Marine Pollution Bulletin xxx (2015) xxx–xxx

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Marine Pollution Bulletin

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Metals in Mediterranean aquatic species

http://dx.doi.org/10.1016/j.marpolbul.2015.02.0340025-326X/� 2015 Elsevier Ltd. All rights reserved.

⇑ Corresponding author. Tel.: +39 0649902067; fax: +39 0649387139.E-mail address: roberto.miniero@iss.it (R. Miniero).

Please cite this article in press as: Iamiceli, A., et al. Metals in Mediterranean aquatic species. Mar. Pollut. Bull. (2015), http://dx.doi.org/1j.marpolbul.2015.02.034

AnnaLaura Iamiceli a, Alessandro Ubaldi g, Dario Lucchetti g, Gianfranco Brambilla a, Vittorio Abate a,Elena De Felip a, Stefania P. De Filippis a, Elena Dellatte a, Silvia De Luca a, Fabiola Ferri a, Igor Fochi a,AnnaRita Fulgenzi a, Nicola Iacovella a, Ivo Moret b,c, Rossano Piazza b,c, Alessandra Roncarati d,Paolo Melotti e, Roberto Fanelli f, Elena Fattore f, Alessandro di Domenico a, Roberto Miniero a,⇑a Toxicological Chemistry Unit, DAMPP, Italian National Institute for Health, Rome, Italyb University Ca’ Foscari, Department of Environmental Science, Informatic and Statistic, Dorsoduro 2137, 30123 Venice, Italyc CNR-Istituto per la Dinamica dei Processi Ambientali, Dorsoduro 2137, 30123 Venice, Italyd School of Veterinary Medical Sciences, EAEVE Certificate, Camerino University, Matelica, Italye Centro di Ricerca Interdipartimentale sulle Tecnologie e l’Igiene delle Piccole Specie, Department of Food Science, Alma Mater Studiorum, Bologna University, Ozzano dell’Emilia, Italyf Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche ‘‘Mario Negri’’, IRCCS, Milan, Italyg Istituto Zooprofilattico Sperimentale del Lazio e Toscana, Rome, Italy

a r t i c l e i n f o

Article history:Available online xxxx

Keywords:FishCrustaceansMediterranean SeaMetalsBackground concentrations

a b s t r a c t

Metals such as arsenic (As), cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), vanadium(V), have been determined in species of Mediterranean marine organisms collected from areas supposedto be at background contamination levels. The Inductively Coupled Plasma Mass Spectrometry (ICP-MS)approach was adopted for the determination of all the metals. Arsenic, Cd and Pb determined in the 42samples, do not exceed the pertinent maximum level except a sample of hake. In wild fish, the concen-tration range for Cr, Ni, V and Cu was, respectively: 0.07–0.09, 87.6–124, 0.022–0.075 and 0.79–1.74 lg/gfresh weight (fw). The farmed fish samples show concentration levels below the wild fish ones, except forCr which range at the same levels. Cadmium and Pb show a high sample number under the quantificationlimit. The elements do not bio-magnify among the species considered and appear to show low variationsin relation to organisms’ position in the food chain and at sampling sites.

� 2015 Elsevier Ltd. All rights reserved.

Environmental monitoring projects play an important role inproviding scientific knowledge for assessing human health andon the impact on ecosystems. Many papers recently published,focus on the risks on human health, deriving from consumptionexposure to individual contaminants or groups of contaminants,occurring in the western and eastern Mediterranean Sea (Minieroet al., 2014; Copat et al., 2013; Damiano et al., 2011; Turkmenet al., 2009; Percın et al., 2011; Suarez-Serrano et al., 2010). Dueto anthropogenic and natural emissions, toxic heavy metals havelong been recognized as the most recurring pollutants inecosystems. Their release into the environment has resulted in anumber of problems. In particular, due to their non-biodegradabil-ity and persistence, they can accumulate in environmental mediaand the food chain, thus posing significant risks to organisms andhuman health. Elements are natural trace components of theaquatic environment, but their levels have increased due to indus-trial, agricultural and mining activities (Eisler, 2010). However,

even if some metals are non-essential, others have an importantrole as micronutrients (eg. Cu).

