
7
7
22
2
,
3
122
497
290
37
41523
1
4
15
o
IO
1,
14
252
4,
12014~1101,0140~10140110110,,014012012060
41
39
1s
7
6
457
12,
1
6
10
3
5
110
0
44
271
43
1,
16
500
94
6
6
7
6
84
0
49
263
35
11
12
6
11
516
107
0
49
0
46
271
37
2
8
16
3
7
5
5
0
62
534
0
103
6,
260
35
2
61622
10
16
3
15
13
4
520
65
10
1
4
85
0
47
236
40
77
0
37
39
276
6
a
16
12
16
5
3
66
536
15
4
7
6
16
551
9,
8
1
*
3
88
0
56
264
36
6
2
23
7
14
525
106
3
7
0
4
0
0
19
4
ZOI
0
14
257
26
6,
519
60
slope across the basin to the Danish slope
83
414
10
3
4
16
9
6
3
106
324
260252268254
0
__6131513
0
2
,o
3
19
10
2
19
6
96
265
12
7
19
4
123
276
deplh (m)
dead X. O-2 cm
Sample no.
Water
1994.
depth trnnscct from the Norwegian
12
3,
263
16
2
7
4
25
16
2
6
92
504
121
0
42
265
3
16
6
5
13
13
6
477
188
0
148
0
74
0
39
30
47
160,20120,30,00120,40,10,4090
56
572
3
6
5
9
14
7
7
93
514
105
0
4
3
104
0
46
46
29,
7
4
2
14
6
15
469
120
16
6
6
0
110
31
33
263
6
5
7
6
10
19
456
595
5
9
36
259
0,
2
0
,
5:
3
6
67
430
2
7
,
60
30
35
9
13
265
3
7
2
12
11
IO
411
2
1
6
6
0
3
1
6
90
6
32
10
279
13
43
407
012
2
2
30
9.012.5
32
4
26,
1
2
2
16
96
6
17
0
4o3
0
6
9
62
38
39
269
376
6
,
2
6
0
9
6
13
3
1
69
5
3
9
50
294
32
1
,
14
15
12
26
70,6O,25
24
196
,I
11
5
2,
22
41
306
,,
0
0
9
7
14
3
1
4
13
1,
264
332
4.5
0
1
0
2
16
253
240
0
,
60
60
27
16
277
60
4
3
3
1
0
0
7
1 3
1
0
1
0
0
0
85
262
44
6.0
61,
68
34
2,
7.0300
27
46
1
0
0
7
0
0
12
236
22
262
1
0
0
0
4
7
0
0
56
166
37
7.0
18
26
1 8
5 4
34
279
1 7
0
0
0
0
0
0
6
166
67
46
19
337
62
140
469
0
68
o
0
1
0
5
o
1
89
117
6
94
50
16
22
0 0
1000
0
0
0
o
0
4
0
0
77 117 115 102
166
0 1
18
I
3
0
2
0
3
1
6
22
4
304
70
216
91 118 104 101 114
320
t 11 I
4
6
5
2
14
,6
365
9
189
22
37
292
o
3
5
4
10
1,
,:
129
41,
113
214
3
34
43
276
4
o
5
5
o
36
272
0
0
49
2
12
8
0
3
35
275
0
2
19
7
2
,“,
116
264
10
0
60
296
0
3
32
7
6
7
4
3
6
1
91
320
:
76
376
21
1,
,30,,0,90,,0120
39
269
3
5
10
13
,“,
9
130
365
4
2
5
9
4
2
0
11
37
256
0
2
46
104
262
2
9
15
12
50
0
0
2
6
0
57
514
0
2
15
0
0
6
2
7,
I66
31
160140
616
6
36
370
150
4
1’:
114
216
12
0
0
45
340
140
1
0
6
50
101
240
I,,
6
3
0
22
43
300
0
5
19
7
11
,“,
166
0
2
25
1406.5
47
279
0
3
14
0
1,
I”,
3
115
166
43
23,
886
735
371
1124
1596
,614
491
2431
300
143
6
1
0
34
32
0
0
0
3
0
26
2433
,018
90
o
5,
56
9
10
52
91
0
77
0
6
3
0
6
91
0
59
62
746
11
9
0
69
640
155155
62
,65
2015
20
6
00
1
6
0
1
00;
66
0
1
4
9
46
392
1
4
5
12
o
D
69
640
662
0
00
*
0
9
29
0
3
15615.0
69
117
303
10
0
30
269
0
9
0
23
1
0
0
102
140
7 0 ff0 95 14 4, 335 158285 498193465
352
10
31
264
0
0
2
39
10
,:
100
403
12
3
7
14
3
4
15
7
13
407
*
0
16
362
1943
652
66
1993. Samples arranged as a
1994 data plus sta. 56 and 69 from 1993. Samples arranged as a
10
143
40
44
3
TO
,;
6
34
10
306
6
4
26
,;
119
412
3
5
2
38
272
1,
,6
16
,O
412
76
1994 data plus -aa. 56 and 69 from
87 119 129 113 100 130
430
Percent abundance of important species (see text) and calculated faunal parameters of dead assemhluge\,
Table 3
Lwhl’
%
Pia.
