Distribution and ecological relevance of fine sediments in organic-enriched lagoons: The case study...

Available online at wwwsciencedirectcom

ARTICLE IN PRESS

wwwelseviercomlocatemarpolbul

Marine Pollution Bulletin xxx (2008) xxxndashxxx

Distribution and ecological relevance of fine sedimentsin organic-enriched lagoons The case study of the Cabras

lagoon (Sardinia Italy)

P Magni ab G De Falco ab S Como b D Casu c A Floris dAN Petrov e A Castelli f A Perilli ab

a CNR-IAMC National Research Council ndash Institute for Coastal Marine Environment Localita Sa Mardini Torregrande 09072 Oristano Italyb International Marine Centre Localita Sa Mardini Torregrande 09072 Oristano Italy

c Dip di Botanica ed Ecologia vegetale Universita di Sassari 07100 Sassari Italyd Dip di Zoologia e Genetica evoluzionistica Universita di Sassari 07100 Sassari Italy

e Institute of Biology of the Southern Seas NASU 99011 Sevastopol Ukrainef Dip di Biologia Universita di Pisa 56126 Pisa Italy

Abstract

In organic-enriched sedimentary systems like many Mediterranean coastal lagoons a detailed analysis of sediment grain size com-position and partitioning within the muds is crucial to investigate sedimentological trends related to both hydrodynamic energy andbasin morphology In these systems sediment dynamics are particularly important because the partitioning and transport of fine sedi-ments can strongly influence the redistribution and accumulation of large amounts of organic matter and consequently the distributionof benthic assemblages and the trophic status and functioning of a lagoon Nevertheless studies on benthicndashsediment relationships havebeen based mainly on a rather coarse analysis of sediment grain size features In muddy systems however this approach may impede aproper evaluation of the relationships and effects of the distribution of fine sediment and organic matter on the biotic benthic compo-nents Here we show that the distribution of sedimentary organic matter (OM) and total organic carbon (TOC) in the Cabras lagoon(Sardinia Italy) can be explained (ie predicted) as a function of a nonlinear increase in the amount of the cohesive fraction of sediments(68 lm grain size particles) and that this fraction strongly influences the structure composition and distribution of macrobenthic assem-blages Even in such a homogeneously muddy system characterized by lsquolsquonaturallyrdquo occurring impoverished communities impaired ben-thic assemblages were found at 68 lm OM TOC contents of about 77 11 and 35 respectively A review of studies conducted inMediterranean coastal lagoons highlighted a lack of direct integrated analysis of sediment features and the biotic components We sug-gest that especially in organic-enriched coastal lagoons monitoring programs should primarily investigate and consider the cohesivefraction of sediments in order to allow a better assessment of benthicndashsediment relationships and ecological quality of the system 2007 Elsevier Ltd All rights reserved

Keywords Fine sediments Mud Organic matter (OM) Macrofauna Ecological quality Coastal lagoons

0025-326X$ - see front matter 2007 Elsevier Ltd All rights reserved

doi101016jmarpolbul200712004

Corresponding author Address CNR-IAMC National ResearchCouncil ndash Institute for Coastal Marine Environment Localita Sa MardiniTorregrande 09072 Oristano Italy Tel +39 0783 22027 fax +39 0783

E-mail address paolomagniiamccnrit (P Magni)

Please cite this article in press as Magni P et al Distribution and ecdoi101016jmarpolbul200712004

1 Introduction

Transitional waters such as estuaries and coastallagoons are classified by the European Water FrameworkDirective (WFD 200060EC) as one of the five categoriesof lsquolsquosurface waterrdquo which also include coastal waters riv-ers lakes and artificial and heavily modified bodies ofwater Due to their partly saline character lsquolsquosubstantially

ological relevance of fine sediments Mar Pollut Bull (2008)

2 P Magni et al Marine Pollution Bulletin xxx (2008) xxxndashxxx

ARTICLE IN PRESS

influenced by freshwater flowsrdquo and their usually high sed-iment-surface-area to water-volume ratio transitionalwaters can be considered a very sensitive aquatic systemwhere benthic components and processes play an impor-tant regulatory function for the whole ecosystem (Viaroliet al 2004) Accordingly there has been a major develop-ment of biotic benthic indices in Europe in recent yearswith special attention paid to the use of macroinvertebratecommunities in assessing the ecological quality status ofcoastal and estuarine waters (Borja et al 2000 Simbouraand Zenetos 2002 Rosenberg et al 2004 Dauvin andRuellet 2007 Muxika et al 2007) as well as coastallagoons (Reizopoulou et al 1996 Fano et al 2003 Bassetet al 2004 Ponti and Abbiati 2004 Reizopoulou and Nic-olaidou 2007 Mistri and Marchini in press) Comparisonsof different biotic indices and assessments of their applica-bility in different geographical areas of the world are nowalso on the rise (Dıaz et al 2004 Arvanitidis et al 2005Magni et al 2005a Quintino et al 2006 Fleischer et al2007 Pranovi et al 2007 Zettler et al 2007 Blanchetet al in press Borja et al in press) In contrast the phys-ical and chemical characteristics of sediments appear to beless explored and more controversial in terms both of theirintegration in the biological elements and their relevance inassessments of environmental quality (Crane 2003 Borjaet al 2004 Borja and Heinrich 2005 Marın-Guiraoet al 2005) This is particularly true in non-tidal (sensu

McLusky and Elliott 2007) transitional systems such asMediterranean coastal lagoons Here only recently qual-ityvulnerability biogeochemical tools and integrated mea-surements of status variables and system metabolism arebeing proposed (Viaroli and Christian 2003 Viaroliet al 2004 Giordani et al in press)

It is a classical general assumption that sedimentaryorganic matter (OM) influences the composition and dis-tribution of macrobenthos (Rhoads 1974 Pearson andRosenberg 1978 Gray 1979) It is also well known thatthe level of OM is related to the grain size composition ofsediments In particular a higher content of OM tends tooccur at an increasing mud (clay) content due to a greatersurface area and higher number of complexing sites of thesediments (Buchanan and Longbottom 1970 Mayer1994ab Tyson 1995) A high mud content together withexcessive OM may then result in a lower permeation ofoxygen an increased microbial oxygen uptakedemandand a subsequent buildup of toxic byproducts (egammonia dissolved sulphide) (Florek and Rowe 1983Santschi et al 1990 Fenchel et al 1998) This can leadto impoverished benthic communities dominated by fewresistant r-selected opportunistic species (Dıaz and Rosen-berg 1995 Como et al 2007) Notwithstanding com-bined and confounding effects of other majorenvironmental factors such as bathymetry and salinity(eg Jones et al 1986 Schlacher and Wooldridge1996 Teske and Wooldridge 2003) clear patterns ofmacrobenthos change have been demonstrated for sometime along marked gradients of mud andor organic mat-


ter enrichment (eg Ishikawa 1989 Quintino and Rodri-gues 1989) In fact it appears that works on benthosndashsediment relationships in marine and estuarine watershave been mainly based on a rather coarse analysis ofsediment grain size features eg on the sand vs mudfractions generally restricted to the few uppermost inte-grated centimeters (eg see Table 1 in Snelgrove and But-man 1994) Several benthic studies on animalndashsedimentassociations have also been conducted in lagoon systemsEspecially in muddy systems however like many of thecoastal lagoons in the Mediterranean Sea this approachmay be of little use In contrast a detailed analysis of sed-iment grain size composition within the muds may revealsedimentological trends related to both hydrodynamicenergy and lagoon morphology which are not detectableotherwise (De Falco et al 2004) In these often eutrophicand organic-enriched systems such analysis is importantalso because the partitioning and transport of fine sedi-ment particles may strongly influence the redistributionand accumulation of large amounts of organic matterand consequently the distribution of macrozoobenthosand the overall trophic status and functioning of alagoon However there is a lack of studies linking the dis-tribution and dynamics of fine sediments to the distribu-tion of benthic macroinvertebrate communities incoastal lagoons

In the present study we aimed at assessing the relation-ships between the distribution of fine sediments the levelsof organic matter in the sediments and the structure andcomposition of macrobenthic assemblages in a Mediterra-nean lagoon system as well as evaluating the overall eco-logical relevance of such relationships For thesepurposes we used the Cabras lagoon (Sardinia Italy) asa case study where we had previously conducted extendedsurveys on both sediment characteristics (De Falco et al2004) and macrozoobenthic assemblages (Magni et al2004b 2005b) For the present study we made a detailedanalysis of sediment particle distribution within the mudswith specific analytical size intervals of 05 lm and focusedon the 68 lm grain size fraction of sediments (hereafterlsquolsquofine sedimentsrdquo) This was based on the fact that the8 lm boundary is known to separate non-cohesive fromcohesive sediments (McCave et al 1995) and because thisfraction was found to be most correlated with the totalorganic carbon (TOC) content of sediments in the Cabraslagoon (De Falco et al 2004) As for the macrozooben-thos the biomass of individual taxa as well as speciesrsquo rich-ness and diversity not used in our previous study (Magniet al 2004b) were analyzed together with the total abun-dances A review of studies reporting OM andor TOCcontent of sediments as well as grain size and biologicalbenthic features in Mediterranean coastal lagoons wasalso made This was to provide a general assessment ofbenthicndashsediment studies and monitoring schemes in thesesystems on a regional scale as well as an operationalframework for both lagoon ecology and managementissues


P Magni et al Marine Pollution Bulletin xxx (2008) xxxndashxxx 3

ARTICLE IN PRESS

2 Materials and methods

21 Study area

The Cabras lagoon is a shallow transitional systemlocated in the Gulf of Oristano on the west coast of theisland of Sardinia (Italy) western Mediterranean Sea(Fig 1) With an area of about 22 km2 it is the largestlagoon in Sardinia and one of the major brackish systemsof the western Mediterranean Sea The drainage systemof the Cabras lagoon has a total extension of 432 km2

(Casula et al 1999) and is characterized by two main trib-utaries called lsquolsquoRiu Mare Fogherdquo and lsquolsquoRiu Tanuirdquo locatedin the northern and southern sectors of the lagoon respec-tively The lsquolsquoRiu Tanuirdquo subtends a watershed which ismuch smaller than the lsquolsquoRiu Mare Fogherdquo but its contribu-tion to the loading formation is very important because ofthe presence of intensive agricultural activities in this areaIn addition the lsquolsquoRiu Tanuirdquo has been subjected to the dis-posal of untreated urban waste waters which were dis-charged into the Cabras lagoon till the year 2000Nutrient loading from the drainage basin has been calcu-lated at 16 tons of total phosphorous and 240 tons of total

0

Gulf ofOristano

CabrasLagoon

-5 m-10 m

-10 m-10 m

-10 m

-5 m

-20 m

-5 m

0 2 km

Sardinia

ITALY

westernMediterranean

Fig 1 Study area and location of sampling stations in the Cabras lagoon (Sardsize composition and organic matter (OM) content were determined in the 0ndash2lagoon which limits the lagoon-gulf water exchange though the channel and thesouthern sectors respectively) are also indicated


nitrogen per year (Casula et al 1999) Despite the currenttrend in increasing salinity caused by a progressive reduc-tion of freshwater input and an increasing demand forwater for land use (eg agriculture) salinity may drop tolt10 psu following rainfall while it rises to gt30 psu duringdry periods (Magni et al 2005b)

In the southern sector of the lagoon the water exchangebetween the lagoon and the adjacent Gulf of Oristano hasbeen severely affected by a channel constructed in the late1970s closed by a dam which raises the high-tide waterlevel (Fig 1) Connection to the adjacent coastal sea ofthe Gulf of Oristano is through narrow convoluted creekswhich flow into the main channel (Como et al 2007)Additional man-made barriers were built in this area inthe late 1990s for capturing fish The Cabras lagoon is thuscharacterized by limited water exchange with the adjacentgulf (tidal amplitude lt25 cm) In contrast tide- andwind-induced currents seem to be effective in circulatingthe internal water mass enough to influence the resuspen-sion and distribution of fine sediment particles within thebasin (De Falco et al 2004)

The Cabras lagoon historically has a high economicrating due to fishery activities (eg Liza ramado Mugil

C1C2

C3C4

C5C6C7

C8C9C10

C11C12C13C14

C15C16C17C18

C19C20C21C22C23C24

C25C26C27C28C29

C30C31

Gulf of Oristano(western Mediterranean)