Recently, great attention was devoted to the study of essentialand toxic trace element content in foodstuffs, as a result of agrowing concern about the health benefits and risks of food con-sumption. This evaluation of risks and benefits of the consumptionof fish and other seafood, has been particularly controversial.Nutritionists consider these products to be an important sourceof high-quality proteins, minerals and essential fatty acids(Roncarati et al., 2012). On the contrary, toxicologists tend toregard seafood as a major vector for toxic substances and inparticular organometals and persistent organic pollutants(Miniero et al., 2014).

The Italian Ministry for Education, University and Researchfinanced, in early 2004, a five-year project (2004–2008) tocharacterize the chemical contamination and nutritional qualityof fish and crustaceans caught in Italian coastal waters (Roncaratiet al., 2012; di Domenico et al., 2011). This paper reports theresults for the metals and the micronutrients already mentionedabove. These elements have been determined in various species

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of marine organisms belonging to different trophic levels collectedin areas supposed to be at background contamination levels. Thedeterminations, in addition, have been carried out also in farmedspecies collected from the same areas as the wild ones. In particu-lar, the objectives of these determinations were: (i) to characterizethe differences between species and sampling areas, (ii) tocompare the determined levels in wild fish with the farmed onescollected in the same areas, (iii) to explore the possibility to definebackground levels for the contaminants considered. These aspectscould be of relevance for the interpretation of the pollution issueposed by Article 3 (comma 5) of the Marine Strategy FrameworkDirective Requirements (2008/56/EC). This comma describes theGood Environmental Status (GES) which means that a number ofconditions, including the pollution, has to avoid the change ofthe marine ecosystem. Point (b), specifies ‘‘. . .Anthropogenic inputsof substances and energy, including noise, into the environment donot cause pollution effects.’’ In Annex I are reported the qualitativedescriptors for determining Good Environmental Status where thePoints 8 and 9, respectively, indicate that ‘‘concentrations of con-taminants are at levels not giving rise to pollution effects’’ and‘‘contaminants in fish and other seafood for human consumptiondo not exceed levels by Community legislation or other relevantstandards’’. In this context, the individuation of a strategy to findthe contaminant background level appears to be of criticalimportance.

In order to characterize the levels of As, Cd, Cr, Cu, Ni, Pb, and Vin Mediterranean aquatic species caught in the most relevant fish-ery zones presumed not to be exposed to direct contaminationsources, the following areas were selected: southern Adriatic (A;Longitude 17�20042E, Latitude 41�00052 N, 10–40 miles off thecoastline of Monopoli), southern Tyrrhenian (B; Longitude15�46016E, Latitude 38�17054 N, 15 miles off the coastline, in frontof Bagnara Calabra), Ionian sea (C; Longitude 14�540625E, Latitude36�230135 N, 15 miles off Porto Palo) (Fig. 1). These areas corre-spond to 18, 10 and 19 FAO Geographical Sub-Areas respectively,all being part of FAO Zone 37 (www.fao.org). Dedicated campaigndetails to collect samples involving local fishing boats, are givenelsewhere (Miniero et al., 2014). Twelve wild aquatic species,including two crustaceans, plus two farmed species, were chosenfor this study and their characteristics are shown in Table SM1

Fig. 1. Areas of the Mediterranean Sea selected for the study. The points A, B and C (see telsewhere (Miniero et al., 2014). Fishery areas are also identified according to the Unite

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(Supplemental Material). The samples from Adriatic, Tyrrhenian,and Ionian seas are respectively identified with the acronyms MOXX, BC XX, and PP XX (Table 1). In general, the same species werecollected from the aforesaid areas with a few differences. Farmedgilthead sea bream and sea bass were collected from offshorebreeding farms situated in the FAO zones close to the areas wherethe wild species were caught. Specimens were collected during2007–2008 over a period of 12 months. After sampling, fish andcrustaceans were frozen on dry ice for transportation to the lab-oratory where they were measured and weighed. For fish specieswith a weight higher than 100 g/specimen, fillets of equal weightfrom individuals of the same species collected at each site werepooled together to obtain a composite sample. For smaller fish spe-cies (e.g. anchovy) and crustaceans, composite samples were madeup using the edible portions of individuals of the same species afterremoval of the head, tail and visceral package. Each compositesample was homogenized and aliquots were stored at �20 �C untilanalysis.

