The origin of modern agglutinated foraminiferal *, Elisabeth Alve John W. Murray
Estuarine, Coastal and Shelf Science 58 (2003) 677–697
The origin of modern agglutinated foraminiferal assemblages: evidence from a stratified fjord
John W. Murray
a,
*, Elisabeth Alve
b
, Andrew Cundy
c a
School of Ocean and Earth Science, Southampton Oceanography Centre, European Way, Southampton SO14 3ZH, UK b
Department of Geology, University of Oslo, PO Box 1047 Blindern, N0316 Oslo, Norway c
School of Chemistry, Physics and Environmental Science, University of Sussex, Falmer, Brighton, BN1 9QJ, UK
Received 17 March 2003; accepted 4 June 2003
Abstract
Loch Etive, a silled 145 m deep fjord on the Scottish west coast, provides an example of modern benthic foraminiferal assemblages at intermediate depths (i.e., below the intertidal zone and above the CCD) consisting almost exclusively of organiccemented agglutinated forms. Since such faunas from intermediate depths are rare in modern oceans but relatively common in the fossil record, the present study allows new insights into one kind of ancient environment for which there are few modern analogues.
The strong dominance of agglutinated forms (both living and in some dead assemblages of foraminifera to the exclusion of calcareous taxa) is attributed to the unusual oceanographic conditions. These include a combination of restricted deep-water renewals and strong influence of freshwater which drains through large areas (relative to the size of the loch) of vegetated land. The result is calm bottom water conditions with commonly occurring oxygen depletion (although not anoxic), brackish water throughout the water column (salinity 28 in the deeper parts), and organic-rich (mostly terrestrially derived) sediments with geochemical properties, which, to a much larger degree than open marine ones, are controlled by local input. This environment supports low abundance and low diversity live assemblages, mainly restricted to the surface 1 cm of sediment. The dead assemblages show similar faunal characteristics, but the calcareous components are, due to carbonate dissolution, even more reduced. One of the calcareous species in Loch Etive is Elphidium albiumbilicatum . Its occurrence is the first record in British waters and it matches the previously suggested southern limit of its distribution.
Analysis of a 90 cm long core representing sediments deposited over the past two centuries shows the presence of a calcareous dominated assemblage, including more marine species, with a higher diversity, in the lower part. This suggests that Loch Etive is in the process of going from a marine, to a more terrestrial dominated environment. The relatively high sedimentation rate (0.5 cm per yr), the apparent lack of smearing through bioturbation, and the presence of faunal changes in response to reduced marine influence over the past centuries, shows that Loch Etive has a good potential for performing high-resolution climatic studies.
Ó 2003 Elsevier Ltd. All rights reserved.
Keywords: agglutinated foraminifera; Loch Etive; fjord; oxygen depletion; carbonate dissolution; climatic history
1. Introduction
In the fossil record there are numerous records of exclusively agglutinated assemblages of foraminifera that are inferred to have lived at intermediate water depths. In modern environments such exclusively
* Corresponding author.
E-mail addresses : jwm1@mail.soc.soton.ac.uk
(J.W. Murray), ealve@geologi.uio.no
(E. Alve), A.B.Cundy@sussex.ac.uk
(A. Cundy).
0272-7714/03/$ - see front matter Ó 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/S0272-7714(03)00179-3 agglutinated (living) assemblages occur to a limited extent in parts of brackish estuaries, fjords, and shallow bays or lagoons but they are mainly confined to intertidal salt marshes and to open oceanic areas below
the CCD most of which are abyssal ( Schro¨der et al.,
) or several hundred metres deep (as around Antarctica, e.g.,
). Yet it is clear that the fossil examples do not always represent these extremes. It is therefore of considerable interest to discover further modern environments in which agglutinated forms make up a very high proportion of the assemblages and which
678 may provide new analogues. Loch Etive in western
Scotland proves to be such an environment.
Loch Etive is a narrow inlet of the sea (fjord)
branching off the Firth of Lorn, Scotland (
Black, 2001; Howe et al., 2002
processes and for providing a high-resolution historical record of environmental change (whether climatic or due to human impact).
From the point of view of foraminiferal ecology,
Loch Etive presents some interesting features. The maximum water depth (145 m) is comparable to that of the outer continental shelf yet it occurs in a basin which is a mere 2 km wide. Like many other fjords, the deep water of the Loch is isolated from the open sea by a succession of shallow sills. Major questions to consider are what is the nature of the foraminiferal fauna and how does it compares with that of the adjacent open continental shelf and other silled fjords? Among the macrofauna there are some arctic taxa which reach their southern limit here (see below); does this apply to any foraminifera? The aim of this preliminary study was to address these questions.
definition of a fjord is ‘‘a deep, high-latitude estuary which has been . . .
excavated or modified by land-based
Syvitski et al., 1987 ). Loch Etive conforms to this
definition since it is glacially overdeepened and steepsided due to erosion during the Quaternary (
). The sediment fill is 30–50 m thick ( Jones and
). Because fjords are sites of active sediment accumulation they provide an excellent opportunity for the study of benthic boundary
2. Area description
J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697
Loch Etive has a shallow sill at the entrance (7 m) and a series of five other sills ranging in depth from 4 to 24 m
(
Edwards and Sharples, 1986 ). There are two deeper
basins—an outer one (maximum depth 70 m, area
11.35 km
2
) and an inner one (sill depth 13 m, maximum depth 145 m, area 16.94 km
2
) which is the present study area. In the deepest area sampled, the surrounding basin slopes are 5–15 (
Howe et al., 2001 ). The mean spring
tidal range is 3.2 m and surface currents are fast in the entrance to the fjord system (334–399 cm/s) and up to
165 cm/s at the narrows between the two main basins
(
). There is no information on tidal currents in deep water but they are likely to be sluggish. This fjord has the largest freshwater input of any Scottish sea loch (
Hiscock, 1998 ). The larger part of the catchment
area drains through the river Awe, which enters the loch at the Bonawe sill. The other part of the catchment area
(only slightly smaller) enters the upper basin mainly through the river Etive, but also through the Kinglass and other lesser rivers. A hydrographic profile for winter shows inner basin salinities of 22 at the surface (but it can fall to 1 after rainfall) to 28 at the bottom with a halocline at around 20 m; bottom temperatures range from around 8 to 10
1972 ). Replenishment of deep waters in the inner basin
is episodic (mean 1.3 yr,
; possibly as infrequent as 2–3 yr,
Although Gage recorded dissolved oxygen values of
40%, depletion becomes greater during prolonged periods of non-renewal of bottom waters and fell to
< 20% ( < 1.5 mg l
1
,
Jones and Black, 2001 ) in 2000.
The value measured was 0.84 mg l
1 by Winkler titration at the bottom of the Bonawe deep in the April
2002, Overnell, pers. comm.), however, anoxia has never been recorded. During periods when the bottom water is stagnant (in the sense of not being replenished) there is return of reduced manganese to the sediment. High rates of total sulphate reduction are associated with high rates of formation of acid volatile sulphide, which is buried in the sediments (
Overnell et al., 1996; Overnell, 2002 ). The
organic content of the sediment (measured as loss on ignition) is around 15% but as most of it is resistant
Fig. 1. Map to show the bathymetry of Loch Etive (based on Edwards and Edelsten, 1977; Howe et al., 2001) and sample transect.
J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697 to decomposition, there is poor correlation between this and oxygen consumption and sulphate reduction
(
). From measurements of the rates of oxygen consumption and inorganic nutrient generation during a stagnant period,
concluded that there was a strong silicate source.
The inner basin is floored with fine grained sediments
(63–92% particles finer than 60 l m,
probably sourced from the River Etive at the head of the fjord, and according to
the rate of sediment accumulation is 0.7 cm yr
1
(but see the discussion below). Observations on the sedimentation of detritus over a one-year period showed that most of the organic material is terrestrial in origin and the rest is from phytoplankton. In deeper waters there was short-term resuspension and redeposition of fine grained material in transit from shallow to deeper levels (
). The concentration of bromine in the surface sediments of the inner basin (400–600 ppm) is correlated with the C : N ratio (12–14) and indicates that around 30–40% of the organic matter is of marine origin
(
Malcolm and Price, 1984 ). The production of phyto-
plankton varies seasonally with peaks in the spring and its abundance is controlled not only by the availability of nutrients but also by hydrographic factors including freshwater runoff (
Solo´rzano and Ehrlich, 1977a,b ).
Primary production was estimated at 70 g C m
2 yr
1 in that part of the outer basin closest to the sampling area and light was considered to be the major limiting factor
(
Wood et al., 1973 ; there are no data for the inner basin).
The macrofauna in the inner basin is dominated by the ophiuroid Amphiura chiajei , five species of polychaetes,
four species of bivalves and a penatulid ( Gage, 1972 ),
essentially an A. chiajei subcommunity like that of the
North Sea ( Buchanan, 1963 ) but also similar to the deep
mud community of Loch Linnhe and Loch Eil (
). A benthic video survey made during August 1999 l when the bottom water oxygen concentration was 2.3 mg
1
, showed evidence for a healthy burrowing infauna of worms and crustaceans (L. Nickell, Dunstaffnage Marine
Laboratory, pers. comm. cited in
water elements which reach their southern limits in this area include a boreo-arctic ascidian (
) and
Thyasira gouldi
latter appear to be sulphur oxidisers (
With the exception of a record of presumed live
Crithionina gramen in a macrofaunal study of Loch
Nevis ( > 1.3 mm,
McIntyre, 1961 ), no studies of living
foraminiferal assemblages from Scottish fjords have previously been undertaken and the only previous study of the dead foraminiferal faunas of Loch Etive was a brief note in
Howe et al. (2002) , recording the dom-
inance of agglutinated forms in the surface sediment.
There have been few studies of the foraminiferal faunas
of west Scotland ( Williamson, 1858; Heron-Allen and
138 m water depth (
1998. One short core was collected per station using a Craib corer, which has a hydraulic damper and a ball closing system, and takes a core 10–15 cm long and
core (EL1, 90 cm) was taken at the deeper station with a controlled-descent gravity corer having a diameter of
10 cm, which returned cores with an undisturbed sediment/water interface (
> 63 l
Table 1
Details of sample locations
Sta.
Lat N Long W
E4
E5
E6
E7
E1
EL1
E2
E3
56 28.185
56 28.185
56 27.859
56 27.847
56 27.847
56 17.846
56 17.439
56 17.439
05 09.896
05 09.896
05 10.898
05 10.902
05 10.871
05 10.790
05 10.969
05 10.969
m fraction was stained in rose Bengal (1 g l water) for at least 1 h, washed again on the 63 to remove the excess stain, and dried at 50 an Atago hand-held refractometer.
l
1
679
Earland, 1916; Edwards, 1982; Hannah and Rogerson,
1997; Murray, 1985, 2003a,b ).