Mare e Foghe

Samplingstations

Down-coresamples

39deg59N

39deg55N

008deg32E08deg27E

CreeksChannel

Lagoonmouth

Dam

Lagooninlet

Cabras

CabrasLagoon

River

TanuiRiver

0 1km

inia western Mediterranean sea) indicates the nine stations where grain4 cm sediment horizon The W-shaped dam in the southern sector of thetwo main tributaries lsquolsquoRiu Mare e Fogherdquo and lsquolsquoRiu Tanuirdquo (northern and



ARTICLE IN PRESS

cephalus Anguilla anguilla) which involve about 250 fisher-men with a yearly fish catch up to about 850 tons(400 kg ha1 year1) as in 1998 (Murenu et al 2004)However especially during the warm season there is a ten-dency for hypoxic and anoxic conditions to occur in near-bottom waters This may lead to dystrophic events such asthe severe one which occurred in June 1999 causing amajor loss of the biological resources of the lagoon and adrastic reduction of total catches in the subsequent yearsfalling below 80 tons in 2002 (Murenu et al 2004) In2006 the total fish catch was reported to be still as lowas 120 tons The major causes of these events are thoughtto be eutrophication and excessive organic enrichment ofsediments which cause the enhancement of sulphate reduc-tion rates during the warm season and the subsequentrelease of toxic dissolved sulphide from the sediment porewater into the water column (Magni et al 2005b in press)

22 Field surveys and laboratory analysis

Four sampling campaigns were conducted between theend of April and the beginning of May 2001 Thirty-onesampling stations spaced 750 m one another were selectedon a regular grid covering the whole lagoon (Fig 1) Previ-ous published work (De Falco et al 2004) reported theanalysis of sediment grain size composition and organicmatter (OM) and total organic carbon (TOC) contents ofsurface sediments (0ndash2 cm) For this work we analyzedthe sediment vertical profiles from cores collected at ninestations on the grid (see Fig 1) using a manual corer(40 cm long 55 cm pound) Sediment samples were sliced at2 cm intervals (4 cm in the last layer) down to the 24 cmlayer Sub-samples from each layer were analyzed for grainsize composition and OM content (see De Falco et al 2004for the description of the analytical procedure) At each ofthe 31 stations (except Stns 15 and 19) duplicate sampleswere collected for macrozoobenthos using a 216 cm2

Ekman-Birge grab In the laboratory the macrozooben-thos were sorted identified to the species level when possi-ble counted under a stereo-microscope and preserved in75 ethanol Following a description of the spatial distri-bution of the abundances of the most dominant taxa(Magni et al 2004b) the wet weight (WW) biomass ofeach taxa was obtained for this work after excess fluidwas carefully blotted off

23 Data analysis

231 Sediment vertical profiles

The variability of sediment grain size and OM in the ver-tical profile (0ndash24 cm sediment horizon) of the nine sedi-ment cores was evaluated using the Hierarchical ClusterAnalysis Individual layers (n = 99) were used as the sam-ple data The entire grain size spectrum expressed at onephi intervals and the OM contents were used as data inputafter the ranking of data value The significance of the dif-ferences among groups of samples identified by the cluster


analysis was then tested by Discriminant Analysis Grainsize (one phi interval) and OM data were used as data inputafter ranking Discriminant Analysis allowed us to investi-gate the significance of group separation the weight of thevariables which provide the clustering and the closeness ofthe single cases (samples) to the centroids of the groups inorder to individuate the outliers

232 Relationships between sediment variables

The relationship between fine sediments (ie 68 lmgrain size particles) and OM was evaluated by means ofa nonlinear least-squares regression model (Bates andWatts 1988) using the nine sediment cores samples asthe input data (n = 99) The function was of the form

y frac14 a ebecx

where y is the fine sediments () x is the OM () and a band c are the parameters of the equation where a is thelsquoplateaursquo value ( fine sediments) b is the ln(ai) and i isthe y value for x = 0 and c is the constant of the modelAccording to this function OM increases nonlinearly withthe increase of fine sediments up to a certain lsquoplateaursquo va-lue beyond which the OM increase is independent fromthe percentage of fine sediments The estimate of the a band c parameters is the result of the best fitting between ob-served data and the predicting function by minimizing thesquare root of the sum of the square errors between ob-served and predicted values A Non-Linear-Estimationbased on the QuasindashNewton algorithm for nonlinear opti-mization was used

233 Macrozoobenthos and relationships with sediment

variables

Differences in macrozoobenthic assemblages were ana-lyzed using a non-metric multidimensional-scaling(nmMDS) ordination model based on the Bray-Curtis dis-similarity matrix (Clarke and Warwick 2001) calculated onthe mean values among replicates within each station Aone-way ANOSIM randomizationpermutation test wasused to check for the significance of differences amonggroups of stations identified by the nmMDS ordinationmodel (Clarke and Warwick 2001) Taxa which contrib-uted the most to these differences were identified by thesimilarity percentages procedure SIMPER (Clarke andWarwick 2001) Correlation coefficients (R) were calcu-lated in order to evaluate the relationships between sedi-ment variables (ie 68 lm grain size particles OM andTOC) and the macrozoobenthos The total number of spe-cies (S) and individuals (N ind 216 cm2) the total bio-mass (gWW 216 cm2) the ShannonndashWeaver diversity (H0calculated with natural logarithm) index and the abun-dances of taxa identified by SIMPER were used as the bio-logical variables

The graphical representation of the spatial distributionof sediment variables and the total abundance and biomassof macrozoobenthos was performed using the Surfer 70

software Smooth-line kriging was used as the gridding



ARTICLE IN PRESS

method where the x and y data columns are the latitudeand the longitude of the sampling stations respectivelyand the z data column is the selected variable All statisticalanalyses were done using the Statistica program of theStatSoft Inc (release 61) and the PRIMER v52 package(Clarke and Warwick 2001)

3 Results


Fig 2 shows the vertical profiles of fine sediments andOM in the 0ndash24 cm depth horizon at nine stations randomlychosen in the Cabras lagoon At most stations both vari-ables showed a sharp increase in the uppermost layers Fromthe whole set of data irrespective of individual stations anddifferent layers two major groups of samples were identifiedby cluster analysis (plots not shown) as being characterizedby fine sediment contents of 743 plusmn 63 and 547 plusmn 143and OM contents of 93 plusmn 19 and 66 plusmn 16 respec-tively By applying the Discriminant Analysis the twogroups of samples (clusters 1 and 2) were found to be signif-

0

5

10

15

20

25Sed

imen

t dep

th (

cm)

30 60 90

le8 microm ()

5 10 15

OM ()

C1

0

5

10

15

20

25

50

le8 micro

5

OM

0

5

10

15

20

25Sed

imen

t dep

th (

cm) 50 75 100

le8 microm ()

5 10 15

OM ()

C18

0

5

10

15

20

25

50le8 micro

5

OM

0

5

10

15

20

25Sed

imen

t de

pth

(cm

) 50 75 100le8 microm ()

5 10 15

OM ()

C28

0

5

10

15

20

25

0le8 microm

0

OM

le8 micromOM

Fig 2 Vertical profiles of fine sediments (ie 68 lm grain size particles) and oin the Cabras lagoon Note the different scales at some stations Fine sediments(30ndash90) and C30 (0ndash60) OM all stations 5ndash15 range except Stn C30 (0


icantly different from each other (93 allocation successd2 = 073 P = 00001) This allowed us to distinguish finerorganic-enriched samples from coarser less organic-enriched samples consistently across different core levelsas graphically represented in Fig 3 Based on this analysisthe thickness of the fine-grained organic-enriched layerwas found to increase from north to south most noticeablyat Stns C22 C26 and C31 In contrast near-shore stationshad fewer (Stn C1) or no (Stn C30) samples belonging tothe organic-enriched group


OM and TOC contents in the Cabras lagoon showed ahighly significant (P lt 0001) linear relationship account-ing TOC for 30 of OM (Fig 4a) In contrast the best-fit relationship between fine sediments and OM wasdescribed by a nonlinear least-squares regression model(Fig 4b see Section 2) According to this model OMincreases progressively as fine sediments increase in therange of about 3ndash7 and much faster in the range of about8ndash12 At 82 of fine sediment content OM increase

C6 C12

75 100

m ()

10 15

()

0

5

10

15

20

25

50 75 100

le8 microm ()

5 10 15

OM ()

C22 C26

75 100m ()

10 15

()

0

5

10

15

20

25

50 75 100le8 microm ()

5 10 15

OM ()

C30 C31

30 60 ()

4 8

()

0

5

10

15

20

25

50 75 100le8 microm ()

5 10 15

OM ()

rganic matter (OM) at the nine stations (circled in Fig 1) randomly chosen(ie 68 lm grain size fraction) all stations 50ndash100 range except Stns C1ndash8)


Fig 3 Graphical representation of individual-layer samples in nine coresections (x-axis indicates the sediment depth in cm) belonging to eitherCluster 1 or Cluster 2 (see below legend) characterized by significantlymarked differences in fine sediment (ie 68 lm grain size particles) andOM contents (tested by the Discriminant Analysis see Section 2) Legend

j Black samples Cluster 1 (fine sediments [68 lm grain size particles]743 plusmn 63 OM 93 plusmn 19) h White samples Cluster 2 (fine sediments[68 lm grain size particles] 547 plusmn 143 OM 66 plusmn 16)

0

20

40

60

80

100

le8 micro

m (

)

y = 821e-32e

R 2 = 067 (n=99)

y = 030xR2 = 075 (n=62)

0

1

2

3

4

5

TO

C (

)

-036x

0 3 6 9 12 15

OM ()

0 3 6 9 12 15

OM ()

a

b

Fig 4 (a and b) Relationships between (a) organic matter (OM) and totalorganic carbon (TOC) and (b) OM and fine sediments (ie 68 lm grainsize particles) In (a) the grey circles refer to the surface sediment (0ndash2 cm)samples (n = 31 see Fig 7b and c) the black circles refer to the verticalprofiles of Stns C1 C12 and C26 (OM Fig 2 TOC De Falco et al(2004)) The linear regression line includes all samples (n = 62) In (b) thebest-fit nonlinear least-squares regression equation is represented (n = 99see Fig 2)


ARTICLE IN PRESS

reaches a plateau indicating that any further increase isindependent of fine sediment content (Fig 4b)

33 Macrozoobenthos and relationships with sedimentvariables

As detailed in Magni et al (2004b) macrozoobenthicassemblages were mainly represented by polychaetes(795) oligochaetes (99) crustaceans (57) and bival-ves (32) Among the most dominant taxa the serpulidFicopomatus enigmaticus and the spionid Polydora ciliata

accounted for 409 and 301 of the total abundancerespectively Polychaetes also dominated in biomass(888) with a major contribution of Neanthes succinea


(622) and F enigmaticus (213) At individual stationsthe total abundance and biomass varied from 135 to15525 ind 216 cm2 and from 005 to 935 gWW

216 cm2 respectivelyMultivariate analysis revealed major differences in the

structure and species composition of macrozoobenthicassemblages among three groups of stations (Fig 5 andTable 1) As indicated by the nmMDS ordination model(Fig 5) one group (hereafter lsquolsquoCentralrdquo) included stationslocated in the relatively deeper central sector of the lagoon(mean water depth 19 m) The other two groups includedshallower stations (mean water depth 16 m) which werenamed lsquolsquoShorerdquo and lsquolsquoReef-shorerdquo based on the exclusivepresence of F enigmaticus in the latter group The ANO-SIM test confirmed the differences among these threegroups of stations (ANOSIM test global R 0673P lt 0001) As indicated by the pairwise test the highestR values were found when comparing the Central withShore and Reef-shore stations (Table 1) Four taxa weremainly responsible for the differences among the threegroups of stations (SIMPER cut-off 60 Table 2) F enig-

maticus was present exclusively in the Reef-shore stations


1

3

20

5

714

29

11

16

28

10

18

30

31

4

9

6

12 13

17

21

22

23

24

25

2627

28

Fig 5 Non-metric multidimensional-scaling (nmMDS) ordination modelStress = 015 Symbols black circles [Central] grey triangles [Shore] whitesquares [Reef-shore] Stations number (see Fig 1) is indicated

Table 1Results of pairwise test from one-way ANOSIM for differences amonggroups of stations (Central Shore Reef-shore)

Group R P () Possiblepermutations

Actualpermutations

Central vs Shore 0782 01 38760 999Central vs Reef-shore 0688 01 817190 999Shore vs Reef-shore 0383 13 5005 999

