0 avis
Managing the quality of fish and shellfish immune capacities after diclofenac exposure in mesocosms
Archive ouverte
International audience. Diclofenac, one of the most prevalent pharmaceutical in surface waters, is a non-steroidal anti-inflammatory drug taken to reduce inflammation and pain. Many authors have shown that environmental exposure of fish and shellfish to diclofenac provokes adverse effects in various organs, compromising animal health and affecting their population dynamics. The use of artificial aquatic ecosystems constitutes a good alternative approach, compared to laboratory or field study, to assess environmental risk. In fact, mesocosms provide a link between field studies (natural environments, without replication) and controlled laboratory experiments (artificial conditions, with replication). In the present work, we want to determine how adult fish (three-spined stickleback, Gasterosteus aculeatus) and shellfish (zebra mussel, Dresseina polymorpha) might react after 3 and/or 6 months of exposure to 0, 0.1, 1 and 10 µg of diclofenac/L. Whatever species used, few effects on immune parameters were shown. In fish, leucocyte mortality tends to increase and respiratory burst and phagocytosis activity tend to decrease in contaminated mesocosms. The present data were in contradiction with many laboratory studies which detected modulation of immune parameters after a few days of exposure to environmental concentrations. These results suggest a great adaptability of animals to contaminant. In fact, in zebra mussel, 3 months of exposure induced an important haemocyte mortality and cellular percentage destabilization whereas no effect was detected at 6 months. Nevertheless, to verify real impact on fish and shellfish health, these data must also be compared to other biomarker responses and to population structure. For instance, at the highest concentration in stickleback populations, a significant decrease of the juvenile recruitment was observed. It could be due to both higher larval and adult mortality than in control conditions. In consequence, the fish length distribution at this concentration was significantly impacted.
Consulter en ligne
Suggestions
Du même auteur