3. Material and methods
Sampling took place at six stations between 26 and
sectioned within a short time (hours) of collection and the samples frozen. With the exception of core E1, the top centimetres of the Craib cores were sampled in two sections: 0.0–0.5 and 0.5–1.0 cm. For E1, three sections were taken: 0.0–0.25, 0.25–0.5, and 0.5–1.0 cm. Below this, the cores were sectioned into 1 cm slices down to
10 cm. Prior to processing, the samples were thawed in
70% ethanol, and then washed on a 63 l m sieve, the core samples (2 cm slices throughout) were frozen, weighed wet, freeze dried, weighed dry and five subsamples for faunal analyses were processed in the same way but without rose Bengal staining. The justification for drying the samples is that although some fragile agglutinated species are destroyed (e.g., Leptohalysis ), such forms would not be well preserved in the fossil record; the aim of the paper is to help interpret the fossil record. The water content was calculated as percent of wet sample, and the total organic carbon (TOC) content was determined by the Leco combustion method (Leco
Industrial Furnace). Salinity of the water overlying the surface sediments in the short cores was measured with
Most stained and at least 250 unstained foraminifera were picked from sub-samples in the top 2 cm. Below this, selected samples were analysed for the short cores and five from the long core, EL1. Taxonomy is based on
Depth (m)
130
137
26
54
72
93
141
138 of m sieve
C. The long
Equipment
Craib corer
Long corer
Craib corer
Craib corer
Craib corer
Craib corer
Craib corer
Craib corer
680
Murray (2003a) . Species diversity was calculated for
samples with > 100 individuals using the Fisher alpha index (
) and the information function,
H ( S ). Cluster analysis, non-metric multidimensional scaling plots (MDS), and H ( S ) were determined using
the program PRIMER v5 ( Clarke and Warwick, 1994;
). For the cluster and MDS, the data were not transformed and similarities were calculated using the Bray–Curtis index (
1957 ). All thecamoebians encountered while picking the
foraminifera were also picked and determined using the taxonomy of
Core E1 was dated via the
137
Cs and
210
Pb dating methods (e.g.,
Cundy and Croudace, 1996 ). Core sub-
samples were counted for 24 h on a Canberra 30% P-type
HPGe gamma ray spectrometer to determine the activities of
137
Cs and other gamma emitters. Limits of detection were typically < 5 Bq/kg and errors were ca. 20%.
210
Pb activity was determined by a proxy method through alpha spectrometric measurement of its grand daughter nuclide
210
Po. The method employed is based on
using double acid leaching of the sediment with
209
Po as an isotopic tracer and autodeposition of the Po isotopes in the leachate on to silver discs. Discs were counted on a Canberra 7401 Alpha Spectrometry system for at least
150,000 s. Detection limits are 0.1 Bq/kg and errors were less than 5%. The
210
Pb excess activity was estimated by subtraction of the value of constant
210
Pb activity at depth
(0.035 Bq/g), using activity values from a parallel core.
Ages were determined using the simple model of
210
Pb dating (see
for review of dating models).
4. Radiometric dates
J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697
137
Cs activity shows a slight increase with depth, from surface activities of ca. 100–190 Bq/kg at 10 cm
(
210
Pb
). The activities observed are similar to those found in surface and near-surface sediments in earlier
studies ( Ridgeway and Price, 1987; Williams et al.,
134
Cs was not detected in any of the samples analysed. Given that the main source of supply of reflects decreasing inputs of time, due to reductions in the observed excess are similar to those found by of 1.2 cm yr
1 reported by
137
Cs to Loch Etive is liquid effluent discharge from the BNFL
Sellafield facility ( Williams et al., 1988
), the up-core decline in
137
Cs activity observed here most probably
137
Cs from Sellafield over
137
Cs discharges since the mid-1970s. While it is not possible to accurately match
137
Cs profile to the Sellafield discharge history due to the relatively short core length, the downcore increase of
137
Cs and the lack of a clear subsurface maximum in activity indicates that the sediment samples post-date the period of maximum discharge from
Sellafield in 1975. Assuming that the entire cored depth of sediment is post-1975 gives a minimum sediment accumulation rate of 4 mm/yr.
210
Pb excess shows a rapid decline in activity over the cored depth, from 0.33 Bq/g at the sediment surface to
0.20 Bq/g at 10 cm depth (
in organic-rich sediments from the inner loch.
Applying the simple model of
210
Pb dating indicates a sediment accumulation rate of 0.1 g cm
2 yr
1
, or 5 mm yr
137
1
(+/ 1 mm/yr). This is broadly consistent with the
Cs data, and agrees well with sediment accumulation rates of 5–8 mm yr
1 reported in earlier studies (see
Williams et al., 1988; Howe et al., 2002; Overnell, 2002 ).
It is however, considerably lower than the rates in excess
for an adjacent inner loch site. This may indicate local variability in sediment accumulation rate, or more likely is an artefact of the method used by Ridgeway and
Price, who date the sediments according to the first appearance of Sellafield-derived
137
Cs in the sediment column (corresponding to 1952). This provides
Fig. 2.
137
Cs and error bars are 2 r
210
Pb excess activity vs. depth, Loch Etive core E1. A chronology derived from
(error bars on the
210
Pb excess
210
Pb dating is also shown (see text for discussion). All graph are smaller than the diamond marker symbol used).
a maximum rate of sediment accumulation, as downward diffusion of
137
Cs may cause pre-1952 sediments to be labelled with
137
Cs, thus giving an erroneously high accretion rate (e.g.,
Cundy and Croudace, 1996 ). The
210
Pb data presented here indicate that sediment at the base of the core (i.e. at 10 cm depth) was deposited in
1978 (+/ 5 yr,
Fig. 2 ). The consistent decline in
210
Pb activity with depth indicates little sediment homogenisation by physical mixing and bioturbation, in agreement with earlier studies (see
5. Sediments
J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697
The sediment was very soft and had water content of
76.0–86.5%, mean 78.5% in long core EL1, 0–90 cm
( n ¼ 31). They are mainly of clay grade and are
Ô packaged Õ as faecal pellets. TOC from long core EL1
( n ¼ 15) yielded values of 5.0% at 0–2 cm, 5.3–5.8% from 2–66 cm, and 6.4–8.0% down to 90 cm. The particulate organic matter is primarily terrestrial
(spores, wood, cuticle; Ian Harding, pers. comm.).
681
Table 2
Summary of live (stained) distributions
Water depth (m)
Core
26
E2
Deuterammina rotaliformis 10
Eggerelloides scaber 10
Paratrochammina ( L .) spp.
10
Leptohalysis scottii 0
Psammosphaera bowmani
Reophax fusiformis
Elphidium excavatum
Lamarckina haliotidea
43
14
5
5
54
E3
10
14
4
0
0
46
1
8
72
E4
5
23
23
0
0
27
0
18
93
E5
0
40
0
17
0
24
1
0
130
E1
0
26
2
0
0
34
0
27
138
E7
3
53
5
0
1
28
0
9
Fisher alpha 4.7
4.4
2.7
3.3
2.1
1.5
Information function H ( S ) 1.75
1.85
1.62
1.65
1.49
1.23
% Agglutinated 43 93 73 89 97 95
0–2 cm, Standing crop per 10 cm
3
0–1 cm, Standing crop per 10 cm
3
12
13
36
35
5
7
19
23
X
35
17
21
Species abundances as % for the 0–2 cm interval. X, no sample at
1–2 cm.
6. Salinity measurements
At the time of sampling, the salinity of the water overlying the core tops ranged from 27 to 30. Thus all stations were brackish and all were from below the halocline.
7. Foraminiferal results
7.1. Living assemblages under-represented in the samples because they were dried during processing. Nevertheless, it reaches abundances of 8–27% at depths > 50 m. Other agglutinated taxa attaining sporadic abundances of 10% include
Deuterammina rotaliformis , Psammosphaera bowmani and Paratrochammina ( Lepidoparatrochammina ) spp.
The only calcareous forms that are common are
Elphidium excavatum at 26 and 72 m and Lamarckina haliotidea at 26 m. On a dendrogram, the samples at 54 and 93–138 m form cluster 1 with 60% similarity while the two samples with calcareous forms are separate clusters 2 and 3 (
Fig. 3 ). On an MDS plot, cluster 1 is
seen to be dominated by E. scaber and R. fusiformis , cluster 2 by E. excavatum and L. haliotidea , whereas cluster 3 has no single dominant species.
The number of stained individuals in each sample down to 2 cm was low and below this they were rare if present at all. The standing crop, based on the 0–1 cm interval, ranges from 7 to 35 per 10 cm
3 sediment and, on the 0–2 cm interval, 5–36 per 10 cm
3 sediment implying that the highest abundance consistently was found in the surface 0–1 cm (
opposed to the other species, Leptohalysis scottii and
Reophax fusiformis were generally equally abundant at all core depths down to 2 cm and dominated the 1–2 cm interval. The highest values occur at 54 and 130 m and there is no correlation between standing crop and water depth. Species diversity values for the top 0–2 cm are low: Fisher alpha 1.5–4.7 and H ( S ) 1.23–1.85. Agglutinated foraminifera are dominant (43% at 26 m, otherwise 73–97%).
Eggerelloides scaber is common throughout (10–46%) but especially at depths > 50 m where it is the dominant form except at 138 m.
Reophax fusiformis is common (14–53%) except at 26 m and dominant at 138 m.
Leptohalysis scottii is fragile and
7.2. Dead assemblages
7.2.1. 0–1 cm
The number of tests per 10 cm
3 of sediment shows a steady decrease with water depth, from 650 at 26 m to
67 at 138 m and 53 at 130 m with a major change
between 54 m (547 tests) and 72 m (189 tests) ( Tables 3 and A.2
). Species diversity is moderately low (Fisher
alpha 2.0–3.9, H ( S ) 0.83–1.73) with the highest values at
130 m. The proportion of agglutinated tests is high throughout ( 96% except at 130 m where it is 91–96%).
Calcareous tests commonly show evidence of dissolution.
Eggerelloides scaber is abundant throughout and is dominant from 26 to 93 m; then Leptohalysis scottii is dominant at 130 m and Reophax fusiformis at 130–138 m.