Table 2Differences (lt and gt) in average abundance of taxa which contribute todissimilarity (cut-off 60) between groups of stations (Central Shore

Reef-shore) identified by SIMPER

Central Shore Reef-shore

Ficopomatus enigmaticus 0 0 lt 37389Tubificidae 1393 gt 55 lt 6556Neanthes succinea 543 lt 3083 lt 3467Polydora ciliata 11629 gt 717 lt 8911

Fig 6 (a and b) Spatial distribution of (a) the total abundance (ind 216 c


ARTICLE IN PRESS


Also at the Reef-shore stations the abundances of N suc-

cinea and the oligochaetes Tubificidae were higher thanat the Central and Shore stations In contrast P ciliata

was most abundant in the Central stations (Table 2)A graphical representation of the distribution of macro-

zoobenthos clearly showed a marked spatial trend with sev-eral central stations being the most impoverished both interms of total abundances and total biomass (Figs 6a andb) In contrast the spatial distribution of fine sedimentsOM and TOC in the surface sediments showed an oppositetrend with values increasing from the near-shore to the cen-tral stations (Figs 7andashc respectively) Consistently wefound several significant (P lt 005) correlations betweenmacrozoobenthos and the sediment variables all of themnegative (Table 3) Most noticeably the fine sediments cor-related negatively with most biotic univariate measuresincluding S N and the total biomass as well as the abun-dances of F enigmaticus Tubificidae and N succineaAmong the dominant taxa N succinea correlated negativelywith all three sediment variables considered in this study Incontrast P ciliata did not show any significant correlation

4 Discussion

41 Fine sediment distribution and organic matter

enrichment

Despite the fact that the relationship between sedimentgrain size and organic matter is well known (eg Mayer1994b Tyson 1995) an evaluation of the distribution oforganic matter in relation to the sediment dynamics incoastal lagoons has received less attention Such an analy-sis is particularly important because the partitioning andtransport of fine sediments may strongly influence theredistribution and accumulation of large amounts of sedi-mentary organic matter which often characterize these sys-tems In our companion paper (De Falco et al 2004) we

m2) and (b) total biomass (gWW 216 cm2) of the macrozoobenthos


Fig 7 (a b and c) Spatial distribution of (a) fine sediments (ie 68 lm grain size particles) (b) organic matter (OM) and (c) total organic carbon (TOC)in surface sediments (0ndash2 cm) in the Cabras lagoon

Table 3Correlation coefficient R between sediment variables (fine sediments[68 lm grain size] organic matter [OM] and total organic carbon [TOC])and the total number of species [S] and individuals [N] total biomassShannonndashWeaver diversity [H0] index and the most dominant taxaidentified by SIMPER (ns non-significant P lt 005 P lt 001)

68 lm OM TOC

S 038 ns 043

N 047 ns ns

Biomass 050 ns ns

H0 ns ns ns

AbundancesFicopomatus enigmaticus 041 ns ns

Tubificidae 049 ns ns

Neanthes succinea 044 038 039

Polydora ciliata ns ns ns

Note all significant correlations are negative


ARTICLE IN PRESS

showed that the surface sediments of the Cabras lagoon arequite homogeneously muddy and that the spatial variabil-ity of TOC can be explained in terms of grain size fraction-ation within the muds In particular the 68 lm grain sizeparticles of sediments are found to be most strongly corre-lated with TOC while the 8ndash64 lm fractions do not showclear trends The fractionation of muddy sediments hasbeen attributed to the resuspension of sediment in high-energy areas resulting in a transport of fine sedimentsand organic matter to the relatively deeper low-energy sec-tors of the lagoon (De Falco et al 2004) The primarysources of organic matter in the sediments of the Cabraslagoon can be related to both a high primary productionin the water column with up to about 40 lg l1 of chloro-phyll a measured in winter (Magni et al unpublished) andto an external input from the two main tributaries As forthe latter input the lsquolsquoRiu Mare Fogherdquo and the lsquolsquoRiuTanuirdquo in the northern and southern sectors of the lagoonrespectively (Fig 1) subtend watersheds with intensivediary and agricultural activities respectively In addition


the southern sector of the lagoon was subjected to the load-ing of high amounts of untreated urban waste waters dis-charged into the lagoon through the lsquolsquoRiu Tanuirdquo until2000 This helps explain a major accumulation oforganic-enriched fine sediments in several southern stationsof the lagoon (eg Stns C22 C26 C31) as revealed by theanalysis of down-core profiles (Figs 2 and 3) The findingsof this study also support our earlier hypothesis that theconstruction of an artificial channel and a dam at thelagoonrsquos inlet at the end of the 1970s has reduced the inter-nal hydrodynamic energy of the lagoon (De Falco et al2004) This may have favoured the trapping depositionand accumulation of organic C-bounding fine sedimentparticles inside the lagoon over the past few decades

In the present study we also show that the distributionof organic matter (OM) can be explained (ie predicted) asa function of a nonlinear increase in the amount of fine sed-iments (ie 68 lm grain size particles) According to thisrelationship (Fig 4b) the OM content of sediments showstwo different trends In its lower range (about 3ndash7) OMincreases progressively as fine sediment increases while inthe upper range of about 8ndash12 (or about 24ndash36 ofTOC) OM increases at a much faster rate than the relativeincrease of fine sediments Such a rapid increase is then fol-lowed by a plateau indicating that at values of above 80of fine sediments OM starts varying independently fromgrain size thus having a less predictable behaviour Theabove two OM ranges (3ndash7 and 8ndash12 OM) roughly cor-respond to the two groups of samples identified by Dis-criminant Analysis (Fig 3) ie coarser less organic-enriched samples (mean values 547 68 lm 66 OM)and finer organic-enriched samples (mean values 74368 lm 93 OM) respectively (Fig 3) The latter sampleswere mostly found in the upper layers of the sediment coressuggesting that they can be used as a proxy for evaluatingthe amount of organic matter accumulated in the sedimentsover the last few decades The relationship between OM



ARTICLE IN PRESS

and grain size thus clearly demonstrates the importance ofquantifying the amount of fine sediments present in eachlagoon system in order to evaluate the extent of organicmatter enrichment In fact the term lsquolsquoorganic enrichmentrdquocannot be given an absolute value because it depends onthe system considered This study provides one such anexample by defining threshold values and ranges of finesediments within the muds This knowledge is also impor-tant because in anthropogenic-polluted lagoons the pres-ence of high amounts of organic-C bounding finesediments can lead to the mobilization and transport ofcontaminants (eg heavy metals) with a potentialenhancement of the toxic effects to biota

42 Benthicndashsediment relationships

This study provides novel insights on benthicndashsedimentrelationships using the Cabras lagoon an enclosed muddycoastal lagoon of the Mediterranean Sea as a case studyIn fact while large variations in grain size compositionandor organic matter content of sediments may evidenceclear patterns in the distribution of the benthos (eg Snel-grove and Butman 1994) the muddy sediments oftenfound in Mediterranean coastal lagoons render such inves-tigations more difficult In addition it is well known thatthe lagoon systems are increasingly affected by excessiveinputs of nutrients and organic matter This is often adirect consequence of human activities (eg sewage dis-charge fish farming) or an indirect consequence (egeutrophication) of the same These factors as well as thelarge environmental variability typical of these systemsdetermine a selection of species and communities whichare able to cope with disturbed conditions and to recolo-nize relatively quickly (Magni et al in press) Here wecould assess the benthicndashsediment relationships upon adetailed analysis of grain size fractionation within the muds(specific analytical size intervals of 05 lm) with a specialfocus on the cohesive fraction of sediments (ie 68 grainsize particles) The most impaired benthic assemblages interms of lowest speciesrsquo diversity and biomass were foundin the central-southern sector of the lagoon In particularone single species in the Central group stations the spionidP ciliata dominated numerically without showing anynegative correlation with fine sediments OM or TOC(Table 3) This is consistent with the fact that spionidsare very opportunistic and show high resilience after distur-bances In fact larval and post-larval stages of Polydoraspp are reported to colonize patches of sediment all yearround (Hansen 1999) Furthermore spionids are alsoknown to switch their feeding mode from filter feeding todeposit feeding depending on the environmental conditionssuch as hydrodynamics (Kihslinger and Woodin 2000)Consistently the Central group stations were characterizedby the highest mean contents of fine sediments OM andTOC in the surface layer ie 775 plusmn 16 113 plusmn 03and 35 plusmn 01 respectively In these organic-enriched sec-tors of the lagoon the periodic occurrence of severe envi-


ronmental conditions (eg extreme hypoxia or anoxia)andor the development of toxic compounds (eg dis-solved sulphide) strongly contribute to a major impoverish-ment of benthic assemblages (Magni et al 2005b) TheTOC values found in the Central group stations supportthe results of Hyland et al (2005) who have shown a majorshift in the benthic data obtained from seven coastalregions of the world and have highlighted the high risksof reduced species richness at TOC values gt35 It isour hope that synoptic data on the structure of benthiccommunities and TOC content of sediments from differentlagoons will be merged and analyzed in order to further testsuch relationships as a general screening-level indicator forevaluating the likelihood of reduced sediment quality andassociated bioeffects in coastal lagoons (Magni et al2005a)

Multivariate analysis of macrozoobenthos also revealedthat in contrast the serpulid F enigmaticus was exclusiveto the Reef-shore group We have previously shown that F

enigmaticus in association with the amphipod Corophium

sextonae correlates positively with the sediment sorting(r) an index of sediment selection due to hydrodynamicenergy (Magni et al 2004b) This is consistent with theinference that F enigmaticus may take advantage of resus-pended food particles along the shores with its filter-feedingactivity In the Reef-shore stations all dominant taxaincluding Tubificidae N succinea and P ciliata as well asthe highest number of species abundances and biomass werefound These results are consistent with the facilitative roleplayed by serpulid reefs F enigmaticus is an invasive cosmo-politan species which is highly tolerant of environmentalstress and anthropogenic disturbance (Bianchi and Morri2001) Extremely common in sheltered bays coastal lagoonsand harbors serpulid reefs can strongly modify the hydro-logical and sedimentary features of a basin by completelyrefilling shallow areas (Schwindt and Iribarne 2000 Bianchiand Morri 2001) At the same time serpulid reefs create sec-ondary hard bottoms (Bianchi and Morri 2001) Theyincrease the habitat structures and provide refuge from pre-dators for many thus favouring the recruitment and thecoexistence of different animals (Bianchi and Morri 1996Schwindt and Iribarne 2000) Overall stations along theshores were characterized by lower contents of fine sedi-ments OM and TOC than the Central group stations Heremore oxygenated waters may help to explain the relativelyricher associations in spite of the opportunistic characteris-tics of the dominant taxa found in the Cabras lagoonincluding tubificids nereids and spionids

The relationship of the macrozoobenthos with fine sed-iments and OM was largely supported by the sedimentanalysis of vertical profiles (ie 0ndash24 cm depth horizon)In particular several stations characterized by a thick layerof fine-grained organic-enriched sediments such as StnsC22 C26 and C28 (Fig 3) had impoverished macrozoo-benthos belonging to the Central stations (Fig 5) In con-trast stations characterized by a vertical profile withcoarser less organic-enriched sediments such as Stns C1



ARTICLE IN PRESS

and C31 had relatively richer macrozoobenthic assem-blages belonging to the Reef-shore stations The analysesof sediment horizons also highlighted an increase of thethickness of the fine-grained organic-enriched layer fromthe north to the central-south area of the lagoon the latterconsidered to be critical in terms of development of dystro-phic events In a subsequent temporal study we haveshown a marked impoverishment of the benthic communi-ties in the southern sector of the lagoon at the end of sum-mer (Magni et al 2005b) This was thought to be the resultof severe hypoxic conditions and an increase in acid-vola-tile sulphide concentrations of sediments caused by exces-sive amounts of sedimentary organic matter The resultsof the present study clearly indicate the importance ofnot restricting the analysis of sediment grain size featuresand composition to a single uppermost layer In fact weshowed that a detailed analysis of the sectioned sedimenthorizons was instrumental in assessing the extent (iethickness) of the organic-enriched layer of sediments in dif-ferent sectors of the lagoon (see also Magni et al in press)This allowed for a better evaluation of the ecological qual-ity of the lagoon and the identification of areas character-ized by impoverished assemblages which could be moresubject than others to the risks of developing dystrophiccrisis (Magni et al 2005b in press)