nlpha
Texfularia fen”,SSima
NO counted
Liebusella
msdius
scottu
&7ere,hvdes
Leproha~prs
f”srkmnis
bulloldes
osloenss
Pu,lenra
S,ai”folvlra
P”l,e”ra
aunculata
badeeanum
rndea
Melonrr
Na”,o”e,,a
Globobulrmine
cm
“,,,a
klev,gat*
BxcB”Bt”ln
x,
Epistnminella
Cassid”,i”a
Elphidrum
1994,
Sample
no
Waterdepth(In,
depth transect from the Norwegian
Percent abundance of important species (see text) and calct~latcd fauna! parameters of live acsemhlages,
Table 2
s
z
-
s
,u
“Ji
162
Pors runn
Live / cm3
5-39
ll
/
> 200
I
OS,I0
Fjoro
%_J
Arendal/
/“/y
58.0".
57.0".
Pors runn
Oslo
Dead / cm3
59.0°.
Fjord
a
< 200
m
-
w
200 - 450
pYJJ 450 - 1000
58.5'.
A
>I000
58.0"-
7.50
Fig. 2. Numerical
8.0'
8.5"
density (no. tests/cm3).
9.0"
(A) Live assemblages.
9.5"
lo.o"
(B) Dead assemblages.
10.5O
E. Abe, J. l+! Murray/Marine
Micropaleontology
163
31 (1997) 157-17.5
Live factor
associations
59.0”.
m
N. iridea
S. fusiformis
58.5”.
G. auricula ta
lizss!
n
N.
H. membranaceum
E. vifrea
58.0”.
Dead factor
associations
58.5”
58.0”
3
7.5”
8.0”
8.5”
9.0”
Fig. 3. Varimax factor associations.
9.5”
(A) Live. (B) Dead
10.0”
10.5”
164
58.5"
58.0'
58.5"
58.0'
................
@........
.......
57.5O
7.0"
Fig. 4. Abundance
7.5O
ofshelf/marginal
8.0"
8.50
9.r
marine species inferred to be transported
9.k
lo:50
into the urea. (A) Percent. (B) Numerical
density (no./cm3)
E. Alve, J.W Murray/Marine
Micropaleontology
Table 4
Varimax factor score matrix for live associations,
1993 and 1994
data (1992data for living assemblages not available)
Variable
C. luevijiutu
E. e.xcavutum
G. auriculatu
P. bulloidrs
P. osloensis
S. fus[fiwmis
N. irideu
E. medius
E. vitretr
H. bradyi
L. goesi
H. membmnuceum
?: tenuissima
R. micucea
M. barleranum
L. scottii
1
2
3
4
0.173
0.128
-0.125
0.172
0.366
0.046
0.687
0.267
0.036
-0.033
0.059
-0.202
-0.008
-0.098
0.417
-0.005
-0.012
-0.040
0.063
0.024
0.099
-0.982
0.018
-0.022
-0.059
0.025
0.026
0.064
0.004
0.046
0.078
-0.036
0.023
0.065
0.665
-0.061
0.413
0.120
-0.188
0.091
-0.106
0.028
0.298
0.068
0.354
0.265
0.141
-0.012
0.057
-0.089
-0.002
0.165
0.071
0.032
0.154
0.020
0.618
0.203
-0.045
0.688
-0.003
0.170
-0.057
31 (1997)
157-175
about 200 m while at shallower depths there is
factor 4, Cassidulina laevigata and Elphidium excavatum. Brizalina skagerrakensis has an anomalously
high varimax factor score value in these samples
(Table 5) as it is not common in the shallow southem area (Table 3). In addition to E. excavatum,
the samples represented by the factor 4 association
include the following species known to be typical of the shelf or marginal marine environments
(Murray, 1991): Ammonia beccarii, Cibicides lobatulus, Eggerelloides scabrus, Gavelinopsis praegeri,
Haynesina germanica, Planorbulina mediterranensis and Textularia truncata. With the exception of E.
scabrus, these are not included in the factor analysis
because they do not make up ~5% of the assemblages in at least two samples. Fig. 4 shows the
relative and absolute abundance
of this group of
species in the dead assemblages.