From each composite sample, two aliquots of about 1.0 gmuscle tissue was taken for As, Cd, Cr, Cu, Ni, Pb and V deter-minations. The aliquots were mineralized for 50 min at 200 �C inan Ethos One microwave system (Milestone S.r.l., Italy) equippedwith 12 pressurized vessels. For the above mentioned deter-minations, the digestion was carried out using a mixture of strongoxidizing agents. The digestion solution was prepared with 6 mL of65% nitric acid (Carlo Erba) and 2 mL of 30% hydrogen peroxide(Carlo Erba). After mineralization, the vessels were opened whena temperature <25 �C was reached, then the content was trans-ferred in falcon tubes and ultra-pure water (Merck) was added tothe samples up to 100 mL for the quantification with InductivelyCoupled Plasma Mass Spectrometry (ICP-MS, Agilent ICPMS7500). Analytical blanks were run in the same way as the samples,and concentrations were determined using standard solutionsprepared with the same acid matrix. Standards for instrument cali-bration were prepared on the basis of mono element certifiedreference solution standard (Merck). Standard reference materialLake Superior fish 1946 NIST was used to validate analyses.Mean recoveries of the certified values for As, Cd, Cu, and Pb were94%, 93%, 92%, and 95% respectively. Chromium, Ni, and V refer-ence values were not given in the analysis certificate of the

he text) identify the sampling points. Further details on sampling strategy are givend Nations Food and Agricultural Organization (FAO).

ean aquatic species. Mar. Pollut. Bull. (2015), http://dx.doi.org/10.1016/

Table 1Chemical concentrations (lg/g, fw) measured in fish and crustaceans from the Mediterranean Sea. Values rounded off to three figures or a maximum of three decimals. LOQs (As,Cd, Cr, Cu, Ni, Pb, V) are identified by ‘‘<’’.

