Multivariate analysis applied to total and living fauna: seasonal ecology of recent benthic Ostracoda off the North Cádiz Gulf coast (southwestern Spain)

ELSEVIER

Marine Micropaleontology

3 1 (1997) 183-203

Multivariate analysis applied to total and living fauna: seasonal ecology of recent benthic Ostracoda off the North C6diz Gulf coast (southwestern Spain) F. Ruiz a,*, M.L. Gonzfilez-Regalado

a, J.M. Mufioz b

u Departamento de Geologia, Universidad de Huelva, 21819 Pales de la Frontera, Huelva, Spain h Departamento de Estadistica e Investigacidn Operativa, Universidad de Sevilla, 41071 Sevilla, Spain Received 7 March

1996; accepted

24 October

1996

Abstract Q-mode principal component analyses of ostracode percentages from 55 samples collected in summer and winter in the Huelva littoral zone (southwestern Spain) delimited four total associations and five living associations. Lkocythereis oblonga, Palmoconcha guttata, Pontocythere elongata and Loxoconcha elliptica associations are represented both in the total and in the biocoenosis distributions. An additional biocoenosis association is characterized by Neocytherideis subulata and Callistocythere rastrifera, two minor species in the total distribution. Salinity differentiates the euryhaline Loxoconcha elliptica association (29-36%0) and four marine associations (>34%0). Under marine conditions, grain size is the main factor delimiting the ostracod fauna, with the Urocythereis oblonga association living in coarser sandy sediments and the Palmoconcha guttata association being widely distributed in silty sands. The Neocytherideis subulata-Callistocythere rastrifera association prefer very fine sandy sediments, whereas the Pontocythere elongata association inhabits all types of substrate. In the estuary of the Tinto and Odiel rivers, one of the most polluted zones of Europe, study of the seasonal distribution of ostracodes and comparison with previous reports indicate some recuperation in this degraded system. Such species as Loxoconcha elliptica, Leptocythere tenera, or Cytheroisfischeri, common in other Atlantic estuaries, are found. In some channel areas, however, the combined effects of metal pollution, medium-grain sand, dredging and strong bottom drift may cause the disappearance of living specimens in some sectors, both in summer and winter. Keywords: Ostracoda; littoral environment; ecology; pollution; Cadiz Gulf

1. Introduction In the last three decades, numerous papers have dealt with recent ostracodes in shallow-marine environments. In most instances, the total fauna was * Corresponding

author.

Fax:

+34-959-530175.

E-mail:

[email protected]

0377-8398/97/$17.00 0 1997 Elsevier Science B.V. All rights reserved. PII SO377-8398(96)00060-6

examined (Llano, 1981; Hamoudi, 1988; Bonaduce et al., 1988; Lachenal, 1989), and few investigations have distinguished between biocoenosis and thanatocoenosis (Kilenyi, 1969; Whatley and Wall, 1975; Barker, 1983; Pascual, 1990). Only on very rare ocassions are associations defined by statistical methods (Breman, 1975; Dingle and Giraudeau, 1993). As a result, paleoecologists cannot determine

184

E Ruiz et al. /Marine

Micropalmntolo~~

which co-occurring fossil ostracodes lived together (Kaesler and Foster, 1990) The aim of this paper is to study seasonal changes of live and total assemblages in the Huelva littoral zone on the Atlantic coast of southwestern Spain. Variations are related to salinity, temperature, depth, grain size, metal pollution and sediment transport. 2. The Huelva littoral zone

31 (1997) lb’.?-203

2.2.2. Temperature In July-August, temperature increases from Isla Cristina (21°C) to Matalascafias (23-24“(Z), in shallow waters (less than 10 m deep). Temperature decreases about 1°C in the outermost zone. In the estuary, water temperature is higher near the surface (26°C) than in the bottom layer (24°C). During January, the mean monthly minimum is 13°C from Isla Cristina to Mazagon and 13.5-14.5”C in the Tort-e de1 Oro-Matalascafias zone.

2.1. Hydrographic and hydrodynamic features The regional oceanography of the Huelva littoral zone is influenced by the North Atlantic geostrophic current, which flows to the east within this study zone. Littoral drift currents transport sand-size sediments from the Portugal coast to the Spanish nearshore zone [( 180-300) x lo3 m3/yr, according to C.E.E.P.Y.C. (1979) and Cuena (1991)]. Tidal regime, wave action and fluvial discharge control the hydrodynamic processes. The tidal regime is mesotidal (mean range 2.15 m; Bon-ego et al., 1993). Dominant waves associated with Atlantic circulation come from the southwest. Fluvial sediment and runoff from the nearby land are important during December and January when rainfall is highest. Medium-grade, saltation-transported sand dominates the sediment input of the Guadiana, Tinto and Odiel rivers (Borrego, 1992). Sediment supply by the Piedras river is restricted due to a dam upstream. 2.2. Water: physical and chemical properties Salinity, temperature, dissolved oxygen and pH data sets were obtained from surveys by the Andalucia Board (1993) and the Spanish Oceanographical Institute (1992). 2.2.1. Salinity During the summer, salinity is nearly constant at 36%0, even in the Tinto-Odiel river estuary, owing to the very strong tidal effect. In winter, salinity decreases somewhat (34-35%0) near the river mouths (Fig. 1). Partial stratification occurs at the confluence of the Tinto and Odiel rivers, the surface layer being less saline (12-14%0) than the bottom layer (29-32%0).

2.2.3. Dissolved oxygen During the summer, the average oxygen concentration is approximately 6.8 mg/l, with a maximum (8 mg/l) off Punta Umbrfa and a minimum (4 mg/l) in the inner part of the estuary. This value is related to high degradation of organic matter, mainly from diatoms. In December-January, values range from 6 to 9 mg/l, the highest near Matalascaiias and the lowest in the area of influence of the Tinto and Odiel rivers. 2.2.4. pH In both seasons, shallow waters of the Northern Cadiz Gulf have a pH range between 8.05 and 8.3. This decreases at the inner zone of the Tinto-Odiel estuary (7.5-7.8 in winter and 6.6-7.2 in summer), with the lower range values at high tides. 2.3. Substrate 2.3.1. Grain size

Fine and very fine sands are the most abundant sediments on the Huelva coast. Coarser grain sizes are dominant in samples from down to 11 m water depth from La Antilla to Punta Umbrfa and near the mouths of the Guadiana, Tinto, and Odiel rivers. Clay and silt deposits were found at the junction of the Tinto and Odiel rivers (Fig. 1). The highest content of bioclastic material, mainly Mollusca, is associated with high percentages of medium-grained sands in the inner part of the Huelva spit and the deeper samples (> 10 m) in front of Punta de1 Gato. The Huelva spit traps medium sand. The percentages of this grain size are very low southeast of Mazagon (Table 1). This reduction in the sedimentary flux and the wave refraction associated with the spit’s action may be related to periodic erosional instability of the Mazagon beach (Borrego, 1992).