0.000
3.3. Relative abundance
Table 5
Varimax
data
factor
score matrix
for dead associations,
1992-1994
Variable
B. skqerrukensis
B. marginuta
C. luevigutu
E. excavutum
H. balthicu
R os1oensi.r
S. fu.sifi?rmis
N. irideu
E. mrdius
E. scabru~
E. vitreu
H. bradyi
7: pusillus
7: tenuissima
Saccammina spp.
M. barleeunum
165
I
2
3
4
0.168
0.038
0.272
-0.049
0.078
0.734
0.006
0.107
0.123
-0.030
0.057
-0.078
-0.057
0.544
-0.084
0.080
0.106
-0.024
-0.054
-0.117
0.009
0.003
-0.979
-0.011
0.079
-0.021
-0.071
0.006
0.004
-0.016
0.018
0.018
0.214
-0.006
0.020
-0.068
-0.010
0.124
0.069
0.175
0.337
-0.030
0.064
0.668
0.341
-0.180
0.424
0.074
0.472
0.192
0.486
0.476
0.093
-0.261
-0.019
-0.048
0.289
0.217
0.026
-0.117
-0.099
-0.129
-0.110
0.122
lus and Eggerelloides
medius. Factor 1, l? osloensis
with 7: tenuissima, occurs on the Norwegian slope
and at the western periphery of the basin. Factor
2, with a high dominance
of S. fusiformis,
characterises the Danish slope at depths greater than
of agglutinated
tests
The proportion of agglutinated forms in the living
assemblages
show an irregular distribution
pattern
with only two values higher than 40% (Fig. 5A).
On the other hand, the proportions
in the dead
assemblages
show a consistent pattern with high
abundance in the basin (40-61%) and progressively
decreasing values up the adjacent slopes (Fig. 5B).
In the shallower waters at the top of the Danish slope
(~200 m) the percent agglutinated values again increase due to the presence of shelf taxa such as E.
scabrus and T. truncata.
3.4. Species diversity
The living assemblages have a range of Fisher
alpha values from 4; to 18. Values of 10 or greater
are confined to a cross-basin
field in the western
area and the lower part of the Danish slope (Fig. 6).
Those of the dead assemblages are generally higher
(8;-18) but do not show any systematic distribution
pattern.
3.5. Tubes
As previously noted in the methods section, tubular agglutinated
foraminifera
were counted separately from the assemblages. This data set includes
166
58.5"
58.0'
57.5".
59.0"
58.5"
58.0°
57.5"
8.0"
Fig. 5. Percent agglutinated
8.5"
tests. (A) Live assemblages.
(B) Dead assemblages.
E. Alve, J.W Murray/Marine
167
Micropaleontology 31 (1997) 157-175
59.0”.
58.5".
58.0".
57.5".
7.5"
8.0"
Fig. 6. Distribution
8.5"
9.5"
10.0"
10.5"
of Fisher alpha values for live assemblages.
all available 1994 samples including those which
were not picked for foraminiferal analysis (Table 1).
Tubes are rare on the Norwegian slope and most
abundant on the Danish slope between about 200
and 500 m (Fig. 7).
3.6. TOC and particulate
9.0"
organic matter
The TOC values are relatively constant (generally
between 2.0 and 2.3%) from the Norwegian slope,
through the basin, and up the Danish slope to around
200 m (Table 1). At depths shallower than 200
m, the values drop to a minimum
of 0.4%. The
visual examination of organic detritus in the >63 pm
fraction (wet sample) shows a pattern with maximum
values between 200 and 500 m on the Danish slope
(Fig. 8) even in those areas with minimum TOC
values. As for Figs. 7, Fig. 8 also shows data from
stations which were not included in the foraminiferal
analysis.
4. Discussion
There is much evidence that the Danish slope is
a disturbed environment
from both natural and human-induced
causes (e.g., trawling). Atlantic water
in the deeper (~200 m) and North Sea water in the
shallower parts enter at high velocities (> 10 cm/s,
Rodhe, 1987). This is the region of highest sand content (lo-80% increasing up slope, Bee et al., 1996)
and also the area richest in organic detritus (Fig. 8)
in the Skagerrak Basin.
4.1. Evidence of transport
The first line of evidence
comes from the
foraminifera. The shallowest samples (sta. 89, 102)
from ~200 m on the Danish slope show a marked
difference in dominant species and general composition between the living and dead assemblages. The
living assemblages
have a high dominance
of S.
fusiformis whereas the dead assemblages are domi-
I68
Tubular agglutinated
foraminifera
59.0”.