43 Implications for monitoring and ecological quality

assessment of coastal lagoons

A significant challenge in studying shallow transitionalwaters such as estuaries and coastal lagoons is that theyare under the influence of multiple factors and have a greatinternal patchiness and heterogeneity which can often biasthe application of the most common indicators and indicesof environmental quality and health status In these sys-tems water-quality criteria that are suited for deep lakesand marine ecosystems cannot be used due to the shallowdepth the pelagic components being quantitatively lessimportant than the benthic subsystem Overall in coastallagoons the sediment-surface-area to water-volume ratiois of paramount importance in determining levels of eco-system metabolism throughout benthic communitiesThere is therefore a need for a common integrated set ofindicators and monitoring approaches for use in shallowtransitional waters that takes the unique properties of thesesystems into account Yet because of the complexity ofmost stressorndashresponse relationships in nature it is usuallyimpractical if not impossible to completely characterize allcontributing variables (Fisher et al 2001) Under these cir-cumstances one should identify a set of basic benthicsed-imentary variables indicative of operative ecosystemproperties and functions which could then be used for clas-sification and quality-assessment purposes (Viaroli et al2004 Hyland et al 2005 Magni et al 2005a)

This work aims at providing a scientific assessment ofbenthic studies carried out on a regional scale in Mediter-ranean coastal lagoons in order to evaluate some general


features of these systems and the monitoring approachesadopted Coastal lagoons are often described as organic-enriched sedimentary systems However this informationis mostly found in individual studies while a quantitativecomparison of organic matter content of sediments in dif-ferent lagoons at the regional (Mediterranean) level is lack-ing Within this context Table 4 provides an overview ofOM and TOC content of sediments reported for severalcoastal lagoons in the Mediterranean Sea as well as themethodology used to determine them The OM and TOCcontents indicate that these systems have generally muchhigher values than those found in coastal marine andestuarine systems (eg Tyson 1995) when we exclude sitesimpacted by aquaculture activities (eg Cancemi et al2003) or accumulations of seagrass leaf litter (eg Comoet al 2007) Table 4 also demonstrates the wide use of lossof weight on ignition method (LOI) for OM determinationYet it should be noted that there is a large variabilityamong studies in the analytical conditions used such asthe temperature and the time of ignition as well as in thesediment layer considered in most cases as being restrictedto one single uppermost layer The Cabras lagoon was oneof the very few lagoons where both OM and TOC contentswere determined and the sediment horizon sectioned andanalyzed in detail with values of both surface and severaldeeper layers (Fig 2) in the upper ranges of the studies con-sidered Whereas the determination of OM by LOI is amore direct and less expensive procedure it is a semi-quan-titative method A parallel analysis of organic matter usinga CHN analyzer is strongly suggested at least on a subsetof samples in order to obtain a more accurate measure ofthe total organic carbon content of sediments (Leong andTanner 1999) The determination of OM by LOI couldthen be reasonably employed on a larger group of sampleseg for routinemonitoring surveys applying site-specificOM vs TOC conversion factors In fact we suggest thatdue to the large variability in the pool of sedimentaryorganic matter in the lagoon systems (eg Puscedduet al 1999 Frangipane 2005) such relationships shouldbe tested and applied in each individual lagoon On arelated note we must caution that methodological differ-ences in the determination of OM among the various stud-ies (Table 4) may render a comparison difficult betweendifferent lagoons andor studies if no proper standardiza-tion is made

The analysis of case studies reported in Table 4 alsohighlights that sediment grain size is often not consideredat all (about half of cases) with only 9 out of 40 studiesreporting combined analysis of grain size organic matter(either as OM or TOC) and benthic communities Further-more among these cases grain size data are mostlyreported to describe the general characteristics of sedimentsof the investigated environment without any statistical cor-relation with the chemical and biological variables Con-founding terms are even used sometimes to describesediment classes (eg the use of the term lsquosiltrsquo is sometimesreferred to the lt63 lm grain size intervals) This review


Table 4Comparison of organic matter (OM) and total organic carbon (TOC) content of sediments in Mediterranean coastal lagoons

Lagoon Sub-basin

Sedimentlayer (cm)

OM ()a TOC ()e Grain size Benthos Authors

Mean andorrange(s) (plusmnSD)

LOI temperaturetime

Mean andorrange (plusmnSD)

Variable used Method

1 SrsquoEna Arrubia (SardiniaItaly)

SWE 0ndash5 20 plusmn 12ndash100 plusmn 30

350 C18 h Nd SandndashMud Sieve + Laser Nd De Falco andGuerzoni (1995)

2 Thau (France) NWE 0ndash5 Nd Nd 067-484 SandndashSiltndashClay Laser Nd Mesnage and Picot(1995)

3 Prevost (France) NWE 0ndash10 101 plusmn 14 550 ClsquolsquoUntilconstant weightrdquo

Nd Nd Nd Nd Bartoli et al (1996)

4 Thau (France) NWE 0ndash5 13 plusmn 02ndash50 plusmn 25

500 C6 h Nd SandndashSilt Sieve Nd De Casabianca et al(1997)

5 Sacca di Goro (Italy) ADR 0ndash2 53 plusmn 10ndash137 plusmn 19

450 C24 h Nd Nd Nd Nd Giordani et al(1997)

6 Nador (Morocco) ALB lsquolsquoSurfacerdquo Nd Nd 24 plusmn 16 (01ndash63) SandndashSiltndashClay Na Nd El-Alami et al(1998)

7 Mejean-Perols (France) NWE 0ndash5 Nd Nd 51 (26ndash71) SandndashSiltndashClay Laser Nd Gomez et al (1998)8 Venice Palude della Rosa

(Italy)ADR 0ndash5 68ndash128 550 CNa Nd Nd Nd Macrobenthos Tagliapietra et al

(1998)9 Stagnone Marsala (Italy) TYR 0ndash1 104ndash172b 450 C2 h 137ndash237f Nd Nd Nd Pusceddu et al

(1999)10 Ghar El Melh (Tunisia) TYR 0ndash2 Nd Nd Nd Nd Nd Nd Added (2001)11 Valle Smarlacca (Italy) ADR 0ndash2 114 plusmn 35 550 C3 h Nd Nd Nd Nd Azzoni et al (2001)12 Orbetello (Italy) TYR 0ndash1 4ndash16h 450 C4 h Nd Nd Nd Macrobenthos Lardicci et al (2001)13 Mellah (Algeria) SWE 0ndash5 94 plusmn 87 (06ndash

236)600 CNa Nd Nd Nd Ndi Draredja and Beldi

(2001)14 Sacca di Goro (Italy) ADR 0ndash10 120 plusmn 01ndash

164 plusmn 01450 C4 h Nd SandndashSiltndashClay Sieve + Pipette Macrobenthos Mistri et al (2001)

15 Bardawil (Egypt) SLE 0ndash2 Nd Nd 12 plusmn 045 (087ndash24)

SandndashSiltndashClay Sieve + Pipette Nd Taher (2001)

16 Fattibello and Spavola(Italy)

ADR 0ndash2 Nd Nd 234 plusmn 116ndash285 plusmn 104

SandndashMud Sieve-X-raySedigraph

Nd Frascari et al (2002)

17 Lesina (Italy) ADR 0ndash1 Nd Nd 04ndash17f SandndashMud Sieve Meiobenthos Gambi et al (2003)18 Valli di Comacchio (Italy) ADR 0ndash05 7ndash20h 500 CNa Nd Nd Nd Macrobenthos Munari et al (2003)19 Berre (France) NWE lsquolsquoSedndashwater

interfacerdquo

Nd Nd 230ndash293 SandndashMud Laser Macrobenthos Rosenberg et al(2003)

20 Cabras (Sardinia Italy) SWE 0ndash2 105 plusmn 24 (35ndash143)

500 C3 h 328 plusmn 072 (096ndash429)

All grain size spectra(one phi interval)

Sieve + Laser Ndj De Falco et al(2004)

21 Monolimni (Greece) AEG 0ndash10 015ndash22 Na Nd Median Sieve + Pipette Macrobenthos Kevrekidis (2004)22 Cabras (Sardinia Italy) SWE 0ndash2 Nd Nd Nd Statistical moments Sieve + Laser Macrobenthos Magni et al (2004b)23 Stagnone Marsala (Italy) TYR 0ndash10 06 plusmn 01ndash

156 plusmn 13450 C4 h 02 plusmn 01ndash

21 plusmn 06fNd Nd Meiobenthos Mirto et al (2004)

24 Tsopeli Tsoukalio Rodiaand Logarou (Greece)

ION 0ndash2 Nd Nd 282 plusmn 155ndash311 plusmn 096 (11ndash53)

SandndashSiltndashClay Sieve + Pipette Macrobenthos Reizopoulou andNicolaidou (2004)

25 Papas (Greece) ION 0ndash2 Nd Nd 461 plusmn 017 (29-56)


26 Molino (Italy) ADR 0ndash3 78ndash134 Na Nd Nd Nd Macrobenthos Sorokin et al (2004)(continued on next page)

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l200712004

Table 4 (continued)

Lagoon Sub-basin

Sedimentlayer (cm)



LOItemperaturetime


Variableused

Method

27 Lesina (Italy) ADR 0ndash5 98 plusmn 17ndash173 plusmn 13 550 C3 h Nd SandndashMud

Sieve Meiobenthos Fabbrocini et al(2005)

28 Venice (Italy) ADR 0ndash5 03ndash223 350 Cc16 h 021ndash150 SandndashSiltndashClay

Sieve + Pipette Ndk Frangipane (2005)


500 C3 h Nd Nd Nd Macrobenthos Magni et al (2005b)

30 Mar Menor (Spain) SWE 0ndash5 22 plusmn 01ndash82 plusmn 03 450 C6 h 090 plusmn 002ndash160 plusmn 024

Nd Nd Macrobenthos Marın-Guirao et al(2005)

31 Laki (Greece) AEG 0ndash10 031ndash215 Na Nd Median Sieve + Pipette Macrobenthos Mogias andKevrekidis (2005)

32 Venice central basin (Italy) ADR 0ndash5 Nd Nd 03ndash2h SandndashMud

Sieve Nd Sfriso et al (2005)

33 Bizerte (Tunisia) TYR lsquolsquoToprdquo Nd Nd 023ndash191 Nd Nd Nd Trabelsi and Driss(2005)

34 Marsala (Italy) TYR 0ndash1 08ndash52d 450 C4 h Nd Nd Nd Nd Culotta et al (2006)35 Tsopeli Tsoukalio Rodia and

Logarou (Greece)ION lsquolsquoSurfacerdquo Nd Nd 292ndash655 Sandndash

SiltndashClaySieve-X-raySedigraph

Nd Karageorgis (2007)

36 Valle Smarlacca (Italy) ADR Na 35ndash177 550 C8 h Nd Nd Nd Macrobenthos Ponti et al (2007)37 Lesina (Italy) ADR 0ndash5 129 plusmn 15ndash

228 plusmn 16b450 C2 h Nd Nd Nd Nd Giordani et al (in

press)38 Sacca di Goro (Italy) ADR 0ndash5 18 plusmn 10ndash145 plusmn 06 450 C2 h Nd Nd Nd Nd Giordani et al (in

press)39 Santa Giusta (Sardinia Italy) SWE 0ndash20l 19ndash167 500 C3 h 048ndash425 Nd Nd Macrobenthos Magni et al (in

press)40 Cabras (Sardinia Italy) SWE 0ndash24l 81 plusmn 22 (26ndash129) 500 C3 h 328 plusmn 072 (096ndash