E Ruiz et al. /Marine

Table 1 Grain-size

distributions

SAMPLES

(in wt.%) and metal concentrations

GR

VCS

CS

A-l A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 A-10 A-11 A-12 A-13 A-14 A-15 A-16 A-17 A-18 A-19

0 0 0 0 1 5 1 0 2 59 0 23 0 10 4 3 3 1 43

0 1 1 0 0 3 5 0 5 8 0 5 0 2 6 3 1 0 9

3 5 7 3 1 2 37 1 12 8 2 5 0 4 36 26 3 1 16

A-20 A-21 A-22 A-23 A-24

10 1 0 2 0

7 1 11 1 0

12 5

A-25 A-26 A-27 A-28 A-29

4 0 3 0 2

3 0 1 1 1

MS 35 44 59 86 2 4 41 3 41 6 6 5 1:

FS

Micropaleontology

185

1113-203

(in ppm) of samples VFS

M+C 0 0 0 0 11 13 0 3 6 1 3 5 2 2 0 0 1 7 0

I

I

55 45 30 11 6 8 14 27 27 9 27 15 34 12 4 8 55 45 3

6 6 3 0 80 64 2 66 9 9 62 42 64 59 1 2 24 43 0

20 9 31 48

7 13 11 57 888 42 8 41 1

I

4 2

31 16 11 13 8

3 0 2 1 3

10 1 18 51 6

35 37 43 38 48

36 60 30 9 40

: i

49 58 14 3 29

31 (1997)

10 1 2 0 1

1

Cr

Ni

Cu

Cd

Pb

As

Hg

12 13

3 4

4 3


4 <2

8 7

0,014 41 0,025 33

40 20 69,5 24 52 26 9

<1 1 <1 <1 < 1 cl
32 24 42 30 29 6 7 12 135

34 17 30 24 27 10 12 19 110

0,262 0,550 0,443 0,230 031 0,086 0,021 0.831 1.270

< 10

< 10

) q 5

I 16 1 3 ; 1

6 cl 1

’

&

s’

)

Zn

154 135 245 178 252 75 62 61 611 1

40 26 27 36

6 5 3 5

60 51 17 53

< < < <

1 1 1 1

50 43 17 53

48 28 25 32

0?253 356 039 207 0,030 153 0,238 112

Cr

Ni

Cu

Cd

Pb

As

Hg

2

3 72


2 54

7 33

0,009 31

I SAMPLES

GR

VCS

CS

MS

FS

VFS

M+C

B-l B-2 B-3 B-4 B-5 B-6 B-7 B-8 B-9 B-10 B-11 B-12 B-13

1 7 7 1 29 3 0 1 0 0 3 16 1

1 4 19 1 13 8 0 0 0 0 2 16 1

18 5 44 1 25 40 0 1 2 0 12 20 2

77 8 24 4 29 41 3 s”

0 30 1 46 1 1 43 36 58 24 17 1 2

0 41

5 52 40 67

3 6 4 45 3 8 51 58 31 71 14 6 25

B-15 B-14 B-16 B-17 B-18 B-19 B-20 B-21 B-22 B-23 B-24 B-25 B-26

0 8 0 1 1 3 3 1 1 1 0 0 0

5 0 0 1 1 2 2 1 2 0 0 0 0

22 7 0 2 3 3 1 2 6 1 0 0 1

34 60 3 16 16 11 5 5 63 4 0 2 6

30 4 26 25 38 21 38 19 27 14 9 12 21

1: 9 52 35 57 19 71 1 79 44 83 70

1: 61

i

; 6 1 1621

Zn

2 0 2 2 1 1 0 2

3

47 2 2

I GR = gravel; VCS = very coarse sand; CS = coarse sand: MS = medium sand: FS = fine sand; VFS = very fine sand; M + C = mud and clay. Boxes highlight high levels of particular metals.

Bottom temperature

Fig. 1. Map showing

the extent of the littoral zone studied, sediment grain size and the main physical-chemical

2.3.2. Metal concentrations of the sediment High metal pollution (Cu, Zn, Pb, Cd, Hg and others) characterizes the Tinto-Odiel estuary (Table 1). Sources of this pollution include: (1) the large amount of suspended material carried from the northem part of the Province of Huelva, one of the most important mining areas in Western Europe, with Cu, Zn, Pb, Au, and Ag ore bodies; (2) since 1960, wastes with high levels of heavy metals derived from vast industrial concentrations (e.g., alkalis, fertilizers and metallurgy) on the estuarine border; and (3) urban effluents. Since 1985, this zone has been subject to a Corrective Plan for Control of Industrial Waste Disposal.

0

Mediumsand

0

Finesands

.

Veny fme sina

water features.

The combined actions of littoral drift currents, fluvial discharge during the wetter months, and tidal reflux causes moderate pollution in samples from shallow waters from Mazagon to Matalascafias. This contamination appeared less significant at greater depths. Analyses from Isla Cristina to Punta Umbrfa revealed low concentrations of metals. Only Cr, Ni and Hg are highly concentrated in muddy sediments near Isla Cristina (> 10 m depth). The source of this contamination is unknown because neither the neighbouring area nor the Guadiana and Carrera rivers are polluted (Morales, 1993).

F: Kuiz et al. /Marine Micropaleontology 31 (1997) 183-203

3. Material and methods Ostracodes were examined from samples collected at 26 stations from August 16 to August 20, 1992, and 29 stations from January 20 to January 30, 1993 (Fig. 1). Five hundred to 1000 cm3 of surface sediment were obtained with a modified Van Veen grab. Samples were stained using a mixture of Rose-Bengal (1 g/l) and alcohol, wet sieved (500, 250 and 125 pm mesh), and dried in an oven at 70°C. If possible, 100 individuals of each fraction were picked from each sample (200 g net). The count was then recalculated to yield the total number of ostracodes in the whole sample (cf. Whatley and Watson, 1990). Ostracodes were considered to be alive on meticulous observation of remains of the stained soft body or traces of cuticle in the valves (cf. Kilenyi, 1969). Sometimes, this procedure includes the breaking of the valves. The next step was to analyse the living and total associations based on percentages computed for the fifteen to twenty most abundant species in each season, which include almost 90% of the total fauna (Tables 1 and 2). The remaining species rarely exceed 1 to 2% of the total fauna, have a much more sporadic distribution (~30% of samples in most cases) and, in consequence, are not suitable for statistical calculation. A Q-mode principal component analysis was computed using the subprogram ‘Factor’ of the Statistical Package for the Social Sciences (SPSS) (cf. Machain-Castillo et al., 1990). First, the data matrix was normalized by rows and the major product moment (correlation coefficient), corresponding to the calculation of the cos @ similarity measure, was computed. Second, its principal components were computed (Reyment and Joreskog, 1993). Ten factors were studied in a preliminary stage, which explained about 90% of the total variance of both living and total populations. Factor loadings of up to 0.4 were considered to be significative from statistical analysis. The first four factors explained 50 to 70% of the variance in the four analysis and showed the primary association pattern (Appendix A). The six remaining ones are controlled by a single species or show no obvious control. These uninformative factors were not considered in the following analysis.

