Environmentally relevant concentration of caffeine—effect on activity and circadian rhythm in wild perch

Abstract

We studied the ecological consequences of widespread caffeine contamination by conducting an experiment focused on changes in the behavioral traits of wild perch (Perca fluviatilis) after waterborne exposure to 10 μg L−1 of caffeine. We monitored fish swimming performance during both light and dark conditions to study the effect of caffeine on fish activity and circadian rhythm, using a novel three-dimensional tracking system that enabled positioning even in complete darkness. All individuals underwent three behavioral trials—before exposure, after 24 h of exposure, and after 5 days of exposure. We did not observe any effect of the given caffeine concentration on fish activity under light or dark conditions. Regardless of caffeine exposure, fish swimming performance was significantly affected by both the light-dark conditions and repeating of behavioral trials. Individuals in both treatments swam significantly more during the light condition and their activity increased with time as follows: before exposure < after 24 h of exposure < after 5 days of exposure. We confirmed that the three-dimensional automated tracking system based on infrared sensors was highly effective for conducting behavioral experiments under completely dark conditions.

No evidence that the widespread environmental contaminant caffeine alters energy balance or stress responses in fish

“…Consistent with our results on general activity, exposure of wild perch ( Perca fluviatilis ) to 10,000 ng/L of caffeine (i.e. a nominal concentration identical to the high‐caffeine treatment in this study) did not affect their general activity during the day nor circadian activity (Cerveny et al, 2022). Similarly, exposure of larval zebrafish ( Danio rerio ) to 1 μg/L caffeine did not impact swimming speed (Zhou et al, 2019), and exposure between a range of 1 and 4070 μg/L did not affect total distance travelled compared to controls (Steele et al, 2018).…”

“…Consistent with our results on general activity, exposure of wild perch (Perca fluviatilis) to 10,000 ng/L of caffeine (i.e. a nominal concentration identical to the high-caffeine treatment in this study) did not affect their general activity during the day nor circadian activity (Cerveny et al, 2022). Similarly, exposure of larval zebrafish (Danio rerio)…”

“…Unfortunately, as with at least one other published study (Cerveny et al, 2022), caffeine was also found in all measured control treatment water samples (at a mean ± SD concentration of 349.2 ± 79.5 ng/L; n = 12) despite water being treated by reverse osmosis. The reasons for this contamination are likely to be the same as those previously discussed in Cerveny et al (2022), including the presence of caffeine in the water source used to supply freshwater to exposure tanks (including control treatment tanks), and/or transfer of caffeine between exposure tanks through aeration and airborne particulates since control and caffeine treatment tanks were housed in the same room to standardise experimental conditions. In urban settings, caffeine has been previously detected in airborne particulates, typically in the hundreds of nanograms per square meter (Cecinato et al, 2017).…”

The odd couple: Caffeine and microplastics. Morphological and physiological changes in Mytilus galloprovincialis

“…In contrast, the highest caffeine concentration in Europe was found in the Aegean Sea, measuring 3.1 μg L À1 . Similarly, Cerveny et al (2022) provided data indicating frequent caffeine concentrations below 1 μg L À1 in aquatic environments, with a maximum of 39.8 μg L À1 in Europe and up to 1.0 mg L À1 in Costa Rica. In some of the most heavily polluted river sites, caffeine concentrations reached 6 μg L À1 (Bottoni et al, 2010).…”

Insights into environmental caffeine contamination in ecotoxicological biomarkers and potential health effects of Danio rerio

“…CAF is a psychoactive drug that belongs to the methylxanthines class and can cause several pharmacological (e.g., stimulant and diuretic) and biological (e.g., cell death and oxidative stress) effects in target and non-target species [ 8 ]. CAF is a non-selective antagonist of adenosine receptors [ 23 ], stimulating the central nervous system and affecting the activity of neurotransmitters [ 29 , 30 ]. Furthermore, several studies already showed acute toxicity of CAF to bacteria ( Pseudomonas putida, EC 50 (17 h) = 3490 mg/L), algae ( Scenedesmus subspicatus, EC 50 (72 h) > 100 mg/L), freshwater invertebrates ( Daphnia magna, EC 50 (48 h) = 182 mg/L), and fish ( Leuciscus idus, LC 50 (96 h) = 87 mg/L) [ 31 ], however, these studies report toxicity at concentrations well above those found in the environment ( Table 1 ).…”