58.5”.
58.0”.
57.50.
;
Fig. 7. Distribution of tubular agglutinated foraminifera on a subjective relative scale from I (few) to 4 (abundant).
those 1994 stations where foraminiferal assemblage analyses were not carried out (see text).
nated by E. excavatum and E. scabrus. The differences can be accounted for in several ways. The first
two explanations
relate to Stainforthia fusiformis.
There may have been blooms of living S. fusiformis
at the time of sampling and therefore the samples
would be unrepresentative
of the main living assemblages. However, since it reproduces throughout the
year, seasonal blooms are unlikely (Murray, 1992;
Alve, 1995a). Second, they might be lost through
dissolution and this may be partially correct. Third,
and more probably, exotic species may be being
transported in from shelf areas.
There are no living representatives of A. beccarii,
H. germanica,
or F! mediterranensis,
whereas C.
lobatulus, E. scabrus, E. excavatum, Gavelinopsis
praegeri and r truncata are represented
by one
or two living individuals
but never at more than
one station. Therefore, they are all considered to be
exotic. In addition, tests of C. lobatulus, E.excavatum
and P mediterrunensis
show chamber breakage and
The map also includes
those of A. beccarii are worn, consistent with some
bedload transport.
Because foraminiferal
tests are hollow, tests and
quartz sand of the same size will have different
threshold velocities. Ciao and Collins (1995) calculated that if the test is 50% hollow then their
settling velocities would be 70% of that of the equivalent sized sand grain. However, once a mixture
of foraminifera
and sands have been hydraulically
sorted (i.e., there will be larger foraminifera
than
the sand grains), both the foraminifera
and the
sand grains have similar thresholds of movement.
Therefore, the dynamic behaviour of the tests would
be essentially
the same as the bulk sediment. It
follows from these arguments that medium sandsized foraminifera will be transported with silt grade
quartz (Oehmig, 1993); transport will include short
periods as bedload (when some damage may occur to
tests due to impact and abrasion) but will be mainly
in suspension (during which damage will be mini-
E. Alve, J.W. Murray/Marine
Micropaleonrolog~
31 (1997)
157-175
I69
Organic detritus
59.0”
j
1 and 2
cl
‘..:.
;..~.‘..‘.,.‘,.‘,,.‘,
;.,:
:.,:,:
....,:,
.. 3
p;y>&&
:::&a 4
.>:.*.....,
LzJ
58.5”
Kristiansandb
4
_
58.0°
57.5”
Fig. 8. Distribution of organic detritus (>63 km wet fraction) on a subjective relative scale from I (little) to 4 (abundant).
includes those 1994 stations where foraminiferal assemblage analyses were not carried out (see text).
mal). In this way, tests can be transported over considerable distances without suffereing severe damage
or abrasion. On the Danish slope the median grain
size is fine sand but there is a wide range of particles
sizes from clay to gravel (Bge et al., 1996) implying that there are no theoretical arguments against
foraminiferal transport and deposition here.
Source areas for the benthic foraminifera can be
determined reliably only on the basis of distributions
of living species. The only relevant study to distinguish live and dead assemblages is that of Murray
(1992) who showed that living and dead E. excuvuturn and E. scabrus are widespread in the southern
North Sea. Total assemblages (living plus dead) off
the west coast of Denmark contain A. beccarii, C.
laevigata, C. lobatulus, E. excavatum and 7: trunrata
(Jarke, 1961; Gabel, 1971; Conradsen et al., 1994;
Bergsten et al., 1996). However, it is not known
whether these occurrences represent in situ living
populations
or already transported dead ones. Al-
The map also
though this is a potential source area, material might
just be in transit from the southern North Sea. On
the other hand, E. scabrus is extremely rare on the
Danish shelf (op. cit.). The most likely source of
transported individuals is from the south under the
influence of the north flowing cyclonic current which
has been shown to extend from the surface water to at
least 40&500 m (Rodhe, 1996). The relative and absolute abundance of transported tests systematically
decrease downslope (Fig. 4). Another indication of
transport is that radiocarbon dating of foraminiferal
samples (E. excavatum assemblage) from the upper
part of a boring on the northernmost tip of Denmark
showed them to be up to 3300 years old, indicating
a strong influence of reworking which was attributed
to the Jutland Current (Conradsen and Heier-Nielsen,
1995; Heier-Nielsen et al., 1995).