Common name Sample IDs As Cd Cr Cu Ni Pb V

Atlantic b. tuna BC CT 3.17 <0.01 0.094 0.885 0.057 <0.02 <0.002Atlantic b. tuna PP CT 1.40 <0.01 0.051 0.438 0.055 <0.02 <0.002Atlantic bonito BC A5 1.50 <0.01 0.068 0.938 0.043 <0.02 0.015Atlantic bonito MO A5 1.60 <0.01 0.064 0.514 0.058 0.030 <0.002Atlantic bonito MO B5 8.24 <0.01 0.136 0.606 0.202 <0.02 0.030Atlantic bonito PP A5 1.39 <0.01 0.063 0.779 0.387 <0.02 0.004Atlantic mackerel BC B4 10.2 <0.01 0.105 0.910 0.113 0.027 0.009Atlantic mackerel MO A4 4.72 <0.01 0.055 1.02 0.069 <0.02 0.014Atlantic mackerel MO B4 11.0 <0.01 0.095 0.849 0.130 <0.02 0.015Atlantic mackerel PP A6 5.14 <0.01 0.058 0.976 0.043 0.042 0.006Atlantic mackerel PP B6 1.03 <0.01 0.123 0.460 0.080 <0.02 0.025Bullet tuna BC A4 1.52 <0.01 0.065 1.66 0.043 0.029 0.008Bullet tuna BC B5 1.92 <0.01 0.109 0.474 0.096 <0.02 0.006Bullet tuna PP B5 2.26 <0.01 0.134 1.61 0.081 0.142 0.004European anchovy BC B2 10.7 0.013 0.082 1.05 0.141 <0.02 0.051European anchovy BC C2 2.92 0.024 0.036 1.03 0.149 <0.02 0.484European anchovy MO B1 13.2 0.012 0.076 1.18 0.115 0.037 0.098European anchovy MO C1 5.82 <0.01 0.043 1.04 0.095 <0.02 0.024European anchovy PP B2 5.59 0.011 0.098 0.820 0.081 <0.02 0.041European hake PP B7 9.90 <0.01 0.111 0.385 0.110 0.542 0.014European hake PP C2 2.65 0.018 0.030 1.33 0.112 <0.02 0.055European hake BC B3 11.5 <0.01 0.120 0.209 0.108 <0.02 0.007European hake BC C3 10.8 <0.01 0.047 0.177 0.142 <0.02 0.008European hake MO B3 12.5 <0.01 0.126 0.163 0.147 0.077 0.013European hake MO C3 6.37 <0.01 0.092 0.173 0.087 <0.02 0.006European hake PP C7 2.88 <0.01 0.038 0.179 0.063 <0.02 <0.002European pilchard PP B3 8.53 <0.01 0.098 0.658 0.066 <0.02 0.040European pilchard PP C3 7.65 0.018 0.034 0.978 0.134 0.086 0.167Norway lobster MO A6 24.3 <0.01 0.068 4.43 0.039 0.037 0.067Norway lobster MO B6 54.0 <0.01 0.122 4.10 0.150 0.032 0.081Rose shrimp BC A6 46.7 0.014 0.079 4.05 0.088 0.055 0.060Rose shrimp BC B6 56.7 0.016 0.096 4.00 0.163 0.093 0.115Rose shrimp PP A4 48.2 0.015 0.073 6.48 0.136 0.040 0.115Rose shrimp PP B4 32.4 0.016 0.116 5.50 0.113 0.035 0.108Surmullet BC B1 22.9 <0.01 0.155 0.425 0.135 0.033 0.054Surmullet BC C1 12.2 <0.01 0.053 0.298 0.048 0.020 0.011Surmullet MO B2 30.5 <0.01 0.093 0.430 0.112 <0.02 0.013Surmullet MO C2 22.2 <0.01 0.059 0.379 0.123 <0.02 0.014Surmullet PP B1 15.8 <0.01 0.107 0.308 0.078 0.067 0.025Surmullet PP C1 38.8 <0.01 0.051 0.402 0.111 <0.02 0.221Swordfish BC CS 0.483 <0.01 0.061 0.338 0.066 <0.02 <0.002Swordfish PP CS 4.30 <0.01 0.049 0.450 0.077 <0.02 <0.002Sea bass AAZ BR A2 0.503 <0.01 <0.01 0.065 0.082 <0.02 0.005Sea bass AAZ BR B2 0.427 <0.01 <0.01 0.087 0.047 <0.02 0.004Gilthead AAZ OR A1 0.977 <0.01 <0.01 0.069 0.042 <0.02 0.004Gilthead AAZ OR B1 1.83 <0.01 <0.01 0.119 0.036 <0.02 <0.002Sea bass MED BR B2 0.365 <0.01 <0.01 0.221 0.072 0.274 <0.002Gilthead MED OR B1 0.752 <0.01 <0.01 0.126 0.147 <0.02 <0.002Sea bass PAN BR A2 0.946 <0.01 <0.01 0.060 0.040 <0.02 0.005Sea bass PAN BR B2 0.755 <0.01 <0.01 0.128 0.039 <0.02 <0.002Gilthead PAN OR A1 2.83 <0.01 <0.01 0.082 0.033 <0.02 0.003Gilthead PAN OR B1 0.889 <0.01 <0.01 0.137 0.048 <0.02 0.003

Table 2Descriptive statistics of the concentration of metals measured in aquatic species fromthe Mediterranean Sea. Values reported in lg/g fw and rounded off to three figures.

Na XMIN Q.25 Q.50 ‹X› CI95% Q.75 XMAX

Wild speciesAs 42 0.483 2.88 8.38 13.7 8.91–18.5 15.8 56.7Cr 42 0.030 0.055 0.078 0.082 0.070–0.090 0.107 0.155Cu 42 0.163 0.402 0.800 1.26 0.790–1.74 1.05 6.48Ni 42 0.033 0.066 0.102 0.106 0.088–0.124 0.133 0.387V 42 0.002 0.006 0.014 0.048 0.022–0.075 0.055 0.484

A. Iamiceli et al. / Marine Pollution Bulletin xxx (2015) xxx–xxx 3

standard reference material used, thus 10 real samples in doubleswith 0.100 lg/g of each analyte to validate analysis were spiked,and the percentage of recovery is given in Table SM2(Supplemental Material). The method quantification limits (LOQ)of the procedures were: As 0.02, Cd 0.01, Cr 0.01, Cu 0.015, Ni0.01, Pb 0.02, and V 0.002 (lg/g fw).