429)g68 lm Sieve + Laser Macrobenthos This study

Details on sediment grain size and benthic invertebrate assemblages are also given when available (SD standard deviation Nd not determined Na not available) Lagoons were classified according tothe ten marine sub-basins in which the whole Mediterranean basin is usually divided (UNEPFAOWHOIAEA (1990)) ADR Adriatic Sea AEG Aegean Sea ALB Alboran Sea ION Ionian SeaNWE Northwestern Mediterranean Sea SLE South-Levantine Sea SWE Southwestern Mediterranean Sea TYR Tyrrhenian Sea (not present Central Sea and North Levantine Sea sub-basins)Studies are listed by the year of publication and within one year by alphabetical order of Authors

a Organic matter (OM) determined by loss of weight on ignition (LOI) except Sorokin et al 2004 (wet chromic oxidation assuming 40 of TOC in OM) Kevrekidis 2004 and Mogias andKevrekidis 2005 (oxidation by H2O2)

b OM bulk in the highest range mainly associated with angiospermsc OM determined by fractionation at various temperatures (ie 250 C 350 C 450 C and 550 C)d OM determined after elimination of carbonatese Total organic carbon (TOC) determined by CHN elemental analyzer except Mesnage and Picot 1995 (reported as a pers comm by Gadel) El-Alami et al 1998 Pusceddu et al 1999 Gambi

et al 2003 Mirto et al 2004 (colorimetric method) Added 2001 (chemical oxidation) Reizopoulou and Nicolaidou 2004 (Tsopeli Tsoukalio Rodia and Lagarou lagoons titration) Trabelsi andDriss 2005 (titration) In Sfriso et al (2005) TOC calculated as the difference between total carbon and inorganic carbon (determined by CHN elemental analyzer)

f Biopolymeric carbon (sum of carbohydrate protein and lipid C-equivalents)g Based on De Falco et al (2004)h Values estimated from figurei Macrobenthos investigated by Draredja (2005)j Macrobenthos investigated by Magni et al (2004b)

k Macrobenthos investigated by Pessa (2005)l Sectioned cores at 2 cm intervals

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ARTICLE IN PRESS

highlights that (bio)geochemical approaches often do notconsider benthic-community features while biologically-oriented approaches lack an evaluation of the (bio)geo-chemical properties of a specific lagoon system

A final consideration can be made of the geographicaldistribution of the studies analyzed here The Adriaticsub-basin was the most studied area (ADR 14 out of 40studies) followed by the southwestern sub-basin (SWEeight out of 40 studies) whereas significant data gapsexisted in the south and southeastern basin In additionmost studies (875) were conducted in fewer Europeancountries (Italy France Greece and Spain) This callsfor increased cooperation and coordination among scien-tists and institutions in the whole Mediterranean basintowards a better understanding of the lagoon and ofcoastal marine and estuarine systems at the regional (basin)level (Magni 2003 Magni et al 2004a)

Overall it appears that much still remains to be donewith regard to the monitoring of Mediterranean coastallagoons and the integration of the results from different dis-ciplines such as analysis of sediment grain size and compo-sitional trends in relation to the distribution andcomposition of the biotic components We have providedhere a framework for evaluating the importance of investi-gating the distribution and dynamics of fine sediments inrelation to both organic enrichment and benthic macroin-vertebrate communities We suggest that monitoring pro-grams especially in organic-enriched lagoons shouldconsider the sediment fraction most tightly correlated withorganic matter (often being the overlooked cohesive frac-tion of sediments) to be integrated in direct correlationanalysis with other major abiotic (eg TOC) and biotic(eg benthic assemblages) variables in order allow a betterassessment of benthicndashsediment relationships and the eco-logical quality of the system

Acknowledgements

This paper was elaborated as part of the SIGLA project(Sistema per il Monitoraggio e la Gestione di Lagune edAmbiente) funded by the Italian Ministry for Scientific Re-search We gratefully acknowledge an anonymous reviewerfor providing insightful comments on the manuscript It iscontribution number MPS-08001 of the EU Network ofExcellence MarBEF

References

Added A 2001 Biogeochemical cycles of Org-C Tot-N and Tot-S in thesediments of the Ghar El Melh Lagoon (north of Tunisia) Journal ofMarine Systems 30 139ndash154

Arvanitidis C Chatzigeorgiou G Koutsoubas D Kevrekidis TDounas C Eleftheriou A Koulouri P Mogias A 2005 Estimat-ing lagoonal biodiversity in Greece comparison of rapid assessmenttechniques Helgoland Marine Research 59 177ndash186

Azzoni R Giordani G Bartoli M Welsh DT Viaroli P 2001 Ironsulphur and phosphorus cycling in the rhizosphere sediments of a


eutrophic Ruppia cirrhosa meadow (Valle Smarlacca Italy) Journal ofSea Research 45 15ndash26

Bartoli M Cattadori M Giordani G Viaroli P 1996 Benthic oxygenrespiration ammonium and phosphorus regeneration in surficialsediments of the Sacca di Goro (Northern Italy) and two Frenchcoastal lagoons a comparative study Hydrobiologia 329 143ndash159

Basset A Sangiorgio F Pinna M 2004 Monitoring with benthicmacroinvertebrates advantages and disadvantages of body sizedescriptors Aquatic Conservation Marine and Freshwater Ecosys-tems 14 S43ndashS58

Bates DM Watts DG 1988 Nonlinear Regression Analysis and itsApplications John Wiley amp Sons New York

Bianchi CN Morri C 1996 Ficopomatus lsquoreefsrsquo in the Po River Delta(Northern Adriatic) their constructional dynamics biology andinfluences on the brackish-water biota Marine Ecology PSZN 1751ndash66

Bianchi CN Morri C 2001 The battle is not to the strong serpulidreefs in the lagoon of Orbetello (Tuscany Italy) Estuarine Coastaland Shelf Science 53 215ndash220

Blanchet H Lavesque N Ruellet T Dauvin JC Sauriau PGDesroy N Desclaux C Leconte M Bachelet G Janson A-L inpress Use of biotic indices in semi-enclosed coastal ecosystems andtransitional waters habitatsmdashimplications for the implementation ofthe European Water Framework Directive Ecological Indicatorsdoi101016jecolind200704003

Borja A Heinrich H 2005 Implementing the European WaterFramework Directive the debate continues Marine PollutionBulletin 50 486ndash488

Borja A Franco J Perez V 2000 A Marine Biotic Index to establishthe ecological quality of soft-bottom benthos within Europeanestuarine and coastal environments Marine Pollution Bulletin 401100ndash1114

Borja A Valencia V Franco J Muxika I Bald J Belzunce MJSolaun O 2004 The water framework directive water alone or inassociation with sediment and biota in determining quality standardsMarine Pollution Bulletin 49 8ndash11

Borja A Dauer D Dıaz R Llanso RJ Muxika I Rodrıguez JGSchaffner L in press Assessing estuarine benthic quality conditionsin Chesapeake Bay A comparison of three indices EcologicalIndicators doi101016jecolind200705003

Buchanan JB Longbottom MR 1970 The determination of organicmatter in marine muds the effect of the presence of coal and theroutine determination of protein Journal of Experimental MarineBiology and Ecology 5 158ndash169

Cancemi G De Falco G Pergent G 2003 Effects of organic matterinput from a fish farming facility on a Posidonia oceanica meadowEstuarine Coastal and Shelf Science 56 961ndash968

Casula R Coni M Diliberto L Murrau A 1999 Comparisonbetween experimental and theoretical assessment of phosphorous andnitrogen loadings flowing into a coastal lagoon In Brebbia CAAnagnostopoulos P (Eds) Proceedings Water Pollution V LemnosGreece WIT Press Southampton UK pp 341ndash351

Clarke KR Warwick RM 2001 Changes in Marine Communities AnApproach to Statistical Analysis and Interpretation second edPRIMER-E Plymouth UK

Como S Magni P Casu D Floris A Giordani G Natale SFenzi GA Signa G De Falco G 2007 Sediment characteristicsand macrofauna distribution along a human-modified inlet in theGulf of Oristano (Sardinia Italy) Marine Pollution Bulletin 54733ndash744

Crane M 2003 Proposed development of Sediment Quality Guidelinesunder the European Water Framework Directive a critique Toxicol-ogy Letters 142 195ndash206

Culotta L De Stefano C Gianguzza A Mannino MR Orecchio S2006 The PAH composition of surface sediments from Stagnonecoastal lagoon Marsala (Italy) Marine Chemistry 99 117ndash127

Dauvin JC Ruellet T 2007 Polychaeteamphipod ratio revisitedMarine Pollution Bulletin 55 215ndash224



ARTICLE IN PRESS

De Casabianca ML Laugier T Marinho-Soriano E 1997 Seasonalchanges of nutrients in water and sediment in a Mediterranean lagoonwith shellfish farming activity (Thau Lagoon France) ICES Journalof Marine Science 54 905ndash916

De Falco G Guerzoni S 1995 Sedimentological characterisation andorganic matter budget of a shallow coastal lagoon SrsquoEna Arrubia(western Sardinia) Plinius Italian Supplement to the European Journalof Mineralogy 14 134ndash136

De Falco G Magni P Terasvuori LMH Matteucci G 2004Sediment grain-size and organic carbon distribution in the Cabraslagoon (Sardinia west Mediterranean) Chemistry and Ecology 20(Supplement 1) S367ndashS377

Dıaz RJ Rosenberg R 1995 Marine benthic hypoxia a review of itsecological effects and the behavioural responses of benthic macrofa-una Oceanography and Marine Biology An Annual Review 33 245ndash303

Dıaz RJ Solan M Raymond MV 2004 A review of approaches forclassifying benthic habitats and evaluating habitat quality Journal ofEnvironmental Management 73 165ndash181

Draredja B 2005 Structure et organisation de la macrofaune benthiquede la lagune Mellah (Algerie Mediterranee Sud-Occidentale) Journalde Recherche Oceanographique 30 24ndash33

Draredja B Beldi H 2001 Caracteres hydrologiques et sedimentolog-iques drsquoun milieu lagunaire mediterraneen (lagune Mellah Algerie)Effets drsquoensablement du chenal de communication avec la merInternational Workshop on the Marine Biodiversity in IslamicCountries Algiers 22ndash24 October 2001

El-Alami M Mahjoubi R Damnati B Kamel S Icole M TaiebM 1998 Sedimentologie et geochimie organiche des sedimentssuperficiels de la lagune de Nador (Maroc nord-oriental) Journal ofAfrican Earth Sciences 26 249ndash259

Fabbrocini A Guarino A Scirocco T Franchi R DrsquoAdamo R2005 Integrated biomonitoring assessment of the Lesina Lagoon(Southern Adriatic Coast Italy) preliminary results Chemistry andEcology 21 479ndash489

Fano EA Mistri M Rossi R 2003 The ecofunctional quality index(EQI) a new tool for assessing lagoonal ecosystem impairmentEstuarine Coastal and Shelf Science 56 709ndash716

Fenchel T King GM Blackburn H 1998 Bacterial BiogeochemistryAcademic Press San Diego p 336

Fisher WS Jackson LE Suter II GW Bertram P 2001 Indicatorsfor human and ecological risk assessment a US EnvironmentalProtection Agency perspective Human and Ecological Risk Assess-ment 7 961ndash970

Fleischer D Gremare A Labrune C Rumohr H Vanden Berghe EZettler ML 2007 Performance comparison of two biotic indicesmeasuring the ecological status of water bodies in the Southern Balticand Gulf of Lions Marine Pollution Bulletin 54 1598ndash1606

Florek RJ Rowe GT 1983 Oxygen consumption and dissolvedinorganic nutrient production in marine coastal and shelf sediments ofthe middle Atlantic bight International Reviews Hydrobiologia 6873ndash112

Frangipane G 2005 Distribuzione spaziale della sostanza organica neisedimenti lagunari e suoi rapporti con morfologia e biota PhD thesisUniversity of Carsquo Foscari Venice Italy

Frascari F Matteucci G Giordano O 2002 Evolution of an eutrophiccoastal lagoon ecosystem from the study of bottom sedimentsHydrobiologia (475476) 387ndash401

Gambi C Totti C Manini E 2003 Impact of organic loads andenvironmental gradients on microphytobenthos and meiofaunal dis-tribution in a coastal lagoon Chemistry and Ecology 19 207ndash223

Giordani G Azzoni R Bartoli M Viaroli P 1997 Seasonalvariations of sulphate reduction rates sulphur pools and ironavailability in the sediment of a dystrophic lagoon (Sacca di GoroItaly) Water Air and Soil Pollution 99 363ndash371

Giordani G Azzoni R Viaroli P in press A rapid assessment of thesedimentary buffering capacity towards free sulphides Hydrobiologia


Gomez E Millet B Picot B 1998 Nutrient accumulation in a lagoonsediment relating to hydrodynamic conditions Oceanologica Acta 21805ndash817

Gray JS 1979 Pollution-induced changes in populations PhilosophicalTransactions of the Royal Society (Series B) 286 545ndash561

Hansen BW 1999 Cohort growth of planktotrophic polychaete larvae ndashare they food limited Marine Ecology Progress Series 178 109ndash119