The second sources of evidence are organic detritus and barium. Observation of wet sediment showed
that particulate organic matter was most abundant
170
E. Alrv, J. N! Murru~~ /Marine
Micropaleotttolo~~
there between 200 and 500 m (Fig. 8). This suggests
that the Danish slope is a depositional sink area for
detrital organic material transported from the south.
This statement is supported by the fact that some of
the suspended material transported into the Skagerrak and northern Kattegat is river borne (e.g., from
the Rhine, Elbe) suspension load from central western Europe (Kuijpers et al., 1993). Another indicator
of provenance and deposition is the Ba content of
the sediment. Ba analyses have been performed on
the surface sediments (bulk top O-2 cm) for all 1992,
1993 and 1994 stations (S&her et al., 1996) and the
source areas are believed to be drilling platforms in
the North Sea. The areas of maximum Ba concentrations (160-435 ppm) coincide with the areas of
maximum organic detritus.
All these lines of evidence demonstrate that the
Danish slope is a depositional
sink for transported
foraminiferal
tests and particulate
organic matter
originating from the south. A similar sink for transported foraminiferal
tests has been documented by
Hughes Clarke and Keij (1973) in the Persian Gulf
at the foot of the 36 m terrace.
4.2. Evidence oj”high benthic fertility
The distribution of benthic foraminifera is known
to be patchy on a scale of centimetres to hundreds of
metres (Murray, 1991, p. 19). In a study specifically
designed to test microdistribution
patterns, Hohenegger et al. (1993) found that in shallow water (14.5
m) major controls on species distributions included
their individual food requirements
and the presence
of microhabitats
such as burrows with oxygenated
haloes in otherwise low-oxygen
sediments. Some
species preferentially
live around burrow openings.
The same controls are thought to pertain in the deep
sea (Gooday, 1990) and may be universal for benthic
foraminifera.
In a separate study from the northern Skagerrak
area (between outer Oslo Fjord and Arendal, Fig. l),
Rygg and Alve (1995) analysed two replicate samples from each of nine stations (50-400 m water
depth, collected in July 1994) which revealed major
patchiness in standing crop. The maximum standing
crop values ranged from 1.3-12.0 times the minimum values at each station but most (5 out of 9)
were in the range 1.5-2.2 times the minimum.
.il (1997) 157-171
In the present study, there is an overall pattern in
the abundance of standing crop (Fig. 2A). The deeper
areas (generally >400 m) have the lowest abundance
values, whereas those on the surrounding slopes range
from low to very high suggesting local patchiness.
However, the relatively low deep basin values are
within the average range for many open shelf areas
(50-200 per 10 cm3, Murray, 1973, p. 201).
The 1993 data from the Danish slope were limited
(three samples shallower than 500 m) and therefore no firm conclusions
could be reached but we
suggested that this is the area of highest food availability (Alve and Murray, 1995). The new 1994 data
set from the slope are more comprehensive
(20 samples) and strongly reinforce the trend seen in the
1993 data.
The TOC values in the sandy sediments on the
Danish slope are low compared with those of the
deep basin muds and this is not surprising as the
TOC content of the sediment is generally inversely
linked to grain size. However, these measurements
do not discriminate between the nutritional value of
the various organic carbon compounds and consequently, they can not be directly equated with potential food availability for the foraminifera. While
processing, we recorded that particulate organic detritus is abundant in the Danish slope sands and
it was for this reason that we measured the presence of potential food in the form of the particulate
organic detritus observed in the >63 km fraction.
Even though some of this organic material may be
refractory (e.g., Van Weering et al., 1987), the associated bacteria may still provide an additional food
source for the foraminifera (for discussion see Alve,
1995b). The maximum standing crop in the 1994
samples is more than twice that recorded in 1993
and one to two orders of magnitude higher than
that recorded for the southern North Sea (Murray,
1992). On a regional scale there is a zone of high
densities between 200 and 500 m on the Danish
slope which broadly correlates with the area of high
organic detritus (Fig. 8).
Two biological studies, one of the macrofauna
(Rosenberg et al., 1996) and the other of the meiofauna (De Bovee et al., 1996), used essentially the
same samples from a NNW-SSE transect across the
Skagerrak (Table 6). Since the benthic foraminifera
are primarily deposit feeders, the most reasonable
E. Alve, J.W. Murray/Marine
Micropaleontology 31 (1997) 157-175
Table 6
Meiofaunal
(surface O-2 cm) and macrofaunal
deposit feeder
data for a transect across the Skagerrak from the Norwegian
slope (0%) to the Danish (AD3)
Station
No.