Chemical-specific data distributions were characterized by thestatistical analysis for As, Cd, Cr, Cu, Ni, Pb, and V of analyticalconcentrations. The output of the statistical analysis includescanonical descriptor ranges (XMIN, XMAX), quartiles (Q), and arith-metic means and their 95% confidence intervals (‹X›, CI.95%). Datadistribution was characterized only when element concentrationsexceeded their limits of quantification (LOQs) in at least 50 % ofsamples. This criterion is more stringent than the one adopted byEFSA on the basis of the WHO guidelines (GEMS/FOOD, 2003). Inorder to distinguish the association of elements characterizingspecific variability quotes of the database, a Principal Component

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Factor Analysis (PCFA) was adopted and, to confirm its findings,the General Linear Models (GLMs) (Fielding, 2007) approach wasapplied (Statgraphics [StatPoint Technologies]).

In Table 1, the sample IDs and the levels of the elements takenin consideration are shown. The distribution parameters of each

ean aquatic species. Mar. Pollut. Bull. (2015), http://dx.doi.org/10.1016/

Table 3Factor loadings of log [element] and sample Factor scores. The samples arerepresented by their IDs. Values rounded off to three figures or a maximum of threedecimals.

Factor 1 Factor 2 Factor 3

Log [element]Arsenic 0.754 0.231 0.355Chromium �0.113 0.866 0.233Copper 0.651 0.234 �0.096Nickel 0.075 0.052 0.946Vanadium 0.781 0.014 0.365

Sample IDsBC CT �0.650 �0.207 �2.51PP CT �1.39 �0.454 �2.14BC A5 3.53 1.54 0.384MO A5 1.69 1.91 1.60MO B5 �0.347 �0.635 1.53PP A5 �1.21 0.664 0.537BC B4 �0.953 1.24 0.514MO A4 �2.81 0.532 �0.271MO B4 3.81 2.42 1.95PP A6 0.176 �0.934 �1.57PP B6 0.589 �2.59 1.35BC A4 �0.533 �2.51 0.667BC B5 �4.39 �2.30 �1.86PP B5 �2.79 �0.783 �1.30BC B2 �0.338 �0.592 �1.03BC C2 �3.38 �0.244 �1.83MO B1 3.93 0.664 �1.58MO C1 2.14 0.710 0.820PP B2 0.612 0.545 0.789PP B7 �0.627 1.77 1.22PP C2 0.170 �0.040 0.900BC B3 0.237 1.37 2.00BC C3 3.63 2.19 1.87MO B3 0.492 �1.13 �0.355MO C3 0.655 �1.73 0.787PP C7 �3.20 �1.00 0.107PP B3 5.11 1.22 1.25PP C3 �3.16 �0.292 2.06MO A6 �0.180 �0.130 �2.29MO B6 1.00 1.36 �0.06BC A6 0.978 0.396 �0.157BC B6 0.911 0.493 �0.416PP A4 3.91 2.05 1.13PP B4 �1.46 2.52 �0.942BC B1 �3.91 0.945 �0.168BC C1 0.793 2.75 0.147MO B2 2.55 �1.06 1.28MO C2 1.10 �3.22 �0.169PP B1 2.53 �0.577 0.551PP C1 �4.17 �3.00 �1.54BC CS �2.08 �2.35 �1.15PP CS �2.94 �1.52 �2.09

