PAH metabolites, GST and EROD in European eel (Anguilla anguilla) as possible indicators for eel habitat quality in German rivers

Abstract

The stock of the European eel (Anguilla anguilla L.) continues to decline and has reached a new minimum in 2011. Poor health status of the spawners due to organic contaminants is one of the possible causes for this dramatic situation. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants, which are rapidly metabolized in vertebrates. EROD (ethoxyresorufin-O-deethylase) and GST (glutathione-S-transferase) are two enzymes involved in PAH detoxification in fish. In this study, PAH metabolites as well as EROD and GST activity in a large, comprising dataset of more than 260 migratory and pre-migratory eels from five large German river basin districts were used to describe PAH exposure and its metabolism as possible indicators for the habitat quality for eels. Eel from the river Elbe appear to be moderately contaminated with PAH. Highest mean values of PAH metabolites were analysed in fish from the river Rhine. However, the results suggest that contaminants such as PAH are metabolized in the fish and may have contributed to EROD activity in eels caught from the Elbe estuary to 600 km upstream. Since the eel's onset of cessation of feeding is closely linked to maturation and migration, we propose bile pigments as new indicators contributing to identify the proportion of migratory eel, which is crucial information for eel management plans. We showed that PAH metabolites normalized to bile pigments as well as EROD could be used to describe the habitat quality and might be suitable parameters in search for suitable stocking habitats.

PAH Metabolites in Bile of European Eel (Anguilla anguilla) from Morocco

“…PAH metabolites in bile were determined by the method described by Kammann et al (2014) with modified HPLC conditions. In brief, 25 lL fish bile were mixed with 95 lL water and 5 lL b-glucuronidase/arylsulfatase solution (30-60 U/mL).…”

Decadal Trends in Polycyclic Aromatic Hydrocarbon (PAH) Contamination Assessed by 1-Hydroxypyrene in Fish Bile Fluid in the Netherlands: Declining in Marine Waters but Still a Concern in Estuaries

“…Van der Oost et al (1994) reported highest 1-OHPyr bile concentrations of approximately 8000 ng/ml (measured by SFS) in eel (Anguilla anguilla) caught in 1991 from freshwater sites near Amsterdam. The mean level of 1-OHPyr in eel collected in 2011 from the river Rhine in Germany near the Dutch border was 3160 ng/ml (measured by HPLC-FL) (Kammann et al, 2014).…”

“…PAH metabolites as biomarker has been determined in a variety of marine, estuarine and fresh water fish species, such as English sole (Collier and Varanasi, 1991), plaice (Richardson et al, 2004), flounder (Ariese et al, 1993;Beyer et al, 1996;Eggens et al, 1996;Kopecka et al, 2006;Vethaak et al, 2011), dab (Kammann, 2007;Vethaak et al, 2009), Atlantic cod (Beyer et al, 1996;Aas et al, 2000), Atlantic hagfish (Sundt et al, 2011), feral finfish (Hellou et al, 2006), eelpout (Tairova et al, 2012), brown bullhead (Yang and Baumann, 2006), trout (Escartín and Porte, 1999a), eel (Van der Oost et al, 1994;Ruddock et al, 2003;Gorbi and Regoli, 2004;Nagel et al, 2012;Kammann et al, 2014), and red mullet (Escartin and Porte, 1999b;Martínez-Gómez et al, 2013). The concentration of PAH metabolites in the bile fluid with dab and flounder as target species has become part of international monitoring programmes, such as the OSPAR Joint Assessment and Monitoring Programme (JAMP) (OSPAR Agreement 2008-09; Technical Annex 2: PAHspecific biological effects monitoring; OSPAR, 2008).…”

Towards science-based sediment quality standards—Effects of field-collected sediments in rainbow trout (Oncorhynchus mykiss)

“…Previous research has clearly established that the uptake and metabolism of PAHs, as assessed by biliary metabolites in fish exposed in the field or under laboratory conditions, can often be clearly related to PAH contamination of water and sediments (Beyer et al, 2010;Brinkmann et al, 2013;Kammann et al, 2013). The major PAH metabolite in fish bile is 1-hydroxypyrene (1-OH-Pyr) and its conjugated forms, which renders this metabolite a particularly suitable biomarker of exposure to PAHs (Ruddock et al, 2003).…”