A polychaete-dominated community in the NW Mediterranean Sea, 20 years after cessation of sewage discharges

Figures & data

Figure 1. Map of the study area showing the sampling station.

Table I. Sediment characteristics and pollutant indicators (na, data not available)

Sediment granulometry (%)		1988	2008
Gravel (> 2 mm)		0.60	3.22
Very coarse sand (1 > 2 mm)			0.30
Coarse sand (0.71 > 1 mm)			0.26
Medium sand (0.5 > 0.71 mm)		4.80	0.21
Fine sand (0.125 > 0.5 mm)			17.36
Very fine sand (> 0.063 mm < 0.125 mm)			53.50
Silt–clay (< 0.063 mm)		94.50	24.96
Total Organic Carbon (TOC) (C)			2.90
Pollutant indicators (mg kg–^1)
Cadmium (Cd)		5–10	<1
Copper (Cu)		46–175	210
Chrome (Cr)		na	490
Nickel (Ni)		na	30
Lead (Pb)		405–521	280
Zinc (Zn)		na	540
Mercury (Hg)		4–9	56
Polychlorinated biphenyls (PCBs)		808	<0.07
Polycyclic aromatic hydrocarbons (PAHs)		318	<0.16

Table II. Species composition with mean annual macroinfaunal abundance (ind. m^–2) and biomass (g dry wt m^–2) for the two periods analysed

TG	SPECIES	1988					2008
		Abundance (ind. m–^2)	%	Biomass (g m–^2)	%	Biomass rank	Abundance (ind. m–^2)	%	Biomass (g m–^2)	%	Biomass rank
SS	Capitella capitata	378,101	98.14	10.0273	78.7	1	1,094	13.42	0.0098	1.0	17
S	Malacoceros fuliginosus	2,546	0.66	1.7412	13.7	2	–	–	–	–
S	Spio decoratus	1,684	0.44	0.2158	1.7	4	–	–	–	–
C	Exogone (Exogone) verugera	851	0.22	0.0080	0.1		11	0.14	0.0002	0.0
SS	Mediomastus fragilis	611	0.16	0.2484	1.9	3	1,411	17.30	0.0455	4.9	4
S	Pseudopolydora antennata	463	0.12	0.0524	0.4	8	14	0.17	0.0027	0.3	30
C	Ophryotrocha hartmanni	422	0.11	0.0039	0.0		847	10.38	0.0043	0.5	28
SS	Heteromastus filiformis	83	0.02	0.0548	0.4	7	–	–	–	–
S	Aonides oxycephala	77	0.02	0.0415	0.3	10	3	0.03	0.0010	0.1
S	Dipolydora coeca	68	0.02	0.0081	0.1		203	2.49	0.0134	1.4	12
S	Prionospio malmgreni	65	0.02	0.0067	0.1		–	–	–	–
C	Neanthes caudata	56	0.02	0.0288	0.2	11	–	–	–	–
S	Poecilochaetus serpens	30	0.01	0.0026	0.0		128	1.57	0.0084	0.9	18
SS	Lagis koreni	21	0.01	0.0090	0.1		8	0.10	0.0046	0.5	27
SS	Notomastus latericeus	18	0.01	0.0226	0.2	12	611	7.49	0.2769	29.7	1
C	Nereididae	15	0.00	0.0037	0.0		–	–	–	–
C	Podarkeopsis capensis	15	0.00	0.0004	0.0		–	–	–	–
C	Sigambra parva	15	0.00	0.0021	0.0		300	3.68	0.0119	1.3	14
S	Prionospio cirrifera	12	0.00	0.0006	0.0		33	0.41	0.0009	0.1
C	Nephtys hombergii	12	0.00	0.0101	0.1		3	0.03	0.0020	0.2	33
S	Parapionosyllis minuta	9	0.00	0.0002	0.0		–	–	–	–
C	Phyllodoce mucosa	9	0.00	0.0006	0.0		–	–	–	–
C	Harmothoe antilopes	9	0.00	0.0138	0.1		–	–	–	–
F	Lanice conchilega	9	0.00	0.0632	0.5	6	–	–	–	–
S	Spiochaetopterus costarum	6	0.00	0.0190	0.1		–	–	–	–
C	Pilargidae	6	0.00	0.0213	0.2		–	–	–	–
C	Phyllodocidae	6	0.00	0.0000	0.0		–	–	–	–
S	Sphaerosyllis pirifera	6	0.00	0.0001	0.0		–	–	–	–
C	Aponuphis bilineata	6	0.00	0.0092	0.1		–	–	–	–
C	Harmothoe sp.	6	0.00	0.0012	0.0		–	–	–	–
C	Glycera unicornis	6	0.00	0.0432	0.3	9	128	1.57	0.1325	14.2	2
SS	Cirratulidae	3	0.00	0.0726	0.6	5	–	–	–	–
S	Armandia cirrhosa	3	0.00	0.0000	0.0		–	–	–	–
F	Polycirrus sp.	3	0.00	0.0000	0.0		–	–	–	–
M	Owenia fusiformis	3	0.00	0.0124	0.1		8	0.10	0.0007	0.1
C	Goniada maculata	3	0.00	0.0003	0.0		–	–	–	–
C	Hesionidae	3	0.00	0.0002	0.0		–	–	–	–
C	Lumbrineris nonatoi	3	0.00	0.0005	0.0		–	–	–	–
C	Lumbrineris latreilli	–	–	–	–		275	3.37	0.0637	6.8	3
S	Spiophanes bombyx	–	–	–	–		467	5.72	0.0316	3.4	5
C	Goniada emerita	–	–	–	–		36	0.44	0.0282	3.0	6
S	Spionidae	–	–	–	–		0	0.00	0.0213	2.3	7
SS	Euclymene oerstedi	–	–	–	–		31	0.37	0.0172	1.8	8
SS	Aricidea (Aricidea) pseudoarticulata	–	–	–	–		114	1.40	0.0153	1.6	9
C	Phyllodoce laminosa	–	–	–	–		19	0.24	0.0144	1.5	10
S	Magelona wilsoni	–	–	–	–		461	5.65	0.0138	1.5	11
S	Scoloplos (Scoloplos) armiger	–	–	–	–		86	1.06	0.0127	1.4	13
S	Spio filicornis	–	–	–	–		656	8.04	0.0119	1.3	15
C	Aponuphis brementi	–	–	–	–		36	0.44	0.0101	1.1	16
C	Sthenelais boa	–	–	–	–		11	0.14	0.0069	0.7	19
C	Eunice vittata	–	–	–	–		8	0.10	0.0064	0.7	20
C	Scoletoma emandibulata mabiti	–	–	–	–		14	0.17	0.0061	0.7	21
C	Glycera alba	–	–	–	–		31	0.37	0.0055	0.6	22
SS	Monticellina dorsobranchialis	–	–	–	–		114	1.40	0.0054	0.6	23
S	Aricidea (Acmira) catherinae	–	–	–	–		69	0.85	0.0050	0.5	24
S	Prionospio fallax	–	–	–	–		122	1.50	0.0049	0.5	25
SS	Pherusa eruca	–	–	–	–		8	0.10	0.0047	0.5	26
C	Eteone syphonodonta	–	–	–	–		3	0.03	0.0035	0.4	29
S	Levinsenia sp.	–	–	–	–		128	1.57	0.0025	0.3	31
C	Pilargis verrucosa	–	–	–	–		6	0.07	0.0022	0.2	32
C	Micronephthys stammeri	–	–	–	–		86	1.06	0.0018	0.2	34
C	Sigalion mathildae	–	–	–	–		3	0.03	0.0017	0.2	35
SS	Peresiella clymenoides	–	–	–	–		81	0.99	0.0017	0.2	36
C	Ophiodromus pallidus	–	–	–	–		22	0.27	0.0014	0.2	37
M	Chone acustica	–	–	–	–		114	1.40	0.0014	0.1	38
S	Paradoneis lyra	–	–	–	–		103	1.26	0.0010	0.1
S	Paradoneis armata	–	–	–	–		58	0.72	0.0008	0.1
C	Malmgreniella castanea	–	–	–	–		22	0.27	0.0007	0.1
C	Lumbrineris impatiens	–	–	–	–		19	0.24	0.0004	0.0
S	Aricidea sp.	–	–	–	–		3	0.03	0.0004	0.0
S	Pseudomalacoceros tridentata	–	–	–	–		8	0.10	0.0004	0.0
C	Nephtys hystricis	–	–	–	–		6	0.07	0.0003	0.0
S	Amage gallasii	–	–	–	–		56	0.68	0.0003	0.0
C	Mysta picta	–	–	–	–		17	0.20	0.0002	0.0
C	Ceratonereis (Composetia) hircinicola	–	–	–	–		8	0.10	0.0001	0.0
C	Phyllodoce rosea	–	–	–	–		11	0.14	0.0001	0.0
SS	Chaetozone setosa	–	–	–	–		11	0.14	0.0001	0.0
S	Armandia polyophthalma	–	–	–	–		3	0.03	0.0001	0.0
F	Vermiliopsis labiata	–	–	–	–		6	0.07	0.0001	0.0
S	Sphaerosyllis taylori	–	–	–	–		11	0.14	0.0000	0.0
C	Leonnates glauca	–	–	–	–		3	0.03	0.0000	0.0
S	Aricidea capensis bansei	–	–	–	–		3	0.03	0.0000	0.0
S	Parapionosyllis brevicirra	–	–	–	–		3	0.03	0.0000	0.0
S	Brania arminii	–	–	–	–		6	0.07	0.0000	0.0
	Polychaeta	–	–	–	–			0.00	0.1121	12.0
	TOTAL	385,261	100	12.75	100		8,158	100	0.9337	100
TG, Trophic Groups.