Few other species exceed 5% abundance ( Ammotium sp. at 54 m, Deuterammina rotaliformis at 26 m,
Miliammina fusca at 26, 93 and 138 m, Trochammina spp. at 26 m and Elphidium excavatum at 130 m).
682 J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697
Fig. 3. Cluster analysis and MDS plots for live data from 0 to 2 cm. The size of the bubbles on the MDS plots reflects the relative importance of the named species. The three clusters are labelled 1–3.
Cluster analysis of the 0.5 cm slice data gives two groups: no. 1 includes the samples from 26 to 93 m and no. 2 those from 130 to 138 m. A similar pattern is
shown by the MDS ordination ( Fig. 4 ). The bubble
plots show that several species contribute to cluster 1 and that E. scaber is unimportant in cluster 2. Sample
E1a is dominated by L. scottii .
7.2.2. Short cores
The dead assemblages from 26 to 93 m are dominated by Eggerelloides scaber with a range of minor species making up > 5%, the most consistent being Reophax fusiformis and Elphidium albiumbilicatum (
138 m, R. fusiformis is dominant with E. scaber subdominant. Agglutinated forms are important throughout. Species diversity is low except at 138 m where it rises to Fisher alpha 4.8. Although in each core there is some variation in the number of tests per 10 cm
3 sediment, the mean values follow the same decrease with water depth as the surface 0–1 cm samples (
Small, juvenile, planktonic foraminifera are present from 2 to 5 cm in core E7 at 138 m water depth.
7.2.3. Long core, 0–90 cm, 138 m water depth
The top 10 cm of this core overlap the equivalent succession of E7. The five samples from 18 to 90 cm have higher species diversity (Fisher alpha 5.3–9.5, H ( S )
1.70–2.65) and the proportion of agglutinated forms falls to 43% at 88–90 cm (
tests per cm
3 sediment is comparable with those at the top of core E7 but much lower than the number from
2 to 10 cm. The dominance of Eggerelloides scaber
J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697 683
Table 3
Summary of dead data for 0–1 cm
26
Water depth (m)
Core
Depth (cm)
E2 E2
54
E3 E3
72
E4 E4
93
E5 E5
130
E1 E1 E1
138
E7 E7
0.0–0.5 0.5–1.0 0.0–0.5 0.5–1.0 0.0–0.5 0.5–1.0 0.0–0.5 0.5–1.0 0.0–0.25 0.25–0.5 0.5–1.0 0.0–0.5 0.5–1.0
Ammotium sp.
Deuterammina rotaliformis
Eggerelloides scaber
Leptohalysis scottii
Miliammina fusca
Reophax fusiformis
Trochammina spp.
Elphidium excavatum
4
14
3
0
65
1
0
8
5
0
5
7
66
0
0
6
2
1
4
8
57
2
7
0
1
1
3
7
71
0
3
0
3
11
1
2
75
3
0
0
0
0
0
8
82
1
0
0
6
12
0
2
67
3
0
0
4
18
1
1
64
1
0
0
3
26
3
6
26
29
0
0
4
41
0
2
39
6
0
0
2
44
0
6
28
4
0
0
1
47
1
3
35
1
0
3
7
55
1
2
29
2
0
0
Fisher alpha
Information function
% Agglutinated
H
0–1 cm, Tests per 10 cm
(
3
S )
Species abundances in %.
2.0
1.25
100 99
650
2.6
3.9
1.32
1.65
99 99
547
3.4
3.4
1.23
1.06
97 96
189
2.8
2.9
0.83
1.27
98 97
116
3.6
3.9
1.30
1.73
91
3.2
1.43
96 94
53
3.1
1.55
3.2
1.39
97 98
67
2.4
1.24
continues down to 32–34 cm and below this Reophax fusiformis takes over until 64–66 cm. The bottom sample, 88–90 cm, has no strongly dominant species; the most abundant forms in rank order are Stainforthia fusiformis , Elphidium excavatum , Elphidium albiumbilicatum , R. fusiformis and E. scaber . Cluster analysis shows a surface group (cluster A) 0.0–1.0 cm, a broad cluster B of samples down to 48–50 cm but excluding
32–34 cm which groups with 64–66 cm in cluster C.
Finally, the bottom sample from 88 to 90 cm remains a separate cluster D. On the MDS plot, the groupings are the same but it can be seen that 48–50 cm lies in an intermediate position between the main group of samples in cluster B and cluster C (
plots show that E. scaber and R. fusiformis are important in cluster B and calcareous forms in cluster D.
8. Thecamoebians
Dead individuals were recorded in small numbers in
all cores at all depths sampled ( Table A2
).
9. Discussion
The strong dominance of agglutinated forms with an organic cement is the outstanding feature of both the live and dead foraminiferal assemblages of Loch Etive.
This resembles some southern Norwegian fjord assemblages (
Alve and Nagy, 1986; Alve, 1995
) but makes them quite unlike any estuarine assemblages previously described from around the British Isles, which normally are highly calcareous, as discussed below. On a global basis, living assemblages dominated by organic cemented agglutinated foraminifera occur to a limited extent in parts of brackish estuaries, fjords, and shallow bays or lagoons but they are mainly confined to tidal marshes and to those parts of the ocean deeper than the
CCD. It has been argued that some of the fossil agglutinated assemblages must be trations due to (taphonomic) loss of calcareous forms through dissolution (
occurrence in Loch Etive of primary living agglutinated assemblages with only a minor calcareous component is most likely related to the unusual oceanographic conditions in the area. These same conditions cause a further postmortem concentration of agglutinated forms in the dead assemblages through the dissolution of most of the calcareous tests.
secondary concen-
). The
9.1. Influence of unusual oceanographic conditions
The stratification of the water masses with a halocline at 20 m leads to episodic exchange of bottom water in the inner basin resulting in the presence of brackish water of almost constant salinity (28) for periods which may exceed one year. In effect, there is no tidal influence on salinity in the deep waters of this basin. Likewise, the annual variation in bottom temperature is around 2 C
(range 8–10 C) so the seasonal influence is small too.
Thus, the environment is very stable for long periods although there is probably seasonal variation in the flux of organic material. The episodic variation in dissolved oxygen does not extend to values low enough to directly influence the benthic foraminifera (from other studies it is apparent that only levels < 1 ml l
1 in the bottom water are critical, e.g.,
). During stagnation the dissolved oxygen levels in Loch Etive are sufficiently low to affect biogeochemical recycling
(
Edwards and Grantham, 1986; Overnell et al., 1995,
and this almost certainly influences the benthos.
The most obvious effect may be on the corrosivity of the water with respect to CaCO
3
. For instance, although ophiuroids are common elements of the macrofauna,
684 J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697
Fig. 4. Cluster analysis and MDS plots for dead data from a 0.0–0.5 and b 0.5–1.0 cm samples. For E1, a 0.0–0.25, b 0.25–0.5, c 0.5–1.0 cm samples.
The size of the bubbles on the MDS plots reflects the relative importance of the named species.
their ossicles are not very common in the sediment.
Some of the calcareous tests of dead foraminifera show evidence of corrosion and are much reduced in abundance in comparison with the living assemblages.
However, down-core there are levels with higher abundances of calcareous forms (e.g., long core 48–90 cm) so there has clearly been temporal variation in corrosivity over a longer time period.
In comparison, deeps on the continental shelf west of
Scotland also have a similar temperature range and probably a seasonal flux of organic matter but the salinity is fully marine throughout the year (34.5–35.2).
Oxygen levels are high and there is no evidence of widespread carbonate dissolution. Indeed, the sediments are rich in carbonate bioclasts and most of the for-
aminiferal fauna is hyaline ( Murray, 2003b ).
Reduction within the sediment of MnO
2 derived from the water column will be accompanied by an increase in pH, although the magnitude of the increase is difficult to estimate (Overnell, pers. comm.). Oxidation of organic carbon is bacterially mediated. The role of oxygen is largely to oxidize the reduced intermediates liberated by the oxidation of organic compounds (nitrite, ammonia,
Mn(II), sulphides, low molecular organic acids, etc.). At the deep station in the inner basin oxidizing equivalents from the input manganese oxides probably amounted to
20–30% of the direct oxygen uptake. At the Airds Bay station oxygen was the dominant electron acceptor
(
Overnell, 2002 ). The question arises as to whether
during these processes the localised release of CO
2 in microenvironments around the bacterial degradation is responsible for creating the mildly acidic conditions that
J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697
Table 4
Summary of down-core dead assemblage distributions
Core
Water depth (m)
Sediment thickness (cm)
E2
26
10
Eggerelloides scaber
Ammotium salsum
Leptohalysis scottii
Miliammina fusca
Paratrochammina ( L .) spp.
Reophax fusiformis
Trochammina spp.
Elphidium albiumbilicatum
Elphidium excavatum
Miliolinella subrotunda
Dom
M
M
M
M
M
M
Fisher alpha
Information function H ( S )
% Agglutinated
Number of tests 10 cm
3 sediment
Mean number of tests 10 cm
3 sediment
Dom, dominant, 55%; M, minor, 5%.
2.0–4.0
1.40–1.60
82–100
147–1029
661
E3
54
10
Dom
M
M
M
2.1–4.0
1.40–1.60
87–99
421–776
500
E4
72
8
Dom
M
M
2.3–3.4
0.69–2.09
87–99
181–632
383
M
M
M
E5
93
7
Dom
1.9–4.0
1.23–1.54
85–90
116–206
148
685 cause the carbonate dissolution. Understanding carbonate dissolution continues to be a problem. ‘‘A major difficulty in understanding the dissolution kinetics of calcite in seawater is that the saturation state of seawater is generally greater than 0.7 with respect to calcite which is approximately a pH of only 0.2. Thus, an understanding of the dissolution behavior of calcite in the ocean, and influences of factors such as inhibitors and temperature, must be obtained over a pH range of
less than 0.2’’ ( Morse and Arvidson, 2002 ). They also
point out that there is a long way to go to bridge the gap between carefully controlled laboratory experiments and observations in complex natural marine environments.
9.2. Features of the living assemblages
Open shelf living assemblages commonly have Fisher alpha species diversity values > 5 and information function ( H ( S )) >
0.75 ( Murray, 1991 ). The values
recorded for the live assemblages here are lower than
Fisher alpha 5 but within the shelf sea range for the information function; however, the alpha values are comparable with those of the southern North Sea
(
Murray, 1992 ). The standing crops in Loch Etive are
low ( < 75 per 10 cm
3 at all but one station) compared with continental shelves which commonly have > 100 individuals per 10 cm
3 sediment. Stanton Deep on the Scottish shelf has an organic flux of 75 g C m
2 yr
1
) and a standing crop (817 per 10 cm
3 sediment for 0–1 cm;
). The organic flux in Etive ranges from 28.4 g C m
2 yr
1 at 26 m to 8.7 g C m
2 yr
1 at 138 m (calculated from a primary production of 70 g C m
2 yr
1 using the equation of
). Therefore, lower standing crop values are to be expected.
