Acute toxicity of anthracene in adult individuals of the amphipod Hyalella curvispina

ESPERT NURIA; MORELL, M; VILLANOVA JL; MARDIROSIAN M.; VEDELAGO S; LASCANO C; VENTURINO A

Montevideo

Congreso; SETAC Latin America 15th Biennial Meeting; 2023

SETAC LA

One of the main economic activities of North Patagonia is oil and gas field exploitation. The region is also characterized by large urban settlements, established along natural and artificial watercourses. Economic and anthropogenic activities generate pollutants that can reach aquatic resources, so their quality might be at risk. Anthracene is a polycyclic aromatic hydrocarbon (PAH) considered potentially harmful, whose environmental analysis and monitoring is considered essential. In the last decades, there has been an increasing concern about the presence of PAH in aquatic ecosystems due to their wide distribution and potential adverse effects on living organisms, even at low concentrations. This study analyzed the acute toxicity of anthracene in the native amphipod Hyalella curvispina, possible behavioral alterations, and the dynamics of anthracene in the exposure media. Individuals were collected from a reference site in Mari Menuco Lake, Neuquén, Argentina. The amphipods were maintained and raised under laboratory conditions. Groups of 10 adults were exposed to a range of anthracene concentrations in 250 ml of filtered and dechlorinated water, during 96 hours, at constant temperature of 23 ± 1°C and 16:8 h (L:D) photoperiod. Bioassays were carried out keeping equal proportions of adult male and female individuals per experimental unit. The concentrations tested were 0.1, 0.5, 1, and 2 mg/l. Each concentration was tested by triplicate and each exposure was repeated at least three times. Mortality and behavioral alterations were employed as endpoints to determine toxicological parameters. Anthracene concentrations throughout the assay were determined by direct fluorometry. No significant differences were observed between control and anthracene-exposed individuals with regards to mortality, so the LC50 could not be calculated. However, the observation of behavioral alterations allowed us to calculate a 24h-EC10 of 0.09 mg/l. Anthracene concentration decreased significantly in the presence of individuals, with a T1/2 of 36.5 hours. Surprisingly, our results suggest that the studied concentrations of anthracene are not lethal for the amphipod H. curvispina. Nevertheless, it generates behavioral alterations such as changes in reaction speed and stillness. This study is of great relevance because the progress made in the research of anthracene toxicity is scarce when compared to its ubiquitous presence in the environment.