Persistent organic pollutants and enzyme activities in European eel (Anguilla anguilla) from Orbetello lagoon

Abstract

1. The aim of the present study was to obtain insights into the environmental quality of Orbetello lagoon using the European eel (Anguilla anguilla) as bioindicator organism.
2. Levels of POPs, including seven polychlorobiphenyls (PCBs) (known as markers of Aroclor 1260), three coplanar PCBs, ΣDDT (op-DDD, pp’-DDD, op-DDT, pp’-DDT, op’-DDE, pp’-DDE), hexachlorobenzene (HCB), hexachlorocyclohexane (HCH: α-HCH, β-HCH, γ-HCH, δ-HCH), polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzo-p-furans (PCDFs) and polybromodiphenylethers (PBDEs), were investigated in eel muscle to study bioaccumulation of toxic compounds.
3. EROD MROD and UDPGT activities were measured in liver microsomal fraction to investigate eel detoxifying/metabolic capacity.
4. Ovaries were analyzed by light microscopy to evaluate potential risk for eel reproduction. Muscle concentrations of PCBs, DDTs, pp’-DDE, HCB and HCHs were in the ng/g lipid weight (l.w.) range while coplanar PCBs were in the pg/g wet weight range.
5. PCDD/Fs were below the detection limit. Toxic equivalents (TEQs) calculated for mono- and non-ortho PCBs were below the risk thresholds established by the European Union.
6. EROD, MROD and UDPGT activities suggested low exposure to chemical inducers in line with the low concentrations of contaminants observed in muscle. Principal components analysis (PCA) showed a potential role of DDTs, especially pp’-DDE, in inducing EROD, MROD and UDPGT activities.
7. All specimens analysed were females; oocytes in advanced stages of development showed normal morphology, whereas those in early stages of development showed histological anomalies.