Pharmaceutical contamination and biotic factors affecting parasitism in common carp ( Cyprinus carpio )

Abstract

Increasing levels of persistent pollutants in the aquatic environment are likely to have serious impacts on host–parasite relationships. In this study, common carp (Cyprinus carpio) of the same age, origin and source were randomly stocked in two pond localities, one fed by treated water from a municipal sewage treatment plant and the other fed by a non‐polluted stream. Fish biometric parameters and health status were evaluated after 2 years of exposure through the determination of somatic condition indices, parasite load and concentration of pharmaceuticals. Municipal pollutants were found at both sites, although at significantly higher levels at the polluted site, with antidepressants, antibiotics, analgesics and beta‐blockers dominant in each case. Owing to a higher availability of natural food, carp from the polluted locality displayed significantly better body condition than those from the control site, while parasite abundance and species richness were higher at the control site. Our results suggest that, compared with fish from control locality exhibiting diverse and abundant natural parasite fauna, fish from the polluted locality were better able to cope with parasites, due to their better condition status. Fish from this study site may have profited from municipal waste water by avoidance of high levels of parasite infections.

Response of Parasite Community Composition to Aquatic Pollution in Common Carp (Cyprinus carpio L.): A Semi-Experimental Study

“…As summarized in Gilbert and Avenant-Oldewage [19], similarly high gyrodactylid abundance levels have been found in fish exposed to eutrophication [22] and sediments contaminated with polynuclear aromatic hydrocarbons (PAHs) and PCBs [59] or pharmaceutical compounds released from sewage treatment plant effluent [24]. Surprisingly, opposing results were observed in three-year-old carp in our previous study [25]; however, in this case, the absence of gyrodactylids in carp from the Cezarka treatment pond was explained by the extremely high condition status of the fish due to excess food availability [31], which helped the fish cope better with parasite infection [25]. In the present study, carp in the two treatment groups had much lower condition factors as a result of decreased natural food availability in autumn [31].…”

“…While eutrophication has been reported as promoting the abundance of dactylogyrid and diplozoid monogeneans [22,61], we observed a reduction in infection in our study, possibly related to the composition of pharmaceutical compounds in the Cezarka treatment pond. For example, while antibiotics and antihelminthics were not detected in fish at significant concentrations during the study, these compounds are regularly present in the water [25,31] and may possibly have had a negative effect on the survival of free-living parasite stages.…”

“…Moreover, monoxenous parasites, i.e., parasites with direct life cycles, tend to show higher susceptibility to a larger variety of environmental stressors [21]. Most such studies, however, have been focused on eutrophication and heavy metal pollution [12,22,23], while the effect of pharmaceutical pollutants on host-parasite interactions remains less explored [8,24,25].…”

“…In our study, we determined pharmaceutical pollutants as high concentrations of PPCPs have recently been detected in both fish and water samples from the treatment pond [26][27][28], while heavy metal concentrations at the same locality are generally low [29]. Although the fish parasite infection was not evaluated prior the experiment, previous studies in the study area (i.e., pond system in Vodnany region) indicate that parasite communities of common carp share similar parasite species with dominance of monogenean and cestode parasites [25,30], but they differ in parasite prevalence and abundance, reflecting seasonal changes [25,30] and water quality [25]. By relocation of experimental fish in both directions, similar initial pool of parasites was achieved at both sites.…”

Effects of multiple stressors in fish: how parasites and contaminants interact

“…( 2020 ) as a consequence of industrial and agricultural activities and effluent of a wastewater treatment plant. The richness and structure of parasite communities were found to follow gradients of salinity and eutrophication, with fecal coliform counts and temperature serving as proxies for the pulp mill and municipal effluents (Blanar et al ., 2011 ), land use and the concentration of hydrocarbons (PAHs) in sediments (Blanar et al ., 2016 ), pharmaceuticals (Pravdová et al ., 2022 ) or levels in PCBs in sediments (Carreras-Aubets et al ., 2012 ) as well as the level of urbanization (Taglioretti et al ., 2018 ). Also anthropogenic activities such as clearcutting (Marcogliese et al ., 2001 ) and precipitation (Marcogliese et al ., 2016 ), which alter the temperature, chemistry and hydrology of aquatic systems and the composition of free-living communities, were found to impact the communities of fish parasites.…”