Migratory behavior of free-living marine nematodes surrounded by sediments experimentally contaminated by mixtures of polycyclic aromatic hydrocarbons

摘要

An experiment was conducted using microcosms with connected sedimentary compartments to assess the effects of three polycyclic aromatic hydrocarbons (PAHs) on free-living marine nematodes from Bizerte Bay (northeastern Tunisia). Over 30?days, the nematofauna were exposed to four treatment sediments, including one with chrysene (150?ppb), chrysene (150?ppb) plus fluoranthene (75?ppb), chrysene (150?ppb) and phenanthrene (15?ppb), and an uncontaminated reference. Numerical and qualitative community simplifications occurred in contaminated sediments relative to the reference. The diversity of nematodes differed based on hydrocarbon combinations. Multivariate analyses revealed communities in contaminated compartments differed from those in the initial natural sediment and reference. Differences in sensitivities of nematodes to hydrocarbons and in migratory abilities occurred.Rhabditissp.,Calamicrolaimus honestus, andOncholaimus campylocercoideswere in all compartments and classified as tolerant to PAHs. Nematodes observed only in control compartments, includingParasphaerolaimus paradoxus, Encheliidae (sp.),Trichotheristus mirabilis, andTheristus pertenuiswere considered sensitive.