187

The associations defined by Q-mode principal component analysis include: (1) one or two dominant species, widely represented in the samples of the Huelva littoral and with high percentages (up to 20%) in some zones; (2) additional common species, closely related with the dominant species in the Factor l-Factor 2 diagram, with a similar Factor 3 or Factor 4 and positive correlation coefficients (up to 0.5); and 3) occasional species, which include species more separate from the dominant species or some additional species in the Factor l-Factor 2 diagram. Their correlation coefficients with both the dominant species or some additional species may be positive but no significative (Appendices B and C). 4. Results

4.1. Total population The total ostracode fauna comprised 75 species belonging to 43 genera (Tables 2 and 3). The dominant species are Urocythereis oblonga, Palmoconcha guttata, Pontocythere elongata, Cytheretta adriatica, Carinocythereis whitei, Loxoconcha rhomboidea and Loxoconcha elliptica (only in estuarine samples). Diversity is low to moderate (15-35 species/sample), except in the innermost part of the Tinto-Odiel estuary (< 10 species). The number of individuals may fluctuate widely from sample to sample. The highest concentrations of forms (>5000 valves/200 g), occurring mostly in t7 m water depth, are recorded off La Antilla, Punta de1 Gato and Matalascafias. Both in summer and winter samplings, four ostracode associations were recognized in the principal component analysis (Appendix A): 4.1.1. Urocythereis oblonga association Occasional species (summer): Aurila convexa. Urocythereis oblonga is the most cosmopolitan species in the area studied, with percentage abundances up to 50% in numerous samples from Isla Cristina to Torre de1 Oro (depth range: 3-18 m). Grain-size distribution changes from medium to very fine sands. Aurila convexa, a rare species, was found to exceed 3% of the total fauna in the shallower fine and very fine sands.

Table 2 Percentages

II

I

of total and living ostracode

(

species sampled

in the summer,

1992 (rounded

to the nearest whole percentage)

/

Table 3 Percentages

in

1

of total and living ostracode

21

131

l

I

,I

I I 111

I

species sampled

11

I I

I

in the winter, 1993 (rounded

to the nearest whole percentage)

1

111

1

EEzfl 1

Z:PG+CW+CR+BB+CN+CP+LT 3:PE+CA+SI+PT+SS+NS

Z:PG+CW+CR+BB+CN+CP 3:PE+CA+SI+PT+SS+NS

Fig. 2. Seasonal

distribution

of total associations

in the Huelva littoral zone. For abbreviations

4.1.2. Palmoconcha guttata association Additional species: Carinocythereis whitei and Cytheridea neapolitana. Occasional species: Costa punctatissima, Basslerites berchoni, Callistocythere rastrifera and Leptocythere tenera. This association is dominant in silty sands from depths of lo-18 m, mainly off Isla Cristina and from Mazagon to Matalascafias (Fig. 2). 4.1.3. Pontocythere elongata association Additional species: Cytheretta adriatica, Semicytherura incongruens and Semicytherura sulcata. Occasional species: Neocytherideis subulata and Palmoconcha turbida. Higher percentages (30-60%)

occur near Tinto-Odiel ther grain sands) nor distribution

of species. see Appendix

the Piedras river river estuary. In size (well-sorted water depth have of these species.

A.

mouth and east of the the Huelva littoral, neimedium sands to silty much influence on the

4.1.4. Loxoconcha elliptica association No additional or occasional species were recognized in the statistical analysis. This form comprises 60-97% of the innermost fauna of the Tinto-Odiel river estuary located in sandy muds. In the coarser sediments of the estuary mouth, L. elliptica is replaced by V. oblonga.

E Ruiz et al. /Marine

4.2. Biocoenosis:

Micropaleontology

seasonal changes

Thirty-three species were found with living specimens (92 in August and 30 in January). In both samplings, Urocythereis oblonga, Palmoconcha guttata, Callistocythere rastrifera, Cytheretta adriatica, Pontocythere elongata, Neocytherideis subulata and Loxoconcha elliptica (only in the TintoOdiel river estuary) dominate the biocoenosis. Species diversity is low, especially in the Tinto-Odiel river estuary and south of lsla Cristina. No living ostracodes inhabit some inner zones of the Huelva spit (Tables 1 and 2). Biocoenosis associations are defined less rigorously than the total associations because of the low abundance of living individuals in most samples. Five associations may be recognized (Fig. 3), with subdivisions according to seasonal changes: 4.2.1. Urocythereis oblonga association Without additional or occasional species. Significant populations have been found between Isla Cristina and Torre de1 Oro wherever the sediment is represented by medium sand. Both in summer and winter samplings the greatest number of live specimens was collected in the deeper samples (lo-16 m) from Isla Cristina to Mazagon and near the end of the Huelva spit (Fig. 4A). Some seasonal changes may be observed in the adult: juvenile ratio. Both in summer and winter, adult females are predominant in the shallower samples. In the deeper zone (> 10 m), females coexist with the older instars (A-l and A-2) in summer, whereas younger instars (A-3 to A-5) are dominant in winter.

31 (1997)

183-203

191

4.2.3. Pontocythere elongata-Cytheretta adriatica association In the summer, both species were found as living in medium to very fine sands. P. elongata is frequent in all samples (Fig. 4E), whereas Cytheretta adriatica is more restricted to samples from Punta Umbrfa to Matalascafias (Fig. 4D). There is no definite relationship between depth and abundance. In January, additional species (Aurila convexa, Semicytherura incongruens and Palmoconcha turbida) and occasional species (Semicytherura sulcata) species are clearly recognized in this association, mainly from Mazagdn to Matalascafias. 4.2.4. Loxoconcha elliptica association In the summer, living specimens were concentrated in the very polluted muds of the innermost part of the Tinto-Odiel estuary, whereas the end of the Huelva spit shows the highest number of live individuals in the winter (Fig. 4F). In winter, this species occurs with some individuals of Leptocythere tenera and CytheroisJischeri. 4.2.5. Neocytherideis subulata-Callistocythere rastrifera association These small species have numerous living individuals occurring together in La Antilla-Punta Umbrfa and Mazagon-Matalascafias areas. Callistocythere rastrifera inhabit between 5 and 18 m (Fig. 4G). N. subulata live in shallow waters (~8 m) in winter, whereas in summer this species may migrate toward deeper zones (10-l 5 m), mainly near the Matalascaiias beach (Fig. 4H). 5. Discussion

4.2.2. Palmoconcha guttata association Additional species: Carinocythereis whitei, Cytheridea neapolitana and Costa punctatissima. Occasional species: Basslerites berchoni. In summer these species (e.g., Fig. 4B: Carinocythereis whitei) have high percentages in sandy silts and very fine sands near Isla Cristina and from Torre de1 Oro to Matalascafias from 11 to 16 m. In winter, P. guttata may migrate toward shallower waters (4-6 m depth), near El Asperillo and the mouth of the Piedras river (Fig. 4C).

