Evaluating the genotoxic damage and hepatic tissue alterations in demersal fish species: a case study in the Ligurian Sea (NW-Mediterranean) D. Pietrapiana a , M. Modena b , P. Guidetti c , C. Falugi a , M. Vacchi b, * a Dipartimento di Biologia Sperimentale, Ambientale ed Applicata (DIBISAA), Universit  a di Genova, Viale Benedetto XV, 16132 Genoa, Italy b Istituto per la Ricerca Scientifica e Tecnologica Applicata al Mare (ICRAM), Via di Casalotti 300, 00166 Rome, Italy c Laboratorio di Zoologia Marina, Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Universit  a di Lecce, Via Provinciale Monteroni, 73100 Lecce, Italy Abstract A protocol for detecting hepatic micronuclei in fish was performed to check genotoxic damage, as an indicator of environmental hydrocarbons exposure, in relation to the ‘‘Haven’’ oil spill. As target fish, we have chosen three demersal species with different habitats and feeding behaviour (i.e., Lepidorhombus boscii, Merluccius merluccius and Mullus barbatus) collected from two differently impacted areas and a control site. Additional analysis was performed by histological detection of hepatic tissue damages such as the presence of necrotic and tumour-like aspects. The three studied species showed different sensitivity to environmental pollutants exposure, L. boscii resulting the more sensitive in terms of both micronuclei incidence and tissue damage. The results of this study show that: (1) the micronucleus test could be an effective and fast method to detect oil pollution; (2) a clear response of L. boscii only to oil contamination for both micronucleus test and liver tissue alterations. Ó 2002 Elsevier Science Ltd. All rights reserved. Keywords: Fish; Genotoxicity; Liver; Micronuclei; PAHs; North-west Mediterranean 1. Introduction Incidental or operational oil spills from all activities related to the transport of petroleum through the sea (tankers’ accident, oil ports for downloading on land, and so on) are reported among the major threats to the marine biota in the Mediterranean Sea, where a fraction of about 20% of the traffic on a world-wide scale transits (Scabb  ıa and Amato, 1992). Petroleum hydrocarbons released to the sea include polyaromatic components (PAHs), which are well known as representing the pri- mary source of persistent toxicity (Neff et al., 1976) and have generated considerable attention because of their potential mutagenic/carcinogenic and otherwise cytotoxic properties (Payne et al., 1988; Torres-Bugar  ın et al., 1998). Benthic and nectobenthic marine fish are exposed to sedimentary hydrocarbons (including PAHs: polycyclic aromatic hydrocarbons) via several routes (i.e., direct contact, respiration using interstitial water, incidental ingestion of sediment, feeding on contaminated preys). Although high residue levels are seldom found in fish, this does not mean that they are immune from poten- tially detrimental effects (Woodhead et al., 1999). In this respect, the liver is one of the major site for hydrocarbon metabolism (Stegeman, 1981). In the liver tissue, PHAs are chiefly metabolised by cytochrome P4501 system, which metabolise PAHs to more easily excretable com- pounds, producing in this process also a range of car- cinogenic and mutagenic intermediates, highly reactive with nucleophilic sites on cellular macromolecules, like DNA. The reaction of these reactive substances with DNA can lead to the formation of DNA lesions (UNEP/ RAMOGE, 1999). This may induce an increased number of micronuclei, formed by chromosomal breakage and/ or chromosomal segregation (Schmid, 1976). Micronucleus frequency may thus provide an indirect evidence of the frequency of chromosomal damage and an insight into the risk of human health arising from Marine Pollution Bulletin 44 (2002) 238–243 www.elsevier.com/locate/marpolbul * Corresponding author. Tel.: +39-06-6156-2236; fax: +39-06-6156- 1906. E-mail address: vacchim@tin.it (M. Vacchi). 0025-326X/02/$ - see front matter Ó 2002 Elsevier Science Ltd. All rights reserved. PII:S0025-326X(01)00249-1