__-._
Depth
OS5
OS3
OS1
S6
AD7
s4
AD3
251
41 I
637
393
294
194
177
(m)
Meiofauna a
(No./10 cm2)
Macrofauna
(No./m’)
999
292
112
2278
_
1342
847
705
1635
1826
_
a After De Bovee et al. (1996).
h After Rosenberg et al. (1996);
and subsurface deposit feeders.
h
5395
only includes
deposit
feeders
comparison is with the density of macrofaunal deposit feeders, In both cases, minimum
numerical
density of individuals are found in the deep basin
and the highest numbers are those on the Danish
slope. These results are in very good agreement with
those presented here but they made no attempt to
measure biological usable organic matter. Rosenberg
et al. (1996) attributed the abundance differences to
water transport, sediment grain size, and sedimentation rates. De Bovee et al. (1996) suggested that at
sta. S4 “the benthic fauna may be stimulated by an
adequate input of organic matter”. They also linked
this with sedimentation rates.
In the present paper, we made some attempt
to quantify organic matter available as food and
suggest that this relates to input from external
sources. In fact, the numerical density of the benthic foraminifera on the Danish slope is comparable
to that of the Mississippi delta which is a well known
area of high benthic fertility (e.g., Lankford, 1959).
Lankford found that the zone of maximum standing crop (average about 2500 live individuals
per
10 cm’) was located on the bottomset beds off the
major distributaries, and it decreased abruptly away
from the delta into the open continental
shelf. The
tests were small in size and he considered that the
turnover rate was only a few weeks thus the species
were opportunistic and utilising the rich food source
(i.e.. high concentration
of nutrients, large bacterial
populations, abundance of organic solids) in an area
of rapid sediment accumulation.
Off Newfoundland,
171
Schafer and Cole (1982) found the highest standing crops (average 2356 per 10 cm*) on the lower
slope/rise (2695 m) on relatively coarse sediments
(0.15-0.04 mm) with low TOC values (~0.4%) under the influence of the Western Boundary Undercurrent. They attributed these high values to the reduced
macrobenthos
there and hence reduced predation.
The dominant species are small in size.
The living S. fusiformis factor association dominates the main part of the Danish slope. Stainforthia fusiformis is an opportunistic
species which
inhabits stressed environments
and is one of the
most rapid recolonisers of formerly anoxic environments especially where there is an abundance of food
(Alve, 1994, 1995a). Consequently,
it is reasonable
to assume that such an opportunistic
species might
rapidly colonise other similar marine environments
(like the Danish slope) subsequent to environmental disturbances,
for instance from the activity of
trawlers scouring the seabed for prawns.
An additional
indicator
of high fertility
is
the abundance of tubular foraminifera.
Jones and
Charnock (1985) classified tubular astrorhizids as
erect, sessile, epifaunal/semi-infaunal
passive suspension feeders. Confirmation of this has been made
for species of Bathysiphon
which have been observed to project from the sediment surface in box
cores taken from the North Carolina slope. Furthermore, their cytoplasm contains a variety of particles
consistent with both suspension and detritus feeding
modes of life (Gooday et al., 1992).
In the northeastern
Atlantic Ocean, Murray and
Alve (1994) found the highest abundance of tubular
forms off northwestern
Africa, in an area of upwelling and therefore high food supply, and also
in areas under the influence of Mediterranean
Water. Gooday (1990) considers
that the large astrorhizids of continental
margins require relatively
large amounts of food because of their cytoplasmic
volume. Also, based on both modem and fossil examples, Kaminski and Kuhnt (1995) suggested that
there is an increased abundance of tubular agglutinated foraminifera in eutrophic regimes.
The Danish slope is subject to the greatest bottom current velocities in the whole study area (mean
velocity in from the Norwegian Trench, z 10 cm/s
at depths > 100 m, Rodhe, 1987). The greatest concentration of abundance of tubular tests is on the
172
E. Ah,
J. W Murray/Murine
Micropalrontolog~
Danish slope, especially in the zone of organicrich sediments between 200 and 500 m. Most are
not branched. Some have very finely agglutinated
tests while others are relatively coarse-grained
and
both can occur in the same sample although coarse
grained ones are dominant.
To conclude, it is inferred that on the Danish
slope the high standing crop values and abundance
of tubular agglutinated foraminifera (with their high
biomass volume because of their large size compared
with other benthic foraminifera
living here) reflect
high food supply and therefore high benthic fertility.
4.3. Taphonomic processes
There are major contrasts between the basin living factor associations of 1993 and 1994 sampling
areas. The 1994 area has an H. membranaceumlE.
vitrea association whereas the 1993 area has a N.
iridea association
with subsidiary M. barleeanum
(all calcareous except H. membranaceum).