5.1. Biocoenosis

vs. total assemblages

Some outstanding discrepancies occur between living and total percentages of species and assemblages. The Urocythereis oblonga association, the most important asseociation in the total analysis from Isla Cristina to Mazagon, is more restricted in the biocoenosis. In the outer zone of the Piedras river spit, its population comprises more than 35% adults and 60-65% young instars from A-l to A-6, almost all dead. Neocytherideis subulata and Callistocythere rastrifera, two secondary species in total

E Ruiz et al. /Marine

192

Micropaleontology

31 (1997) 183-203

LEGEND

I

3:PE+CA

1:uo

LEGEND

Z:PG+CW+CN+CP+BB 3:PE+CA+AC+SI+fT+SS

17 ’ N

Fig. 3. Seasonal

WINTER distribution

of the biocoenosis

associations

in the Huelva littoral zone. For abbreviations

percentages, comprise up to 50% of the living forms. Another significant difference was recorded in the shallower sediments of Mazagon-Matalascafias area. The Pontocythere elongata-Cytheretta adriatica association, widely distributed and dominant in both seasonal total percentages, is poorly represented in living specimens. This association also contain numerous instars (A-3 to A-6) of Urocythereis oblonga, a typical population age structure of low-energy thanatocoenosis (Brouwers, 1988). Living specimens of Neocytherideis subulata and Callistocythere rastrifera again occur in great abundance, both in summer and winter samplings.

of species. see Appendix

A

For both the Palmoconcha guttata and the Loxoconcha elliptica associations, there is a high fidelity between total and biocoenoses percentages, in marine samples down to 10 m depth water and in the TintoOdiel estuary, respectively. 5.2. Ostracodes

and environmental

parameters

Salinity separates the marine associations (U. oblonga, P elongata, P. guttata and Neocytherideis subu&a) from an euryhaline association (Loxoconcha elliptica). The former are restricted to 34-37%0, whereas the latter may tolerate lower salinites. In

E Ruiz

-

et al. /Marine Micropaleontology 31 (1997) 183-203

SUMMER

BIOCOENOSIS

wINTERE!il

D Association3

I

0

100

0

Fig. 4. Seasonal

distribution

of the living populations

of the main species in the Huelva littoral zone.

193

F. RUii et al. /Marine

Micropaleontology

the estuary, in addition to Loxoconcha elliptica, only such moderately euryhaline forms as Pontocythere elongata and Urocythereis oblonga are found alive in summer. This secondary marine biocoenosis is a characteristic feature of southwestern European estuaries with a high to medium tidal range (Carbonel 1973a; Pascual, 1990). Typical estuarine forms, such as Cytherois,fischeri, inhabit this environment in January. Temperature may have some influence on the distribution of the biocoenosis. In summer, the Pontocythere elongata (Fig. 4C-G) and Callistocythere rastrifera (Fig. 4A-E) associations are widely distributed in the Huelva littoral. In the winter, however, both associations are most abundant in the warmest waters (> 14”(Z), from Mazagon to Matalascaiias. Influence of grain size on living species is consistently high. Larger species such as Urocythereis oblonga and Pontocythere elongata, adults of which are up to 1 mm long, prefer medium and fine sands. This distribution has also been observed off southern France (Oh and Carbonel, 1978; Carbonel, 1980). Neocythrrideis subulata live almost exclusively in very fine sands at the Huelva littoral. This species may even inhabit fine sands on the Mediterranean coasts (Athersuch et al., 1989). The Palmoconcha guttata assemblage is abundant in marine silty sands and silts. This relation

Plate I Bars equals

100 wm. (A-14): samples. casranea (Sars). Left valve (A- 13). 2. Leptocythere castanra (Sars). Right valve (A-13). 3. Leptocytherr hacescoi (Rome). Left valve (A- 13). 4. Leptocyherr bacescoi (Rome). Right valve (A- IO). 5. Cytheridea nrupolitana Kollmann. Right valve (A-9). 6. Neocytherideis subulata (Brady). Left valve (A-l 3). 7. Neocytheridris subulata (Brady). Right valve (A-13). 8. Pormqthere elongata (Brady). Left valve (A-27). 9. fontocythere elongata (Brady). Right valve (A-27). IO. Curinoc\thrreis whit@i (Baird). Right valve (A-5). I 1. Costa prmcfatissima Ruggieri. Right valve (A-6). 12. Hiltrnrzarlrlic~thrrr wzuciata (Brady). Right valve (A-9). 13. Hiltennannic~there emaciatu (Brady). Left valve (A-9). 14. Hilt~r,nannic:vthrrr ruhra (Muller). Left valve (A-9). IS. Hiltrrrnunnicl\therr ruhru (Muller). Right valve (A-9). 16. Uroc~therris oblonga (Brady). Female: right valve (A- 16). 17. Urocytherris oblonga (Brady). Male: right valve (A- 16). IX. Hr~sslerirr.~ brrchoni (Brady). Left valve (A-9). 19. B~t.s.skrires berchoni (Brady). Right valve (A-5).

I.

Leptocythere

31 (19971 3833-203

195

is evident both in the Mediterranean and Atlantic margins (Yassini, 1980; Llano, 1981). Loxoconcha elliptica is most densely concentrated in estuarine sediments rich in mud, such as the Gironde estuary in southeastern France (Carbonel, 1973b). Other species, such as Cytheretta adriatica, Semicytherura incongruens, Semicytherura sulcata and Hiltermannicythere rubra, are ubiquitous. These species are less sensitive to changes of grain size in the littoral areas (Bonaduce et al., 1975). The impact of the human pressure on the ostracode distribution is little studied. The area supports a great deal of tourism during the summer. At this time, some species such as Neocytherideis subulata migrate to deeper waters in the proximity of very frequented beaches (Torre de1 Oro, Matalacafias). In the other direction, the Palmoconcha guttata assemblage may migrate near the coast (5-6 m depth) in this season, in less visited areas such as the mouth of the river Piedras. 5.3. Ostracodes

and pollution

Preliminary results from samples collected in 1991 indicated that, in the Tinto-Odiel estuary, ostracodes only lived in some distributary channels near Punta Umbrfa, which were very protected from metallic pollution by heavy metals. In the main channel, live ostracodes were not found (Ruiz Muiioz et al., 1994). This is a feature of estuarine and shallow-marine areas with serious pollution by industrial wastes (Bodergat and Ikeya. 1990). In the summer of 1992, however, a Loxoconcha elliptica-dominated biocoenosis occurred both in the inner part of the estuary (20 individuals/sample) and, to a lesser extent, near the mouth (3 individuals/sample). At this time, diatoms, a food of this species (Athersuch et al., 1989) have a similar pattern (Spanish Oceanographical Institute, 1992). Dissolved oxygen and pH have normal values in this littoral zone because of tidal control. In the winter of 1993, most of the live individuals were collected near the end of the Huelva spit, whereas few specimens were present at the confluence of the Tinto and Odiel rivers (Fig. 4D). In December and January, fluvial input causes a sudden drap in pH values and increases in the metal pollution. Moreover, tidal currents are very strong (11