Hyland J Balthis L Karakassis I Magni P Petrov A Shine JVestergaard O Warwick R 2005 Organic carbon content ofsediments as an indicator of stress in the marine benthos MarineEcology Progress Series 295 91ndash103

Ishikawa K 1989 Relationship between bottom characteristics andbenthic organisms in the shallow water of Oppa Bay Miyagi MarineBiology 102 265ndash273

Jones AR Watson-Russell CJ Murray A 1986 Spatial patterns inthe macrobenthic communities of the Hawkesbury estuary New SouthWales Australian Journal of Freshwater Research 37 521ndash543

Karageorgis AP 2007 Geochemical study of sediments from theAmvrakikos Gulf lagoon complex Greece Transitional WatersBulletin 1 (3) 3ndash8

Kevrekidis T 2004 Seasonal variation of macrozoobenthic communitystructure at low salinities in a Mediterranean lagoon (Monolimnilagoon Northern Aegean) International Review of Hydrobiology 89407ndash425

Kihslinger RL Woodin SA 2000 Food patches and a surface depositfeeding spionid polychaete Marine Ecology Progress Series 201 233ndash239

Lardicci C Como S Corti S Rossi F 2001 Recovery of themacrozoobenthic community after sever dystrophic crises in a Med-iterranean coastal lagoon (Orbetello Italy) Marine Pollution Bulletin42 202ndash214

Leong LS Tanner PN 1999 Comparison of methods for determina-tion of organic carbon in marine sediment Marine Pollution Bulletin38 875ndash879

Magni P 2003 Biological benthic tools as indicators of coastal marineecosystems health Chemistry and Ecology 19 363ndash372

Magni P Malej A Moncheva S Vanden Berghe E Appeltans WCuvelier D van Avesaath PH Hummel H Heip CHR Mees J(Eds) 2004a Electronic conference on lsquoThe Southern and EasternMediterranean Sea and the Black Sea new challenges for marinebiodiversity research and monitoringrsquo ndash summary of discussions 6ndash24September 2004 Flanders Marine Institute (VLIZ) OostendeBelgium viii p 108

Magni P Micheletti S Casu D Floris A De Falco G Castelli A2004b Macrofaunal community structure and distribution in a muddycoastal lagoon Chemistry and Ecology 20 (Suppl 1) S397ndashS409

Magni P Hyland J Manzella G Rumohr H Viaroli P Zenetos A(Eds) 2005a Proceedings of the Workshop lsquolsquoIndicators of Stress inthe Marine Benthosrdquo Torregrande-Oristano (Italy) 8ndash9 October 2004Paris UNESCOIOC IMC iv + 46 pp IOC Workshops Reports195

Magni P Micheletti S Casu D Floris A Giordani G Petrov ADe Falco G Castelli A 2005b Relationships between chemicalcharacteristics of sediments and macrofaunal communities in theCabras lagoon (Western Mediterranean Italy) Hydrobiologia 550105ndash119

Magni P Rajagopal S van der Velde G Fenzi GA KassenbergJ Vizzini S Mazzola A Giordani G in press Sedimentfeatures macrozoobenthic assemblages and trophic relationships(d13C and d15N analysis) following a dystrophic event with anoxiaand sulphide development in the Santa Giusta lagoon (westernSardinia Italy) Marine Pollution Bulletin doi101016jmarpolbul200710015

Marın-Guirao L Augusto C Marın A Javier L Vita R 2005Establishing the ecological quality status of soft-bottom mining-impacted coastal water bodies in the scope of the Water FrameworkDirective Marine Pollution Bulletin 50 374ndash387



ARTICLE IN PRESS

Mayer LM 1994a Surface area control of organic carbon accumulationin continental shelf sediments Geochimica et Cosmochimica Acta 581271ndash1284

Mayer LM 1994b Relationships between mineral surfaces and organiccarbon concentrations in soils and sediments Chemical Geology 114347ndash363

McCave IN Menighetti B Robinson SG 1995 Sortable silt and finesediment sizecomposition slicing parameters for palaeocurrents speedand palaeooceanography Paleoceanography 10 593ndash610

McLusky DS Elliott M 2007 Transitional waters a new approachsemantics or just muddying the waters Estuarine Coastal and ShelfScience 71 359ndash363

Mesnage V Picot B 1995 The distribution of phosphate in sedimentsand its relation with eutrophication of a Mediterranean coastal lagoonHydrobiologia 297 29ndash41

Mirto S La Rosa T Mocciaro G Costa K Sara G Mazzola A2004 Meiofauna and benthic microbial biomass in a semi-enclosedMediterranean Marine system (Stagnone of Marsala Italy) Chemistryand Ecology 20 (Supplement 1) S387ndashS396

Mistri M Rossi R Fano EA 2001 Structure and secondaryproduction of a soft bottom macrobenthic community in a brackishlagoon (Sacca di Goro north-eastern Italy) Estuarine Coastal andShelf Science 52 605ndash616

Mistri M Marchini A in press The fuzzy index of ecosystem integrity(FINE) a new indicator of environmental integrity for lagoonalecosystems Hydrobiologia

Mogias A Kevrekidis T 2005 Macrozoobenthic community structurein a poikilohaline Mediterranean lagoon (Laki Lagoon northernAegean) Helgoland Marine Research 59 167ndash176

Munari C Modugno S Ghion F Castaldelli G Fano EA RossiR Mistri M 2003 Recovery of the macrobenthic community in theValli di Comacchio northern Adriatic Sea Italy Oceanologica Acta26 67ndash75

Murenu M Olita A Sabatini A Follesa MC Cau A 2004Dystrophy effects on the Liza ramada (Risso 1826) (Pisces Mugilidae)population in the Cabras lagoon (central-western Sardinia) Chemistryand Ecology 20 (Supplement 1) S425ndashS433

Muxika I Borja A Bald J 2007 Using historical data expertjudgement and multivariate analysis in assessing reference conditionsand benthic ecological status according to the European WaterFramework Directive Marine Pollution Bulletin 55 16ndash29

Pearson TH Rosenberg R 1978 Macrobenthic succession in relationto organic enrichment and pollution of the marine environmentOceanography and Marine Biology An Annual Review 16 229ndash311

Pessa G 2005 Aspetti metodologici dello studio del macrozoobenthosnegli ambienti acquatici di transizione PhD thesis University of CarsquoFoscari Venice Italy

Ponti M Abbiati M 2004 Quality assessment of transitional watersusing a benthic biotic index the case study of the Piallassa Baiona(northern Adriatic Sea) Aquatic Conservation Marine and Freshwa-ter Ecosystems 14 S31ndashS41

Ponti M Colangelo MA Ceccherelli VU 2007 Compositionbiomass and secondary production of the macrobenthic invertebrateassemblages in a coastal lagoon exploited for extensive aquacultureValle Smarlacca (northern Adriatic Sea) Estuarine Coastal ShelfScience 75 78ndash79

Pranovi F Da Ponte F Torricelli P 2007 Application of bioticindices and relationship with structural and functional features ofmacrobenthic community in the lagoon of Venice an example over along time series of data Marine Pollution Bulletin 54 1607ndash1618

Pusceddu A Sara G Armeni M Fabiano M Mazzola A 1999Seasonal and spatial changes in the sediment organic matter of a semi-enclosed marine system (W-Mediterranean Sea) Hydrobiologia 39759ndash70

Quintino V Rodrigues AM 1989 Environment gradients and distri-bution of macrozoobenthos in three Portuguese coastal systemsObidos Albufeira and Alvor In Ryland JS Tyler PA (Eds)


Reproduction Genetics and Distribution of Marine Organisms Olsenamp Olsen Fredensborg pp 441ndash450

Quintino V Elliott M Rodrigues AM 2006 The derivationperformance and role of univariate and multivariate indicators ofbenthic change case studies at differing spatial scales Journal ofExperimental Marine Biology and Ecology 330 368ndash382

Reizopoulou S Nicolaidou A 2004 Benthic diversity of coastalbrackish-water lagoons in western Greece Aquatic ConservationMarine and Freshwater Ecosystems 14 S93ndashS102

Reizopoulou S Nicolaidou A 2007 Index of size distribution (ISD) amethod of quality assessment for coastal lagoons Hydrobiologia 577141ndash149

Reizopoulou S Thessalou-Legaki M Nicolaidou A 1996 Assessmentof disturbance in Mediterranean lagoons an evaluation of methodsMarine Biology 125 189ndash197

Rhoads DC 1974 Organismndashsediment relation on the muddy sea floorOceanography and Marine Biology An Annual Review 12 263ndash300

Rosenberg R Blomqvist M Nilsson HC Cederwall H DimmingA 2004 Marine quality assessment by use of benthic species-abundance distributions a proposed new protocol within the Euro-pean Union Water Framework Directive Marine Pollution Bulletin49 728ndash739

Rosenberg R Gremare A Amouroux JM Nilsson HC 2003Benthic habitats in the northwest Mediterranean characterised bysedimentary organics benthic macrofauna and sediment profileimages Estuarine Coastal and Shelf Science 57 297ndash311

Santschi P Hohener P Benoit G Buchholtz-ten Brink M 1990Chemical processes at the sedimentndashwater interface Marine Chemistry30 269ndash315

Schlacher TA Wooldridge TH 1996 Axial zonation patterns ofsubtidal macrozoobenthos in the Gamtoos estuary South AfricaEstuaries 19 680ndash696

Schwindt E Iribarne OO 2000 Settlement sites survival and effects onbenthos of an introduced reef-building polychaete in a SW Atlanticcoastal lagoon Bulletin of Marine Science 67 73ndash82

Sfriso A Favaretto M Ceoldo S Facca C Marcomini A 2005Organic carbon changes in the surface sediments of the Venice lagoonEnvironment International 31 1002ndash1010

Simboura N Zenetos A 2002 Benthic indicators to use in ecologicalquality classification of Mediterranean soft bottoms marine ecosys-tems including a new biotic index Mediterranean Marine Science 3277ndash111

Snelgrove PVR Butman CA 1994 Animalndashsediment relationshipsrevisited cause versus effect Oceanography and Marine BiologyAnnual Review 32 111ndash177

Sorokin YI Sorokin PY Zakuskina OY Dallocchio F 2004Features of hypereutrophic Molino lagoon ecosystem dominated bysedentary polychaetes Hydrobiologia 518 189ndash200

Tagliapietra D Pavan M Wagner C 1998 Macrobenthic commu-nity changes related to eutrophication in Palude della Rosa(Venetian lagoon Italy) Estuarine Coastal and Shelf Science 47217ndash226

Taher AG 2001 Geochemistry of recent marine sediments inthe Bardawil lagoon northern Sinai Egypt Hydrobiologia 4575ndash16

Teske PR Wooldridge TH 2003 What limits the distribution ofsubtidal macrobenthos in permanently open and temporarily openclosed South African estuaries Salinity vs sediment particle sizeEstuarine Coastal and Shelf Science 57 225ndash238

Trabelsi S Driss MR 2005 Polycyclic aromatic hydrocarbons insuperficial coastal sediments from Bizerte Lagoon Tunisia MarinePollution Bulletin 50 344ndash348

Tyson RV 1995 Sedimentary Organic Matter Chapman amp HallLondon 615 pp

UNEPFAOWHOIAEA 1990 Assessment of the state of pollution ofthe Mediterranean sea by organohalogen compounds UNEPMAPTechnical Report no 39 Athens Greece



ARTICLE IN PRESS

Viaroli P Christian RR 2003 Description of trophic status hyper-autotrophy and dystrophy of a coastal lagoon through a potentialoxygen production and consumption index-TOSI trophic oxygenstatus index Ecological Indicators 3 237ndash250

Viaroli P Bartoli M Giordani G Magni P Welsh DT2004 Biogeochemical indicators as tools for assessing sediment


qualityvulnerability in transitional aquatic ecosystems AquaticConservation Marine and Freshwater Ecosystems 14S19ndashS29

Zettler ML Schiedek D Bobertz B 2007 Benthic biodiversity indicesversus salinity gradient in the southern Baltic Sea Marine PollutionBulletin 55 258ndash270