Both the dominant species, Eggerelloides scaber and
Reophax fusiformis , are infaunal (
) but none of the infaunal species were found to live far below the sediment–water interface; virtually all were in the top 2 cm and 68–84 % in the surface 1 cm. The TROX model was put forward by
to explain depth of life in the sediment and the control exerted by oxygen and organic flux (given in relative terms as oligotrophic to eutrophic). Recently,
described a transect of stations across the
Bay of Biscay margin and for the first time provided data on the values of organic flux in the eutrophic and mesotrophic fields. Their stations D and B are most similar to Etive and both lie in the eutrophic field. D has an organic flux of 34.1 g C m
2 yr
1 of which the labile fraction is 26.6 g C m
2 yr
1
; the oxygen profile reaches zero at 8 mm. Nevertheless, live foraminifera extend down to 7–8 cm below the sediment surface although they are rare below 4 cm. B has an organic flux of 9.2 g
C m yr
1
2 yr
1 of which the labile fraction is 6.6 g C m
2
; the oxygen profile reaches zero at 19 mm.
Nevertheless, live foraminifera extend down to 6 cm below the sediment surface although they are again rare below 4 cm. In Loch Etive, in spite of the high content of organic matter in the sediment and the relatively lowered oxygen levels in the overlying water, the redox boundary is a few cm below the sediment surface (based on geochemical criteria,
) and yet the infaunal foraminifera are confined to this zone.
Living assemblages dominated by Eggerelloides scaber are known from Oslofjord and Drammensfjord,
Norway ( Alve and Nagy, 1986; Alve, 1995 ), the Baltic
Sea (
Lutze et al., 1983 ) and Arcachon lagoon, France
(
Le Campion, 1970 ). On the continental shelf they occur
E7
138
10
Sub-dom
M
M
Dom
M
M
M
2.4–4.8
1.24–1.92
79–98
67–154
115
686 J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697
Fig. 5. Cluster analysis and MDS plots for dead data from core E7 down to 10 cm and long core EL1 from 19 to 90 cm. The sample depths are expressed by the top number (e.g., 1 ¼ 1 : 0 2 : 0 cm). The size of the bubbles on the MDS plots reflects the relative importance of the named species.
in the southern North Sea ( Richter, 1967 ), the Celtic
Sea (
Murray, 1979 ) and the English Channel ( Murray,
1970 ). Dead or total assemblages are also known
from Gullmar Fjord, Sweden (
) and
the continental shelf off Galicia ( Colom, 1984
). These assemblages are associated with salinities > 24 for most of the year, a wide range of water temperatures (1–20 C) and substrates of sand or mud (
Living assemblages dominated by Reophax fusiformis are known from the Norwegian continental shelf
(
Mackensen et al., 1985 ), Celtic Sea ( Murray, 1979 ),
the English Channel (
) and NW Africa
(
Lutze, 1980 ). These occur in normal salinities at tem-
peratures of 1 to 13 C and on substrates of sand and muddy sand and at depths down to > 3000 m (
1991 ). Dead assemblages dominated by this species are
rarely recorded perhaps because the tests are relatively fragile.
Elphidium albiumbilicatum (
living in shallow (e.g., 5–46 m, T 1.6–18.0
C, salinity 0.1
to 31.5,
Alve, 1995 ) and deeper fjordic (e.g., 28–43 m,
T
3–5 C, salinity 26,
;
J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697 687
Fig. 6.
Elphidium albiumbilicatum (Weiss) SEM pictures. Scale bars 20 l m except for right hand picture, which is 50 l m.
116 m, T 5–8 C, salinity 34.4–34.8,
) as well as in shallow ( < 6 m) open waters around the Skagerrak and Kattegat and
considered that this represented its southern limit of distribution.
found it to be one of the most eurythermal and euryhaline species in the Drammensfjord, Oslofjord. It has not been previously reported from modern sediments in British waters so its occurrence in Loch Etive is of considerable interest. Apart from temperature control, it was thought that its depth distribution was dependent mainly on
salinity ( Alve and Murray, 1999
). Brackish salinities showing a narrow range of variation are present in Loch
Etive throughout the year. This is in marked contrast to
British tidal estuaries where there is both diurnal and seasonal variation in temperature and salinity.
Leptohalysis scottii seems to be a characteristic fjordfauna element. In addition to Loch Etive, species of this very distinctive, fragile, slender genus are common in
Scandinavian fjords (e.g.,
2000; Gustafsson and Nordberg, 2000, 2001
) as well as in Canadian ones (
Blais-Stevens and Patterson, 1998;
). It was particularly abundant
(63% of live assemblage and had the third highest standing crop of all 62 surface samples) at a station in the inner part of Sandebukta, Oslofjord, which was located between the outlet from a paper mill and a river-
influenced tidal flat ( Alve and Nagy, 1986
). Indeed,
Blais-Stevens and Patterson (1998, p. 213)
speculate that
‘‘A high proportion of plant debris, a muddy substrate, and probably lower oxygen levels seem to create ideal conditions for Leptohalysis catella ’’. It is also known from eastern Canada where it shows a considerable increase in abundance as a consequence of organic enrichment due to fish farming (
). Although
Ernst et al. (2000) , based on
experimental data, regarded L. scottii as being a prominent epifaunal/shallow infaunal species intolerant to the environmental conditions in deeper sediment layers,
Gustafsson and Nordberg (2001)
found its maximum abundance sometimes in the 0–1 cm and sometimes in the 1–2 cm layer and live specimens were present down to 3 cm (the deepest layer investigated). The trend described by the latter authors is in accordance with our findings in Loch Etive.
9.3. Taphonomic impacts
Two taphonomic processes have influenced the composition of the dead assemblages: destruction of tests and transport.
The loss of calcareous tests through dissolution is attributed to the unusual oceanographic conditions.
Living assemblages which are already rich in agglutinated forms give rise to dead assemblages even more dominated by them. Dissolution of calcareous tests clearly takes place soon after death at the surface but their greater abundance at depth in some cores indicates that this has not always been so intense. It is possible to simulate natural dissolution of calcareous foraminifera experimentally. When normal calcareous-rich original dead assemblages (ODAs) are treated with dilute acid to remove the calcareous forms the resultant acid-treated assemblages (ATAs) are composed entirely of organiccemented agglutinated forms. ATAs from the Celtic Sea and western English Channel have abundant Eggerelloides scaber at depths of < 90 m although the depth
range of the species is down to 150 m ( Murray and Alve,
).
Reophax fusiformis is of low abundance in the
ATAs of the Celtic Sea and western Channel (
Murray and Alve, 2000 ). Destruction of agglutinated tests may
also take place. Some taxa are fragile and their tests are probably under-represented, e.g., Leptohalysis scottii which can be destroyed during sample drying and processing. Of the dominant taxa, E. scaber is more robust than R. fusiformis .
There is evidence of transport of tests both into and within Loch Etive. The best indicator of inward transport from the open sea is the occurrence of juvenile planktonic forms in core (E7 2–4 cm). Also, when bottom water renewal takes place, some live juveniles of benthic species may be introduced and some may colonise the area for short or long periods depending on the prevailing conditions. The open sea is the
688 J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697 ultimate source of all the benthic foraminiferal colonisers (see review by
Alve, 1999; Alve and Goldstein,
2002 ). The presence of small numbers of benthic marsh
taxa, such as Ammotium sp., Jadammina macrescens and
Trochammina inflata , shows that there has been advection of material from the intertidal zone into deeper waters, even throughout the duration of the long core.
This transport is to be expected in such a narrow inlet where deep water lies close to land. However, because the fjord sides are steep, marsh development is very localised so there is not a large source area. Whereas in the Scottish shelf deeps transported foraminiferal tests constitute a major part of the dead assemblages
( 50%), in Loch Etive they are very minor and are mostly from the adjacent marshes.
Thecamoebians are protozoans with unilocular tests that live in freshwater bogs, lakes and rivers. Some appear to be tolerant of very low salinities (
1967; Scott et al., 2001 ) but their occurrence in brackish
or marine sediments is mainly the result of inward transport by rivers. Nevertheless, they can give some indication of the source environment.
Centropyxis spp.
are tolerant of extreme conditions and occur in coastal lakes/ponds affected by salt spray (
Difflugia oblonga lives in gyttja (organic-rich lake sediments composed mainly of plant debris) and is normally present where the pH is < 6.2 (
9.4. Environmental change over the past 200 years
The resolution of down-core faunal changes can be affected by macrofaunal bioturbation but in Loch Etive there is no evidence of this on the timescale of the half life of
210
Pb. The down-core foraminiferal records provide information on the sub-recent history of the fjord. The most prominent faunal changes are the reduction (both absolute and relative abundance) in
Eggerelloides scaber and Reophax fusiformis and the increase in both Elphidium excavatum and Stainforthia fusiformis towards the base of the long core, EL1
(
Fig. 7 ). It can be argued that this is a taphonomically
induced pattern. However, if destruction of agglutinated tests (which no doubt is going on to a certain extent) is the main reason for the reduction in E. scaber and R.
fusiformis , one would expect a much faster reduction in the latter because it is more fragile. This is not the case.
Moreover, if carbonate dissolution is the main reason why S. fusiformis is hardly present at shallower core levels it should at least be a common component in the living assemblages but it is not. Unpublished data from the Oslofjord, show that in areas where it hardly is present in the dead assemblages, it still dominates the living ones. Consequently, it seems that although taphonomic processes have altered the assemblages, they still contain enough information to suggest that the environmental conditions in Loch Etive have changed over the time period represented by the core sediments.
The renewal/replenishment of the bottom water of the upper basin of Loch Etive is determined largely by the amount of freshwater on the surface. (After heavy rain the salinity of the surface water can drop to 1.) At the sill, the water is partially mixed on the ebb tide, and so during rainy periods the salinity of the incoming water of the flood tide at the sill is lower than that of the deep water behind the sill, and tidal exchange affects only the surface water. However, this tidal movement does very gradually erode the salinity of the deep water by turbulent diffusion. After a period of prolonged low rainfall the incoming water is much less brackish and then water on a flood spring tide is able to displace the old deep water. This renewal of deep water on spring tides continues as long as the amount of freshwater remains low (Overnell, pers. comm.). Thus, higher concentrations of normal marine foraminifera in the sediment at depth may indicate sustained periods of very low river flow during spring tides.
