title: An early approach for the evaluation of repair processes in fish after exposure to sediment contaminated by an oil spill.
abstract: A chronic bioassay was carried out under laboratory conditions using juvenile Solea senegalensis to determine the toxicity of contaminants from an oil spill(Prestige). Also, the repair processes in fish affected by contaminants due to oil exposure were evaluated. Over 30 days individuals were exposed to clean sediment (control) and to sediment contaminated by a mixture of polyaromatic hydrocarbons (PAHs) and other substances. The physicochemical parameters of the tanks (salinity, temperature, pH and dissolved oxygen) were controlled during the exposure period. Clean sediment from the Bay of Cadiz (Spain) was used as negative control and was mixed with fuel oil to prepare the dilution (0.5% w:w dry-weight). After the exposure period, fish were labeled and transferred to "clean tanks" (tanks without sediment) in order to study the recovery and the repair processes in the exposed organisms. A biomarker of exposure (ethoxyresorufin-O-deethylase activity - EROD activity) and a biomarker of effect (histopathology) were analyzed during the exposure and recovery period. After 10, 20 and 30 days of exposure, individuals showed significant induction (P < 0.05) of the EROD activity and also presented diverse histopathological damages. The analysis of both the biomarkers of exposure and effect, after the 5th and 10th day of recovery in the "clean tank", enabled a first evaluation of the repair process of the induced damages due to the fuel oil exposure. After the recovery phase, control individuals showed a more significant decrease (P < 0.05) of the alteration of the measured biomarkers than in the oil-exposed fish. While in the oil-exposed fish the EROD activity showed some recovery, the histopathological damages did hardly improve. According to our results, tissue repair processes probably need longer recovery periods to observe significant improvement of the affected organs. This will be further investigated in the future.
authors.affiliation: Instituto de Ciencias Marinas de Andalucia, CSIC, Puerto Real, Cadiz, Spain. maria.salamanca@uca.es
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Salamanca
authors.forename: Natalia
authors.initials: N
authors.lastname: Jimenez-Tenorio
authors.forename: Diana F
authors.initials: DF
authors.lastname: Reguera
authors.forename: Carmen
authors.initials: C
authors.lastname: Morales-Caselles
authors.forename: T Angel
authors.initials: TA
authors.lastname: Delvalls
mesh_terms: D000818:Animals; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D005399:Fishes; D019015:Geologic Sediments; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D010578:Petroleum / Q000633:toxicity*; D011083:Polycyclic Compounds / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D010578:Petroleum; D011083:Polycyclic Compounds; D014874:Water Pollutants, Chemical; D019363:Cytochrome P-450 CYP1A1