196

F: Ruiz et al. /Marine

Micropaleontology

m/s) near the bottom. These factors inhibit the development of Loxoconcha elliptica and other estuarine species (Pascual, 1990). These data suggest that some recuperation has occurred in this degraded system. A similar conclusion is derived from study of foraminifera, which have recolonized some estuarine areas such as the salt marshes or the channel border (Gonzalez-Regalado et al., 1996). This observation is confirmed by the new presence of other crustaceans (Balanus concavus) and the decrease of siliceous nannoplankton in recent years in the Tinto-Gdiel estuary (A.M.A., 1995). Nevertheless, live ostracodes have not been found in any channel samples either in summer or winter; samples were mainly taken near the ‘Nuevo Puerto’ industrial estate, one of the most important industrial areas of southern Spain. Metallic pollution, dredging, strong currents near the bottom, periodic oxygen deficiency and high sediment size (medium and coarse sands) are stressful conditions for ostracodes (Kilenyi, 1969; Carbonel, 1980; Ruiz Mufioz et al., 1996) and all come together in this area. In the littoral zone, pollution is significant only seaward of Isla Cristina, in samples from depths of more than 10 m in areas with silty substrate. The high metal contents (mainly Cr, Ni and Hg) does not have a detectable effect on the ostracodes. Important percentages of the Palmoconcha guttata association, are present in this substrate in the study area. However, such filter-feeding organisms as some bivalves may accumulate metallic elements in their soft tissues. This occurs mainly near the Tinto-Odiel estuary, even if the metallic pollution of both waters and sediments is low to moderate. In the Punta Umbrfa-Mazagon area, concentrations of Cu obtained in the commercial bivalve Charnellea gallina (25-40 ppm) exceeded the maximum Cu level allowed in Spain (20 ppm) for human consumption (User0 et al., 1996). 6. Conclusions Quantitative analyses of distribution and abundances of shallow-water ostracodes off the Huelva

31 (1997) 183-203

littoral zone delimit four associations in the total fauna that are widely represented in the adjacent Mediterranean and Atlantic areas. Salinity differentiates the estuarine Loxoconcha elliptica association from marine, grain-size-delimited Urocythereis oblonga, Palmoconcha guttata and Pontocythere elongata associations. In adition, a new association (Callistocythere rastrifera-Neocytherideis subulata), with low percentages in the total abundance, may be dominant in the biocenoenosis in the La Antilla-Punta de1 Gato and Mazagon-Matalascafias zones. These differences between total and living associations were judged to be significant mainly in shallow samples (~8 m deep) with high percentages of very fine sands. In the Tinto-Odiel estuary, ostracodes, together with other organisms such as benthic foraminifera, may be used as indicators of the environmental recuperation. In recent years, these crustaceans have partially recolonized the main estuarine channel from the relatively unpolluted distributary channel near Punta Umbrfa. Only some channel areas, with stressing conditions, are barren of live ostracodes. From these encouraging data, it can be seen that meticulous investigations of this system in the future should provide an excellent study of the response of benthic meiobiocenosis to ranging pollution levels. Acknowledgements

This project was funded by the Chemical and Basic Industrial Association of Huelva and the ‘Palecomar’ group of the Huelva University. Mr. Eduardo Gdmez (Agrobiological Institute, Sevilla) provided photographic advice. We thank Dr. T. Cronin and Prof. R.L. Kaesler for the critical reading of this report, and Ms. M. Carmen Sanchez (Pablo VI Institute, Seville) and Mr. Juan Pablo Mora for their help with the manuscript.

SPECIE.9

I

FACTOR

_

- .

0.900

0,781 0>92

0,908

A

~,

0545

.

.

_

_

-

y_

-

-

_.

.

_

,._

I

SPECIES

_

I

-

0591.

2

154

16,7

Lso* 10.3

0,543.

ocm-

0,644

3

1,475 9.8

049%

0,480.

0,421 0,442.

0,497

4

I

_

.

.

y$

047

-

0.894 0300 0,4n0.8’19

0.445

1

,

gf6

o,m

Oh0

::z

048 0.43%

0,632.

0,474

0*4%

2

__

4

0,.70 0,531

0.739

^

2,024 11.2

.

1,7u 9,6

o,.w 0,449. 0,413. 0.614.

0,470.

0,479

0,528

3

-

,.

.-

WINTER: BIOCOENOSIS ANALYSIS

2502

0,432.

0.56

WY

0,417

0512 0,641.

2511

OJlO

O$=

O>lS OMO 0,470 O,SSS 0,655

0,449.

1

SUMMER: BIOCOENOSIS ANALYSIS

of total and living faunas

FACTOR

analysis and factor 1 vs. factor 2 diagrams

WINTER: TOTAL ANALYSIS

Appendix A. Seasonal main component

_-

_.

-

.-

198

I I

On

I

On

.LE’O

I

I

SS

1

10’0 -11‘0

DO’0 -10‘0

81‘0 89'0

21‘0

-60‘0 -80‘0

-61‘0

-a‘0

-%I‘0

-86‘0

90‘0

LO’0

SP‘O

62'0

W‘O

z!Fo

-91‘0

-60‘0

QI‘O

-bI‘O

-11‘0

8Z’O -Iz'0

*I‘0

-90‘0

-SC0

-90‘0

-LE‘O

ma

9co

-SO‘0

bO‘0

-11‘0

mm&

-LO‘0

-91‘0

-60‘0

-60‘0

2;‘:

MO

80‘0

Ova

EE'O

-60‘0

-60‘0

-CI‘O

-60‘0

-PI‘0

%oo;

ZI‘O

-91‘0

%I‘0

-b‘I‘O

-90‘0

-CO%

+I$

-01‘0

-SE‘0

IZ‘O

c1‘0

10‘0

-El‘0

01‘0

EI'O

onqnr

~~ctqw~

oBI4qqo spJllylx301/)

-PI‘0

-LI‘O

-LI’O -6Z'O

EI‘O

to‘0 %I‘0

-EO‘O

srr 11‘0

91‘0

-wo

-61‘0

-90'0

‘ -1E‘O

-El‘0

-80‘0

ZI‘O

6Z‘O SI‘O

-60‘0

-11‘0

60'0

-91‘0

EZ‘O

-60‘0

ZI‘O

61‘0

ZI‘O

81‘0

-01‘0

-90‘0

ZO‘O

ZO‘O

-11‘0

ez'0

m -61‘0 -a'0

v2p~lA?luoq, 7toJaIo7

"PW'J WvvJowlvd ~lV@m(~O~lVd tW,"Q"S ‘,,&,,t,&O+,

m ~~~Um4 M!!?Y -I,,‘0 VlV%tO~~ .WPt,lhO,UOd

I SO‘0

-SZ‘O -90‘0

QI‘O I I I

-SI'O

60‘0

v~.yilp mpomxq -01'0 v.mw a~a~hmtdql -81‘0 -91‘0 orqnr “IJh+umcuaq,tl!H
-PO‘0

-91'0

wo

-11‘0

-SI‘O

-60‘0 vuvq~odvm

I

TI‘O

SC0

vG&rsvr

'JO,sy,O~

mpa,smg

l-ii I -

oranuaJupmt/

W‘O

I

~"oyxoq

3V

-11‘0

tm~qvmmd m-q .-SO‘0 -ZI‘O yyh4 spJa@mu~m~

vap+e/rh~ v~yvgpv vrtuaqrh~

WO

01‘0 zk?o

-91‘0

1

01‘0

IZ‘O

dI‘0 -SC0 I

-!x‘O

ZC‘O 1

-PI‘0

-61'0

-SC‘0

aa

I

21'0

83

w6

M3

OZ‘O

I

ma QZ'O

d3

im5 91‘0

V3

SI'O

-Leo

-se0

QCO

-9E’O 80‘0 -1Zkl

Tr7l 10‘0 10‘0

PO'0

CO‘0

-61‘0

ZI‘O

IZ‘O

vim -61‘0 -u)‘O oco ml I

nI3

E!