ARTICLE IN PRESS

influenced by freshwater flowsrdquo and their usually high sed-iment-surface-area to water-volume ratio transitionalwaters can be considered a very sensitive aquatic systemwhere benthic components and processes play an impor-tant regulatory function for the whole ecosystem (Viaroliet al 2004) Accordingly there has been a major develop-ment of biotic benthic indices in Europe in recent yearswith special attention paid to the use of macroinvertebratecommunities in assessing the ecological quality status ofcoastal and estuarine waters (Borja et al 2000 Simbouraand Zenetos 2002 Rosenberg et al 2004 Dauvin andRuellet 2007 Muxika et al 2007) as well as coastallagoons (Reizopoulou et al 1996 Fano et al 2003 Bassetet al 2004 Ponti and Abbiati 2004 Reizopoulou and Nic-olaidou 2007 Mistri and Marchini in press) Comparisonsof different biotic indices and assessments of their applica-bility in different geographical areas of the world are nowalso on the rise (Dıaz et al 2004 Arvanitidis et al 2005Magni et al 2005a Quintino et al 2006 Fleischer et al2007 Pranovi et al 2007 Zettler et al 2007 Blanchetet al in press Borja et al in press) In contrast the phys-ical and chemical characteristics of sediments appear to beless explored and more controversial in terms both of theirintegration in the biological elements and their relevance inassessments of environmental quality (Crane 2003 Borjaet al 2004 Borja and Heinrich 2005 Marın-Guiraoet al 2005) This is particularly true in non-tidal (sensu

McLusky and Elliott 2007) transitional systems such asMediterranean coastal lagoons Here only recently qual-ityvulnerability biogeochemical tools and integrated mea-surements of status variables and system metabolism arebeing proposed (Viaroli and Christian 2003 Viaroliet al 2004 Giordani et al in press)

It is a classical general assumption that sedimentaryorganic matter (OM) influences the composition and dis-tribution of macrobenthos (Rhoads 1974 Pearson andRosenberg 1978 Gray 1979) It is also well known thatthe level of OM is related to the grain size composition ofsediments In particular a higher content of OM tends tooccur at an increasing mud (clay) content due to a greatersurface area and higher number of complexing sites of thesediments (Buchanan and Longbottom 1970 Mayer1994ab Tyson 1995) A high mud content together withexcessive OM may then result in a lower permeation ofoxygen an increased microbial oxygen uptakedemandand a subsequent buildup of toxic byproducts (egammonia dissolved sulphide) (Florek and Rowe 1983Santschi et al 1990 Fenchel et al 1998) This can leadto impoverished benthic communities dominated by fewresistant r-selected opportunistic species (Dıaz and Rosen-berg 1995 Como et al 2007) Notwithstanding com-bined and confounding effects of other majorenvironmental factors such as bathymetry and salinity(eg Jones et al 1986 Schlacher and Wooldridge1996 Teske and Wooldridge 2003) clear patterns ofmacrobenthos change have been demonstrated for sometime along marked gradients of mud andor organic mat-


ter enrichment (eg Ishikawa 1989 Quintino and Rodri-gues 1989) In fact it appears that works on benthosndashsediment relationships in marine and estuarine watershave been mainly based on a rather coarse analysis ofsediment grain size features eg on the sand vs mudfractions generally restricted to the few uppermost inte-grated centimeters (eg see Table 1 in Snelgrove and But-man 1994) Several benthic studies on animalndashsedimentassociations have also been conducted in lagoon systemsEspecially in muddy systems however like many of thecoastal lagoons in the Mediterranean Sea this approachmay be of little use In contrast a detailed analysis of sed-iment grain size composition within the muds may revealsedimentological trends related to both hydrodynamicenergy and lagoon morphology which are not detectableotherwise (De Falco et al 2004) In these often eutrophicand organic-enriched systems such analysis is importantalso because the partitioning and transport of fine sedi-ment particles may strongly influence the redistributionand accumulation of large amounts of organic matterand consequently the distribution of macrozoobenthosand the overall trophic status and functioning of alagoon However there is a lack of studies linking the dis-tribution and dynamics of fine sediments to the distribu-tion of benthic macroinvertebrate communities incoastal lagoons

In the present study we aimed at assessing the relation-ships between the distribution of fine sediments the levelsof organic matter in the sediments and the structure andcomposition of macrobenthic assemblages in a Mediterra-nean lagoon system as well as evaluating the overall eco-logical relevance of such relationships For thesepurposes we used the Cabras lagoon (Sardinia Italy) asa case study where we had previously conducted extendedsurveys on both sediment characteristics (De Falco et al2004) and macrozoobenthic assemblages (Magni et al2004b 2005b) For the present study we made a detailedanalysis of sediment particle distribution within the mudswith specific analytical size intervals of 05 lm and focusedon the 68 lm grain size fraction of sediments (hereafterlsquolsquofine sedimentsrdquo) This was based on the fact that the8 lm boundary is known to separate non-cohesive fromcohesive sediments (McCave et al 1995) and because thisfraction was found to be most correlated with the totalorganic carbon (TOC) content of sediments in the Cabraslagoon (De Falco et al 2004) As for the macrozooben-thos the biomass of individual taxa as well as speciesrsquo rich-ness and diversity not used in our previous study (Magniet al 2004b) were analyzed together with the total abun-dances A review of studies reporting OM andor TOCcontent of sediments as well as grain size and biologicalbenthic features in Mediterranean coastal lagoons wasalso made This was to provide a general assessment ofbenthicndashsediment studies and monitoring schemes in thesesystems on a regional scale as well as an operationalframework for both lagoon ecology and managementissues



ARTICLE IN PRESS


21 Study area



0

Gulf ofOristano

CabrasLagoon

-5 m-10 m

-10 m-10 m

-10 m

-5 m

-20 m

-5 m

0 2 km

Sardinia

ITALY







C1C2

C3C4

C5C6C7

C8C9C10

C11C12C13C14

C15C16C17C18

C19C20C21C22C23C24

C25C26C27C28C29

C30C31


Mare e Foghe

Samplingstations

Down-coresamples

39deg59N

39deg55N

008deg32E08deg27E

CreeksChannel

Lagoonmouth

Dam

Lagooninlet

Cabras

CabrasLagoon

River

TanuiRiver

0 1km




ARTICLE IN PRESS





23 Data analysis







y frac14 a ebecx



variables






ARTICLE IN PRESS


3 Results



0

5

10

15

20

25Sed

imen

t dep

th (

cm)

30 60 90

le8 microm ()

5 10 15

OM ()

C1

0

5

10

15

20

25

50

le8 micro

5

OM

0

5

10

15

20

25Sed

imen

t dep

th (

cm) 50 75 100

le8 microm ()

5 10 15

OM ()

C18

0

5

10

15

20

25

50le8 micro

5

OM

0

5

10

15

20

25Sed

imen

t de

pth

(cm

) 50 75 100le8 microm ()

5 10 15

OM ()

C28

0

5

10

15

20

25

0le8 microm

0

OM

le8 micromOM






C6 C12

75 100

m ()

10 15

()

0

5

10

15

20

25

50 75 100

le8 microm ()

5 10 15

OM ()

C22 C26

75 100m ()

10 15

()

0

5

10

15

20

25

50 75 100le8 microm ()

5 10 15

OM ()

C30 C31

30 60 ()

4 8

()

0

5

10

15

20

25

50 75 100le8 microm ()

5 10 15

OM ()





0

20

40

60

80

100

le8 micro

m (

)

y = 821e-32e

R 2 = 067 (n=99)

y = 030xR2 = 075 (n=62)

0

1

2

3

4

5

TO

C (

)

-036x

0 3 6 9 12 15

OM ()

0 3 6 9 12 15

OM ()

a

b



ARTICLE IN PRESS











1

3

20

5

714

29

11

16

28

10

18

30

31

4

9

6

12 13

17

21

22

23

24

25

2627

28




Actualpermutations








ARTICLE IN PRESS






4 Discussion


enrichment






68 lm OM TOC

S 038 ns 043

N 047 ns ns

Biomass 050 ns ns

H0 ns ns ns







ARTICLE IN PRESS







ARTICLE IN PRESS












ARTICLE IN PRESS











Lagoon Sub-basin

Sedimentlayer (cm)



LOI temperaturetime




























interfacerdquo



500 C3 h 328 plusmn 072 (096ndash429)












P

Ma

gn

iet

alM

arin

eP

ollu

tion

Bu

lletinx

xx

(2

00

8)

xx

xndash

xx

x11

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004

Table 4 (continued)

Lagoon Sub-basin

Sedimentlayer (cm)



LOItemperaturetime


Variableused

Method





























12P

M

ag

ni

eta

lMa

rine

Po

llutio

nB

ulletin

xx

x(

20

08

)x

xx

ndashx

xx

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004


ARTICLE IN PRESS




Acknowledgements


References


























ARTICLE IN PRESS









































ARTICLE IN PRESS












































ARTICLE IN PRESS








ARTICLE IN PRESS


21 Study area



0

Gulf ofOristano

CabrasLagoon

-5 m-10 m

-10 m-10 m

-10 m

-5 m

-20 m

-5 m

0 2 km

Sardinia

ITALY







C1C2

C3C4

C5C6C7

C8C9C10

C11C12C13C14

C15C16C17C18

C19C20C21C22C23C24

C25C26C27C28C29

C30C31


Mare e Foghe

Samplingstations

Down-coresamples

39deg59N

39deg55N

008deg32E08deg27E

CreeksChannel

Lagoonmouth

Dam

Lagooninlet

Cabras

CabrasLagoon

River

TanuiRiver

0 1km




ARTICLE IN PRESS





23 Data analysis







y frac14 a ebecx



variables






ARTICLE IN PRESS


3 Results



0

5

10

15

20

25Sed

imen

t dep

th (

cm)

30 60 90

le8 microm ()

5 10 15

OM ()

C1

0

5

10

15

20

25

50

le8 micro

5

OM

0

5

10

15

20

25Sed

imen

t dep

th (

cm) 50 75 100

le8 microm ()

5 10 15

OM ()

C18

0

5

10

15

20

25

50le8 micro

5

OM

0

5

10

15

20

25Sed

imen

t de

pth

(cm

) 50 75 100le8 microm ()

5 10 15

OM ()

C28

0

5

10

15

20

25

0le8 microm

0

OM

le8 micromOM






C6 C12

75 100

m ()

10 15

()

0

5

10

15

20

25

50 75 100

le8 microm ()

5 10 15

OM ()

C22 C26

75 100m ()

10 15

()

0

5

10

15

20

25

50 75 100le8 microm ()

5 10 15

OM ()

C30 C31

30 60 ()

4 8

()

0

5

10

15

20

25

50 75 100le8 microm ()

5 10 15

OM ()





0

20

40

60

80

100

le8 micro

m (

)

y = 821e-32e

R 2 = 067 (n=99)

y = 030xR2 = 075 (n=62)

0

1

2

3

4

5

TO

C (

)

-036x

0 3 6 9 12 15

OM ()

0 3 6 9 12 15

OM ()

a

b



ARTICLE IN PRESS











1

3

20

5

714

29

11

16

28

10

18

30

31

4

9

6

12 13

17

21

22

23

24

25

2627

28




Actualpermutations








ARTICLE IN PRESS






4 Discussion


enrichment






68 lm OM TOC

S 038 ns 043

N 047 ns ns

Biomass 050 ns ns

H0 ns ns ns







ARTICLE IN PRESS







ARTICLE IN PRESS












ARTICLE IN PRESS











Lagoon Sub-basin

Sedimentlayer (cm)



LOI temperaturetime




























interfacerdquo



500 C3 h 328 plusmn 072 (096ndash429)












P

Ma

gn

iet

alM

arin

eP

ollu

tion

Bu

lletinx

xx

(2

00

8)

xx

xndash

xx

x11

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004

Table 4 (continued)

Lagoon Sub-basin

Sedimentlayer (cm)



LOItemperaturetime


Variableused

Method





























12P

M

ag

ni

eta

lMa

rine

Po

llutio

nB

ulletin

xx

x(

20

08

)x

xx

ndashx

xx

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004


ARTICLE IN PRESS




Acknowledgements


References


























ARTICLE IN PRESS









































ARTICLE IN PRESS












































ARTICLE IN PRESS








ARTICLE IN PRESS





23 Data analysis







y frac14 a ebecx



variables






ARTICLE IN PRESS


3 Results



0

5

10

15

20

25Sed

imen

t dep

th (

cm)

30 60 90

le8 microm ()

5 10 15

OM ()

C1

0

5

10

15

20

25

50

le8 micro

5

OM

0

5

10

15

20

25Sed

imen

t dep

th (

cm) 50 75 100

le8 microm ()