Core EL1 has not been dated, but assuming the same mean accumulation rate as in nearby core E1 (0.5 cm/yr) then it may represent around 180 years of record. At the base there is a calcareous dominated assemblage with a higher proportion of marine species and higher diversity
(Fisher alpha > 5) as compared to the present-day conditions. The upward decrease in Stainforthia fusiformis is particularly noteworthy. This is an opportunistic species flourishing in stressed environments, including oxygen depleted Scandinavian silled fjords (see discussion in
Alve, 2003 ), but it seems to require salinities
> 28 for most of the year (
Gustafsson and Nordberg, 2000 ). Conse-
quently, its increased abundance in the lower parts of the core suggests somewhat higher salinity than that of the present-day. The shallower 48–66 cm core interval represents an intermediate situation with a smaller calcareous component, but still substantially larger than the more recent assemblages. This suggests lower corrosivity of the bottom/pore water as compared to the present-day situation and is probably related to a greater marine influence. Species diversity is high up to the 18–20 cm level which may date from around 1958 and this suggests that the bottom salinities were closer to that of normal seawater during this period than they are now.
In core E7 (2–4 cm, representing 1988–1992) another example of greater penetration of marine water is indicated by the presence of planktonic tests. Thus the foraminiferal record has the potential to provide palaeoceanographic reconstructions in this climatically sensitive fjord.
10. Conclusions
The most outstanding feature of the living benthic foraminiferal assemblages is that they are strongly
J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697 689
Fig. 7. Occurrence of foraminifera in cores E7 and EL1.
dominated by agglutinated foraminifera, a feature normally associated with deeper water environments below the CCD or with intertidal marshes. The dead assemblages are further enriched in agglutinated forms indicating that postmortem dissolution of calcareous tests is active. Therefore, this area provides a new analogue with which fossil assemblages may be compared.
The cause of these unusual assemblages is attributed to the prevailing oceanographic and sedimentary conditions. The isolation of the inner basin of Loch Etive by a series of shallow sills, combined with the high input of freshwater, prevents the continuous exchange of marine bottom water and leads to salinity stratification.
Between periods of renewal, the bottom waters become depleted in oxygen but they do not become anoxic.
Although the sediments are rich in organic matter, most is terrestrial, and the organic flux is low. Inferred bacterial decay of organic matter, and the geochemical changes associated with the oxidation processes, may be responsible for generating slightly corrosive bottom waters and causing carbonate dissolution.
The historical record over the past two centuries, interpreted from subsurface foraminiferal assemblages, shows that in the past there was greater renewal of the bottom waters (indicating a lower input of freshwater).
Loch Etive has good potential for performing highresolution palaeoclimatic studies.
Acknowledgements
We thank Julian Overnell, SAMS, and the crew of
Ô Seol Mara Õ for assistance with sampling. Ian Croudace is thanked for access to the radiochemistry facilities.
Julian Overnell is also thanked for discussion of aspects of the oceanography and geochemistry and for very helpful comments on the manuscript. Bill
Austin (St. Andrews) kindly read the final manuscript.
The referees, Dave Scott (Dalhousie, Canada) and
Julian Overnell, are thanked for their helpful comments.
Appendix Table A1
Data on living (stained) foraminifera
26
Water depth (m):
Core
Depth (cm)
E2 E2 E2
54
E3 E3 E3
72
E4 E4 E4
93
E5 E5 E5
138
E7 E7 E7
130
E1 E1 E1
0.0–0.5 0.5–1.0 1.0–2.0 0.0–0.5 0.5–1.0 1.0–2–0 0.0–0.5 0.5–1.0 1.0–2.0 0.0–0.5 0.5–1.0 1.0–2.0 0.0–0.5 0.5–1.0 1.0–2.0 0.0–0.25 0.25–0.5 0.5–1.0
Ammotium sp.
Cuneata arctica
Deuterammina rotaliformis 1
0
0
Eggerelloides scaber
Glomospira gordialis
Paratrochammina ( L .) spp.
1
Leptohalysis scottii
Miliammina fusca
Psammosphaera bowmani
Reophax fusiformis
Textularia earlandi
Textularia skagerrakensis
Trochammina spp.
Unidentified agglut
Buliminella elegantissima
Elphidium excavatum
Elphidium albiumbilicatum 0
Fissurina marginata 0
0
8
Lamarckina haliotidea
Miliolinella subrotunda
Stainforthia fusiformis
Unidentified calc
0
0
2
0
Number counted
Number in sample
Number per 10 cm
3
% Agglutinated
% Agglut in top 1 cm
2
1
0
0
0
0
0
1
0
0
16
32
25
38
Species abundances as numbers.
2
100
1
2
69
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
1
0
0
1
0
0
0
4
27
11
50
0
0
7
5
1
0
2
0
2
1
0
30
4
1
0
2
2
0
0
0
0
0
57
57
44
93
0
0
1
2
0
0
1
0
0
0
0
6
0
0
0
0
0
0
0
0
0
0
10
33
26
100
96
0
0
0
4
1
0
3
0
1
0
0
1
1
0
0
1
0
1
0
0
0
0
13
95
37
85
0
0
1
5
0
0
2
0
0
0
0
2
0
0
0
0
0
1
0
0
0
0
11
11
9
91
0
0
0
0
0
0
1
0
0
0
0
3
0
0
0
2
0
0
0
0
0
0
6
6
5
67
79
0
0
0
0
0
0
1
0
0
0
0
1
0
0
0
3
0
0
0
0
0
0
5
5
2
40
2
0
0
6
0
0
4
0
0
0
0
14
0
0
0
1
1
0
0
1
0
0
29
29
22
90
0
0
0
8
0
0
2
1
0
0
0
17
0
0
0
0
1
0
0
0
0
1
30
30
23
93
91
2
0
0
7
1
0
9
0
0
0
0
4
0
0
0
0
4
0
0
0
1
0
28
28
11
82
1
14
0
0
0
0
1
0
0
0
1
15
0
0
0
2
0
0
0
0
0
0
34
34
26
94
1
14
0
0
0
0
2
0
0
0
0
4
0
0
0
0
0
0
0
0
0
0
21
21
16
100
97
0
11
0
0
0
0
4
0
0
0
0
2
0
0
0
2
0
0
0
0
0
0
19
19
7
89
0
11
1
0
0
0
2
0
0
0
0
10
0
0
0
0
0
0
0
0
0
0
24
24
38
100
0
0
0
9
0
6
8
0
0
0
0
17
0
0
0
1
0
0
0
0
0
0
41
41
64
98
99
0
1
0
4
0
0
15
0
0
0
0
4
0
0
0
0
0
0
0
0
1
1
26
26
20
92
96
Table A2
Data on dead foraminifera
Water depth (m)
Core
Depth (cm)
26 54 72 93
E2 E2 E2 E2 E2 E2 E2 E3 E3 E3 E3 E3 E3 E3 E4 E4 E4 E4 E4 E4 E5 E5 E5
0.0–0.5 0.5–1.0 1.0–2.0 3.0–4.0 5.0–6.0 7.0–8.0 9.0–10.0 0.0–0.5 0.5–1.0 1.0–2–0 3.0–4.0 5.0–6.0 7.0–8.0 9.0–10.0 0.0–0.5 0.5–1.0 1.0–2.0 3.0–4.0 5.0–6.0 7.0–8.0 0.0–0.5 0.5–1.0 1.0–2.0
0 0 0 0 0 1 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0
Ammonia beccarii
Biloculina inflata
Bolivinid
Buccella sp.
Bulimina sp.
Buliminella elegantissima
Cibicides lobatulus
Cornuspira involvens
Elphidium albiumbilicatum
0
0
0
0
0
0
0
0
0
1
26
0
0
10
9
0
0
1
0
0
2
0
24
0
0
0
0
0
0
0
0
0
0
0
243
1
0
0
1
0
1
6
0
0
0
2
0
22
0
0
12
10
0
1
0
0
0
0
0
21
0
0
0
0
1
0
0
0
0
0
0
178
1
0
0
0
0
1
2
0
0
0
3
0
24
0
0
4
3
0
2
3
0
0
0
0
20
0
0
0
0
1
0
0
0
0
1
0
379
0
0
0
0
0
0
1
0
0
0
5
1
16
0
0
1
3
0
2
1
0
0
0
0
0
0
0
0
6
2
0
0
0
0
1
0
173
2
0
0
0
0
0
0
0
0
0
4
0
30
2
0
8
5
0
7
0
0
0
3
0
0
0
0
0
0
1
0
0
0
0
1
0
206
2
0
0
0
0
2
0
1
0
0
1
0
19
0
1
6
14
0
0
2
0
0
6
0
0
0
0
0
0
0
0
0
0
0
0
0
210
3
0
0
1
0
0
0
1
0
0
0
1
6
0
0
6
13
0
1
1
0
0
9
0
0
0
0
0
4
0
0
0
0
0
0
0
244
2
0
0
0
0
0
0
7
0
0
0
0
6
0
0
7
12
0
2
1
0
0
0
0
0
0
0
0
8
0
0
0
1
0
2
0
197
1
0
0
0
0
0
0
1
0
0
0
0
9
0
1
6
10
0
5
1
0
0
8
0
0
0
0
0
4
0
0
0
0
0
1
0
189
6
0
0
0
0
1
0
2
0
0
0
0
11
0
2
7
2
0
3
1
0
0
2
25
0
0
0
0
0
0
0
2
0
0
0
0
195
9
0
0
0
0
1
0
9
0
0
1
0
20
0
3
9
3
0
1
1
0
0
2
0
0
0
0
0
2
0
0
0
17
0
0
2
196
8
0
0
1
0
0
0
9
0
0
0
0
18
1
2
10
5
0
4
2
0
0
5
0
0
0
0
0
1
0
0
0
23
1
0
0
135
11
0
0
0
1
16
0
1
0
0
0
0
15
0
0
14
30
0
0
0
0
0
0
0
0
0
0
0
4
0
0
0
0
0
3
0
157
3
0
0
0
0
0
18
5
0
0
0
0
18
0
0
14
24
0
1
0
0
0
4
0
0
0
0
0
4
2
0
0
0
0
1
0
162
4
0
0
0
0
0
17
0
0
0
1
0
12
0
2
13
43
0
1
1
0
0
2
0
0
0
0
0
7
0
0
0
0
0
0
0
183
2
0
0
0
0
0
10
0
0
0
0
0
48
0
0
4
6
0
2
2
0
0
0
0
23
0
0
0
0
0
0
1
0
0
0
0
160
0
0
0
0
0
0
2
0
0
0
1
1
22
0
1
13
11
0
3
0
0
0
11
0
0
0
0
0
8
1
0
0
2
0
2
0
246
4
0
0
0
0
0
21
0
0
0
0
0
20
0
0
15
13
0
1
0
0
0
14
0
0
0
0
0
0
0
0
0
0
0
3
0
181
8
0
0
0
0
0
16
0
0
0
1
0
10
0
0
2
17
0
0
1
0
0
4
0
0
0
0
0
0
1
0
0
0
0
1
0
235
0
0
0
1
0
0
0
0
0
0
3
0
16
0
1
8
0
0
4
4
0
0
0
0
0
0
0
0
0
0
0
0
3
0
0
0
86
0
1
0
0
0
1
0
0
0
0
3
0
30
1
1
6
2
0
2
3
0
0
1
0
0
0
0
0
0
0
0
0
7
0
0
0
108
0
0
0
0
0
0
0
0
0
0
2
0
59
7
0
19
1
0
5
3
0
0
0
0
10
0
0
0
0
1
0
0
17
0
0
0
212
0
0
0
0
0
1
0
0
1
0
3
( continued on next page )
Table A2 ( continued )
Water depth (m) 26 54 72 93
Core
Depth (cm)
E2 E2 E2 E2 E2 E2 E2 E3 E3 E3 E3 E3 E3 E3 E4 E4 E4 E4 E4 E4 E5 E5 E5
0.0–0.5 0.5–1.0 1.0–2.0 3.0–4.0 5.0–6.0
7.0–8.0
9.0–10.0 0.0–0.5 0.5–1.0 1.0–2–0 3.0–4.0 5.0–6.0 7.0–8.0 9.0–10.0 0.0–0.5 0.5–1.0 1.0–2.0 3.0–4.0
5.0–6.0 7.0–8.0 0.0–0.5 0.5–1.0 1.0–2.0
Elphidium excavatum 0
Elphidium magellanicum 0
Elphidium margaritaceum 0
Elphidium williamsoni
Elphidium
Fissurina sp.