However,
the time-averaged
dead assemblages show a single
H. bradyi association with subsidiary Saccammina
spp., I: pusillus, and E. medius (all agglutinated)
throughout the deep water area from northeast to
southwest. G. auriculata, H. membranaceum,
N. iridea and E. vitrea show some postmortem reduction
in abundance. Indeed, N. iridea is scarcely preserved
in the dead assemblages (generally t5%), although
it is one of the most common living species (generally lO-30%) and its empty tests are well preserved
at pre-1970 levels in sediment cores from the deep
basin indicating a recent increase in the intensity of
carbonate dissolution (Alve and Murray, 1995; Alve,
1996). It appears that the dissolution of either of the
two calcareous dominated living associations gives
rise to essentially the same agglutinated dominated
dead association.
Dissolution leads to an increase in dead agglutinated tests so that whereas most slope dead assemblages are 2O-39% agglutinated those of the basin
have 50-79%. Not only are these values higher but
the pattern is more ordered than that of the living
assemblages
(compare Fig. 5A and B). The high
numbers of dead agglutinated
tests in the shallow
area of the Danish slope are considered to be due
to the introduction of transported species, such as E.
scubrus (discussed above) rather than to dissolution.
.?I (IYY7J
4.4. Distribution
palaeoecology
157-l
75
patterns as a model for
Patterns
of modern
foraminiferal
distribution
serve as models for the palaeoecological
interpretation of fossil assemblages, especially those from the
Quatemary. Recent regional distributional
studies of
Skagerrak foraminifera include those of Conradsen
et al. (1994) and Bergsten et al. (1996). The former
authors summarised the results from several studies
which used different methods of sample collection
and different sieve sizes (> 100 or > 125 pm) during
processing. Bergsten et al. (1996) used the > 125 pm
fraction of thirteen cores (along a transect from 177
m on the Norwegian side to 58 m on the Danish side)
extending down 8 cm into the sediment and therefore
time-averaged
over several decades, In both cases,
total (living plus dead) assemblages were described.
This contrasts with the >63 pm fraction and the
separation of living and dead assemblages used here.
The latter is essential if taphonomic processes are to
be interpreted. Furthermore, we have demonstrated
that there have been fauna1 changes, particularly
in the deep basin, over the last 5 decades. These
changes are obscured in the average total data of
Bergsten et al. (1996).
Conradsen et al. (1994) recognised a basinal association of Bolivina skagerrakensis (= Brizalina of
this paper), with a Cassidulina laevigata association
on the southern Norwegian slope and an Elphidium
excavatum association on the Danish slope and shelf.
Bergsten et al. (1996) found a Huplophragmoides
bradyi basinal association, a Uvigerina peregrina association on the Norwegian slope and the deep part
of the Danish slope but over most of the latter there
is a S. fusiformis association. In addition, at depths
of < 100 m there is an E. excavatum association.
These results contrast markedly with those presented here (except for the S. fusiformis association
on the Danish slope). This is due partly to the differing sieve sizes and partly to their use of total
assemblages.
However, it is curious that there is
scarcely any similarity in the dominant species between the two studies based on total assemblages.
In both studies it was inferred that the distribution
patterns were related to (unspecified
attributes of
the) bottom water masses. For example, Bergsten
et al. (1996) related the S. fusiformis
association
E. Alve, J.W Murray/Marine
Micropaleontology
31 (1997)
173
157-175
to inflowing North Atlantic water. However, this is
inconsistent
with the known hydrography of silled
Norwegian fjords in which this species is dominant
(Alve, 1995b). We regard this as an opportunistic
species (as discussed above) and therefore not linked
to a specific water mass. The Norwegian slope lacks
the abundant organic detritus of the Danish slope and
has a different living association (G. auriculata). The
deep basin has two different living assemblages but
there is no obvious water mass explanation for this
except that the basin water has a longer residence
time. However, the water is not oxygen deficient
(Aure and Dahl, 1994).
A common feature of all these studies is that only
a few associations
are differentiated
in this large
area. Consequently,
the foraminifera
show essentially the same broad pattern of high fauna1 similarities over large areas as recognised in the macrofauna
(Rosenberg et al., 1996).
There is a broad correlation between higher live
Fisher alpha values (> 10) and the inflow of oceanic
water along the foot of the Danish slope and the
deeper parts of the Basin (Fig. 6). The dead assemblages are more diverse throughout the whole area
with few alpha values (10. This is a consequence
of the time averaging of species populations together
with the effects of postmortem alteration. At the top
of the Danish slope ~200 m, the dead assemblages
are enriched in transported species.
abundance of tubular agglutinated foraminifera both
of which have responded to the high availability
of food (particulate organic matter and associated
bacteria). The numerical densities are comparable
with those of the Mississippi delta, which is a well
known area of high benthic fertility.