5 10 15

OM ()

C18

0

5

10

15

20

25

50le8 micro

5

OM

0

5

10

15

20

25Sed

imen

t de

pth

(cm

) 50 75 100le8 microm ()

5 10 15

OM ()

C28

0

5

10

15

20

25

0le8 microm

0

OM

le8 micromOM






C6 C12

75 100

m ()

10 15

()

0

5

10

15

20

25

50 75 100

le8 microm ()

5 10 15

OM ()

C22 C26

75 100m ()

10 15

()

0

5

10

15

20

25

50 75 100le8 microm ()

5 10 15

OM ()

C30 C31

30 60 ()

4 8

()

0

5

10

15

20

25

50 75 100le8 microm ()

5 10 15

OM ()





0

20

40

60

80

100

le8 micro

m (

)

y = 821e-32e

R 2 = 067 (n=99)

y = 030xR2 = 075 (n=62)

0

1

2

3

4

5

TO

C (

)

-036x

0 3 6 9 12 15

OM ()

0 3 6 9 12 15

OM ()

a

b



ARTICLE IN PRESS











1

3

20

5

714

29

11

16

28

10

18

30

31

4

9

6

12 13

17

21

22

23

24

25

2627

28




Actualpermutations








ARTICLE IN PRESS






4 Discussion


enrichment






68 lm OM TOC

S 038 ns 043

N 047 ns ns

Biomass 050 ns ns

H0 ns ns ns







ARTICLE IN PRESS







ARTICLE IN PRESS












ARTICLE IN PRESS











Lagoon Sub-basin

Sedimentlayer (cm)



LOI temperaturetime




























interfacerdquo



500 C3 h 328 plusmn 072 (096ndash429)












P

Ma

gn

iet

alM

arin

eP

ollu

tion

Bu

lletinx

xx

(2

00

8)

xx

xndash

xx

x11

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004

Table 4 (continued)

Lagoon Sub-basin

Sedimentlayer (cm)



LOItemperaturetime


Variableused

Method





























12P

M

ag

ni

eta

lMa

rine

Po

llutio

nB

ulletin

xx

x(

20

08

)x

xx

ndashx

xx

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004


ARTICLE IN PRESS




Acknowledgements


References


























ARTICLE IN PRESS









































ARTICLE IN PRESS












































ARTICLE IN PRESS








ARTICLE IN PRESS


3 Results



0

5

10

15

20

25Sed

imen

t dep

th (

cm)

30 60 90

le8 microm ()

5 10 15

OM ()

C1

0

5

10

15

20

25

50

le8 micro

5

OM

0

5

10

15

20

25Sed

imen

t dep

th (

cm) 50 75 100

le8 microm ()

5 10 15

OM ()

C18

0

5

10

15

20

25

50le8 micro

5

OM

0

5

10

15

20

25Sed

imen

t de

pth

(cm

) 50 75 100le8 microm ()

5 10 15

OM ()

C28

0

5

10

15

20

25

0le8 microm

0

OM

le8 micromOM






C6 C12

75 100

m ()

10 15

()

0

5

10

15

20

25

50 75 100

le8 microm ()

5 10 15

OM ()

C22 C26

75 100m ()

10 15

()

0

5

10

15

20

25

50 75 100le8 microm ()

5 10 15

OM ()

C30 C31

30 60 ()

4 8

()

0

5

10

15

20

25

50 75 100le8 microm ()

5 10 15

OM ()





0

20

40

60

80

100

le8 micro

m (

)

y = 821e-32e

R 2 = 067 (n=99)

y = 030xR2 = 075 (n=62)

0

1

2

3

4

5

TO

C (

)

-036x

0 3 6 9 12 15

OM ()

0 3 6 9 12 15

OM ()

a

b



ARTICLE IN PRESS











1

3

20

5

714

29

11

16

28

10

18

30

31

4

9

6

12 13

17

21

22

23

24

25

2627

28




Actualpermutations








ARTICLE IN PRESS






4 Discussion


enrichment






68 lm OM TOC

S 038 ns 043

N 047 ns ns

Biomass 050 ns ns

H0 ns ns ns







ARTICLE IN PRESS







ARTICLE IN PRESS












ARTICLE IN PRESS











Lagoon Sub-basin

Sedimentlayer (cm)



LOI temperaturetime




























interfacerdquo



500 C3 h 328 plusmn 072 (096ndash429)












P

Ma

gn

iet

alM

arin

eP

ollu

tion

Bu

lletinx

xx

(2

00

8)

xx

xndash

xx

x11

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004

Table 4 (continued)

Lagoon Sub-basin

Sedimentlayer (cm)



LOItemperaturetime


Variableused

Method





























12P

M

ag

ni

eta

lMa

rine

Po

llutio

nB

ulletin

xx

x(

20

08

)x

xx

ndashx

xx

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004


ARTICLE IN PRESS




Acknowledgements


References


























ARTICLE IN PRESS









































ARTICLE IN PRESS












































ARTICLE IN PRESS









0

20

40

60

80

100

le8 micro

m (

)

y = 821e-32e

R 2 = 067 (n=99)

y = 030xR2 = 075 (n=62)

0

1

2

3

4

5

TO

C (

)

-036x

0 3 6 9 12 15

OM ()

0 3 6 9 12 15

OM ()

a

b



ARTICLE IN PRESS











1

3

20

5

714

29

11

16

28

10

18

30

31

4

9

6

12 13

17

21

22

23

24

25

2627

28




Actualpermutations








ARTICLE IN PRESS






4 Discussion


enrichment






68 lm OM TOC

S 038 ns 043

N 047 ns ns

Biomass 050 ns ns

H0 ns ns ns







ARTICLE IN PRESS







ARTICLE IN PRESS












ARTICLE IN PRESS











Lagoon Sub-basin

Sedimentlayer (cm)



LOI temperaturetime




























interfacerdquo



500 C3 h 328 plusmn 072 (096ndash429)












P

Ma

gn

iet

alM

arin

eP

ollu

tion

Bu

lletinx

xx

(2

00

8)

xx

xndash

xx

x11

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004

Table 4 (continued)

Lagoon Sub-basin

Sedimentlayer (cm)



LOItemperaturetime


Variableused

Method





























12P

M

ag

ni

eta

lMa

rine

Po

llutio

nB

ulletin

xx

x(

20

08

)x

xx

ndashx

xx

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004


ARTICLE IN PRESS




Acknowledgements


References


























ARTICLE IN PRESS









































ARTICLE IN PRESS












































ARTICLE IN PRESS







1

3

20

5

714

29

11

16

28

10

18

30

31

4

9

6

12 13

17

21

22

23

24

25

2627

28




Actualpermutations








ARTICLE IN PRESS






4 Discussion


enrichment






68 lm OM TOC

S 038 ns 043

N 047 ns ns

Biomass 050 ns ns

H0 ns ns ns







ARTICLE IN PRESS







ARTICLE IN PRESS












ARTICLE IN PRESS











Lagoon Sub-basin

Sedimentlayer (cm)



LOI temperaturetime




























interfacerdquo



500 C3 h 328 plusmn 072 (096ndash429)












P

Ma

gn

iet

alM

arin

eP

ollu

tion

Bu

lletinx

xx

(2

00

8)

xx

xndash

xx

x11

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004

Table 4 (continued)

Lagoon Sub-basin

Sedimentlayer (cm)



LOItemperaturetime


Variableused

Method





























12P

M

ag

ni

eta

lMa

rine

Po

llutio

nB

ulletin

xx

x(

20

08

)x

xx

ndashx

xx

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004


ARTICLE IN PRESS




Acknowledgements


References


























ARTICLE IN PRESS









































ARTICLE IN PRESS












































ARTICLE IN PRESS









68 lm OM TOC

S 038 ns 043

N 047 ns ns

Biomass 050 ns ns

H0 ns ns ns







ARTICLE IN PRESS







ARTICLE IN PRESS












ARTICLE IN PRESS











Lagoon Sub-basin

Sedimentlayer (cm)



LOI temperaturetime




























interfacerdquo



500 C3 h 328 plusmn 072 (096ndash429)












P

Ma

gn

iet

alM

arin

eP

ollu

tion

Bu

lletinx

xx

(2

00

8)

xx

xndash

xx

x11

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004

Table 4 (continued)

Lagoon Sub-basin

Sedimentlayer (cm)



LOItemperaturetime


Variableused

Method





























12P

M

ag

ni

eta

lMa

rine

Po

llutio

nB

ulletin

xx

x(

20

08

)x

xx

ndashx

xx

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004


ARTICLE IN PRESS




Acknowledgements


References


























ARTICLE IN PRESS









































ARTICLE IN PRESS












































ARTICLE IN PRESS








ARTICLE IN PRESS












ARTICLE IN PRESS











Lagoon Sub-basin

Sedimentlayer (cm)



LOI temperaturetime




























interfacerdquo



500 C3 h 328 plusmn 072 (096ndash429)












P

Ma

gn

iet

alM

arin

eP

ollu

tion

Bu

lletinx

xx

(2

00

8)

xx

xndash

xx

x11

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004

Table 4 (continued)

Lagoon Sub-basin

Sedimentlayer (cm)



LOItemperaturetime


Variableused

Method





























12P

M

ag

ni

eta

lMa

rine

Po

llutio

nB

ulletin

xx

x(

20

08

)x

xx

ndashx

xx

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004


ARTICLE IN PRESS




Acknowledgements


References


























ARTICLE IN PRESS









































ARTICLE IN PRESS












































ARTICLE IN PRESS








ARTICLE IN PRESS











Lagoon Sub-basin

Sedimentlayer (cm)



LOI temperaturetime




























interfacerdquo



500 C3 h 328 plusmn 072 (096ndash429)












P

Ma

gn

iet

alM

arin

eP

ollu

tion

Bu

lletinx

xx

(2

00

8)

xx

xndash

xx

x11

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004

Table 4 (continued)

Lagoon Sub-basin

Sedimentlayer (cm)



LOItemperaturetime


Variableused

Method





























12P

M

ag

ni

eta

lMa

rine

Po

llutio

nB

ulletin

xx

x(

20

08

)x

xx

ndashx

xx

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004


ARTICLE IN PRESS




Acknowledgements


References


























ARTICLE IN PRESS









































ARTICLE IN PRESS












































ARTICLE IN PRESS








Lagoon Sub-basin

Sedimentlayer (cm)



LOI temperaturetime




























interfacerdquo



500 C3 h 328 plusmn 072 (096ndash429)












P

Ma

gn

iet

alM

arin

eP

ollu

tion

Bu

lletinx

xx

(2

00

8)

xx

xndash

xx

x11

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004

Table 4 (continued)

Lagoon Sub-basin

Sedimentlayer (cm)



LOItemperaturetime


Variableused

Method





























12P

M

ag

ni

eta

lMa

rine

Po

llutio

nB

ulletin

xx

x(

20

08

)x

xx

ndashx

xx

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004


ARTICLE IN PRESS




Acknowledgements


References


























ARTICLE IN PRESS









































ARTICLE IN PRESS












































ARTICLE IN PRESS







Table 4 (continued)

Lagoon Sub-basin

Sedimentlayer (cm)



LOItemperaturetime


Variableused

Method





























12P

M

ag

ni

eta

lMa

rine

Po

llutio

nB

ulletin

xx

x(

20

08

)x

xx

ndashx

xx

AR

TIC

LE

INP

RE

SS

Please

citeth

isarticle

inp

ressas

Magn

iP

et

alD

istribu

tion

and

ecolo

gicalrelevan

ceo

ffi

ne

sedim

ents

M

arP

ollu

tB

ull

(2008)d

oi101016jm

arpo

lbu

l200712004


ARTICLE IN PRESS




Acknowledgements


References


























ARTICLE IN PRESS









































ARTICLE IN PRESS












































ARTICLE IN PRESS








ARTICLE IN PRESS




Acknowledgements


References


























ARTICLE IN PRESS









































ARTICLE IN PRESS












































ARTICLE IN PRESS








ARTICLE IN PRESS









































ARTICLE IN PRESS












































ARTICLE IN PRESS








ARTICLE IN PRESS












































ARTICLE IN PRESS








ARTICLE IN PRESS







Distribution and ecological relevance of fine sediments in organic-enriched lagoons: The case study...

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Transcript of Distribution and ecological relevance of fine sediments in organic-enriched lagoons: The case study...