Epistominella vitrea spp.
Guttulina lactea
Haynesina germanica
Hyalinea balthica
Lagena substriata
Lamarckina haliotidea
0
0
0
0
0
0
0
0
0
Miliolinella subrotunda
Patellina corrugata
Pyrgo williamsoni
Quinqueloculina sp.
Stainforthia fusiformis
Triloculina tricarinata
Unidentified calcareous
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
2
0
0
0
0
0
1
0
1
0
0
0
3
0
0
0
0
0
0
1
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
15
0
0
0
0
0
2
0
0
0
0
1
34
0
0
0
0
0
0
16
0
0
1
0
0
0
1
0
0
0
0
5
0
0
0
0
0
1
2
0
0
0
0
0
1
0
0
0
0
3
0
0
0
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
1
3
0
0
0
1
0
0
0
0
0
0
0
3
0
0
0
0
0
0
5
0
0
0
0
0
1
0
0
0
0
0
4
2
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
8
0
0
2
0
0
0
0
0
0
0
0
10
0
0
1
0
0
2
4
0
0
2
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
1
0
0
0
0
0
0
0
0
1
0
0
0
0
0
19
0
0
0
2
1
0
0
2
0
0
0
0
2
0
0
0
0
238 276
485 921
273
1987
250 250 295
1083 1260 1623
263
1052
275
275
212
212
466
466
263
1083
330 277
1260 1623
129
129
168
168
365
365
Number counted
Number in whole sample
Number of tests per 10 cm
3 sediment
493
986
764
Number of tests g sediment
% Agglutinated 100
Fisher alpha
Information function
H ( S )
2.0
1.25
274
685
531
99
2.6
1.32
353 252
2376 378
925
95
4.0
147
89
2.9
1.31
1.20
328
1968
766
82
3.5
1.59
276
1840
716
89
3.7
1.60
256
2645
1029
96
2.9
1.44
Planktonic
Centropyxis aculeata
Centropyxis constricta
Difflugia globulus
Difflugia oblonga
Difflugia proteiformis
Difflugia urceolata
Phryganella nidulus
Pontigulasia compressa
Estimated year of deposition
3
7
3
1
8 8
2
1
2
1
9
6
5
1
6
4
6
20
11
2
12
1
7
2
2
1
15
3
376 714
99 99
3.9
3.4
1.65
1.23
10
17
3
2
8
5
773
98
4.0
1.24
3
11
1
421
96
3.8
1.15
1
1
9
2
490
92
3.8
1.04
3
2
6
632
98
2.5
0.82
100
2.1
0.85
4
12
7
1
409
5
4
213
97
3.4
1.06
164
96
2.8
0.83
1
5
181
91
3.2
0.89
3
421
87
3.2
1.29
9
6
490
92
3.0
2.09
1
4
6
632
99
2.3
0.69
4
12
3
100
98
2.9
1.27
2
1
9
5
1
1
130.2
142
97
3.6
1.30
1
6
2
90
4.0
1.54
3
12
4
2
Water depth (m)
Core
Depth (cm)
Ammodiscus gullmarensis
Ammoscalaria runiana
Ammoscalaria pseudospiralis
Ammotium sp.
Cribrostomoides jeffreysii
Cuneata arctica
Deuterammina rotaliformis
Eggerelloides medius
Eggerelloides scaber
Glomospira gordialis
Goesella waddensis
Haplphragmoides wilberti
Jadammina macrescens
Lepidotrochammina ochracea
Leptohalysis catella
Leptohalysis scottii
Miliammina fusca
Paratrochammina ( L .) spp.
Psammosphaera bowmani
Reophax fusiformis
Reophax sp.
Spiroplectammina biformis
Textularia earlandi
Textularia skagerrakensis
Trochammina inflata
Trochamminids— globular
Trochammina spp.
Webbinella hemisphaerica
Unidentified agglutinated
Ammonia beccarii
Biloculina inflata
Bolivinid
Buccella sp.
Bulimina sp.
Buliminella elegantissima
Cibicides lobatulus
Cornuspira involvens
Elphidium albiumbilicatum
Elphidium excavatum
13
0
38
0
0
0
9
7
4
0
0
8
0
0
0
0
1
0
0
0
0
19
0
0
0
E5
4–5
0
0
1
0
0
1
0
0 0
150 199
0
0
0
0
0
0
0
0
0
0
0
0
0
1
E5
6–7
0
0
0
6
0
62
0
0
0
0
5
2
0
0
7
0
0
0
0
0
0
0
0
0
44
0
0
3
8
0
34
0
0
0
2
5
0
0
0
21
0
0
0
0
0
0
0
0
0
19
0
0
0
0
172
2
0
0
0
0
0
0
0
0
93
E5
2–3
0
0
1
1
0
20
1
0
0
3
2
0
0
0
0
0
0
0
0
1
0
0
0
0
1
0
0
1
0
0
9
0
0
0
10
1
1
0
0
1
0
0
0
0
0
0
1
0
0
0
0
0
2
0
0
0
0
9
0
0
0
0
0
0
130 138
E1 E1 E1 E7 E7 E7 E7 E7 E7 E7 E7 E7 E7 E7 EL1 EL1 EL1 EL1 EL1
0.0–0.25 0.25–0.5 0.5–1.0
0.0–0.5 0.5–1.0 1.0–2.0 2.0–3.0 3.0–4.0 4.0–5.0 5.0–6.0
6.0–7.0 7.0–8.0 8.0–9.0 9.0–10.0 18–20 32–34 48–50 64–66 88–90
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
1
2
0
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
19
0
0
0
0
0
0
0
1
0
0
15
0
0
0
0
0
0
0
0
2
0
25
0
0
0
1
0
0
0
0
0
0
29
0
0
0
0
0
0
0
0
9
0
54
0
0
0
0
0
0
0
0
7
0
96
2
0
0
0
0
0
0
1
2
0
61
1
0
0
0
0
0
0
0
1
0
76
3
0
0
0
0
0
0
0
0
0
88
2
0
0
1
0
0
0
0
4
0
79
0
0
0
1
0
0
0
0
1
0
86
1
0
0
0
0
0
0
1
1
0
83
1
0
0
0
0
0
0
0
2
0
78
2
0
0
0
0
2
1
2
0
0
137
0
0
1
1
0
0
1
0
0
0
55
0
0
0
0
0
0
0
2
0
0
34
0
0
0
2
0
1
2
0
0
0
21
0
0
0
0
0
0
28
0
0
0
0
0
0
0
1
0
2
0
24
0
0
0
2
1
2
0
0
0
0
0
0
0
4
0
0
0
0
0
0
0
3
0
1
1
3
0
34
0
0
2
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
2
0
2
7
1
0
56
0
0
2
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
2
0
1
10
0
0
86
0
0
2
0
0
6
0
0
0
0
0
0
0
0
0
0
0
2
15
0
4
10
20
0
112
1
2
1
0
0
2
0
0
3
1
0
3
0
0
3
0
0
8
22
0
2
12
6
3
97
0
0
3
0
0
3
0
0
0
0
0
1
0
0
0
1
0
7
16
0
1
9
9
3
127
0
0
2
0
0
7
0
0
0
0
0
0
0
0
0
0
0
11
17
0
4
16
18
1
109
0
0
1
0
0
4
0
0
1
0
0
0
0
0
1
1
0
11
8
0
5
12
10
1
101
0
0
2
0
0
5
0
0
0
0
0
0
0
1
0
2
0
17
13
0
9
7
18
0
95
0
0
0
0
0
1
0
0
0
0
0
0
0
0
1
0
0
17
7
0
16
13
17
1
74
0
0
1
0
0
0
0
0
0
1
0
0
0
1
1
0
0
20
11
0
14
14
11
0
66
0
0
2
0
0
2
0
0
0
1
0
0
0
0
0
0
0
32
11
0
3
15
32
0
2
0
104
0
1
5
0
0
2
0
1
0
0
1
0
0
0
1
19
2
1
5
9
2
1
28
0
1
6
0
0
4
19
0
0
1
0
0
0
0
0
0
0
1
2
6
0
70
0
0
0
3
11
4
0
0
2
0
2
17
2
0
24
0
1
8
1
0
1
19
0
0
0
2
0
0
15
0
0
0
0
1
0
26
0
0
3
1
0
0
0
2
19
0
0
1
0
0
0
2
0
0
0
0
39
30 11 39
( continued on next page )
1
0
26
0
4
0
3
15
6
0
0
4
Table A2 ( continued )
Water depth (m)
Core
Depth (cm)
Elphidium magellanicum
Elphidium margaritaceum
Elphidium williamsoni
Elphidium sp.