4 A. Iamiceli et al. / Marine Pollution Bulletin xxx (2015) xxx–xxx

chemical not exceeding a not quantified level frequency of 50 % areshown in Table 2. The regulated chemical levels (As, Cd and Pb) donot exceed the pertinent Maximum Level (ML) ruled by Regulation1881/2006/EC except for a sample of hake (PP B7, Table 1) which isalso the XMAX determined in the 42 samples analyzed (Table 2). Thenumber of the LOQs for Cd and Pb concentration levels exceededthe threshold of 50% of samples. All the distributions describedin Table 2 were not normally distributed (Shapiro and Wilk’s Wstatistics, P < 0.05) but their log-transformed versions generallyconfirmed a P-value greater than 0.05, and the hypothesis thatthe data were from a normally distributed population was notrejected in these cases. By comparing the concentration levels ofthe ten samples of farmed species (Table 1) with the element-specific distribution frequency parameters shown in Table 2, thefollowing features can be observed: As concentrations in farmedfish are below the pertinent Q25 value estimated for wild species,Cr data overlaps the wild ones, Cu results are lower then the Q50

value, Ni are below the Q50 value, V in the farmed samples showsconcentrations one order of magnitude below the ones showed bythe wild organisms. Considering the element-specific concentra-tion ranges among the species (Table 2), their CI95% do not exceedone magnitude order and, in particular, the magnitude order is thesame for Cr and V. Seventy-five percent of As, Cu, and V data falls inthe respective CI95% range. When the metal-specific variabilityresults so low, despite the different food chain position of organ-isms and the sampling sites, the determined concentrations couldapproach the background levels. Nevertheless, the above-men-tioned findings suggest that a great consideration should be givento the species-specific accumulation mechanisms.

The factor loadings shown in Table 3 globally take into account73.4% of the dataset variability. The ‘‘markers’’ with the highestloadings are As, Cu, and V for Factor 1, Cr for Factor 2 and Ni forFactor 3 (Table 3). The highest Factor 1 scores (Table 3) character-ize all the crustaceans samples, while among the fish only thesurmullet and, to a lesser extent, the European anchovy are theonly organisms showing a species-specific characteristic pattern.In general, the crustaceans and fish with a length below 22 cmand a weight below 108 g (Table SM1) are characterized. This couldreflect the relationships between the body surface and the volumeof the organisms considered and other features as the metalloth-ionein organism contents. Decapod crustaceans have evolvedmechanisms to regulate the tissue and consequently also the bodyconcentrations of essential metals such as Cu (Rainbow, 1998,2002). They do not, however, appear to regulate the body concen-trations of non-essential metals such as As (Anderson et al., 1997;Sanchez Lopez et al., 2004). Therefore, the metals can be accumu-lated to a greater extent than essential elements (Suarez-Serranoet al., 2010). In fish, the accumulation of metals is an interactiveprocess depending on element concentration in water and theextent and efficiency of biotic binding sites on fish body surfaces.The uptake appears to depend on the ratio of surface area/weightand by various physiological processes, such as osmoregulation,but not from ventilation (Zhang and Wang, 2007; Hattink et al.,2006). The aforesaid ratio is higher in small organisms than in lar-ger ones and this appears to explain the Factor score distribution.Indeed, the above mentioned species (European anchovy, surmul-let, European pilchard) show the smallest sizes (Table SM1). This,in addition, appears to confirm that the metal dietary uptakeresults inversely correlated to fish size (Zhang and Wang, 2007).However, the group of organisms mentioned above live in closecontact with sediments (rose shrimp and Norway lobster) or arecoastal and live in the neritic zone (European anchovy, surmullet,European pilchard). Therefore, in relation to the possible contam-ination sources, this zone is under anthropogenic pressure morethan the pelagic one (Suarez-Serrano et al., 2010). Table 3 suggestssome additional comments. In general the above-mentioned

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organisms show high and positive scores for Factors 1, 2 and 3 withsome exceptions. Furthermore, Factor 2 marks a wide range oforganisms with different sizes not showing any clear species- orsize-specific pattern. Factor 3 confirms the trends already observedfor the other two and, in addition, this suggests that there are somefish that are characterized only to a minor extent. For example, twobullet tuna samples are characterized by Factor 2 and two Atlanticbonito samples by the Factor 3. This could be the result of a shift inprey composition influenced by the sampling area and samplingperiod, but these factors do not appear to influence significantlythe database.

