Responses of fish populations to chemical stress in estuaries : molecular, biochemical and immunotoxicologic approach
type: Dataset
description: Coastal and estuarine environments are mainly impacted by anthropogenic activities that lead to several stress (chemical and/or thermal stress, hypoxia…). Presence of complex mixtures of contaminants could create serious damages in aquatic ecosystems and also in human populations.During this work, two studies were carried out in France and Québec, on two species: the European flounder (Platichthys flesus) and the Atlantic tomcod (Microgadus tomcod), these fishes being considered as sentinel species of the water estuarine quality. A multi-parameter approach was conducted considering the fish responses to the chemical stress, from molecular to individual levels (gene expression, detoxification process, functioning of the immune system, energetic metabolism and condition index). The main objective of this study was to identify the more pertinent biomarkers to evaluate the estuarine water quality.Firstly, the flounder responses were studied in controlled conditions after 29 days of contamination with environmentally relevant concentrations of PAHs and PCBs in food, followed by a 14 days recovery period. The contaminated diet impacted the immune system and showed an increase of the detoxification process and of the DNA damages. Up-regulation of the complement C3 and TNF-receptor gene expressions could be explain by an inflammatory response in liver. The lysozyme level was also impacted and appeared to be the more sensitive immune parameter to the chemical stress. This study underlined a significant correlation between the Cytochrome P450 1A1 expression level and the DNA damage.Secondly, the previous markers were explored on the flounder and the tomcod, considering the fish population responses to contaminants in the field. These two studies underlined the complexity of the immune responses to contamination, some functions being inhibited (capacity of phagocytosis) whereas others being enhanced (expression of C3 and TNF-R, proliferation of lymphocytes). Moreover, this mul…
landing page: https://theses.hal.science/tel-00951704
identifier: NNT: 2012BRES0063
keyword: fishes
keyword: infoeu-reposemanticsdoctoralthesis
keyword: milieux-estuariens
keyword: poissons
keyword: sdvsalife-sciences-q-bioagricultural-sciences
keyword: stress-chimique
keyword: theses
issued: 2026-05-06T06:08:11.769460
modified: 2026-05-06T06:08:11.769465
language: fr
contact point: Organization
  fn: CCSD

test_moissonnage_selune
type: Agent

Responses of fish populations to chemical stress in estuaries : molecular, biochemical and immunotoxicologic approach
type: Distribution
format: HTML
access URL: https://theses.hal.science/tel-00951704
issued: 2026-05-06T06:08:11.783680
modified: 2026-05-06T06:08:11.759965