Epistominella vitrea
Fissurina spp.
Guttulina lactea
Haynesina germanica
Hyalinea balthica
Lagena substriata
Lamarckina haliotidea
Miliolinella subrotunda
Patellina corrugata
Pyrgo williamsoni
Quinqueloculina sp.
Stainforthia fusiformis
Triloculina tricarinata
Unidentified calcareous
Number counted
Number in whole sample
Number of tests per
10 cm
3 sediment
Number of tests g sediment
% Agglutinated
Fisher alpha
Information function H ( S )
92
2.1
1.23
Planktonic
Centropyxis aculeata
Centropyxis constricta
Difflugia globulus
Difflugia oblonga
Difflugia proteiformis
Difflugia urceolata
Phryganella nidulus
Pontigulasia compressa
Estimated year of deposition
1
1
13
1
2
Species abundances as numbers.
93
E5
2–3
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
265
530
206
E5
4–5
0
0
0
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
253 331
380 331
148 129
E5
6–7
0
0
0
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
92
2.3
85
1.9
1.42
1.23
1
8
3
2
13
1
7
1
130 138
E1 E1 E1 E7 E7 E7 E7 E7 E7 E7 E7 E7 E7 E7 EL1 EL1 EL1 EL1 EL1
0.0–0.25 0.25–0.5 0.5–1.0
0.0–0.5 0.5–1.0 1.0–2.0 2.0–3.0 3.0–4.0 4.0–5.0 5.0–6.0
6.0–7.0 7.0–8.0 8.0–9.0 9.0–10.0 18–20 32–34 48–50 64–66 88–90
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
0
1
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
9
1
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
4
0
0
0
0
0
0
0
0
0
2
0
1
0
0
1
0
1
5
0
0
0
1
0
0
0
0
0
0
0
1
0
0
0
0
0
8
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
9
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
18
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
2
1
0
0
2
0
0
0
0
0
0
0
2
0
0
0
0
0
2
0
2
0
0
1
0
0
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
2
0
1
1
0
0
1
0
2
0
2
1
1
3
0
2
0
0
0
0
0
1
0
1
0
0
1
0
0
0
0
8
0
3
0
0
0
0
0
3
1
0
0
2
1
0
0
2
8
3
0
5
1
1
0
0
0
2
0
0
2
2
0
0
2
1
1
9
0
45
1
2
35
35
55
49
48
75
54
54
42
72
72
56
101
101
78
189
189
74
308
308
128
220
330
119
277
300
143
275
367
136
262
349
154
263
395
116
248
248
298
242
242
242
336
336
74
154
156
28
222
222
40
137
137
30
263
263
62
91
3.9
1.73
1
2
2
2
96
3.2
1.43
1
1
1
94
3.1
1.55
3
1
97
3.2
98
2.4
1.39
1.24
2
1
1998
1
2
4
89
2.9
1.56
3
2
13
3
3
2
32
10
6
1992
84
4.8
1.88
17
8
87
4
1.71
12
1
14
12
1
86
4.3
1.69
1
1
20
3
1
1988
89
4
1.71
1
14
3
5
84
3.5
1.79
20
10
2
3
3
83
3.2
84
4.8
1.71
1.88
3
19
2
5
2
10
1
10
3
79
3.8
1.92
13
3
16
4
1978
8
37
14
1
1958
76
92
5.3
1.7
38
86
9
2.27
8
28
47
69
5.3
2.23
11
27
26
1
28
2
17
1
1930 1898 1866
34
69
9.5
2.65
10
19
62
43
6.4
2.47
10
66
17
1818
References
Alve, E., 1995. Benthic foraminiferal distribution and recolonization of formerly anoxic environments in Drammensfjord, southern Norway. Marine Micropaleontology 25, 169–186.
Alve, E., 1999. Colonization of new habitats by benthic foraminifera: a review. Earth Science Review 46, 167–185.
Alve, E., 2000. Environmental stratigraphy. A case study reconstructing bottom water oxygen conditions in Frierfjord, Norway, over the past five centuries. In: Martin, R.E. (Ed.), Environmental
Micropaleontology. Kluwer Academic/Plenum Publishers, New
York, pp. 323–349.
Alve, E., 2003. A common opportunistic foraminiferal species as an indicator of rapidly changing conditions in a range of environments. Estuarine, Coastal and Shelf Science 57, 501–514.
Alve, E., Goldstein, S.T., 2002. Resting stage in benthic foraminifera propagules: a key feature for dispersal? Evidence from two shallow-water species. Journal of Micropalaeontology 21,
95–96.
Alve, E., Murray, J.W., 1999. Marginal marine environments of the
Skagerrak and Kattegat: a baseline study of living (stained) benthic foraminiferal ecology. Palaeogeography, Palaeoclimatology, Palaeoecology 146, 171–193.
Alve, E., Nagy, J., 1986. Estuarine foraminiferal distribution in
Sandebukta, a branch of the Oslo Fjord. Journal of Foraminiferal
Research 16, 261–284.
Ansell, A.D., 1974. Sedimentation of organic detritus in Lochs Etive and Creran, Argyll, Scotland. Marine Biology 27, 263–273.
Appleby, P.G., Oldfield, F., 1992. Applications of
210
Pb to sedimentation studies. In: Ivanovich, M., Harmon, R.S. (Eds.), Uranium-
Series Disequilibrium. Applications to Earth, Marine and
Environmental Sciences, second ed. Oxford Science, Oxford, pp.
731–778.
Berger, W.H., Fischer, K., Lai, C., Wu, G., 1988. Ocean carbon flux: global maps of primary production and export production. In:
Agegian, C.R. (Ed.), Biogeochemical Cycling and Fluxes between the Deep Euphotic Zone and other Oceanic Realms: NOAA
National Undersea Research Program. Research reports, vol. 88, pp. 131–176.
Bernhard, J.M., Sen Gupta, B.K., Borne, P.F., 1997. Benthic foraminiferal proxy to estimate dysoxic bottom-water oxygen concentrations: Santa Barbara Basin, U.S. Pacific continental margin. Journal of Foraminiferal Research 27, 301–310.
Blacknell, W.M., Ansell, A.D., 1975. Features of the reproductive cycle of an arctic bivalve from a Scottish sea loch. Publicazioni del
Stazione Zoologica di Napoli 39(Suppl.), 26–52.
Blais-Stevens, A., Patterson, R.T., 1998. Environmental indicator potential of foraminifera from Saanich Inlet, Vancouver Island,
British Columbia, Canada. Journal of Foraminiferal Research 28,
210–219.
Bray, J.R., Curtis, J.T., 1957. An ordination of the upland forest communities of Southern Wisconsin. Ecological Monographs 27, 325–349.
Buchanan, J.B., 1963. The bottom fauna communities and their sediment relationships off the coast of Northumberland. Oikos 14,
154–175.
Clarke, K.R., Gorley, R.N., 2001. PRIMER v5: User Manual/
Tutorial. PRIMER-E, Plymouth.
Clarke, K.R., Warwick, R.M., 1994. Changes in Marine Communities: an Approach to Statistical Analysis and Interpretation. Natural
Environment Research Council, 144 pp.
Colom, G., 1984. Foraminı´feros Ibe´ricos. Investigacio´n Pesquera 38,
1–245.
Craib, J.S., 1965. A sampler for taking short undisturbed marine cores.
Journal du Conseil Permanent International pour l’Exploration de la Mer 30, 34–39.
J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697 695
Cundy, A.B., Croudace, I.W., 1996. Sediment accretion and recent sealevel rise in the Solent, southern England: inferences from radiometric and geochemical studies. Estuarine, Coastal and Shelf
Science 43, 449–467.
Edwards, A., Edelsten, D.J., 1977. Deep water renewal of Loch Etive: a three basin Scottish fjord. Estuarine, Coastal and Marine Science
5, 575–593.
Edwards, A., Grantham, B.E., 1986. Inorganic nutrient regeneration in Loch Etive bottom water. In: Skreslet, S. (Ed.), The Role of
Freshwater Outflow in Coastal Marine Ecosystems. Springer-
Verlag, Berlin, pp. 195–204.
Edwards, A., Sharples, F., 1986. Scottish Sea Lochs: a Catalogue.
Scottish Marine Biological Association/Nature Conservancy
Council, Oban, 110 pp.
Edwards, P.G., 1982. Ecology and distribution of selected foraminiferal species in the North Minch Channel, northwest Scotland. In:
Banner, F.T., Lord, A.R. (Eds.), Aspects of Micropalaeontology.
Allen and Unwin, London, pp. 111–141.
Ellison, R.L., 1995. Paleolimnological analysis of Ullswater using testate amoebae. Journal of Paleolimnology 13, 51–63.
Ernst, S.R., Duijnstee, I.A.P., Jannink, N.T., van der Zwaan, G.J.,
2000. An experimental mesocosm study of microhabitat preferences and mobility in benthic foraminifera: preliminary results. In:
Hart, M., Kaminski, M.A., Smart, C. (Eds.), Proceedings of the
Fifth International Workshop on Agglutinated Foraminifera,
Plymouth England, September 1997, Grzybowski Foundation
Special Publication no. 7, 101–104.
Fisher, R.A., Corbet, A.S., Williams, C.B., 1943. The relationship between the number of species and the number of individuals in a random sample of an animal population. Journal of Animal
Ecology 12, 42–58.
Flynn, W.W., 1968. Determination of low levels of polonium-210 in environmental materials. Analytica Chimica Acta 43, 221–227.
Fontanier, C., Jorissen, F.J., Licari, L., Alexandre, A., Anschutz, P.,
Carbonel, P., 2002. Live benthic foraminiferal faunas from the Bay of Biscay: faunal density, composition, and microhabitats. Deep-
Sea Research I 49, 751–785.
Gage, J., 1972. A preliminary survey of the benthic macrofauna and sediments in Lochs Etive and Creran, sea-lochs along the west coast of Scotland. Journal of the Marine Biological Association of the United Kingdom 52, 237–276.
Gustafsson, M., Nordberg, K., 1999. Benthic foraminifera and their response to hydrography, periodic hypoxic conditions and primary production in the Koljo¨ Fjord on the Swedish west coast. Journal of Sea Research 41, 163–178.
Gustafsson, M., Nordberg, K., 2000. Living (stained) benthic foraminifera and their response to the seasonal hydrographic cycle, periodic hypoxia and to primary production in Havstens
Fjord on the Swedish west coast. Estuarine, Coastal and Shelf
Science 51, 743–761.
