Epsilon Archive for Student Projects

Abstract

The increasing global detection of pharmaceutical contaminants in aquatic ecosystems is of significant environmental concern. Especially concerning are pharmaceuticals that affect non target species like fish through bioconcentration of pharmaceutical contaminants, which can have severe ecological consequences. Ecotoxicological studies are increasing but few studies have focused on what factors determine bioconcentration of pharmaceuticals in fish tissues. Metabolic performance plays a vital role in essential functions such as growth, reproduction, and movement and is hypothesized to play an important role in the intake and further bioaccumulation of contaminants. This study aimed to examine the effect of metabolic performance on the bioconcentration of the pharmaceutical oxazepam, comparing concentrations during two different exposure times. Additionally, I looked at possible predictors of metabolic performance in brown trout (Salmo trutta) from two different hatchery strains. Their metabolic performance was assessed in an intermittent respirometry setup by measuring their standard metabolic rate (SMR), maximum metabolic rate (MMR) and absolute aerobic scope (AAS). Afterwards the fish were exposed to an oxazepam concentration of 18 μg/L for a short period of 24 hours and a longer one of seven days. The results revealed a significantly higher concentration of oxazepam in trout’s blood plasma during the exposure time of seven days as well as a significantly higher concentration for fish showing increased metabolic performance. The results also showed that length was a predictor of all metabolic measurement AAS, SMR and MMR but not exhaustion time. The results highlight the significance of studying the mechanisms and factors driving bioconcentration of pharmaceuticals in fish, including the role of metabolic performance for predicting the movement of contaminants through aquatic food chains, evaluating long-term ecological risks and implementation of conservation management strategies, especially as pharmaceutical consumption continues to rise worldwide.