On the other hand, the Norwegian slope and deep
basin have average standing crop values compared
with shelf seas elsewhere and show no evidence of
the introduction of transported exotic tests.
Apart from transport, another active taphonomic
process is the dissolution of calcareous tests. This
is evident from the increase in the abundance of
non-calcareous
agglutinated foraminifera in the dead
compared with the living assemblages especially in
the deep basin. Additionally,
some calcareous tests
were extremely chalky and fragile.
The distribution of living and dead foraminiferal
associations
recognised
in this study differ from
those of previous studies based on different size
fractions and total (live + dead) assemblages. Sfainforthia ,fus(formis is an opportunistic
species which
colonises the disturbed parts of the Danish slope in
the area of high particulate organic matter. The area
of living high diversity in the deep western part of
the basin may be a reflection of incoming Atlantic
Water.
5. Summary
We thank the Norwegian
Geological
Survey
(NGU) and the University of Bergen, particularly
Hans Schrader, for providing the samples, Per Ivar
Steinsund for providing the factor analysis program,
Terje Thorsnes for providing the raw data for the
bathymetric map and Eigil Whist for help with the
final preparation of the maps. NGU is also thanked
for providing the TOC data and, with the Institute of
Marine Research, Bergen, for funding E.A.
and conclusions
The Skagerrak basin is an epicontinental
shelf sea
basin and provides a modem analogue of past examples. In this paper new data on both live and dead assemblages are presented on each of 36 foraminiferal
samples and a discussion of the whole data set (56
samples for living and dead plus an additional thirteen for dead only), including those published by
Alve and Murray (1995), is given.
Indicators of transport to the Danish slope include
the abundance
of exotic dead foraminiferal
tests
and particulate organic matter, and concentrations
of barium. This suggests that the Danish slope is a
depositional sink for these components.
Likewise, the Danish slope is considered to be
an area of high benthic fertility based on the high
standing crop values of benthic foraminifera and the
Acknowledgements
Appendix
Generic
A. Fauna1 reference list
names are in accordance
with Loeblich
and Tappan
(1987)
(Link)
= Nautilus beccarii Link. 1758.
(Qvale and Nigam) = Bo/i\?ncr .ska,syrrakensis Qvale and Nigam, 1985.
Bulimina marginata d’orbigny.
1826.
Ammonia
beccarii
Brixdina
skagerrukensis
174
E. Alve. .I. U! Murray/Marine
Micro~,aleontolng~, 31 ( IYY~J 157-175
Cassidulina laevigata d’orbigny,
1826.
Cibicides lobatulus (Walker and Jacob) = Nautilus lobatulus
Walker and Jacob, 1798.
Eggerelloides medius (Hoglund) = Verneuilina media Hoglund,
1947.
Eggerelloides
scabrus
(Williamson)
=
Bulimina
scabra
Williamson, 1858.
Elphidium
excavatum
(Terquem)
= Polystomellu
excavatu
Terquem, 1875.
Epistominella vitrea Parker, 1953.
Guvelinopsis praegeri (Heron Allen and Earland) = Discorhinu
pruegeri Heron Allen and Earland, 1913.
Globobulin~ina auriculata (Bailey) = Bulimina auriculata Bailey, 1851.
Haplophragmoides
bradyi (Robertson)
= Trochammina bradyi
Robertson, 1891.
Haplophragmoides
membranaceum Hoglund, 1947.
Haynesina
germanica
(Ehrenberg)
= Nonionina
germanica
Ehrenberg, 1840.
Leptohalysis scottii (Chaster) = Reophax scottii Chaster, 1892.
Liebusella goesi Hoglund, 1947.
Melonis
barleeanum
(Williamson)
= Nonionina
barleeana
Williamson, 1858.
Nonionella it-idea Heron-Allen and Earland, 1932.
Planorbulina mediterranensis d’orbigny,
1826.
bulloides
(d’orbigny)
=
Nonionina
bulloides
Pullenia
d’orbigny,
1846.
Pullenia osloensir Feyling-Hanssen,
1954.
Stuinforthia
fus(formis
(Williamson)
= Bulimina
pupoides
d’orbigny
var. ,fusiformis Williamson, 1858.
Textularia tenuissima Earland, 1933.
Textularia truncuta Hoglund. 1947.
Trochamminopsis
pusillus (Hoglund)
= Trochammina pusilla
Hoglund, 1947.
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