80‘0

m

ZI‘O

21‘0

m

80‘0 El'0

'PZLO

CVO

-ZI‘O

m

1

80‘0

M3

LZ’O QZ‘O CO’0

9p'O -11‘0

-sI‘O

I

-1‘0

-ZI'O
N3

I

,I‘0

IZ‘O

Tm 21‘0

-LO60 CO‘0 -LO‘0 -CO‘0

-90‘0

-z&Y0 -WO QO‘O SO‘0

-LI‘0 SO‘0

SI‘O

m

-10‘0

-10‘0

-11‘0

-n'O El'0

-60‘0

-vZ‘O

rz'o

11‘0 -PO

90‘0

-90‘0

d3

ix%

-01‘0

2m

-81‘0 -62‘0

V3

I

-1‘0

0

zn -Z'O

avo I

N3

I

-I!20 1

XII

9E‘O

17

-01‘0

oz'o -61'0

01‘0

WO -El‘0 I

+I‘0

31

-6E'O

zll

-60‘0 I

9ELo

-ZI‘O I

SC'0

XB

%I‘0

Ll

I

31

QI‘O

I

XT

-11‘0

62‘0

SN

-90‘0

-9Z‘O -I!?0

3d

PC‘0

-6Z‘0 7ml

-9Z‘O -PO‘0

SC0

-8Z‘O

%?% -EI‘O

PC0

-01‘0 10‘0

-PO’0

PC10 -0!20

-fI‘O -El'0

81‘0

-LI‘O

SN

LE‘O LO‘0

SC0

61‘0

-91‘0

ZE'O

-10‘0

m

Ckl

I

91'0

.Ld

-9110 1

I

Ld

-LO‘0

3d

QZ‘O

IS

-1E‘O EfO OZ‘O

(M

m

-80‘0 I

SS

-82‘0 m3 ml

1 I

3d

81'0 1

m

IS

200

I;: Ruiz et al. /Marine

Micropaleontology

31 (/Y!?7) IX-203

E Ruiz ef al. /Marine

Micropaleonrology

Appendix D. Taxonomic appendix

31 (1997)

& Moyes

197 I

duce, Ciampo

The list includes all taxa cited in the paper. The taxonomy is based on Carbonel (1973a,b) Bonaduce et al. (1975). Aranki (1987) and Athersuch et al. (1989). Bibliographical references are given in these papers. For illustrations of taxa see Plates I and II. Acanthocythereis hystrix (Reuss)=Cypridina hystrix Reuss 1850 = Cvthereis hystrix (Reuss) Ruggieri 1953 = Trachyleberis hystrix (Reuss) Ruggieri 1962. Aurila convexa (Baird) = Cythere convexa Baird 1850. Basslerites berchoni (Brady) = Cyrhere berchoni Brady 1869 = Cylhere terns Brady & Norman 1889 = Basslerires teres (Brady) Ruggieri 1950. Bosquetina dentata (Muller) = Cythereis denrara Muller 1894. Buntonia subulata Ruggieri 1954 = Buntonia subulara Ruggieri var. subulara Sissingh 1972. Bythocythere minima Bonaduce, Ciampo & Masoli 197.5. Bythocyythere zetlandica Athersuch, Home & Whittaker 1983. Bythocythere sp. Callistocythere javidofusca (Ruggieri) = Leptocythere jlavidofusca Ruggieri 1950. Callistocythere rasrrifera (Ruggieri) = Leptocythere rastrifera Ruggieri 1953. Callistocyihere sp. Carinocythereis carinata (Roemer)=Cytherina carinata Roemer 1838 = Cythereis antiquata Baird 1850 = Carinocythereis antiquara (Baird) Caraion 1960. Carinocythereis whitei (Baird) = Cythereis whitei Baird 1850 = Cythereis aspera Brady 1865 = Carinocythereis bairdii Uliczny 1969 = Carinocythereis carinata (Roemer) Carbonel

Plate II Bars equals 100 pm. (A-11): samples. 1. Aurila convexa (Baird). Left valve (A-7). 2. Aurila convexa (Baird). Right valve (A-3). 3. Cytheretta adriatica Ruggieri. Right valve (A-14). 4. Loculicytheretra pavonia (Brady). Right valve (A-14). 5. Loculicytheretta pavonia (Brady). Ventral view (A-15). 6. Loxoconcha elliptica Brady. Left valve (A-21). 7. Loxoconcha elliptica Brady. Right valve (A-21). 8. Loxoconcha rhomboidea (Fisher). Left valve (A-10). 9. Loxoconcha rhomboidea (Fisher). Right valve (A-10). 10. Palmoconcha turbida (Muller). Left valve (A-S). 11. Palmoconcha turbida (Muller). Right valve (A-5). 12. Palmoconcha gutlata (Norman). Left valve (A-6). 13. Pabnoconcha guttata (Norman). Right valve (A-6). 14. Sagmatocythere napoliana (F’uri). Left valve (A- 12). 15. Sagmalocyrhere napoliana (Puri). Right valve (A-12). 16. Semicytherura acuticostata (Sars). Right valve (A-9). 17. Semicytherura acuticostala (Sars). Left valve (A-9). 18. Semicytherura incongncens (Muller). Left valve (A-10). 19. Semicytherura incongruens (Muller). Right valve (A-10). 20. Semicytherura sulcata (Muller). Left valve (A-l 1). 21. Semicytherura sulcata (Muller). Right valve (A-l 1).

201

183-203

=

Carinocyrhereis

antiquara

(Baird)