The aforementioned findings are confirmed by the GLMs(Table 4). On the whole, elements do not seem to bio-magnifyamong the species considered. The lack of significance betweenthe species length and weight and metal levels (not shown inTable 4) can be regarded as an absence of bio-magnification. Thishas been observed also by other authors (Barwick and Maher,2003; Nfon et al., 2009). In Table 4, at species-specific level, only

ean aquatic species. Mar. Pollut. Bull. (2015), http://dx.doi.org/10.1016/

Table 4Statistical significance of linear regression models (LRMs) and influencing factors. Each P estimate is associated with the paired df-adjusted R2 value � 100 (in parenthesis).

As, lg/g fw Cr, lg/g fw Cu, lg/g fw Ni, lg/g fw V, lg/g fw

Species, P-value 0.0000 0.814 0.0000 0.730 0.333R2 (df adjusted) (%) 84.7 (77.6) – 95.3 (93.2) – –Sampling area, P-value 0.849 0.715 0.179 0.790 0.385R2 (df adjusted) (%) – – – – –

A. Iamiceli et al. / Marine Pollution Bulletin xxx (2015) xxx–xxx 5

As and Cu are really significant and predictive, thus confirming theobservations on crustaceans and small fish mentioned above: theseorganisms appear to show distinct element accumulation featureswith respect to larger fish. However, there are some sample-specific body burdens (Table 1), but these features do not resultspecies-specific nor sampling site specific (Table 4), therefore thisvariability could be attributed only to intra-species influence.Chromium, Ni, and V, on the contrary, do not result significant atspecies-specific level thereby confirming the concentrations con-sistency observed in the element-specific frequency distribution.

Following the element magnitude loadings order given inTable 3 and their Factor-specific order, As shows a wide inter-specific variability, with the highest values detected in crustaceans.As is naturally present in rocks, therefore it may influence princi-pally the coastal environments rather than the pelagic ones, andfor this reason the fish bullet tuna, Atlantic bonito, bluefin tunaand swordfish result less influenced. The European anchovy sam-ples of this study show higher concentration levels than thosedetermined in samples collected in a southern Italian market(Copat et al., 2013) and from the Black Sea (Korkmaz Gorur et al.,2012) but they are in the same range of samples collected fromthe Adriatic sea (Bilandzic et al., 2011). The As levels determinedin samples of red mullet collected along the Spanish coast, showedconcentrations ranging from 6.9 lg/g fw (a reference site) to19.8 lg/g fw (a contaminated site) (Martinez-Gómez et al., 2012).Levels below 10 lg/g fw appear to be common among marineorganisms, but values exceeding 30.0 lg/g fw have also beenreported (Eisler, 2010). This wide range appears to comply withthe As concentration levels determined by this study, thereforethe highest levels (Table 1 and 38.8–56.7 lg/g fw) would reflectessentially species characteristics. However, most of the As in edi-ble fish tissues is in the least hazardous form of arsenobetaine(Eisler, 2010). As previously observed, the Cu concentrationsfollows a group-specific characterization but, although Cu is anessential element, excessive levels become detrimental. Finfishmuscle contained from 0.1 to 2.0 lg/g fw of Cu (Eisler, 2010), arange corresponding to the concentrations determined in all finfishstudied (Table 1). The dietary uptake is likely to be the main routefor Cu bioaccumulation in fish (Dang et al., 2009) but the levelsdetermined, although coastal environments may present elevatedCu concentrations (Eisler, 2010), do not appear to enforce that localcontaminated food resources influence the fish Cu body burden.Indeed, finfish appear to regulate Cu body burden by metalloth-ionein contents (Dang et al., 2009). The scientific literature on Vdeterminations in fish appears to be scarce (Eisler, 2010) but,recently, V was determined in European anchovies from a southernItalian market (Copat et al., 2013). The concentration levels deter-mined in the anchovies of this work fall in the same range, butmost of the remaining samples show concentrations in the rangeLOQ–0.1 lg/g fw.