Figure 2. Seasonal abundance (left-hand graphs) and biomass data (right-hand graphs) of key species at the studied station (September 1987 to September 1988).

Table III. Mean annual main community parameters and biotic indices calculated

	1988	Status	2008	Status
Abundance (ind. m–^2)	385,261		8158
Biomass (g dry wt m–^2)	12.75		0.93
Polychaete species	38		60
Shannon [Hʹ log2] (bits·ind.–^1)	0.19 ± 0.06		3.91 ± 0.13
Margalef index [d]	0.85 ± 0.14		4.00 ± 0.36
Simpson index [1–λʹ]	0.04 ± 0.01		0.90 ± 0.01
AMBI (abundance)	5.34 ± 0.14	Heavily disturbed	2.67 ± 0.30	Slightly disturbed
PAMBI (productivity)	4.82 ± 0.80	Bad	2.43 ± 0.21	Good
M-AMBI (abundance)	0.81 ± 0.07	High	0.95 ± 0.06	High

Figure 3. Abundance data (upper graph) and biomass data (lower graph) of the studied series and comparison with the reference station from the MacroBen database. Triangles represent data for 1987–88 from the studied site; squares represent data for 2008 from the studied site and circles are data from the Blanes reference station – pooled data from 1992 to 1996.

Figure 4. k-dominance curves for abundance (open circles) and biomass (open triangles) of macrofauna inhabiting the studied site during the two periods analysed.

Figure 5. Main recruitment peaks and biomass values for the two main populations during September 1987 and September 1988.