Bona-

& Masoli 1975. Caudites calceolarus (Costa) = Cytherina calceolara Costa 1853 = Caudires rectangularis (Brady) Ruggieri 1952. Celtia quadridentata (Baird) = Cyrhere quadridenrata Baird I850 = Carinocythereis quadridenrata (Baird) Yassini 1969 = Falunia quadridentala (Baird) Uliczny 1969. Costa edwardsii (Roemer) = Cytherina edwardsii Roemer 1838 = Trachyleberis edwardsii (Roemer) Ruggieri 1950 = Cythereis edwardsii (Roemer) Ruggieri 1953 = Costa edwardsii (Roemer) var. edwardsii Ruggieri 196 1. Costa punctatissima Ruggieri 1962 = Costa punctarissima Ruggieri var. samiensis Uliczny 1969. Costa reymenti Aranki 1987. Cyprideis torosa (Jones) = Candona torosa Jones 1850 = Cytheridea lirtoralis Brady 1868 = Cyprideis littoralis (Jones) Sars 1928. Cytheretta adriatica Ruggieri 1952. Cytheridea neapolitana Kollmann = Cythere mulleri Von Munster 1830 = Cyrheridea mulleri (Munster) Muller 1894 = Cytheridea acuminata var. neapolitana Kollmann, Ruggieri 1967. Cyrherois ,jischeri (Sars) = Paradoxosroma ,fischeri Sars 1866 = Cytherois virens Muller 1884. Cytheropteron depressum Brady & Norman 1889. Cytheropteron latum Muller 1894. Cytheropreron nodosum Brady 1868. Echinocythereis laticarina (Brady) = Cythere laricarina Brady 1868. Hemicyrherura cf. H. cellullosa (Norman). Hetemcythereis albomaculata (Baird) = Qrhereis albomaculata Baird 1838. Hiltermannicythere emaciata (Brady) = Cythere emaciata Brady 1867 = CytherPis emaciata (Brady) Elofson 1940 = Carinocythereis emaciata (Brady) Ruggieri 1959 = Falunia emaciata (Brady) Uliczny 1969. Hilrermannicythere rubra (Muller) = Cythereis rubra Muller 1894 = Carinocythereis sp. Barbeito-Gonzales 197 1. Ilyocypris gibba (Ramdohr) = Cypris gibba Ramdohr 1808. Incongruellina marginara (Terquem) = Cythere marginara Terquem 1878 = Ruggieria matginata Moyes 1965 = Carinovalva carinata (Moyes) Carbonel 1985. Leptocythere bacescoi (Rome) = Cyrhere bacescoi Rome 1942 = Leprocythere mellitica Ruggieri 1950. Leptocythere baltica (Brady) = Cyrhere baltica Brady 1869. Leptocyrhere castanea (Sars) = Cythere castanea Sars 1866. Leptocythere,faba@ormis (Muller) = Cythere fabaeformis Muller 1884. Leprocythere macallana (Brady & Robertson) = Cythere macallana Brady & Robertson 1869 = Cythere levis Muller 1894 = Leptocythere levis (Muller 1894) Yassini 1969. Leptocythere pellucida (Baird) = Cythere pellucida Baird 1873 = Cythere confusa Brady & Norman 1889. Leptocyrhere tenera (Brady) = Cythere tenera Brady 1868. Limnocythere inopinata (Baird) = Cythelv inopinata Baird 1868. Loculicytheretra pavonia (Brady) = Cythere pavonia Brady 1866 = Leptocyrhere?? pavonia (Brady) Triebel 1941.

202

R Ruiz et al. /Marine

Micropaleontology

Loxoconcha elliptica Brady 1868. Loxoconcha rhomboidea (Fisher) = Cythere rhomboidea Fisher 1855 = Loxoconcha baitdii Neviani 1927. Microcytherura angulosa (Seguenza) = Cytheridea angulosa Seguenza 1863 = Tetrucyterura arrgulosa (Seguenza) Ruggieri 1952, Microcytherura julva (Brady & Robertson) = Cytherura fulva Brady & Robertson 1874. Neocytherideis subulata (Brady) = Cythereis subulata Brady 1868 = Neocytherideis elongatus Puri 1952 = Nrocytherideis sp. A Llano 1981. Palmoconcha yuttatu (Norman) = Cythere guttata Norman 1865 = Lo.xoconcha guttata (Norman) Brady 1868 = Lindisfamiu guttuta (Norman) Athersuch & Home 198 I. Pultnoconcha turbida Muller 1912 = Lindisfarnia turbida (Mullet-) Home & Kilenyi 1981. Paracytheridea depressa Muller 1894 = Paracytheridea bovettensis (Seguenza) Masoli 1968. Puradoxostoma simile Muller 1894. Paradoxostoma triste Muller 1894. Phlyctocythere pellucida (Muller) = Loxoconcha pellucida Muller 1894. Pontocypris mytiloides (Norman) = Cythere mytiloides Norman 1862 = Pontocypris serrulata Sars 1866 = Erythrocyapris serrata Muller 1894. Pontocythere elongata (Brady) = Cytheridea elongata Brady 1868 = Cushmanidea elongnta (Brady) Puri 1958 = Hemicytherideis elongata (Brady) = Aranki 1987. Potamocypris sp. Procytherideis subspirulis (Brady, Crosskey & Robertson) = Cythereis subspiralis Brady, Crosskey & Robertson 1874 = Neocytherideis subspiralis (Brady, Crosskey & Robertson) Breman 1975. Pseudocythere caudata Sars 1866. Pseudocytherura calcarata (Seguenza) = Cytheropteron calcaraturn Seguenza 1880 = Cytherura culcarata Seguenza 1885 = Paracytheridea calcarata (Seguenza) Ruggieri 1952. Pterigocythereis jonesii (Baird) = Cythereis jonesii Baird 1850 = Pterigocythereis fimbriata (Munster) Ruggieri 1959. Sagmatocythere napoliana (Puri) = Loxoconcha napoliana Puri 1963. Setnicytherura acuticostata (Sars) = Cytherura acuticostata Sars 1866 = Semicytherura acuticostuta (Muller) var. ventricosa Breman 1976. Semicytheruru arcachonensis Yasini 1969. Semicytherura incongruens (Muller) = Cytherura incongruens Muller 1894. Semicytheruru qundridentutu (Hartmann) = Cytheruru quadridentuta Hartmann 1953. Semicytherura sella (Sars) = Cytherura sella Sars 1866 = Cytherura jlavecens Brady 1869. Semicytherura sulcata (Muller) = Cytherura sulcata Muller 1894. Semicytherura cf. S. amorpha Bonaduce, Ciampo & Masoli 1975. Semicytherura cf. S. quadratovolatilis Hartmann 1953. Semicytherura sp.

31 (1997) 1X3-203

Thaerocythere lusitanica nensis Liebau 1982.

Liebau

1991 = Quadracythere

hopto-

Triebelina ruripila (Muller) = Bairdia raripilu Muller 1894. Urocythereis oblonga (Brady) = Cythere oblonga Brady Hemicythere oblonga (Brady) Sars 1928.

I868 =

Xestoleberis aurantia (Baird) = Cythere aurantia Baird 1838 = Xestoleberis pusilla Elofson 194 1. Xestoleberis

communis

Xestoleberis

plana Muller 1894.

Muller 1894.