Gustafsson, M., Nordberg, K., 2001. Living (stained) benthic foraminiferal response to primary production and hydrography in the deepest part of the Gullmar Fjord, Swedish West Coast, with comparisons to Ho¨glund’s 1927 material. Journal of Foraminiferal
Research 31, 2–11.
Hannah, F., Rogerson, A., 1997. The temporal and spatial distribution of foraminiferan in marine benthic sediments of the Clyde
Sea area, Scotland. Estuarine, Coastal and Shelf Science 44, 377–383.
Heron-Allen, E., Earland, A., 1916. Foraminifera of the west coast of
Scotland dredged by Prof. W.R. Herdman FRS, on the cruise of the SY Runa, July–Sept. 1913. Being a contribution to Spolia
Runiana . Transactions of the Linnean Society London Series 2
(Zoology) 11, 197–300.
Hiscock, K. (Ed.), 1998. Marine Nature Conservation Review. Benthic
Marine Ecosystems of Great Britain and the North-East Atlantic.
Joint Nature Conservation Committee, Peterborough, pp. 360–364.
696 J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697
Howe, J.A., Overnell, J., Inall, M.E., Wilby, A.D., 2001. A side-scan sonar image of a glacially over-deepened sea loch, upper Loch
Etive, Argyll, Scotland. Scottish Journal of Geology 37, 3–10.
Howe, J.A., Shimmield, T., Austin, W.E.N., Longvar, O., 2002. Postglacial depositional environments in a mid-high latitude glacially overdeepened sea loch, inner Loch Etive, western Scotland. Marine
Geology 185, 417–433.
Jones, K., Black, K., 2001. Scottish sea lochs—keys to past and present environmental change. The Scottish Association for Marine
Science Newsletter 23, 5–6.
Jorrisen, F.J., De Stigter, H.C., Widmark, J.G.V., 1995. A conceptual model explaining benthic foraminiferal microhabitats. Marine
Micropaleontology 26, 3–15.
Le Campion, J., 1970. Contribution a` l’e´tude des foraminife`res du
Bassin d’Arcachon et du proche oce´an. Bulletin de l’Institute
Ge´ologique du Bassin Aquitaine 8, 3–98.
Lutze, G.F., 1980. Depth distribution of benthic foraminifera on the continental margin off NW Africa.
Ô Meteor Õ Forschungs-Ergebnisse C6, 21–40.
Lutze, G.F., Mackensen, A., Wefer, G., 1983. Foraminiferen der Kieler
Bucht: 2. Salinita¨tsanspru¨che von Eggerella scabra (Williamson).
Meyniana 35, 55–65.
Mackensen, A., Sejrup, H.P., Jansen, E., 1985. The distribution of living foraminifera on the continental slope and rise off southwest
Norway. Marine Micropaleontology 9, 275–306.
Malcolm, S.J., Price, N.B., 1984. The behaviour of iodine and bromine in estuarine surface sediments. Marine Chemistry 15, 263–271.
McIntyre, A.D., 1961. Quantitative differences in the fauna of boreal mud associations. Journal of the Marine Biological Association of the United Kingdom 41, 599–616.
Millar, R.H., 1988. The occurrence of the ascidian Didemnum albidum
(Verrill, 1871) on the west coast of Scotland. Sarsia 73, 147–148.
Morse, J.W., Arvidson, R.S., 2002. The dissolution kinetics of major sedimentary carbonate minerals. Earth Science Reviews 58,
85–119.
Murray, J.W., 1965. On the foraminiferids of the Plymouth region.
Journal of the Marine Biological Association of the United
Kingdom 45, 481–505.
Murray, J.W., 1967. An ecological study of the Thecamoebina of Christchurch Harbour, England. Journal of Natural History 1, 377–387.
Murray, J.W., 1970. Foraminifers of the Western approaches to the
English Channel. Micropaleontology 16, 471–485.
Murray, J.W., 1979. Recent benthic foraminiferids of the Celtic Sea.
Journal of Foraminiferal Research 9, 193–209.
Murray, J.W., 1985. Recent foraminifera from the North Sea (Forties and Ekofisk areas) and the continental shelf west of Scotland.
Journal of Micropalaeontology 4, 117–125.
Murray, J.W., 1991. Ecology and Palaeoecology of Benthic Foraminifera. Longman, Harlow, 397 pp.
Murray, J.W., 1992. Distribution and population dynamics of benthic foraminifera from the southern North Sea. Journal of Foraminiferal Research 22, 114–128.
Murray, J.W., 2003a. An illustrated guide to the benthic foraminifera of the Hebridean shelf, west of Scotland, with notes on their mode of life. Palaeontologia Electronica, 5, issue 2, art. 1: 31 pp., 1.4 Mb.
http://www-odp.tamu.edu/paleo/2002_2/guide/issue2_02.htm.
Murray, J.W., 2003b. Foraminiferal assemblage formation in depositional sinks on the continental shelf margin west of Scotland.
Journal of Foraminiferal Research 33, 101–121.
Murray, J.W., Alve, E., 1999a. Natural dissolution of shallow water benthic foraminifera: taphonomic effects on the palaeoecological record. Palaeogeography, Palaeoclimatology, Palaeoecology 146,
195–209.
Murray, J.W., Alve, E., 1999b. Taphonomic experiments on marginal marine foraminiferal assemblages: how much ecological information is preserved? Palaeogeography, Palaeoclimatology, Palaeoecology 149, 183–197.
Murray, J.W., Alve, E., 2000. Do calcareous dominated shelf foraminiferal assemblages leave worthwhile ecological information after their dissolution? In: Hart, M., Kaminski, M.A., Smart, C.
(Eds.), Proceedings of the Fifth International Workshop on Agglutinated Foraminifera, Plymouth England, September 1997,
Grzybowski Foundation Special Publication no. 7, 311–331.
Overnell, J., 2002. Manganese and iron profiles during early diagenesis in Loch Etive, Scotland. Application of two diagenetic models.
Estuarine, Coastal and Shelf Science 54, 33–44.
Overnell, L., Edwards, A., Grantham, B.E., Harvey, S.M., Jones, K.J.,
Leftley, J.W., Smallman, D.J., 1995. Sediment–water column coupling and the fate of the spring phytoplankton bloom in
Loch Linnhe, a Scottish sea loch—sediment processes and sediment–water fluxes. Estuarine, Coastal and Shelf Science 41,
1–19.
Overnell, J., Harvey, S.M., Parkes, R.J., 1996. A biogeochemical comparison of sea loch sediments. Manganese and iron contents, sulphate reduction and oxygen uptakes. Oceanologica Acta 19,
41–55.
Patterson, R.T., Guilbault, J.P., Thomson, R.E., 2000. Oxygen level control on foraminiferal distribution in Effingham Inlet, Vancouver
Island, British Columbia, Canada. Journal of Foraminiferal
Research 30, 321–335.
Pearson, T.H., 1970. The benthic ecology of Loch Linnhe and Loch
Eil, a sea-loch system on the west coast of Scotland. I. The physical environment and distribution of the macrofauna. Journal of
Experimental Marine Biology and Ecology 5, 1–34.
Qvale, G., Markussen, B., Thiede, J., 1984. Benthic foraminifers in fjords: response to water masses. Norsk Geologisk Tidsskrift 64,
235–249.
Richter, G., 1967. Faziesbereiche rezenter un subrezenter Wattensedimente nach ihren Foraminiferen-Gemeinschaften. Senckenbergiana Lethaea 48, 291–335.
Ridgeway, I.M., Price, N.B., 1987. Geochemical associations and postdepositional mobility of heavy metals in coastal sediments: Loch
Etive, Scotland. Marine Chemistry 21, 229–248.
Schafer, C.T., Winter, G.V., Scott, D.B., Pocklington, P., Cole, F.E.,
Honig, C., 1995. Survey of living foraminifera and polychaete populations at some Canadian aquaculture sites: potential for impact mapping and monitoring. Journal of Foraminiferal Research 25, 236–259.
Schro¨der, C.J., Scott, D.B., Medioli, F.S., Bernstein, B.B., Hessler, R.R.,
1988. Larger agglutinated foraminifera: comparison of assemblages from central North Pacific and western North Atlantic (Nares abyssal plain). Journal of Foraminiferal Research 18,
25–41.
Scott, D.B., Medioli, F.S., Schafer, C.T., 2001. Monitoring in Coastal
Environments using Foraminifera and Thecamoebian Indicators.
Cambridge University Press, Cambridge, 177 pp.
Solo´rzano, L., 1977. Chemical investigations of Loch Etive,
Scotland. III. Particulate organic carbon and particulate organic nitrogen. Journal of Experimental Marine Biology and Ecology 29,
81–89.
Solo´rzano, L., Ehrlich, B., 1977a. Chemical investigations of Loch
Etive, Scotland. I. Inorganic nutrients and pigments. Journal of
Experimental Marine Biology and Ecology 29, 45–64.
Solo´rzano, L., Ehrlich, B., 1977b. Chemical investigations of Loch
Etive, Scotland. II. Dissolved organic compounds. Journal of
Experimental Marine Biology and Ecology 29, 65–79.
Southward, E.C., 1986. Gill symbionts in thyasirids and other bivalve molluscs. Journal of the Marine Biological Association of the
United Kingdom 66, 889–914.
Syvitski, J.P.M., Burrell, D.C., Skei, J., 1987. Fjords, Processes and
Products. Springer-Verlag, New York, 379 pp.
Ward, B.L., Barrett, P.J., Vella, P., 1986. Distribution and ecology of benthic foraminifera in McMurdo Sound, Antarctica. Palaeogeography, Palaeoclimatology, Palaeoecology 58, 139–153.
J.W. Murray et al. / Estuarine, Coastal and Shelf Science 58 (2003) 677–697
Williams, T.M., MacKenzie, A.B., Scott, R.D., Peice, N.B., Ridgeway, I.M., 1988. Radionuclide distributions in the surface sediments of Loch Etive. In: Guary, J.C., Guegueniat, P.,
Penkreath, R.Y. (Eds.), International Symposium on Radioactivity and Oceanography: Radionuclides—a Tool for Oceanography. Cherbourg, France, pp. 341–350.
697
Williamson, W.C., 1858. On the Recent Foraminifera of Great Britain.
Royal Society, London, 107 pp.
Wood, B.J.B., Tett, P.B., Edwards, A., 1973. An introduction to the phytoplankton, primary production and relevant hydrography of Loch Etive. Journal of Ecology 61,
569–585.
