ABSTRACT
Nine fish species of commercial interest from six teleost families and two species of elasmobranchs were selected for characterisation of hepatic biomarkers used in early-warning assessment of pollutant exposure. The sampling was carried out in front of the Barcelona coast (NW Mediterranean) during December 2006 at shelf (53 m) and slope (660 m) depths. The enzymes considered included the antioxidant defence catalase (CAT) and glutathione reductase (GR), phase I ethoxyresorufin O-deethylase (EROD) and phase II glutathione S-transferase (GST). Protein yield (PY) was used as a general marker of hepatic protein synthesis. Significant interspecies differences were evidenced, although each marker varied independently. Enzymatic activities in teleosts were higher than in elasmobranchs; they were very low in Scyliorhinus canicula (mainly a benthic feeder), but not so low in Galeus melastomus (pelagic feeder). In relation to depth, shallow water, shelf-living species had higher metabolic activities. Trophic variables were significantly related to PY and EROD activity, and were especially high in benthic/suprabenthic feeders. Trophic level (deduced from stable isotopy) and stomach fullness were associated with all hepatic markers, except GR. Swimming capacity was related to all hepatic enzymes. Our findings can be applied, not only from the perspective of conservation ecology regarding pollution, but also in fisheries, due to the economic interest of the species involved.
Subject(s)
Ecosystem , Environmental Monitoring/methods , Fish Proteins/metabolism , Fishes/metabolism , Liver/metabolism , Water Pollutants, Chemical/analysis , Xenobiotics/metabolism , Animals , Antioxidants/metabolism , Biomarkers/metabolism , Catalase/metabolism , Cytochrome P-450 CYP1A1/metabolism , Glutathione Reductase/metabolism , Glutathione Transferase/metabolism , Liver/drug effects , Liver/enzymology , Mediterranean Sea , Spain , Species Specificity , Water Pollutants, Chemical/toxicityABSTRACT
We selected muscle tissue from nine commercial fish species, seven teleosts and two elasmobranchs, frequently caught in the NW Mediterranean trawling grounds in two different habitats (the continental shelf at 53 m and the slope at 660 m) for cholinesterases (ChEs) characterisation and activities determination, as well as the measure of lipid peroxidation (LP) levels. Acethyl- (AChE), butyryl- (BChE) and propionyl- (PrChE) cholinesterase were chosen as exposure markers of neurotoxic chemicals/molecules and LP as an effect marker of oxidative damage. The use of diagnose inhibitors: eserine sulphate, iso-OMPA and BW284c51 confirmed the measurement of true ChEs as well as the presence of pseudocholinesterases. The present study has evidenced the existence of interspecies differences, especially between teleosts and elasmobranchs but not in relation to depth. Moreover, the good correlation observed between all ChEs in most of the studied fish, supports the use of AChE as neurotoxic marker in field pollution monitoring. The non-metric multidimensional scaling analysis identified the commercial species hake Merluccius merluccius, among teleosts, and the shark, Galeus melastomus, as more adequate sentinel species in commercial fishing grounds. AChE activity showed a relationship with the fish trophic level, while all ChEs revealed a relationship with the feeding habits (benthic, suprabenthic, pelagic) and the stomach fullness. BChE activity and LP levels were the only markers to show a relationship with their swimming capacity.