References A.M.A., 1995. Informe Esturion. Informe preliminar. Volume I, 234 pp. Andalucia Board, 1993. Recursos marinos de1 Golfo de Cddiz: litoral de Huelva. Informe Ttcnico, 145 pp. Aranki, J.F., 1987. Marine Lower Pliocene Ostracods of Southern Spain with notes on Recent fauna. Bull. Geol. Inst. Univ. Uppsala, 13: l-93. Athersuch, J.. Home, D.J. and Whittaker, J.E., 1989. Marine and Brakish Water Ostracods. Synop. Br. Fauna (N. S.) 43, 343 pp. Barker, D., 1983. The relationship between ostracod and sediment grain size. Mar. Micropaleontol., 8: 51-63. Bodergat, A.M. and Ikeya, N., 1990. Distribution of recent ostracoda in the Ise and Mikawa bays, Pacific coast of central Japan. In: T. Hanai, N. Ikeya and K. Ishizaki (Editors), Evolutionary Biology of Ostracoda. Elsevier, Tokio, pp. 207-2 18. Bonaduce, G., Ciampo, G. and Masoli, M., 1975. Distribution of Ostracoda in the Adriatic Sea. Pubbl. Stn. Zoo]. Napoli, 40: 1-314. Bonaduce, G.. Masoli, M. and Pugliese, N., 1988. Remarks on the benthic ostracods on the Tunisian Shelf. In: T. Hanai, N. Ikeya and K. Ishizaki (Editors), Evolutionary Biology of Ostracoda. Elsevier, Tokio, pp. 1087-I 100. Borrego, J., 1992. Sedimentologia del estuario del rio Odiel (Huelva, S.O. Espatia). Ph.D. Thesis, Seville Univ., 311 pp. Borrego, J., Morales, J.A. and Pendon, J.G., 1993. Holocene filling of an Estuarine Lagoon along the Mesotidal Coast of Huelva: the Piedras River Mouth, southwestern Spain. J. Coastal Res., 9(l): 242-254. Breman, E., 1975. The distribution of ostracodes in the bottom sediments of the Adriatic Sea. Ph.D. Thesis, Free Univ. Amsterdam, 165 pp. Brouwers, E.M., 1988. Paleobathymetry on the continental shelf based on examples using ostracods from the Gulf of Alaska. In: P. de Deccker, J.P. Colin and J.P Peypouquet (Editors), Ostracoda in the Earth Sciences. Elsevier, Amsterdam, pp. 55-76. Carbonel, I?, 1973a. Ensembles fauniques d’ostracodes du plateforme continental du Golfe de Gascogne. Bull. Inst. Gtol. Bassin d’Aquitaine, 14: 83-87. Carbonel, P., 1973b. Les ensembles fauniques d’ostracodes rtcents de l’estuaire de la Gironde. Bull. Inst. GCol. Bassin d'Aquitaine. 14: 75-8 1. Carbonel, P., 1980. Les ostracodes et leur interet dans la definition des ecosystemes estuariens et de plateforme continentale.

FI Rui; et al. /Marine

Essais d’application

a des domaines

anciens.

Micropalrontolog~

Mem. Inst. Geol.

Bassin d’ Aquitaine 1I, 350 pp. C.E.E.P.Y.C., 1979. Plan de estudio de la din&mica litoral de la provincia de Huelva. Informe Direction General de Puerto5 y Costas. Madrid. 37 pp. Cuena, G.J.. 1991. Proyecto de regeneration de las playas de Isla Cristina. Mem. M.O.P.T., 48 pp. Dingle. R.V. and Giraudeau. J., 1993. Benthic Ostracoda in the Benguela system (SE Atlantic): A multivariate analysis. Mar. Micropaleontol.. 22: 7 l-92. Gonzalez-Regalado, M.L.. Ruiz Mufioz, F. and Borrego, J., 1996. Evolucitin de la distribution de 10s foraminiferos bentonicos cn un medio contaminado: el estuario del rio Odiel (Huelva. SO de Espaiia). Rev. Esp. Paleontol., I l(l): I-10. Kdrsler. R.L. and Foster. D.W., 1990. Ontogeny of Bradleya uorrnani (Brady): shape analysis of landmarks. In: T. Hanai. N. lkeya and K. Ishizaki (Editors), Evolutionary Biology of Ostracoda. Elsevier, Tokyo, pp. 207-218. Kilenyi. T.I.. 1969. The problems of the ostracod ecology in the Thames estuary. In: J. Neale (Editor), The Taxonomy, Morphology dnd Ecology of Recent Ostracoda. Oliver and Boyd. pp. 25 l-267. Hamoudi. M.. 1988. Les oatracodes, marqueurs des evolutions paleohydrologiques et paleoclimatiques au Plio-Pleistocene. Exemple: marge continental ouest-marocaine et mer Tyrrhenienne. Ph.D. Thesis. Bordeaux Univ., 120 pp. Lachenal. A.M., 1989. Ecologic des ostracodes du domaine mediterraneen: application au Golfe de Gabes (Tunisie Orientale). Les variations au niveau marin depuis 30.000 ans. Dot. Lab. Gdol. Lyon 108. 238 pp. Llano. M., 1981. Interet des ostracodes dans I’interpretation des phenomenes hydrologiques sur les plateaux continentaux: la plateforme atlantique marocaine. Ph.D. Thesis, Bordeaux Univ.. 247 pp. Machain-Castillo. M.L.. Perez-Guzman, A.M. and Maddocks. R.F., 1990. Ostracoda of the terrigenous continental platform of the southern Gulf of Mexico. In: R.C. Whatley and C. Maybury (Editors), Ostracoda and Global Events. Chapman and Hall. London, pp. 341-354. Morales, J.A.. 1993. Sedimentologia de1 estuario de1 rfo Guadi-

31 (1997)

ana (S.0

703

183-203

Espafia-Portugal).

Ph.D. Thesis,

Seville Univ., 300

PP. Oh. J.K. and Carbonel, P., 1978. Les ostracodes du delta de I’Eyre: repartition au tours de I’annee 1977. Bull. Inst. C&II. Bassin d’ Aquitaine, 24: 125-l 30. Pascual, A.. 1990. Utilization de 10s foraminiferoa y ostracodos para un mejor conocimiento de1 medio ambiente en 10s esuarios vizcainos: aplicacion a las rids de Guernica y de Bilbao. Ph.D. Thesis. Univ. Pais Vasco, 345 pp. Reyment. R.A. and Joreskog, K.G.. 1993. Applied Factor Analysis in the Natural Sciences. Cambridge Univ. Press, Cambridge, 371 pp. Ruiz Muiioz, F., Gonzalez-Regalado, M.L. and Borrego. J.. 1994. Ostracodos y contamination: el estuario del rio Odiel (Hueha. SO Espatia). Coloq. Paleontol., 46: 175-l 89. Ruiz Mutioz, F., Gonzalez-Regalado. M.L. and Morales, J.A.. 1996. Distribution y ecologia de 10s foraminiferos y ostracodos actuales de1 estuario mesomareal del rio Guadiana (S.O. Espatia). Geobios (in press). Spanish Oceanographical Institute, lYY2. Variation espacio-tern poral de parametros fisico-quimicos y biologicos en la ria de Huelva y area de influencia. en el period0 1987-l 99 I Informe Tecnico. 103 pp. Usero. J.. Gonzalez-Regalado, E. and Grdcia. I.. 1996. Trace metals in the bivalve mollusc C‘hamrlleu gallha from the Atlantic coast of southern Spain. Mar. Pollut. Bull., 32(3): 305-3 10. Whatley, R.C. and Wall, D.R., 1975. The relation between ostra coda and algae in littoral and sublittoral marine environments. In: F.M. Swain (Editor), Biology and Paleobiology of Ostracoda Paleontol. Res. Inst., Ithaca. NY, pp. 173-203. Whatley, R.C. and Watson, K.A.. 1990. A preliminary account of the distribution of Ostracoda in recent reef and rect associated environments in the Pulau Seribu or Thousand Island group, Java Sea. In: T. Hanai, N. Ikeya and K. Ishizaki (Editors), Evolutionary Biology of Ostracoda. Elsevier, Tokio, pp. 341-354. Yassini, I., 1980. The littoral system ostrdcodes from the Bay of Ismail, Algiers. Algeria. Rev. Esp. Micropaleontol., I l(3): 353-416.