The combined use of chemical and biochemical markers in Rutilus rutilus to assess the effect of dredging in the lower course of the Ebro River

Abstract

The lower course of the Ebro River is polluted with high concentrations of organochlorine compounds dumped by a chloro-alkali plant during the last century. A remediation plan, including building of a protective wall, removal and disposal of polluted sediments started in 2012. With the aim of assessing the effects of dredging of contaminated sediments and potential alterations of water quality, areas located upstream (RR) and downstream (BE, A) the chemical plant (FL) were monitored prior (October 2012) and during dredging (June 2013) using roach (Rutilus rutilus) as sentinel organisms. Concentrations of organochlorine compounds (OCs) in fish muscle and biliary levels of polycyclic aromatic hydrocarbons (PAHs), galaxolide (HHCB) and alkyphenols (APEs) were determined together with selected enzymatic activities (7-ethoxyresorufin-O-deethylase (EROD), 7-benzyloxy-4-trifluoromethyl-coumarin O-debenzyloxylase (BFCOD) and UDP-glucuronyltransferase (UGT)) in the liver. The obtained results proved the effectiveness of the wall retaining suspended particles and avoiding further contamination of downstream sites as fish sampled at downstream sites showed up to 9-fold higher concentrations of OCs in muscle during wall construction than during dredging. EROD and UGT activities were induced in fish from downstream sites; however, no clear response to the observed pollution gradient was detected.

A network-based approach on detecting dredgers’ illegal behavior of dumping dredged sediments

“…In order to detect suspended sediment concentration, for both Cutroneo et al 15 and Blanco et al, 16 the dredger needs to be equipped with an acoustic Doppler current profiler (ADCP). ADCP is a kind of equipment which makes use of the Doppler effect of acoustic wave scattered back from particles within the water column to measure water current velocities over a depth range.…”

“…There are several researches on sediment-related issues. The issues can be divided into several types: sediment dredge-and-dump strategies, 14 suspended sediment concentration monitoring, 15 sediment pollution problem, 16 and the ecological effect. 17 And at present, Haimann et al 18 propose an ecologically oriented integrated monitoring system which consists of several stages, for example, preliminary assessment stage and post-dumpling monitoring stage.…”

Use of fish otoliths as a temporal biomarker of field uranium exposure

“…Rutilus rutilus generally stays in backwaters or close to bottom waters to winter and undertakes short migrations during breeding season when the water temperature exceeds 20°C. They are often included in biomonitoring studies (Blanco et al, 2018;Geraudie et al, 2017;Reynders et al, 2008).…”