Pb and Cd show an high number of LOQ although Pb concentra-tion in the sample PP B7 (Table 1), a hake, shows the highest Pbconcentration of the pertinent data. However, the other Cd andPb concentration ranges appear to be lower than the ones deter-mined in different fish species collected from the Aegean and theMediterranean Seas around Turkey (Turkmen et al., 2009).Nonetheless, the determined Cd concentrations appear to follow

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an already seen pattern: they have been determined only in smallsize fish such as the European anchovy and in the crustacean RoseShrimp. The range of concentrations determined in fish from theAdriatic sea sampled approximately 12 years ago (KljakovicGaspic et al., 2003), are in the same range as mentioned above.Therefore, the concentration determined in sample PP B7 couldreflect a local exposure situation which, however, is not diffusedamong the other species collected in the same area. The Cr concen-trations are well distributed among the species and do not showany sample pattern falling in the range of 0.03–0.16 lg/g fw. Thisrange appears to be compatible with Cr concentrations in tissuesof most species of finfishes reported by Eisler (2010) which rangefrom 0.1 to 0.4 lg/g fw. However, elevated chromium burdens of151.0 lg/g fw were recorded in the past in fish from chromium-contaminated coastal bays in Egypt (Dahab et al., 1990). Niconcentrations, except for sample PP A5, a European pilchard,range 0.02–0.2 lg/g fw thus reflecting the concentrations foundin edible tissues of most marine teleosts (Eisler, 2000). All thefarmed fish show, in general, lower concentrations then the onesdetermined in wild ones with the following specifications: As con-centrations are one-to-two magnitude orders lower; Cr concentra-tions are always below the LOQ; Cu and Ni concentrations result inthe same magnitude order or even lower; V levels are in the samerange as wild species. Therefore, metals contributions through feedappear to be low and compatible with the concentrations deter-mined in the largest wild fish. The size of seabream and seabasssamples, is approximately three-to-five times the threshold of108 g determined in wild fish (Table 2). This suggests that themetal content observed in farmed fish depends from the accumu-lation mechanisms also noticed in wild fish.

The elements Cr, Ni, and probably V, not showing a site nor aspecies-specific pattern, could be at background contaminationlevels. By comparing the Upper Confidence Limit (UCL95%) andthe Q75 values of the pertinent distributions of Table 2, Cr and Niappear to confirm this issue. Indeed by considering these valuesthey show the same pattern whereas As, Cu, and V, on the contrary,show an opposite one with the Q75 values always included in CI95%

range. Vanadium, while showing the Cr and Ni behavior under theLRMs evaluation, does not follow the same one of the Table 2. Thisis probably due to samples BC C2, PP C3, BC B6, PP B4, and PP C1(Table 1) which although showing the highest concentrations theyhave not a distance from the other samples. However, the rangeUCL95%—Q75 appears to be a good indicator of background concen-trations when sample biodiversity is high, but a further limit suchas the Q95, not taken in consideration here because the reducedsample number, could strengthen this approach. On the other side,considering the As and Cu concentrations, the biological accumula-tion mechanisms can increase the chemical body burden evenwhen there is not an exposure source. This suggests that to definea strategy to find the background contamination levels essentiallythree issues need to be taken in consideration: i) the sampling ofspecies from different trophic levels, ii) the sampling of the samespecies from different areas, iii) the consideration of species-speci-fic features in the accumulation mechanisms. The environmentmay increase the metal contents in organisms, but in this studyall the area-specific differences were not significant. This appearsto confirm that contamination sources are not present in the areas

ean aquatic species. Mar. Pollut. Bull. (2015), http://dx.doi.org/10.1016/

6 A. Iamiceli et al. / Marine Pollution Bulletin xxx (2015) xxx–xxx

sampled. The farmed fish metal body burdens seem to be lowerthan the ones determined in wild species and because their sizesexceed the threshold of 108 g, their low levels appear to dependon the fish size rather than on possible feed contents. This suggeststhat a metal concentration reduction in feed contents woulddecrease their possible impact on the coastal environments orwhere the offshore breeding farms are set.

Acknowledgments

This study was funded by the Italian Ministry for Education,University, and Research, Rome. The Authors are also grateful toProf. Gennaro Citro, Project Tutor, to Dr. Giuseppe Palma fromFederpesca for providing fish during the sampling campaigns,and to Mrs. Anna Maria Lopomo, Mr. Stefano Pignata, andDr. Antonella Pilozzi for their technical assistance.

Appendix A. Supplementary material

Supplementary data associated with this article can be found, inthe online version, at http://dx.doi.org/10.1016/j.marpolbul.2015.02.034.

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